@article{gaddy_kingon_irving_2013, title={Effects of alloying and local order in AuNi contacts for Ohmic radio frequency micro electro mechanical systems switches via multi-scale simulation}, volume={113}, ISSN={["0021-8979"]}, DOI={10.1063/1.4804954}, abstractNote={Ohmic RF-MEMS switches hold much promise for low power wireless communication, but long-term degradation currently plagues their reliable use. Failure in these devices occurs at the contact and is complicated by the fact that the same asperities that bear the mechanical load are also important to the flow of electrical current needed for signal processing. Materials selection holds the key to overcoming the barriers that prevent widespread use. Current efforts in materials selection have been based on the material's (or alloy's) ability to resist oxidation as well as its room-temperature properties, such as hardness and electrical conductivity. No ideal solution has yet been found via this route. This may be due, in part, to the fact that the in-use changes to the local environment of the asperity are not included in the selection criteria. For example, Joule heating would be expected to raise the local temperature of the asperity and impose a non-equilibrium thermal gradient in the same region expected to respond to mechanical actuation. We propose that these conditions should be considered in the selection process, as they would be expected to alter mechanical, electrical, and chemical mechanisms in the vicinity of the surface. To this end, we simulate the actuation of an Ohmic radio frequency micro electro mechanical systems switch by using a multi-scale method to model a current-carrying asperity in contact with a polycrystalline substrate. Our method couples continuum solutions of electrical and thermal transport equations to an underlying molecular dynamics simulation. We present simulations of gold-nickel asperities and substrates in order to evaluate the influence of alloying and local order on the early stages of contact actuation. The room temperature response of these materials is compared to the response of the material when a voltage is applied. Au-Ni interactions are accounted for through modification of the existing Zhou embedded atom method potential. The modified potential more accurately captures trends in high-temperature properties, including the enthalpy of mixing and melting temperatures. We simulate the loading of a contacting asperity to several substrates with varying Ni alloying concentrations and compare solid solution strengthening to a phase-separated system. Our simulations show that Ni concentration and configuration have an important effect on contact area, constriction resistance, thermal profiles, and material transfer. These differences suggest that a substrate with 15 at. % Ni featuring phase segregation has fewer early markers that experimentally have indicated long-term failure.}, number={20}, journal={JOURNAL OF APPLIED PHYSICS}, author={Gaddy, Benjamin E. and Kingon, Angus I. and Irving, Douglas L.}, year={2013}, month={May} }
 @article{lam_haridasan_feng_steer_kingon_maria_2012, title={Scaling Issues in Ferroelectric Barium Strontium Titanate Tunable Planar Capacitors}, volume={59}, ISSN={["1525-8955"]}, DOI={10.1109/tuffc.2012.2179}, abstractNote={We report on the geometric limits associated with tunability of interdigitated capacitors, specifically regarding the impact of a parasitic non-tunable component that necessarily accompanies a ferroelectric surface capacitor, and can dominate the voltage-dependent response as capacitor dimensions are reduced to achieve the small capacitance values required for impedance matching in the X band. We present a case study of simple gap capacitors prepared and characterized as a function of gap width (i.e., the distance between electrodes) and gap length (i.e., the edge-to-edge gap distance). Our series of measurements reveals that for gap widths in the micrometer range, as gap lengths are reduced to meet sub-picofarad capacitance values, the non-tunable parasitic elements limit the effective tunability. These experimental measurements are supported by a companion set of microwave models that clarify the existence of parallel parasitic elements.}, number={2}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Lam, Peter G. and Haridasan, Vrinda and Feng, Zhiping and Steer, Michael B. and Kingon, Angus I. and Maria, Jon-Paul}, year={2012}, month={Feb}, pages={198–204} }
 @article{haridasan_lam_feng_fathelbab_maria_kingon_steer_2011, title={Tunable ferroelectric microwave bandpass filters optimised for system-level integration}, volume={5}, ISSN={["1751-8733"]}, DOI={10.1049/iet-map.2010.0461}, abstractNote={Tunable bandpass filters are critical components in emerging radio frequency front-ends. A system-aware design guideline and figure of merit (FOM) are developed for optimum system-level performance. The optimisation metric discussed here deviates from earlier guidelines as the filter bandwidth is allowed to vary in the tunable range, constrained only by the downstream system analogue to digital converter. The system-aware FOM uses worst-case filter design parameters and a tuning sensitivity term that captures the frequency tunability relative to material tunability. A 6.74-8.23-GHz tunable barium strontium titanate-based filter is presented as an example to illustrate the design methodology.}, number={10}, journal={IET MICROWAVES ANTENNAS & PROPAGATION}, author={Haridasan, V. and Lam, P. G. and Feng, Z. and Fathelbab, W. M. and Maria, J-P. and Kingon, A. I. and Steer, M. B.}, year={2011}, month={Jul}, pages={1234–1241} }
 @article{markham_ward_aiman-smith_kingon_2010, title={The Valley of Death as Context for Role Theory in Product Innovation}, volume={27}, ISSN={["1540-5885"]}, DOI={10.1111/j.1540-5885.2010.00724.x}, abstractNote={The purpose of this paper is to define and explain the front end of product innovation as a discrete segment of development between research and product development. The Valley of Death is used as a metaphor to describe the relative lack of resources and expertise in this area of development. The metaphor suggests that there are relative more resources on one side of the valley in the form of research expertise and on the other side by commercialization expertise and resources. Within this valley a set of interlocking roles are examined that move projects from one side to the other. The empirical methodology used in this study gathered data from 272 Product Development & Management Association (PDMA) members with extensive experience in the front end of product development using a Web-based survey instrument. Extensive pretests with experienced practitioners were conducted to develop the instrument. Results indicate that significant development takes place before projects enter into a firm's formal product development process. The data also support the roles of champion, sponsor, and gatekeeper as major actors that work together to develop and promote projects for introduction into the formal process. Champions make the organization aware of opportunities by conceptualizing the idea and preparing business cases. Sponsors support the development of promising ideas by providing resources to demonstrate the project's viability. Gatekeepers set criteria and make acceptance decisions. The data also reveal a dynamic interdependence between role players. It is concluded that the Valley of Death is a productive tool for identifying and understanding a critical area of development that has not been adequately addressed. This research finds a dynamic interplay between roles to accomplish tasks that are not well understood in practice or the literature. The implications of this research are far-ranging. It suggests that companies must understand the challenges in the valley, must develop the skills, and must make resources available to master the front end of product innovation. Recognizing roles, providing resources, and establishing expectations and accountability in this area of development become manageable in light of these results. Theoretically, this research informs role theory of a dynamic set of relationships previously treated as static. It also empirically investigates an area of product development where there is limited data. This paper opens profitable inquiries by focusing on an area of development not adequately researched yet drives the activities and investment made in subsequent steps of product development.}, number={3}, journal={JOURNAL OF PRODUCT INNOVATION MANAGEMENT}, author={Markham, Stephen K. and Ward, Stephen J. and Aiman-Smith, Lynda and Kingon, Angus I.}, year={2010}, month={May}, pages={402–417} }
 @article{yang_lichtenwalner_morris_krim_kingon_2009, title={Comparison of Au and Au-Ni Alloys as Contact Materials for MEMS Switches}, volume={18}, ISSN={["1941-0158"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-67349128609&partnerID=MN8TOARS}, DOI={10.1109/JMEMS.2008.2010850}, abstractNote={This paper reports on a comparison of gold and gold-nickel alloys as contact materials for microelectromechanical systems (MEMS) switches. Pure gold is commonly used as the contact material in low-force metal-contact MEMS switches. The top two failure mechanisms of these switches are wear and stiction, which may be related to the material softness and the relatively high surface adhesion, respectively. Alloying gold with another metal introduces new processing options to strengthen the material against wear and reduce surface adhesion. In this paper, the properties of Au-Ni alloys were investigated as the lower contact electrode was controlled by adjusting the nickel content and thermal processing conditions. A unique and efficient switching degradation test was conducted on the alloy samples, using pure gold upper microcontacts. Solid-solution Au-Ni samples showed reduced wear rate but increased contact resistance, while two-phase Au-Ni (20 at.% Ni) showed a substantial improvement of switching reliability with only a small increase of contact resistance. Discussion of the effects of phase separation, surface topography, hardness, and electrical resistivity on contact resistance and switch degradation is also included.}, number={2}, journal={JOURNAL OF MICROELECTROMECHANICAL SYSTEMS}, author={Yang, Zhenyin and Lichtenwalner, Daniel J. and Morris, Arthur S., III and Krim, Jacqueline and Kingon, Angus I.}, year={2009}, month={Apr}, pages={287–295} }
 @article{lam_feng_haridasan_kingon_steer_maria_2009, title={The Impact of Metallization Thickness and Geometry for X-Band Tunable Microwave Filters}, volume={56}, ISSN={["1525-8955"]}, DOI={10.1109/TUFFC.2009.1122}, abstractNote={The impact of dc resistance on the performance of X-band filters with ferroelectric varactors was investigated. Two series of combline bandpass filters with specific geometries to isolate sources of conductor losses were designed and synthesized. Combining the changes in filter geometry with microwave measurements and planar filter solver (Sonnet software) simulations quantitatively identified the dependency of insertion loss on overall metallization thickness and local regions of thin metallization. The optimized 8-GHz bandpass filters exhibited insertion losses of 6.8 dB. These filters required 2.5 ¿m of metal thickness (or 3 effective skin depths) to achieve this loss. The trend of loss with thickness indicates diminishing return with additional metal. The integration scheme requires thin regions of metal in the immediate vicinity of the varactors. It is shown through experiment and simulation that short distances (i.e., 15 ¿m) of thin metallization can be tolerated provided that they are located in regions where the resonant microwave current is low.}, number={5}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Lam, Peter G. and Feng, Zhiping and Haridasan, Vrinda and Kingon, Angus I. and Steer, Michael B. and Maria, Jon-Paul}, year={2009}, month={May}, pages={906–911} }
 @article{kirsch_sivasubramani_huang_young_quevedo-lopez_wen_alshareef_choi_park_freeman_et al._2008, title={Dipole model explaining high-k/metal gate field effect transistor threshold voltage tuning}, volume={92}, ISSN={["1077-3118"]}, DOI={10.1063/1.2890056}, abstractNote={An interface dipole model explaining threshold voltage (Vt) tuning in HfSiON gated n-channel field effect transistors (nFETs) is proposed. Vt tuning depends on rare earth (RE) type and diffusion in Si∕SiOx∕HfSiON∕REOx/metal gated nFETs as follows: Sr<Er<Sc+Er<La<Sc<none. This Vt ordering is very similar to the trends in dopant electronegativity (EN) (dipole charge transfer) and ionic radius (r) (dipole separation) expected for a interfacial dipole mechanism. The resulting Vt dependence on RE dopant allows distinction between a dipole model (dependent on EN and r) and an oxygen vacancy model (dependent on valence).}, number={9}, journal={APPLIED PHYSICS LETTERS}, author={Kirsch, P. D. and Sivasubramani, P. and Huang, J. and Young, C. D. and Quevedo-Lopez, M. A. and Wen, H. C. and Alshareef, H. and Choi, K. and Park, C. S. and Freeman, K. and et al.}, year={2008}, month={Mar} }
 @article{zohni_buckner_kim_kingon_maranchi_siergiej_2008, title={Effects of adhesion layers on the ferroelectric properties of lead zirconium titanate thin films deposited on silicon nitride coated silicon substrates}, volume={516}, ISSN={["0040-6090"]}, DOI={10.1016/j.tsf.2007.10.130}, abstractNote={We have investigated the addition of silicon nitride (Si3N4) thin films into sol–gel deposited lead zirconium titanate (PZT) stacks and quantified the effects of various adhesion layers on the ferroelectric characteristics of these stacks. Although previous research has investigated issues related to the adhesion characteristics of PZT films, this research considers four specific adhesion layers deposited onto a silicon nitride coated substrate: zirconium (Zr), zirconium dioxide (ZrO2), titanium (Ti) and tantalum (Ta), and compares experimental characteristics of each. Adhesion layer thicknesses of 15 nm and 25 nm were tested with pyrolysis temperatures of 600 °C and 650 °C. For many of the adhesion layers, the remnant polarization Pr and capacitance–voltage (C–V) characteristics are similar to conventional PZT stacks deposited onto silicon dioxide (SiO2) coated substrates, but only Ta withstands the thermal processing required for PZT deposition.}, number={18}, journal={THIN SOLID FILMS}, author={Zohni, Omar and Buckner, Gregory and Kim, Taeyun and Kingon, Angus and Maranchi, Jeff and Siergiej, Richard}, year={2008}, month={Jul}, pages={6052–6057} }
 @article{lebeau_jur_lichtenwalner_craft_maria_kingon_klenov_cagnon_stemmer_2008, title={High temperature stability of Hf-based gate dielectric stacks with rare-earth oxide layers for threshold voltage control}, volume={92}, ISSN={0003-6951 1077-3118}, url={http://dx.doi.org/10.1063/1.2901036}, DOI={10.1063/1.2901036}, abstractNote={The thermal stability of DyOx∕HfSiON and HoOx∕HfSiON gate dielectric stacks on silicon was studied by scanning transmission electron microscopy techniques and correlated with their electrical characteristics. Intermixing of the rare-earth elements with the HfSiON was observed, but there was no diffusion into the interfacial SiO2. Rapid thermal annealing (1000°C) produced little detectable change in the concentration profile of the rare-earth elements but caused thinning of the interfacial SiO2 layer along with a corresponding increase in the rare-earth oxide layer thickness. These reactions could be explained with oxygen deficiency in the rare-earth oxide layer and its greater thermodynamic stability relative to SiO2. Negative flat band voltage shifts were observed relative to a control sample with no DyOx or HoOx. Mechanisms by which the observed microstructure changes could give rise to negative flatband voltage shifts are discussed.}, number={11}, journal={Applied Physics Letters}, publisher={AIP Publishing}, author={LeBeau, James M. and Jur, Jesse S. and Lichtenwalner, Daniel J. and Craft, H. Spalding and Maria, Jon-Paul and Kingon, Angus I. and Klenov, Dmitri O. and Cagnon, Joël and Stemmer, Susanne}, year={2008}, month={Mar}, pages={112912} }
 @article{rezvanian_brown_zikry_kingon_krim_irving_brenner_2008, title={The role of creep in the time-dependent resistance of Ohmic gold contacts in radio frequency microelectromechanical system devices}, volume={104}, number={2}, journal={Journal of Applied Physics}, author={Rezvanian, O. and Brown, C. and Zikry, M. A. and Kingon, A. I. and Krim, J. and Irving, D. L. and Brenner, D. W.}, year={2008} }
 @article{kim_park_shen_lee_kingon_yoon_kim_2008, title={Thickness dependence of submicron thick Pb(Zr0.3Ti0.7)O-3 films on piezoelectric properties}, volume={34}, ISSN={["0272-8842"]}, DOI={10.1016/j.ceramint.2007.07.016}, abstractNote={The effects of thickness on the piezoelectric and electric properties of tetragonal composition, polycrystalline, (1 1 1)-textured Pb(Zr0.3Ti0.7)O3 films are investigated. The effective piezoelectric coefficient d33 is characterized by a double-beam laser interferometer and is measured to increase with film thickness although extrinsic contribution such as 90° domain wall motion is negligible from the nonlinearity of piezoelectric coefficient. Constituent parameters to affect piezoelectric coefficient such as polarization and dielectric properties were analyzed based on the semiempirical phenomenological equation. The effectiveness of poling was also evaluated as a function of film thickness. These results present that the increase of effective d33 in these tetragonal PZT films can be mainly due to enhanced intrinsic contributions.}, number={8}, journal={CERAMICS INTERNATIONAL}, author={Kim, Dong-Joo and Park, Jung-Hyun and Shen, Dongna and Lee, Joo Won and Kingon, Angus I. and Yoon, Young Soo and Kim, Seung-Hyun}, year={2008}, month={Dec}, pages={1909–1915} }
 @article{yang_lichtenwalner_morris_menzel_nauenheim_gruverman_krim_kingon_2007, title={A new test facility for efficient evaluation of MEMS contact materials}, volume={17}, ISSN={["1361-6439"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-51649090154&partnerID=MN8TOARS}, DOI={10.1088/0960-1317/17/9/006}, abstractNote={A novel test facility for the efficient evaluation of microelectromechanical system (MEMS) switches and the development of alternative contact materials is described. The facility utilizes the upper cantilever from commercial MEMS contact switches, and tests these against alternative bottom contact materials within a modified atomic force microscope (AFM). The test closely approximates the real switch, but can accommodate a wider range of test conditions and contact materials. The facility allows alternative contact materials to be easily and quickly incorporated, and therefore evaluated by measuring the number of cycles to failure. The evolution of the wear surfaces of the switch contact materials under test can also be easily examined. In order to demonstrate the facility, the evolution of the contact resistance and wear of a commercial RF MEMS cantilever with Au contacts was monitored under accelerated test conditions, comparing the behavior of Au bottom contacts to an alternative Au–Ni alloy contact material. The Au–Ni (20 at.%) alloy displayed reduced wear rates and improved switch cycle lifetimes compared to pure Au, while retaining acceptable values of contact resistance.}, number={9}, journal={JOURNAL OF MICROMECHANICS AND MICROENGINEERING}, author={Yang, Z. and Lichtenwalner, D. and Morris, A. and Menzel, S. and Nauenheim, C. and Gruverman, A. and Krim, J. and Kingon, A. I.}, year={2007}, month={Sep}, pages={1788–1795} }
 @article{inoue_lichtenwalner_jur_kingon_2007, title={Analysis of interface states in LaSixOy metal-insulator-semiconductor structures}, volume={46}, ISSN={["0021-4922"]}, DOI={10.1143/jjap.46.6480}, abstractNote={Using a comprehensive model to simulate interface state effects on metal–insulator–semiconductor (MIS) device in capacitance–voltage (C–V) behavior, interface properties of LaSixOy gate dielectric MIS structures were analyzed. Under low temperature (400 °C) processing conditions amenable to low (0.6 nm) equivalent oxide thickness (EOT), LaSiO-based MIS capacitors on n- and p-type substrates have a high density localized interface state. The peak densities of this localized state for MIS devices on n- and p-type substrates are (2.0–2.5)×1013 and 2.5×1012 cm-2 eV-1, respectively, lying deep in the Si bandgap (within 0.1 eV of midgap). Positive fixed charge density is derived as in the range of 1013 cm-2 and is found to be distributed close to the interface region. In the case of the p-type MIS capacitor, positive fixed charge and positively charged interface states shift the C–V curve in the negative direction. Interface states in the n-type MOS capacitor capture electrons, compensating for the positive fixed charge and positively charged interface states. Thus less shift of the C–V curve is observed, compared to the p-type case. Interface state and fixed charge densities drastically reduce by raising post annealing temperature, to <1012 cm-2 eV-1 on n-type Si, but with concurrent EOT increase. Forming gas annealing (FGA) is effective for reducing the localized interface state density, but only when the temperature is 600 °C or higher. Results point to a need to minimize defect densities during or immediately after dielectric deposition. The high levels of positive defect states warrant further detailed investigation of the charge trapping characteristics of these dielectrics, as La-containing dielectrics are important for threshold voltage control for metal–oxide–semiconductor field effect transistor (MOSFET) devices.}, number={10A}, journal={JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS}, author={Inoue, Naoya and Lichtenwalner, Daniel J. and Jur, Jesse S. and Kingon, Angus I.}, year={2007}, month={Oct}, pages={6480–6488} }
 @article{vankova_kingon_2007, title={Effects of annealing on the electrical properties of highly resistive float zone p-type silicon}, volume={401}, ISSN={["0921-4526"]}, DOI={10.1016/j.physb.2007.08.135}, abstractNote={This paper reports effects of heat treatment in nitrogen or forming gas ambient on the electrical properties of highly resistive float zone p-type silicon (Si). Capacitance–voltage and Hall Effect measurements were used to examine role of impurities associated with annealing. A reduction in the free carrier density was observed for both the nitrogen and forming gas anneals. In addition, temperature-dependent capacitance measurements revealed the appearance of deep traps with a concentration of 2×1011 cm−3, following the nitrogen anneal.}, journal={PHYSICA B-CONDENSED MATTER}, author={Vankova, V. and Kingon, A. I.}, year={2007}, month={Dec}, pages={155–158} }
 @article{lichtenwalner_hydrick_kingon_2007, title={Flexible thin film temperature and strain sensor array utilizing a novel sensing concept}, volume={135}, ISSN={["0924-4247"]}, DOI={10.1016/j.sna.2006.07.019}, abstractNote={Flexible arrays of resistive temperature and strain sensors have been designed, and fabricated on polyimide sheets. We describe a novel sensor design concept, utilizing materials selection combined with specific device layout design, such that both temperature and strain values can be determined from resistance values of parallel sensor pairs, regardless of complex strain fields or temperature distribution. Fabrication of thin film Pt and NiCr resistive sensor arrays, with Cu conducting lines, on polyimide demonstrates the sensing concept. Temperature and strain sensing capabilities are demonstrated for temperatures up to 200 °C and up to 2% tensile strain.}, number={2}, journal={SENSORS AND ACTUATORS A-PHYSICAL}, author={Lichtenwalner, Daniel J. and Hydrick, Aaron E. and Kingon, Angus I.}, year={2007}, month={Apr}, pages={593–597} }
 @article{jur_lichtenwalner_kingon_2007, title={High temperature stability of lanthanum silicate dielectric on Si (001)}, volume={90}, ISSN={["0003-6951"]}, DOI={10.1063/1.2712805}, abstractNote={Integration of a high-κ dielectric into complementary metal-oxide-semiconductor devices requires thermal stability of the amorphous dielectric phase and chemical compatibility with silicon. The stability of amorphous lanthanum silicate on Si (001) is investigated by means of metal-insulator-semiconductor capacitor measurements, back side secondary ion mass spectrometry (SIMS) depth profiling, and high-resolution transmission electron microscopy (HRTEM) after a 1000°C, 10s anneal in nitrogen ambient. Back side SIMS depth profiling of the TaN∕LaSiOx∕Si gate stack reveals no detectable lanthanum in the silicon substrate, and HRTEM shows stability of the amorphous LaSiOx. An effective work function near 4.0eV is obtained for these gate stacks, making the stack design ideal for n-type metal-oxide-semiconductor device fabrication.}, number={10}, journal={APPLIED PHYSICS LETTERS}, author={Jur, J. S. and Lichtenwalner, D. J. and Kingon, A. I.}, year={2007}, month={Mar} }
 @article{zohni_buckner_kim_kingon_maranchi_siergiej_2007, title={Investigating thin film stresses in stacked silicon dioxide/silicon nitride structures and quantifying their effects on frequency response}, volume={17}, ISSN={["0960-1317"]}, DOI={10.1088/0960-1317/17/5/026}, abstractNote={We have investigated the frequency shift caused by thin film stresses in silicon nitride (Si3N4) and silicon dioxide (SiO2) layers used during the fabrication of lead zirconium titanate (PZT) microelectromechanical (MEMS) devices. The films are deposited via thermal oxidation and low pressure chemical vapor deposition onto bare silicon wafers. Although previous research has reported stresses in these films, this paper introduces approaches to measure, model and predict the effects of these stresses on the frequency response of MEMS devices. Thin film stresses in each layer of a PZT stack are measured using a curvature measurement system, and these measurements are correlated to finite element analysis results and experimental vibration data. These comparisons illustrate the significance of the thin film stresses and their effect on the mechanical behavior of MEMS devices, in particular that as the membrane structures get thinner the frequency shift becomes much larger.}, number={5}, journal={JOURNAL OF MICROMECHANICS AND MICROENGINEERING}, author={Zohni, Omar and Buckner, Gregory and Kim, Taeyun and Kingon, Angus and Maranchi, Jeff and Siergiej, Richard}, year={2007}, month={May}, pages={1042–1051} }
 @article{kim_kingon_maria_croswell_2007, title={Lead zirconate titanate thin film capacitors on electroless nickel coated copper foils for embedded passive applications}, volume={515}, ISSN={["0040-6090"]}, DOI={10.1016/j.tsf.2007.02.085}, abstractNote={Lead zirconate titanate (PZT, 52/48) thin film capacitors were prepared on electroless Ni coated Cu foil by chemical solution deposition for printed wiring board embedded capacitor applications. Phase development, dielectric properties, and leakage characteristics of capacitors were investigated, in particular as a function of the process temperature. Dielectric properties of the capacitors were dependent on the crystallization temperature, and capacitance densities of more than 350 nF/cm2 and loss tangent of less than 0.03 were measured for capacitors crystallized below 600 °C. Lowest leakage current densities (around 2 × 10− 7 A/cm2 at 10 V direct current (DC)) and highest breakdown fields could be obtained for capacitors crystallized at 650 °C. Capacitors with different thickness and a two-layer capacitor model were used in analyzing the interface layer between PZT and the underlying electroless Ni. From the capacitance and leakage measurements, it is suggested that the interface reaction layer has low permittivity (K around 30) and high defect concentration, which has an important effect on the electrical properties of capacitors. This interface is from the reaction of the electroless nickel layer with the adjacent PZT, and may specifically be moderated by the nickel phosphide (Ni–P) phase, transformed from amorphous Ni during the annealing step. The results have significant implications for embedded capacitors in printed wiring boards. They demonstrate that the process can be tuned to produce either voltage independent capacitors with low leakage and high breakdown fields (above 30 V DC), or the more usual hysteretic, switching, ferroelectric capacitors with higher capacitance densities.}, number={18}, journal={THIN SOLID FILMS}, author={Kim, Taeyun and Kingon, Angus I. and Maria, Jon-Paul and Croswell, Robert T.}, year={2007}, month={Jun}, pages={7331–7336} }
 @article{fu_wu_vilarinho_kingon_wordenweber_2007, title={Low dielectric loss BaNd2Ti5O14 thick films prepared by an electrophoretic deposition technique}, volume={90}, number={5}, journal={Applied Physics Letters}, author={Fu, Z. and Wu, A. Y. and Vilarinho, P. M. and Kingon, A. I. and Wordenweber, R.}, year={2007} }
 @article{brenner_irving_kingon_krim_padgett_2007, title={Multiscale analysis of liquid lubrication trends from industrial machines to micro-electrical-mechanical systems}, volume={23}, ISSN={["0743-7463"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34548529657&partnerID=MN8TOARS}, DOI={10.1021/la701280k}, abstractNote={An analytic multiscale expression is derived that yields conditions for effective liquid lubrication of oscillating contacts via surface flow over multiple time and length scales. The expression is a logistics function that depends on two quantities, the fraction of lubricant removed at each contact and a scaling parameter given by the logarithm of the ratio of the contact area to the product of the lubricant diffusion coefficient and the cycle time. For industrial machines the expression confirms the need for an oil mist. For magnetic disk drives, the expression predicts that existing lubricants are sufficient for next-generation data storage. For micro-electrical-mechanical systems, the expression predicts that a bound + mobile lubricant composed of tricresyl phosphate on an octadecyltrichlorosilane self-assembled monolayer will be effective only for temperatures greater than approximately 200 K and up to approximately MHz oscillation frequencies.}, number={18}, journal={LANGMUIR}, author={Brenner, D.W. and Irving, D.L. and Kingon, A.I. and Krim, Jacqueline and Padgett, C.W.}, year={2007}, month={Aug}, pages={9253–9257} }
 @misc{cross_tsukada_horii_gruverman_kingon_2007, title={Semiconductor device and its manufacture method, and measurement fixture for the semiconductor device}, volume={7,241,656}, number={2007 Jul. 10}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cross, J. S. and Tsukada, M. and Horii, Y. and Gruverman, A. and Kingon, A.}, year={2007} }
 @misc{cross_tsukada_horii_gruverman_kingon_2007, title={Semiconductor device having die attachment and die pad for applying tensile or compressive stress to the IC chip}, volume={7,239,026}, number={2007 Jul. 3}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cross, J. S. and Tsukada, M. and Horii, Y. and Gruverman, A. and Kingon, A.}, year={2007} }
 @article{nath_fathelbab_lam_ghosh_aygun_gard_maria_kingon_steer_2006, title={Discrete Barium Strontium Titanate (BST) thin-film interdigital varactors on alumina: Design, fabrication, characterization, and applications}, ISBN={["978-0-7803-9541-1"]}, ISSN={["2576-7216"]}, DOI={10.1109/mwsym.2006.249652}, abstractNote={Discrete barium strontium titanate (BST) thin-film capacitors in industry standard 0603 footprint are introduced and characterized. BST capacitors have a voltage-dependent permittivity, enabling BST thin-film capacitors to be used as tuning elements in frequency agile devices. The capacitance changed by 1.5:1 at 35 V (116 kV/cm) bias. The temperature dependence of the capacitance was measured to be less than plusmn 20 % from -100 degC to +100 degC. A 2nd-order tunable combline bandpass filter on FR4 substrate has been implemented using the discrete BST varactors. The filter showed a center frequency tuning of 22% from 2.14 GHz to 2.61 GHz upon application of 130 V (433 kV/cm) bias. The zero-bias insertion loss was 4.9 dB which decreased to 2.9 dB at the high bias state. The return loss was better than 11 dB over the tuning range. Nonlinear characterization of the filter using two-tone test and a digitally-modulated CDMA 2000 signal showed an IP3 of +32 dBm and an ACPR of better than -50 dBc up to 26 dBm of input power, respectively}, journal={2006 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST, VOLS 1-5}, author={Nath, Jayesh and Fathelbab, Wael M. and Lam, Peter G. and Ghosh, Dipankar and Aygun, Seymen and Gard, Kevin G. and Maria, J. -P. and Kingon, Angus I. and Steer, Michael B.}, year={2006}, pages={552–555} }
 @article{agronin_molotskii_rosenwaks_rosenman_rodriguez_kingon_gruverman_2006, title={Dynamics of ferroelectric domain growth in the field of atomic force microscope}, volume={99}, number={10}, journal={Journal of Applied Physics}, author={Agronin, A. and Molotskii, M. and Rosenwaks, Y. and Rosenman, G. and Rodriguez, B. J. and Kingon, A. I. and Gruverman, A.}, year={2006} }
 @article{kim_kingon_maria_croswell_2006, title={Electrical properties of lead zirconate titanate thin films with a ZrO2 buffer layer on an electroless Ni-coated Cu foil}, volume={89}, ISSN={["1551-2916"]}, DOI={10.1111/j.1551-2916.2006.01240.x}, abstractNote={ The effect of zirconia (ZrO2) buffer layers on the phase development and electrical properties of lead zirconate titanate (PZT, 52/48) capacitors on an electroless Ni (P)‐coated Cu foil was investigated. It was demonstrated that the buffer layer can be used to engineer the final properties. The incorporation of the ZrO2 buffer layers retained acceptable capacitance densities (>350 nF/cm2 for 50 nm thick ZrO2), while significantly reducing leakage currents and improving reliability (<10−7 A/cm2 after 1 h at 25 VDC for 100 nm thick ZrO2), compared with PZT thin films directly on electroless Ni (P). The results are particularly important for embedded capacitor applications. }, number={11}, journal={JOURNAL OF THE AMERICAN CERAMIC SOCIETY}, author={Kim, Taeyun and Kingon, Angus I. and Maria, Jon-Paul and Croswell, Robert T.}, year={2006}, month={Nov}, pages={3426–3430} }
 @article{wu_vilarinho_kingon_2006, title={Electrophoretic deposition of lead zirconate titanate films on metal foils for embedded components}, volume={89}, number={2}, journal={Journal of the American Ceramic Society}, author={Wu, A. Y. and Vilarinho, P. M. and Kingon, A. I.}, year={2006}, pages={575–581} }
 @article{kim_hanson_gruverman_kingon_streiffer_2006, title={Ferroelectric behavior in nominally relaxor lead lanthanum zirconate titanate thin films prepared by chemical solution deposition on copper foil}, volume={88}, number={26}, journal={Applied Physics Letters}, author={Kim, T. and Hanson, J. N. and Gruverman, A. and Kingon, A. I. and Streiffer, S. K.}, year={2006} }
 @misc{setter_damjanovic_eng_fox_gevorgian_hong_kingon_kohlstedt_park_stephenson_et al._2006, title={Ferroelectric thin films: Review of materials, properties, and applications}, volume={100}, number={5}, journal={Journal of Applied Physics}, author={Setter, N. and Damjanovic, D. and Eng, L. and Fox, G. and Gevorgian, S. and Hong, S. and Kingon, A. and Kohlstedt, H. and Park, N. Y. and Stephenson, G. B. and et al.}, year={2006}, pages={051606} }
 @article{setter_damjanovic_eng_fox_gevorgian_hong_kingon_kohlstedt_park_stephenson_et al._2006, title={Ferroelectric thin films: Review of materials, properties, and applications (vol 100, art no 051606, 2006)}, volume={100}, number={10}, journal={Journal of Applied Physics}, author={Setter, N. and Damjanovic, D. and Eng, L. and Fox, G. and Gevorgian, S. and Hong, S. and Kingon, A. and Kohlstedt, H. and Park, N. Y. and Stephenson, G. B. and et al.}, year={2006} }
 @article{lichtenwalner_jur_jha_inoue_chen_misra_kingon_2006, title={High-temperature stability of lanthanum silicate gate dielectric MIS devices with Ta and TaN electrodes}, volume={153}, ISSN={["1945-7111"]}, DOI={10.1149/1.2218757}, abstractNote={The high-temperature stability of lanthanum silicate gate dielectric metal-insulator-semiconductor (MIS) devices with either Ta or TaN electrodes has been studied. After a 1000°C, 10 s rapid thermal annealing (RTA) treatment, devices with Ta gate metal undergo an equivalent oxide thickness (EOT) increase from 0.62 to 1.57 nm or higher, while devices with TaN as the gate electrode experience an EOT increase from 0.62 to only 1.12 nm. An EOT less than 1.0 nm is achieved after a 5 s 1000°C RTA, with a corresponding gate leakage of 0.1 A/cm 2 . Medium-energy ion scattering and X-ray diffraction (XRD) analysis reveal that the Ta gate metal undergoes a phase change due to reaction with N 2 above 800°C, while for TaN no change in the XRD spectrum is detected. Interface state defect densities and leakage currents are reduced after the high-temperature processing. Results reveal the importance of the entire gate stack design and processing in obtaining good device properties.}, number={9}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Lichtenwalner, Daniel J. and Jur, Jesse S. and Jha, Rashmi and Inoue, Naoya and Chen, Bei and Misra, Veena and Kingon, Angus I.}, year={2006}, pages={F210–F214} }
 @article{wu_vilarinho_srinivasan_kingon_reaney_woodward_ramos_alves_2006, title={Microstructural studies of PZT thick films on Cu foils}, volume={54}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2006.03.006}, abstractNote={This paper explains the limits of processing conditions for Pb(Zr, Ti)O3 (PZT) thick films on Cu substrates. PZT thick films in the thickness range 5–20 μm deposited on flexible Cu foils by electrophoretic deposition showed poorer properties when compared with PZT thick films deposited on Pt foils under identical conditions. Although the density of the sintered films and the electrical properties were improved by introducing a PbO coating on the top of the films, the dielectric and ferroelectric properties of PZT thick films on Cu were still inferior to those of films deposited on Pt. Rutherford backscattering spectrometry, X-ray diffraction and transmission electron microscopy revealed the formation of a Cux–Pb alloy when sintering above 950 °C, accompanied by Ti enrichment of the PZT and the formation of ZrO2 phases. As the sintering temperature increased, the concentration of the metallic phase increased and spread throughout the film. A new Pb–Cu alloy phase was identified. The poorer electrical properties of PZT thick films on Cu were correlated with these microstructural features.}, number={12}, journal={ACTA MATERIALIA}, author={Wu, Aiying and Vilarinho, P. M. and Srinivasan, S. and Kingon, A. I. and Reaney, I. M. and Woodward, D. and Ramos, A. R. and Alves, E.}, year={2006}, month={Jul}, pages={3211–3220} }
 @article{victor_nath_ghosh_boyette_maria_steer_kingon_stauf_2006, title={Noise characteristics of an oscillator with a barium strontium titanate (BST) varactor}, volume={153}, ISSN={["1350-2417"]}, DOI={10.1049/ip-map:20050068}, abstractNote={The phase noise of an oscillator with a thin-film barium strontium titanate (BST) capacitive tuning element, or varactor, is characterised and benchmarked against the same oscillator with a silicon semiconductor junction varactor. Phase noise tracks closely with varactor Q within a specific voltage range as expected. Compared to the semiconductor varactor-based oscillator, the BST-based oscillator demonstrates reduced phase noise degradation near zero volts, but greater phase noise degradation when operated near breakdown.}, number={1}, journal={IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION}, author={Victor, A and Nath, J and Ghosh, D and Boyette, B and Maria, JP and Steer, MB and Kingon, AI and Stauf, GT}, year={2006}, month={Feb}, pages={96–102} }
 @article{kingon_2006, title={Perovskites: Is the ultimate memory in sight?}, volume={5}, ISSN={["1476-1122"]}, DOI={10.1038/nmat1623}, number={4}, journal={NATURE MATERIALS}, author={Kingon, A}, year={2006}, month={Apr}, pages={251–252} }
 @misc{cross_tsukada_horii_gruverman_kingon_2006, title={Semiconductor device having a stress layer for applying tensile of compressive stress to the ferroelectric film}, volume={7,075,135}, number={2006 Jul. 11}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cross, J. S. and Tsukada, M. and Horii, Y. and Gruverman, A. and Kingon, A.}, year={2006} }
 @article{aiman-smith_bean_cantwell_chapas_collins_kingon_mugge_2006, title={Social networks key to harnessing nanoscience knowledge explosion}, volume={49}, number={3}, journal={Research Technology Management}, author={Aiman-Smith, L. and Bean, A. S. and Cantwell, A. and Chapas, R. and Collins, M. J. and Kingon, A. I. and Mugge, P. C.}, year={2006}, pages={2–4} }
 @misc{maria_kingon_2006, title={Structures including perovskite dielectric layers and variable oxygen concentration gradient layers}, volume={7,074,507}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Maria, J.-P. and Kingon, A. I.}, year={2006} }
 @misc{borland_ihlefeld_kingon_maria_2006, title={Thin film dielectrics for capacitors and methods of making thereof}, volume={7,029,971}, number={2006 Apr. 18}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Borland, W. J. and Ihlefeld, J. F. and Kingon, A. I. and Maria, J. P.}, year={2006} }
 @article{ghosh_laughlin_nath_kingon_steer_maria_2006, title={Tunable high-quality-factor interdigitated (Ba, Sr)TiO3 capacitors fabricated on low-cost substrates with copper metallization}, volume={496}, ISSN={["0040-6090"]}, DOI={10.1016/j.tsf.2005.09.025}, abstractNote={Interdigitated capacitors containing the field-tunable ferroelectric Ba0.75Sr0.25TiO3, polycrystalline alumina substrates, and copper metallization have been fabricated. Dielectric layers were prepared by magnetron sputtering, while the Cu metallization was evaporated. The dielectric tunability of the Ba0.75Sr0.25TiO3 was 40% at an applied electric field of 12 V/μm. This corresponds to a 3-μm electrode gap width and a 35 V dc bias. Low-frequency (1 MHz) loss tangent measurements indicate a dielectric Q (quality factor) of ∼100 while microwave measurements reveal a zero bias device Q of ∼30 at 26 GHz. These values are comparable or superior to numerous reports of barium strontium titanate interdigitated capacitors prepared using single crystalline substrates and noble metallization. As such, this technology is significantly less expensive and more amenable to large-volume manufacturing.}, number={2}, journal={THIN SOLID FILMS}, author={Ghosh, D and Laughlin, B and Nath, J and Kingon, AI and Steer, MB and Maria, JP}, year={2006}, month={Feb}, pages={669–673} }
 @inproceedings{victor_nath_ghosh_aygun_nagy_maria_kingon_steer_2006, title={Voltage controlled GaN on Si HFET power oscillator using thin?film ferroelectric varactor tuning}, DOI={10.1109/eumc.2006.281206}, abstractNote={A 1.6 GHz power oscillator with a GaN-on-Si heterostructure field effect transistor (HFET) is reported. The voltage-controlled oscillator used a thin-film barium strontium titanate (BST) interdigital varactor as the tuning element. The surface-mount varactor was fabricated using sputtered BST film and copper metallization on alumina. An output power of 1.6 W (32 dBm) is obtained with a DC conversion efficiency of 25.5%. Flat tuning sensitivity of 500 kHz/V, 49 MHz linear frequency tuning, and power flatness of better than 0.5 dB are obtained with 0-100 V tuning voltage. The maximum oscillator phase noise is -81.4 dBc/Hz at 100 kHz offset}, booktitle={Proceedings of the 36th European Microwave Conference, (EuMW2006), Manchester, UK}, publisher={London: Horizon House}, author={Victor, A. and Nath, J. and Ghosh, D. and Aygun, S. and Nagy, W. and Maria, J.-P. and Kingon, A. I. and Steer, M. B.}, year={2006}, pages={87–90} }
 @article{alshareef_quevedo-lopez_wen_harris_kirsch_majhi_lee_jammy_lichtenwalner_jur_et al._2006, title={Work function engineering using lanthanum oxide interfacial layers}, volume={89}, ISSN={["1077-3118"]}, DOI={10.1063/1.2396918}, abstractNote={A La2O3 capping scheme has been developed to obtain n-type band-edge metal gates on Hf-based gate dielectrics. The viability of the technique is demonstrated using multiple metal gates that normally show midgap work function when deposited directly on HfSiO. The technique involves depositing a thin interfacial of La2O3 on a Hf-based gate dielectric prior to metal gate deposition. This process preserves the excellent device characteristic of Hf-based dielectrics, but also allows the realization of band-edge metal gates. The effectiveness of the technique is demonstrated by fabricating fully functional transistor devices. A model is proposed to explain the effect of La2O3 capping on metal gate work function.}, number={23}, journal={APPLIED PHYSICS LETTERS}, author={Alshareef, H. N. and Quevedo-Lopez, M. and Wen, H. C. and Harris, R. and Kirsch, P. and Majhi, P. and Lee, B. H. and Jammy, R. and Lichtenwalner, D. J. and Jur, J. S. and et al.}, year={2006}, month={Dec} }
 @article{nath_ghosh_fathelbab_maria_kingon_franzon_steer_2005, title={A tunable combline bandpass filter using Barium Strontium Titanate interdigital varactors on an alumina substrate}, ISBN={["0-7803-8845-3"]}, ISSN={["2576-7216"]}, DOI={10.1109/mwsym.2005.1516670}, abstractNote={Barium strontium titanate (BST) has a field-dependent permittivity that enables it to be used as a dielectric in a voltage-tunable capacitor or varactor. A tunable combline bandpass filter was designed and characterized using BST varactors fabricated on a polycrystalline alumina substrate with copper metallization and is 14 mm /spl times/ 14 mm in size. The center frequency of the filter varies from 1.6 to 2.0 GHz with the application of 200 V tuning voltage. A 25% tuning range was achieved using tuning field strength of 300 kV/cm. The zero bias insertion loss was 6.6 dB and this decreased to 4.3 dB at the high bias state. The return loss was better than 10 dB.}, journal={2005 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM, VOLS 1-4}, publisher={Piscataway, NJ: IEEE}, author={Nath, J and Ghosh, D and Fathelbab, W and Maria, JP and Kingon, AI and Franzon, PD and Steer, MB}, year={2005}, pages={595–598} }
 @article{nath_ghosh_maria_kingon_fathelbab_franzon_steer_2005, title={An electronically tunable microstrip bandpass filter using thin-film barium-strontium-titanate (BST) varactors}, volume={53}, ISSN={["1557-9670"]}, DOI={10.1109/TMTT.2005.854196}, abstractNote={A tunable third-order combline bandpass filter using thin-film barium-strontium-titanate varactors and fabricated on a sapphire substrate is reported. Application of 0-200-V bias varied the center frequency of the filter from 2.44 to 2.88 GHz (16% tuning) while achieving a 1-dB bandwidth of 400 MHz. The insertion loss varied from 5.1 dB at zero bias to 3.3 dB at full bias, while the return loss exceeded 13 dB over the range. The third-order intercept of the filter was found to be 41 dBm.}, number={9}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Nath, J and Ghosh, D and Maria, JP and Kingon, AI and Fathelbab, W and Franzon, PD and Steer, MB}, year={2005}, month={Sep}, pages={2707–2712} }
 @article{dehoff_rodriguez_kingon_nemanich_gruverman_cross_2005, title={Atomic force microscopy-based experimental setup for studying domain switching dynamics in ferroelectric capacitors}, volume={76}, ISSN={["1089-7623"]}, DOI={10.1063/1.1850652}, abstractNote={This article describes an experimental setup for combined measurements of domain switching dynamics and switching currents in micrometer scale ferroelectric capacitors. The setup is based on a commercial atomic force microscope (AFM) that is equipped with a piezoresponse mode for domain imaging and with a wide bandwidth current amplifier for switching current recording. The setup allows combined domain/current measurements in capacitors as small as 1μm2 with switching times resolved down to 10ns. The incorporation of switching current measurement capability into piezoresponse AFM makes detailed analysis of switching behavior in ferroelectric memory devices possible.}, number={2}, journal={REVIEW OF SCIENTIFIC INSTRUMENTS}, author={Dehoff, C and Rodriguez, BJ and Kingon, AI and Nemanich, RJ and Gruverman, A and Cross, JS}, year={2005}, month={Feb} }
 @article{ihlefeld_laughlin_hunt-lowery_borland_kingon_maria_2005, title={Copper compatible barium titanate thin films for embedded passives}, volume={14}, ISSN={["1573-8663"]}, DOI={10.1007/s10832-005-0866-6}, number={2}, journal={JOURNAL OF ELECTROCERAMICS}, author={Ihlefeld, J and Laughlin, B and Hunt-Lowery, A and Borland, W and Kingon, A and Maria, JP}, year={2005}, month={Mar}, pages={95–102} }
 @article{gruverman_rodriguez_dehoff_waldrep_kingon_nemanich_cross_2005, title={Direct studies of domain switching dynamics in thin film ferroelectric capacitors}, volume={87}, ISSN={["1077-3118"]}, DOI={10.1063/1.2010605}, abstractNote={An experimental approach for direct studies of the polarization reversal mechanism in thin film ferroelectric capacitors based on piezoresponse force microscopy (PFM) in conjunction with pulse switching capabilities is presented. Instant domain configurations developing in a 3×3μm2 capacitor at different stages of the polarization reversal process have been registered using step-by-step switching and subsequent PFM imaging. The developed approach allows direct comparison of experimentally measured microscopic switching behavior with parameters used by phenomenological switching models. It has been found that in the low field regime (just above the threshold value) used in the present study, the mechanism of polarization reversal changes during the switching cycle from the initial nucleation-dominated process to the lateral domain expansion at the later stages. The classical nucleation model of Kolmogorov–Avrami–Ishibashi (KAI) provides reasonable approximation for the nucleation-dominated stage of switching but is inapplicable to the slow switching stage. It has been suggested that the switching dynamics can be approximated by averaging the KAI model over a broad distribution of switching times.}, number={8}, journal={APPLIED PHYSICS LETTERS}, author={Gruverman, A and Rodriguez, BJ and Dehoff, C and Waldrep, JD and Kingon, AI and Nemanich, RJ and Cross, JS}, year={2005}, month={Aug} }
 @article{rodriguez_nemanich_kingon_gruverman_kalinin_terabe_liu_kitamura_2005, title={Domain growth kinetics in lithium niobate single crystals studied by piezoresponse force microscopy}, volume={86}, ISSN={["1077-3118"]}, DOI={10.1063/1.1845594}, abstractNote={The kinetics of sidewise domain growth in an inhomogeneous electric field has been investigated in stoichiometric LiNbO3 single crystals by measuring the lateral domain size as a function of the voltage pulse magnitude and duration using piezoresponse force microscopy. The domain size increases linearly with the voltage magnitude suggesting that the domain size is kinetically limited in a wide range of pulse magnitudes and durations. In spite of that, the written domains exhibit strong retention behavior. It is suggested that the switching behavior can be described by the universal scaling curve. Domain kinetics can be described as an activation process by calculating the field distribution using the charged sphere model under the assumption of an exponential field dependence of the wall velocity. The activation energy is found to be a function of the external field.}, number={1}, journal={APPLIED PHYSICS LETTERS}, author={Rodriguez, BJ and Nemanich, RJ and Kingon, A and Gruverman, A and Kalinin, SV and Terabe, K and Liu, XY and Kitamura, K}, year={2005}, month={Jan} }
 @article{ghosh_laughlin_nath_kingon_steer_maria_2005, title={High Q (Ba, Sr) TiO3 interdigitated capacitors fabricated on low cost polycrystalline alumina substrates with copper metallization}, volume={26}, DOI={10.1002/9780470291252.ch13}, abstractNote={Barium Strontium Titanate (BST) ferroelectric thin films are attractive for radio frequency and microwave applications. However, for many non-military uses, the high cost of conventionally processed devices is a limitingfactor. This high cost stems from the use of single-crystalline sapphire, MgO, or LaAlO 3 substrates and Pt or Au metallization commonly used. Here we present a device process and materials complement offering a low cost alternative. Planar interdigitated capacitors Ba 0 . 7 5 Sr 0 . 2 5 TiO 3 (BST) thin films with chromium/copper top electrodes were fabricated on polycrystalline alumina substrates using a single step photolithographic technique and lift-off. RF magnetron sputtering was used for fabrication of BST thin films while Cu thin films were thermally evaporated The dielectric tunability of the Ba 0 . 7 5 Sr 0 . 2 5 TiO 3 IDCs was 40 % for an applied electric field of 120 kV/cm, which corresponds to 3 μm electrode gap spacing and a 35 volt dc bias. Low frequency (1MHz) loss measurements reveal a dielectric Q ∼ 100 while a device Q of ∼ 30 is obtained at 26 GHz. The reduction of Q between 0.1 and 26 GHz can be attributed to the metallization. Leakage current measurements of the BST planar varactors show current densities of 1.0 x 10 - 6 A / cm 2 for an electric field of 100 kV/cm. These dielectric characteristics (tunability and Q value) are comparable to numerous reports of IDCs with BST films prepared on expensive single crystalline substrates using noble metallization. As such, this technology is significantly less expensive, and amenable to large volume manufacturing.}, number={5}, journal={Ceramic Engineering and Science Proceedings}, author={Ghosh, D. and Laughlin, B. J. and Nath, J. and Kingon, A. I. and Steer, M. B. and Maria, J. P.}, year={2005}, pages={125–132} }
 @article{brewer_wicaksana_maria_kingon_franzen_2005, title={Investigation of the electrical and optical properties of iridium oxide by reflectance FTIR spectroscopy and density functional theory calculations}, volume={313}, number={38355}, journal={Chemical Physics}, author={Brewer, S. H. and Wicaksana, D. and Maria, J. P. and Kingon, A. I. and Franzen, S.}, year={2005}, pages={25–31} }
 @article{rodriguez_gruverman_kingon_nemanich_cross_2005, title={Investigation of the mechanism of polarization switching in ferroelectric capacitors by three- dimensional piezoresponse force microscopy}, volume={80}, ISSN={["1432-0630"]}, DOI={10.1007/s00339-004-2925-2}, abstractNote={A mechanism for the switching behavior of (111)-oriented Pb(Zr,Ti)O3-based 1×1.5 μm2 capacitors has been investigated using three-dimensional piezoresponse force microscopy (3D-PFM). A combination of vertical and lateral piezoresponse force microscopy (VPFM and LPFM) has been used to map the out-of-plane and the in-plane components of the polarization. The three-dimensional polarization distribution was reconstructed by quantitative analysis of the PFM amplitude images of poled PZT capacitors while taking into account contrast variations in the PFM phase images. The switching behavior of the capacitors was determined by comparison of the static domain patterns in the same capacitors after both positive and negative poling. While 180° degree switching was observed, surprisingly, the switching process was dominated by 90° polarization vector rotation. Furthermore, central regions of the capacitors were characterized by the presence of charged domain boundaries, which could lead to imprint (preference of one polarization state over another).}, number={1}, journal={APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING}, author={Rodriguez, BJ and Gruverman, A and Kingon, AI and Nemanich, RJ and Cross, JS}, year={2005}, month={Jan}, pages={99–103} }
 @article{lichtenwalner_jur_kingon_agustin_yang_stemmer_goncharova_gustafsson_garfunkel_2005, title={Lanthanum silicate gate dielectric stacks with subnanometer equivalent oxide thickness utilizing an interfacial silica consumption reaction}, volume={98}, ISSN={["1089-7550"]}, DOI={10.1063/1.1988967}, abstractNote={A silicate reaction between lanthana and silica layers has been utilized to eliminate interfacial silica in metal-insulator-semiconductor devices and to obtain devices with very low equivalent oxide thickness (EOT). This provides a simple process route to interface elimination, while producing a silicate dielectric with a higher temperature stability of the amorphous phase. The La2O3 layers in this study are deposited by reactive evaporation on (001) Si covered by a ∼0.8–1.0-nm-thick SiO2 chemical oxide, and are capped in situ with a Ta gate, followed by a reaction anneal, which lowers the EOT from greater than 1.5 nm for the as-deposited bilayer stack to as low as 0.5 nm. Electron energy-loss spectroscopy and medium-energy ion scattering are used to show that a temperature of 400 °C is sufficient for the formation of the silicate gate dielectric. Gate leakage currents as low as 0.06A∕cm2 are obtained for stacks having an EOT of 0.63 nm, orders of magnitude below that of SiO2 having the same EOT value. Electrical breakdown is observed at applied fields above 16MV∕cm.}, number={2}, journal={JOURNAL OF APPLIED PHYSICS}, author={Lichtenwalner, DJ and Jur, JS and Kingon, AI and Agustin, MP and Yang, Y and Stemmer, S and Goncharova, LV and Gustafsson, T and Garfunkel, E}, year={2005}, month={Jul} }
 @article{kingon_srinivasan_2005, title={Lead zirconate titanate thin films directly on copper electrodes for ferroelectric, dielectric and piezoelectric applications}, volume={4}, ISSN={["1476-4660"]}, DOI={10.1038/nmat1334}, number={3}, journal={NATURE MATERIALS}, author={Kingon, AI and Srinivasan, S}, year={2005}, month={Mar}, pages={233–237} }
 @article{maria_boyette_kingon_ragaglia_stauf_2005, title={Low loss tungsten-based electrode technology for microwave frequency BST varactors}, volume={14}, ISSN={["1385-3449"]}, DOI={10.1007/s10832-005-6587-z}, number={1}, journal={JOURNAL OF ELECTROCERAMICS}, author={Maria, JP and Boyette, BA and Kingon, AI and Ragaglia, C and Stauf, G}, year={2005}, month={Jan}, pages={75–81} }
 @misc{maria_kingon_2005, title={Methods of controlling oxygen partial pressure during annealing of a perovskite dielectric layer}, volume={6,936,301}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Maria, J.-P. and Kingon, A. I.}, year={2005} }
 @misc{maria_kingon_dunn_streiffer_cheek_zhang_savic_2005, title={Multi-layer conductor-dielectric oxide structure}, volume={6,841,080}, number={2005 Jan. 11}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Maria, J.-P. and Kingon, A. and Dunn, G. J. and Streiffer, S. and Cheek, K. and Zhang, M.-X. and Savic, J.}, year={2005} }
 @article{bean_chapas_collins_kingon_2005, title={Nanoscience and technology: Firms take first steps}, volume={48}, number={3}, journal={Research Technology Management}, author={Bean, A. S. and Chapas, R. and Collins, M. J. and Kingon, A. I.}, year={2005}, pages={07-} }
 @article{markham_gentry_hume_ramachandran_kingon_2005, title={Strategies and tactics for external corporate venturing}, volume={48}, ISSN={["1930-0166"]}, DOI={10.1080/08956308.2005.11657305}, abstractNote={OVERVIEW: By providing a window on emerging technologies, market opportunities, new business models, and distribution channels, corporate venturing can be an important source of technological innovation for corporations. However, effective implementation requires a clear view of the objectives, dedication to understanding the process, and discipline. There are two major tactics for external investing: invest in a venture capital fund, or invest directly in a start-up company, and the strategy a company chooses should be tied to its objectives. For example, best-of-class companies whose objective is to acquire a window on technology will invest in VC funds to gain access to their wider deal flow. One of the most challenging aspects of corporate venturing is finding the right people, and corporations must be willing to devote significant time and resources to working closely with their portfolio companies if they wish to gain satisfactory value from their external investments.}, number={2}, journal={RESEARCH-TECHNOLOGY MANAGEMENT}, author={Markham, SK and Gentry, ST and Hume, D and Ramachandran, R and Kingon, AI}, year={2005}, pages={49–59} }
 @article{victor_nath_ghosh_boyette_maria_steer_kingon_stauf_2004, title={A voltage controlled oscillator using Barium strontium titanate (BST) thin film varactor}, ISBN={["0-7803-8451-2"]}, DOI={10.1109/rawcon.2004.1389079}, abstractNote={Barium strontium titanate (BST) has a field-dependent permittivity and can be used as a dielectric in voltage tunable capacitors or varactors. These BST-based varactors are passive devices and have significantly different properties compared to semiconductor varactors. A voltage tunable oscillator using a BST thin film varactor was designed and characterized. The frequency of oscillation varied from 34.8 MHz to 44.5 MHz (28% tuning) upon application of 7 V tuning voltage. The VCO gain was 1.38 MHz/V and the 2nd harmonic was over 23 dB below the fundamental throughout the tuning range.}, journal={RAWCON: 2004 IEEE RADIO AND WIRELESS CONFERENCE, PROCEEDINGS}, author={Victor, A and Nath, J and Ghosh, D and Boyette, B and Maria, JP and Steer, MB and Kingon, AI and Stauf, GT}, year={2004}, pages={91–94} }
 @article{kim_kingon_maria_croswell_2004, title={Ca-doped lead zirconate titanate thin film capacitors on base metal nickel on copper foil}, volume={19}, ISSN={["0884-2914"]}, DOI={10.1557/jmr.2004.0387}, abstractNote={Ca-doped lead zirconate titanate (52/48) thin film capacitors were prepared on electroless nickel-coated copper foils for embedded capacitor applications. The impact of Ca doping and process parameter variations was studied. Ca addition significantly reduced the temperature coefficient of capacitance. Specifically, the temperature variation was reduced to less than 10% between 300 and 580 K through calcium addition. Optimized capacitance densities and loss tangents were 400 nF/cm2 and 0.02, respectively. Crystallization temperatures of 600 °C yielded these optimized electrical properties, while higher temperatures resulted in interfacial reactions. The influence of oxygen partial pressure during crystallization was also studied. Dielectric properties were sensitive to pO2, with optimal properties occurring in a narrow pO2 window centered about 10−3 Torr. The trends with oxygen pressure were mirrored by changes in phase assemblage. Electrical transport across the dielectric layers was not strongly dependent upon doping level. This insensitivity was attributed to a thin interfacial layer present in all samples. Interface analysis using equivalent circuit analogues showed the nature of the interface to be highly resistive (insulating), rather than semiconducting or conducting.}, number={10}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Kim, T and Kingon, AI and Maria, JP and Croswell, RT}, year={2004}, month={Oct}, pages={2841–2848} }
 @article{kingon_collins_gentry_bean_2004, title={Corporate responses nanoscience and nanotechnology}, volume={47}, number={3}, journal={Research Technology Management}, author={Kingon, A. I. and Collins, M. J. and Gentry, S. T. and Bean, A. S.}, year={2004}, pages={08-} }
 @misc{maria_kingon_2004, title={Lanthanum oxide-based dielectrics for integrated circuit capacitors}, volume={6,753,567}, number={2004 June 22}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Maria, J.-P. and Kingon, A. I.}, year={2004} }
 @inproceedings{nath_ghosh_maria_steer_kingon_stauf_2004, title={Microwave properties of BST thin film interdigital capacitors on low cost alumina substrates}, ISBN={1580539920}, booktitle={Proceedings of the 34th European Microwave Conference (EuMc), Amsterdam}, publisher={London: Horizon House}, author={Nath, J. and Ghosh, D. and Maria, J.-P. and Steer, M. B. and Kingon, A. I. and Stauf, G. T.}, year={2004}, pages={1497–1500} }
 @article{palmer_dessent_mulling_usher_grant_eischen_kingon_franzon_2004, title={The design and characterization of a novel piezoelectric transducer-based linear motor}, volume={9}, ISSN={["1941-014X"]}, DOI={10.1109/TMECH.2004.828647}, abstractNote={Before microminiature robots can be realized, new direct drive micromotor systems must be developed. In this research, a linear motor system for a miniature jumping robot was desired. However, current systems must display better force/torque characteristics than is currently available. This paper deals with the design, construction, and testing, of a macro-scale, unidirectional, direct drive linear piezomotor that operates like an inchworm. It uses a parallel arrangement of unimorph piezoelectric transducers, in conjunction with passive mechanical latches, to perform work on a coil spring. Experimental results showed that the linear piezomotor achieved a maximum no-load velocity of 161 mm/s, and a blocked force of 14 N, at a drive signal frequency of 100 Hz. Thereafter, back slip in the latch assembly restricted the forward motion. Based on the results obtained with the macro-level linear piezomotor, it is concluded that smaller direct drive piezomotor designs based on unimorph piezoelectric transducers are achievable. System scalability will be addressed in a future publication.}, number={2}, journal={IEEE-ASME TRANSACTIONS ON MECHATRONICS}, author={Palmer, JA and Dessent, B and Mulling, JF and Usher, T and Grant, E and Eischen, JW and Kingon, AI and Franzon, PD}, year={2004}, month={Jun}, pages={392–398} }
 @article{rodriguez_gruverman_kingon_nemanich_cross_2004, title={Three-dimensional high-resolution reconstruction of polarization in ferroelectric capacitors by piezoresponse force microscopy}, volume={95}, ISSN={["1089-7550"]}, DOI={10.1063/1.1638889}, abstractNote={A combination of vertical and lateral piezoresponse force microscopy (VPFM and LPFM, respectively) has been used to map the out-of-plane and in-plane polarization distribution, respectively, of (111)-oriented Pb(Zr,Ti)O3-based (PZT) ferroelectric patterned and reactively-ion-etched capacitors. While VPFM and LPFM have previously been used to determine the orientation of the polarization vector in ferroelectric crystals and thin films, this is the first time the technique has been applied to determine the three-dimensional polarization distribution in thin-film capacitors and, as such, is of importance to the implementation of nonvolatile ferroelectric random access memory. Sequential VPFM and LPFM imaging have been performed in poled 1×1.5 μm2 PZT capacitors. Subsequent quantitative analysis of the obtained piezoresponse images allowed the three-dimensional reconstruction of the domain arrangement in the PZT layers of the capacitors. It has been found that the poled capacitors, which appear as uniformly polarized in VPFM, are in fact in a polydomain state as is detected by LPFM and contain 90° domain walls. Despite the polycrystallinity of the PZT layer, regions larger than the average PZT grain size are found to have the same polarization orientation. This technique has potential for clarifying the switching behavior and imprint mechanism in micro- and nanoscale ferroelectric capacitors.}, number={4}, journal={JOURNAL OF APPLIED PHYSICS}, author={Rodriguez, BJ and Gruverman, A and Kingon, AI and Nemanich, RJ and Cross, JS}, year={2004}, month={Feb}, pages={1958–1962} }
 @article{kim_maria_kingon_streiffer_2003, title={Evaluation of intrinsic and extrinsic contributions to the piezoelectric properties of Pb(Zr1-xTX)O-3 thin films as a function of composition}, volume={93}, ISSN={["0021-8979"]}, DOI={10.1063/1.1566478}, abstractNote={The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured, 200-nm-thick polycrystalline lead zirconate titanate (PZT) films have been investigated as a function of Zr/Ti ratio. The distinct peak in piezoelectric coefficient at the morphotropic phase boundary found in bulk PZT ceramics is not observed in thin film PZTs. Measurements of the temperature dependence of relative permittivity and the nonlinear behavior of relative permittivity and piezoelectric coefficient suggest that non-180° domain wall motion in these films is negligible, indicating that the extrinsic contribution to the room temperature permittivity is dominated by only 180° domain wall motion. The semiempirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive and elastic coefficients. The small deviation between calculated and measured piezoelectric coefficients as well as the dependence of piezoelectric and polarization behavior on the external field, i.e., hysteresis loop, are suggested to be primarily due to backswitching of 180° domains.}, number={9}, journal={JOURNAL OF APPLIED PHYSICS}, author={Kim, DJ and Maria, JP and Kingon, AI and Streiffer, SK}, year={2003}, month={May}, pages={5568–5575} }
 @misc{maria_kingon_2003, title={Lanthanum oxide-based gate dielectrics for integrated circuit field effect transistors}, volume={6,531,354}, number={2003 Mar. 11}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Maria, J.-P. and Kingon, A. I.}, year={2003} }
 @article{gruverman_rodriguez_kingon_nemanich_tagantsev_cross_tsukada_2003, title={Mechanical stress effect on imprint behavior of integrated ferroelectric capacitors}, volume={83}, ISSN={["0003-6951"]}, DOI={10.1063/1.1593830}, abstractNote={Stress-induced changes in the imprint and switching behavior of (111)-oriented Pb(Zr,Ti)O3 (PZT)-based capacitors have been studied using piezoresponse force microscopy. Visualization of polarization distribution and d33-loop measurements in individual 1×1.5-μm2 capacitors before and after stress application, generated by substrate bending, provided direct experimental evidence of stress-induced switching. Mechanical stress caused elastic switching in capacitors with the direction of the resulting polarization determined by the sign of the applied stress. In addition, stress application turned capacitors into a heavily imprinted state characterized by strongly shifted hysteresis loops and almost complete backswitching after application of the poling voltage. It is suggested that substrate bending generated a strain gradient in the PZT layer, which produced asymmetric lattice distortion with preferential polarization direction and triggered polarization switching due to the flexoelectric effect.}, number={4}, journal={APPLIED PHYSICS LETTERS}, author={Gruverman, A and Rodriguez, BJ and Kingon, AI and Nemanich, RJ and Tagantsev, AK and Cross, JS and Tsukada, M}, year={2003}, month={Jul}, pages={728–730} }
 @misc{maria_kingon_dunn_streiffer_k._m.-x._savic_2003, title={Multi-layer conductor-dielectric oxide structure}, volume={6,541,137}, number={2003 Apr. 1}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Maria, J.-P and Kingon, A. and Dunn, G. and Streiffer, S.Cheek and K., Zhang and M.-X. and Savic, J.}, year={2003} }
 @article{wu_ro_kingon_mulling_2003, title={Piezoelectric resonating structures for microelectronic cooling}, volume={12}, DOI={10.1088/0964-1726/12/2/304}, abstractNote={The design of piezoelectric resonating structures was investigated for generating acoustic streaming which may be used for cooling microelectronic components. The vibration characteristics of different piezoelectric structures were simulated by the finite element method and validated with analytical approaches. Considering the product of resonance frequency and dynamic tip deflection as a performance merit, the effects of length and location of the actuators as well as the boundary conditions were analyzed for four different piezoelectric resonator designs. Results show that there exist optimal length and location of actuators on the passive structures.}, number={2}, journal={Smart Materials & Structures}, author={Wu, T. and Ro, P. I. and Kingon, A. I. and Mulling, J. F.}, year={2003}, pages={181–187} }
 @article{gruverman_rodriguez_kingon_nemanich_cross_tsukada_2003, title={Spatial inhomogeneity of imprint and switching behavior in ferroelectric capacitors}, volume={82}, ISSN={["0003-6951"]}, DOI={10.1063/1.1570942}, abstractNote={Piezoresponse force microscopy has been used to perform nanoscale characterization of the spatial variations in the imprint and switching behavior of (111)-oriented Pb(Zr,Ti)O3-based capacitors on Pt electrodes. Mapping of polarization distribution in the poled capacitors as well as local d33–V loop measurements revealed a significant difference in imprint and switching behavior between the peripheral and inner parts of the capacitors. It has been found that the inner regions of the capacitors are negatively imprinted (with the preferential direction of the normal component of polarization upward) and tend to switch back after application of the positive poling voltage. On the other hand, switchable regions at the edge of the integrated capacitors generally exhibit more symmetric hysteresis behavior. Application of an ac switching voltage, contrary to what was expected, resulted in an increase of the negatively imprinted regions. The observed effect has been explained by incomplete or asymmetric switching due to the mechanical stress conditions existing in the central parts of the capacitors.}, number={18}, journal={APPLIED PHYSICS LETTERS}, author={Gruverman, A and Rodriguez, BJ and Kingon, AI and Nemanich, RJ and Cross, JS and Tsukada, M}, year={2003}, month={May}, pages={3071–3073} }
 @article{tombak_maria_ayguavives_jin_stauf_kingon_mortazawi_2003, title={Voltage-controlled RF filters employing thin-film barium-strontium-titanate tunable capacitors}, volume={51}, ISSN={["1557-9670"]}, DOI={10.1109/TMTT.2002.807822}, abstractNote={Tunable lowpass and bandpass lumped-element filters employing barium-strontium-titanate (BST)-based capacitors are presented. A new metallization technique is used, which improves the quality factor of the tunable BST capacitors by a factor of two. The lowpass filter has an insertion loss of 2 dB and a tunability of 40% (120-170 MHz) with the application of 0-9 V DC bias. The bandpass filter (BPF) has an insertion loss of 3 dB and a tunability of 57% (176-276 MHz) with the application of 0-6 V DC. The third-order intercept point of the BPF was measured to be 19 dBm with the application of two tones around 170 MHz.}, number={2}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Tombak, A and Maria, JP and Ayguavives, FT and Jin, Z and Stauf, GT and Kingon, AI and Mortazawi, A}, year={2003}, month={Feb}, pages={462–467} }
 @article{maria_wickaksana_parrette_kingon_2002, title={Crystallization in SiO2-metal oxide alloys}, volume={17}, ISSN={["0884-2914"]}, DOI={10.1557/JMR.2002.0234}, abstractNote={HfO2–SiO2 and La2O3–SiO2 amorphous alloys were prepared, and their crystallization behavior was studied. The results suggest that higher permittivities can be achieved in the La-containing system without devitrification. The crystallization mechanisms between systems are distinctly different, yet observations are consistent with bulk material. Hf-containing materials tend toward phase separation, while La-containing materials tend toward silicate formation. For Hf-containing films, negligible thickness or time dependence was observed. In La-containing films, rapid thermal anneals could improve crystallization resistance, and thickness effects related to interface reactions were observed. These behaviors are discussed in the context of phase diagrams and metastable immiscibility.}, number={7}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Maria, JP and Wickaksana, D and Parrette, J and Kingon, AI}, year={2002}, month={Jul}, pages={1571–1579} }
 @article{gruverman_rodriguez_nemanich_kingon_2002, title={Nanoscale observation of photoinduced domain pinning and investigation of imprint behavior in ferroelectric thin films}, volume={92}, ISSN={["1089-7550"]}, DOI={10.1063/1.1497698}, abstractNote={Piezoresponse force microscopy has been used to investigate the nanoscale mechanism of imprint behavior of ferroelectric PbTiO3 thin films by studying the photoinduced changes in the hysteresis loops of individual grains. Illumination of the film with UV light resulted in a voltage shift opposite to that observed in ferroelectric thin film capacitors. This effect is attributed to the generation of an electric field within the surface dielectric layer as a result of the interaction between photoinduced charges and polarization charges. Application of a small nonswitching bias to the film with simultaneous UV illumination resulted in domain pinning in the grains where the polarization direction coincided with the direction of the applied field, in agreement with the proposed model. Domain pinning was also observed in grains with polydomain structure suggesting that charge entrapment at the existing domain boundaries in the bulk of the film contributes to the suppression of switchable polarization. However, a symmetric character of hysteresis loops observed in such grains implies that charge entrapment in the bulk of the film does not cause the voltage shift. It has been suggested that a thin high-dielectric interfacial layer can improve the imprint behavior of ferroelectric capacitors.}, number={5}, journal={JOURNAL OF APPLIED PHYSICS}, author={Gruverman, A and Rodriguez, BJ and Nemanich, RJ and Kingon, AI}, year={2002}, month={Sep}, pages={2734–2739} }
 @article{kim_park_woo_lee_ha_hwang_shim_kingon_2002, title={Orientation effects in chemical solution derived Pb(Zr-0.3,Ti-0.7)O-3 thin films on ferroelectric properties}, volume={416}, ISSN={["0040-6090"]}, DOI={10.1016/S0040-6090(02)00726-5}, abstractNote={The solely orientation-related effects on ferroelectric and piezoelectric properties of Pb(Zr0.3,Ti0.7)O3 (PZT) thin films with identical processing conditions were investigated using near lattice matched Pt electrodes, that is, (111)-textured Pt for (111)-oriented PZT thin films and (100)-textured Pt for (100)-oriented films. As a result, the film composition, microstructure, and topography were highly similar in all cases. (111)-oriented tetragonal PZT films exhibited highly rectangular P–V hysteresis loops with a slightly better fatigue endurance than the (100)-oriented films. However, the measured d33 values of (100)-oriented PZT films were somewhat higher than those of (111)-oriented films, indicating a consistency with C–V curves. It was shown that in tetragonal symmetry, the intrinsic effect was largest in the piezoelectricity of PZT thin films.}, number={1-2}, journal={THIN SOLID FILMS}, author={Kim, SH and Park, DY and Woo, HJ and Lee, DS and Ha, J and Hwang, CS and Shim, IB and Kingon, AI}, year={2002}, month={Sep}, pages={264–270} }
 @article{rodriguez_gruverman_kingon_nemanich_2002, title={Piezoresponse force microscopy for piezoelectric measurements of III-nitride materials}, volume={246}, ISSN={["0022-0248"]}, DOI={10.1016/S0022-0248(02)01749-9}, abstractNote={Piezoelectric constants and polarity distributions of epitaxial AlN and GaN thin films are investigated by piezoresponse force microscopy (PFM). The magnitude of the effective longitudinal piezoelectric constant d33 is determined to be 3±1 and 2±1 pm/V for wurtzite AlN and GaN/AlN layers grown by organo-metallic vapor phase epitaxy on SiC substrates, respectively. Simultaneous imaging of surface morphology as well as the phase and magnitude of the piezoelectric response is performed by PFM on a GaN film with patterned polarities on a c-Al2O3 substrate. We demonstrate that the polarity distribution of GaN based lateral polarity heterostructures can be deduced from the phase image of the piezoresponse with nanometer scale spatial resolution. We also present images of AlN/Si samples with regions of opposite piezoresponse phase, which indicate the presence of antiphase domains. We discuss the potential application of this technique for determination of the orientation of bulk crystals.}, number={3-4}, journal={JOURNAL OF CRYSTAL GROWTH}, author={Rodriguez, BJ and Gruverman, A and Kingon, AI and Nemanich, RJ}, year={2002}, month={Dec}, pages={252–258} }
 @article{rodriguez_gruverman_kingon_nemanich_ambacher_2002, title={Piezoresponse force microscopy for polarity imaging of GaN}, volume={80}, ISSN={["1077-3118"]}, DOI={10.1063/1.1483117}, abstractNote={The polarity distribution of GaN based lateral polarity heterostructures is investigated by piezoresponse force microscopy (PFM). Simultaneous imaging of surface morphology, as well as the phase and magnitude of the piezoelectric response, is performed by PFM on a GaN film with patterned polarities on a c-Al2O3 substrate. We demonstrate that the polarity distribution of GaN based lateral polarity heterostructures can be deduced from the phase image of the piezoresponse with nanometer scale spatial resolution.}, number={22}, journal={APPLIED PHYSICS LETTERS}, author={Rodriguez, BJ and Gruverman, A and Kingon, AI and Nemanich, RJ and Ambacher, O}, year={2002}, month={Jun}, pages={4166–4168} }
 @article{stemmer_chen_keding_maria_wicaksana_kingon_2002, title={Stability of ZrO2 layers on Si (001) during high-temperature anneals under reduced oxygen partial pressures}, volume={92}, ISSN={["1089-7550"]}, DOI={10.1063/1.1481970}, abstractNote={Electron energy-loss spectroscopy and high-resolution transmission electron microscopy were used to investigate ZrO2 layers grown by electron-beam evaporation in a molecular-beam epitaxy system. ZrO2/Si layers were investigated before and after uncapped annealing at 1000 °C under different oxygen partial pressures. The thickness of a SiO2-like, low-dielectric constant layer at the silicon interface was found to depend on the oxygen partial pressure during annealing. At oxygen partial pressures of about 10−4 torr the interfacial silicon oxide thickness increased through oxygen diffusion through the ZrO2 layer and silicon consumption at the interface. At oxygen partial pressures in the range of approximately 10−5 torr, only a thin (1 nm) interfacial silicon oxide layer was present, as required for low-equivalent oxide thicknesses of gate stacks incorporating alternative oxides. Further reduction of the oxygen partial pressures (about 10−7 torr) during annealing resulted in zirconium silicide formation at the interface. ZrO2 films annealed at the optimal partial pressure for a thin interfacial oxide were found to crystallize and contain no silicon. High-resolution analytical capabilities afforded by scanning transmission electron microscopy techniques proved essential in analyzing the stability of these ultrathin layers.}, number={1}, journal={JOURNAL OF APPLIED PHYSICS}, author={Stemmer, S and Chen, ZQ and Keding, R and Maria, JP and Wicaksana, D and Kingon, AI}, year={2002}, month={Jul}, pages={82–86} }
 @article{parker_maria_kingon_2002, title={Temperature and thickness dependent permittivity of (Ba,Sr)TiO3 thin films}, volume={81}, ISSN={["1077-3118"]}, DOI={10.1063/1.1490148}, abstractNote={The temperature and thickness dependence of permittivity of (Ba,Sr)TiO3 has been investigated. The films were deposited by liquid-source metalorganic chemical vapor deposition onto Pt/SiO2/Si, with thicknesses ranging from 15 to 580 nm. The dielectric response was measured from 100 to 520 K. As film thickness decreased, the maximum dielectric constant decreased, the temperature at which the maximum dielectric constant occurred decreased, and the peak in the dielectric constant became more diffuse. A model incorporating a thickness independent interior and a nonferroelectric surface cannot account for these thickness dependencies. To appropriately model these observations a physical model containing thickness and temperature dependent interior and surface components is necessary.}, number={2}, journal={APPLIED PHYSICS LETTERS}, author={Parker, CB and Maria, JP and Kingon, AI}, year={2002}, month={Jul}, pages={340–342} }
 @article{tombak_maria_ayguavives_jin_stauf_kingon_mortazawi_2002, title={Tunable barium strontium titanate thin film capacitors for RF and microwave applications}, volume={12}, ISSN={["1558-1764"]}, DOI={10.1109/7260.975716}, abstractNote={The measurement results for thin film barium strontium titanate (BST) based voltage tunable capacitors intended for RF applications are reported. At 9 V DC, BST capacitors fabricated using MOCVD (metalorganic chemical vapor deposition) method achieved 71% (3.4:1) tunability. The measured device quality factor (Q) for BST varactors is comparable with the device Q for commercially available varactor diodes of similar capacitance. The typical dielectric loss tangent was in the range 0.003-0.009 at VHF. Large signal measurement and modeling results for BST thin film capacitors are also presented.}, number={1}, journal={IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS}, author={Tombak, A and Maria, JP and Ayguavives, F and Jin, Z and Stauf, GT and Kingon, AI and Mortazawi, A}, year={2002}, month={Jan}, pages={3–5} }
 @article{gruverman_kholkin_kingon_tokumoto_2001, title={Asymmetric nanoscale switching in ferroelectric thin films by scanning force microscopy}, volume={78}, ISSN={["1077-3118"]}, DOI={10.1063/1.1366644}, abstractNote={Scanning force microscopy (SFM) has been used to perform nanoscale studies of the switching behavior of Pb(Zr, Ti)O3 thin films via the direct observation of their domain structures. The study revealed a significant asymmetry of a switching pattern which is a function of the voltage polarity and original domain structure of individual grains. The phenomenon of asymmetric switching is attributed (1) to the presence of an internal built-in electric field at the bottom interface and (2) to the mechanical stress exerted by the SFM tip. The former effect results in incomplete 180° switching, while the latter effect leads to a 90° rotation of the polarization vector. The resulting shear stress deformation of the grain underneath the tip combined with the applied field effect propels polarization reversal in the adjacent grains.}, number={18}, journal={APPLIED PHYSICS LETTERS}, author={Gruverman, A and Kholkin, A and Kingon, A and Tokumoto, H}, year={2001}, month={Apr}, pages={2751–2753} }
 @article{kim_ha_hwang_kingon_2001, title={Ca- and Sr-doped (Pb1-xLax)(ZryTi1-y)(1-x/4)O-3 thin films for low-voltage operation}, volume={394}, number={1-2}, journal={Thin Solid Films}, author={Kim, S. H. and Ha, J. and Hwang, C. S. and Kingon, A. I.}, year={2001}, pages={131–135} }
 @article{ayguavives_jin_tombak_maria_mortazawi_kingon_2001, title={Contribution of dielectric and metallic losses in RF/microwave tunable varactors using (Ba,Sr)TiO3 thin films}, volume={39}, number={1-4}, journal={Integrated Ferroelectrics}, author={Ayguavives, F. and Jin, Z. and Tombak, A. and Maria, J. P. and Mortazawi, A. and Kingon, A. I.}, year={2001}, pages={1343–1352} }
 @article{yoon_wicaksana_kim_kim_kingon_2001, title={Effect of hydrogen on true leakage current characteristics of (Pb,La)(Zr,Ti)O-3 thin-film capacitors with Pt- or Ir-based top electrodes}, volume={16}, ISSN={["2044-5326"]}, DOI={10.1557/JMR.2001.0163}, abstractNote={The degradation behavior of polarization and leakage current characteristics of sol-gel-derived (Pb,La)(Zr,Ti)O3 (PLZT) thin films, with Pt, Ir, and IrO2 top electrodes, by annealing under a 4% H2/96% N2 atmosphere were investigated. The leakage current behaviors of Pt/PLZT/Pt and IrO2/PLZT/Pt capacitors annealed at 300 °C for 20 min in 4% H2 were well consistent with the space-charge-influenced injection model proposed. However, IrO2/PLZT/Pt capacitors recovered at 700 °C for 10 min in Ar ambient after hydrogen anneal were not consistent with the proposed model because a conducting phase of IrPb was formed between the top electrode and PLZT during the recovery anneal at 700 °C in Ar ambient and modified the Schottky barrier height. The true leakage current behavior of IrO2/PLZT/Pt capacitors recovered after hydrogen forming are similar to those of Ir/PLZT/Pt capacitors without the hydrogen-forming gas anneal. The P–E loops of Pt/PLZT/Pt and Ir/PLZT/Pt capacitors showed good recovery through recovery anneal after H2 treatment. However, IrO2/PLZT/Pt capacitors depended on the recovery anneal atmosphere (Ar or O2).}, number={4}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Yoon, SG and Wicaksana, D and Kim, DJ and Kim, SH and Kingon, AI}, year={2001}, month={Apr}, pages={1185–1189} }
 @article{yoon_kingon_kim_2001, title={Electrical properties of Pb1-xLax(ZryTi1-y)(1-x/4)O-3 thin films with various iridium-based top electrodes}, volume={33}, number={1-4}, journal={Integrated Ferroelectrics}, author={Yoon, S. G. and Kingon, A. I. and Kim, S. H.}, year={2001}, pages={155–164} }
 @article{baumann_streiffer_bai_ghosh_auciello_thompson_stemmer_rao_eom_xu_et al._2001, title={Epitaxial Pb(Mg1/3Nb2/3)O-3-PbTiO3 thin films grown by MOCVD}, volume={35}, number={1-4}, journal={Integrated Ferroelectrics}, author={Baumann, P. K. and Streiffer, S. K. and Bai, G. R. and Ghosh, K. and Auciello, O. and Thompson, C. and Stemmer, S. and Rao, R. A. and Eom, C. B. and Xu, F. and et al.}, year={2001}, pages={1881–1888} }
 @article{maria_wicaksana_kingon_busch_schulte_garfunkel_gustafsson_2001, title={High temperature stability in lanthanum and zirconia-based gate dielectrics}, volume={90}, ISSN={["0021-8979"]}, DOI={10.1063/1.1391418}, abstractNote={Gate dielectrics composed primarily of lanthana and zirconia were prepared by reactive evaporation. The stability of the layers during high temperature anneals was investigated. By controlling the oxygen partial pressure during heat treatment, lanthana and zirconia films could be protected against reaction with the underlying Si substrate and against the growth of low-ε interface layers. The electrical thickness of the dielectrics could be maintained after a 900 °C exposure. The critical oxygen pressure at 900 °C for low-ε interface formation beneath ZrO2 and La2O3 dielectrics was ∼2e−4 Torr. The interfaces that formed beneath the ZrO2 and La2O3 layers are distinctly different. The sub-ZrO2 interface, influenced primarily by phase separation, tends towards pure SiO2, while the sub-La2O3 interface, influenced primarily by silicate formation, tends towards a La–Si–O alloy. For both materials, reducing the oxygen pressure to values below 10−7 Torr resulted in rapid degradation of the metal oxide. This dielectric degradation is believed to be linked to SiO evaporation. These results suggest that at high temperatures, a window of optimal oxygen partial pressure exists in which the stability of many oxides in contact with silicon can be achieved.}, number={7}, journal={JOURNAL OF APPLIED PHYSICS}, author={Maria, JP and Wicaksana, D and Kingon, AI and Busch, B and Schulte, H and Garfunkel, E and Gustafsson, T}, year={2001}, month={Oct}, pages={3476–3482} }
 @article{maria_cheek_streiffer_kim_dunn_kingon_2001, title={Lead zirconate titanate thin films on base-metal foils: an approach for embedded high-permittivity passive components}, volume={84}, DOI={10.1111/j.1151-2916.2001.tb01029.x}, abstractNote={An approach for embedding high‐permittivity dielectric thin films into glass epoxy laminate packages has been developed. Lead lanthanum zirconate titanate (Pb0.85La0.15(Zr0.52Ti0.48)0.96O3, PLZT) thin films were prepared using chemical solution deposition on nickel‐coated copper foils that were 50 μm thick. Sputter‐deposited nickel top electrodes completed the all‐base‐metal capacitor stack. After high‐temperature nitrogen‐gas crystallization anneals, the PLZT composition showed no signs of reduction, whereas the base‐metal foils remained flexible. The capacitance density was 300–400 nF/cm2, and the loss tangent was 0.01–0.02 over a frequency range of 1–1000 kHz. These properties represent a potential improvement of 2–3 orders of magnitude over currently available embedded capacitor technologies for polymeric packages.}, number={10}, journal={Journal of the American Ceramic Society}, author={Maria, J.-P. and Cheek, K. and Streiffer, S. and Kim, S. H. and Dunn, G. and Kingon, A.}, year={2001}, pages={2436–2438} }
 @article{mulling_usher_dessent_palmer_franzon_grant_kingon_2001, title={Load characterization of high displacement piezoelectric actuators with various end conditions}, volume={94}, ISSN={["0924-4247"]}, DOI={10.1016/S0924-4247(01)00688-4}, abstractNote={Piezoelectric ceramic transducers are characterized by relatively small strains on the order of 0.1%. One method of achieving significantly larger displacements is to utilize flexural mode actuators, such as unimorphs or bimorphs. In this paper, we investigate a particular type of stressed unimorph flexural actuator, viz. the ‘THUNDER’ actuators. (THUNDER™ is a trademark of Face International Corporation). These stressed unimorphs are of interest due to their particularly large flexural strains. To determine their versatility as high displacement actuators, it was necessary to investigate their actuation capability as a function of load. In addition, our investigation determined that end conditions have an appreciable effect, which has also not been reported in the literature. Therefore, experimental results of the load capabilities of these high displacement actuators with various end conditions are presented here. Commercially available rectangular actuators were chosen for this study. The actuators had been constructed by bonding thin PZT ceramics (0.152 mm thick, 1.37 cm wide, 3.81 cm long) to stainless steel sheets (0.20 mm thick, 1.27 cm wide, 6.35 cm long). They were operated in a flexural mode. It was shown that progressively restrictive end conditions increased the stiffness, ranging from 2.5 to 23 N/m, enhancing the load capabilities of the actuator. In some cases, displacement actually increased as a function of load. This enhanced stiffness was obtained at a cost of reduced no load flexural strain (defined as the ratio of flexural displacement and ceramic length), ranging from 1.08% for free-end conditions to 0.2% for highly restricted end conditions. The load bearing capabilities were tested out to 10 N for most end conditions.}, number={1-2}, journal={SENSORS AND ACTUATORS A-PHYSICAL}, author={Mulling, J and Usher, T and Dessent, B and Palmer, J and Franzon, P and Grant, E and Kingon, A}, year={2001}, month={Oct}, pages={19–24} }
 @article{chen_roeder_kim_maria_kingon_2001, title={Metalorganic chemical vapor deposition Pb(Zr,Ti)O-3 and selected lower electrode structures as a pathway to integrated piezoelectric microelectromechanical systems}, volume={19}, ISSN={["1071-1023"]}, DOI={10.1116/1.1401747}, abstractNote={The actuation mechanism is an important aspect of many micromachined devices. Electrostatic actuation has been the prevailing actuation method due to its relative ease in implementation using conventional silicon microfabrication techniques. Other mechanisms are becoming more accessible to micromachine designs as new materials are introduced into the microfabrication process. Recent progress in nonvolatile memory has led to successful incorporation of Pb(Zr,Ti)O3 (PZT) thin films into microelectronic devices. The present work expands on this area and investigates PZT thin films and electrode/barrier combinations for applications in micromachined devices. Incorporation of PZT thin films into silicon micromachined devices requires electrode systems and deposition techniques that are compatible with silicon microfabrication. In this study, Ir/IrOx and Ir/(Ti,Al)N lower electrode systems were developed to suppress diffusion of reactive species (e.g., Pb) into silicon-based microelectromechanical system devices and to enhance PZT film adhesion. Piezoelectric PZT thin films from 0.3 to 1 μm thick were prepared on silicon wafers with these electrode structures by metalorganic chemical vapor deposition. Hysteresis loops of longitudinal piezoelectric coefficient (d33) were measured by dual-beam interferometry and used to characterize piezoelectric activity in these films. The effective d33 exhibited an apparent dependence on film thickness. d33 values up to 70 pm/V were obtained for 1 μm films, while thinner films exhibited lower d33 values between 54 and 60 pm/V. The dielectric loss (tan δ) was below 2% for most films irrespective of their thickness.}, number={5}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Chen, IS and Roeder, JF and Kim, DJ and Maria, JP and Kingon, AI}, year={2001}, pages={1833–1840} }
 @article{hugon_varniere_letendu_agius_vickridge_kingon_2001, title={O-18 study of the oxidation of reactively sputtered Ti1-xAlxN barrier}, volume={16}, ISSN={["0884-2914"]}, DOI={10.1557/JMR.2001.0356}, abstractNote={The preparation of high-permittivity perovskite materials requires high-temperature (550–750 °C) oxidizing environments, providing stringent limitations on the choice of electrode materials. To minimize interdiffusion and oxidation reactions, an electrically conductive diffusion barrier such as Ti1−xAlxN is needed below the electrode material (Pt, IrO2, RuO2…). Ti1−xAlxN films were deposited by multitarget reactive sputtering in a mixture of Ar and N2. The stability of these films has been investigated under typical conditions for crystallization of perovskite dielectrics. Sample composition was characterized using Rutherford backscattering spectroscopy and nuclear reaction analysis. In particular, the concentration depth profiles of both 18O and 27Al were measured before and after RTA treatments via the narrow resonances of 18O(p,α)15N at 151 keV (FWHM = 100 eV) and 27Al(p,γ)28Si at 992 keV (FWHM = 100 eV). The different 18O excitation curves show that the oxidation resistance increases with Al incorporation. The Al excitation curves indicate a uniform Al content for as-deposited TixAl1−xN and reveal Al diffusion to the surface during the oxidation process which indicates the formation of an Al-rich oxide layer at the TixAl1−xN surface, leaving a layer depleted in Al below it.}, number={9}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Hugon, MC and Varniere, F and Letendu, F and Agius, B and Vickridge, L and Kingon, AI}, year={2001}, month={Sep}, pages={2591–2599} }
 @article{yoon_kingon_2001, title={Recovery characteristics of hydrogen-damaged (Pb,La)(Zr,Ti)O-3 capacitors with Pt and IrO2 top electrodes}, volume={148}, ISSN={["0013-4651"]}, DOI={10.1149/1.1375170}, abstractNote={The effect of hydrogen on ferroelectric properties was investigated for 
                     
                        (
                        Pb
                        ,
                        La
                        )
                        (
                        Zr
                        ,
                        Ti
                        )
                        
                           O
                           
                              3
                           
                        
                         
                        (
                        PLZT
                        )
                     
                     
                   films with Pt and 
                     
                        
                           IrO
                           
                              2
                           
                        
                     
                     
                   top electrodes. The P-E hysteresis loop and fatigue properties of the Pt/PLZT/Pt capacitor are completely recovered by recovery anneal at 700°C in 
                     
                        
                           O
                           
                              2
                           
                        
                     
                     
                   ambient after a hydrogen-forming gas anneal. On the other hand, 
                     
                        
                           IrO
                           
                              2
                           
                        
                        /
                        PLZT
                        /
                        Pt
                     
                     
                   capacitor after recovery anneal does not show a complete recovery for ferroelectric properties. The 
                     
                        
                           IrO
                           
                              2
                           
                        
                     
                     
                   top electrode in the 
                     
                        
                           IrO
                           
                              2
                           
                        
                        /
                        PLZT
                        /
                        Pt
                     
                     
                   capacitor is completely reduced to Ir metal in 4% 
                     
                        
                           H
                           
                              2
                           
                        
                     
                     
                   at 300°C and then change to the 
                     
                        
                           IrO
                           
                              2
                           
                        
                        /
                        Ir
                     
                     
                   complex phase after recovery anneal at 700°C in 
                     
                        
                           O
                           
                              2
                           
                        
                     
                     
                   ambient. The ferroelectric properties of PLZT capacitors greatly depend on the residual hydrogen near the film/top electrode interface after recovery anneal. © 2001 The Electrochemical Society. All rights reserved.}, number={7}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Yoon, SG and Kingon, AI}, year={2001}, month={Jul}, pages={F137–F139} }
 @article{stemmer_maria_kingon_2001, title={Structure and stability of La2O3/SiO2 layers on Si(001)}, volume={79}, ISSN={["0003-6951"]}, DOI={10.1063/1.1383268}, abstractNote={High-resolution transmission electron microscopy and electron energy-loss spectroscopy (EELS) were used to investigate La2O3/SiO2/Si structures. The La2O3 layers were deposited on thermal SiO2 on silicon, followed by rapid thermal annealing treatments at 600 °C and 800 °C in a nitrogen ambient. After annealing at 600 °C, the oxide layers were amorphous. After an 800 °C treatment, crystallites appeared in the original La2O3 layer, and the total oxide layer thickness increased by 17%, most likely due to the oxygen diffusion and reaction at the Si/SiO2 interface. EELS, using a 0.2 nm probe, showed that rapid thermal annealing at 600 °C did not cause significant La diffusion into the SiO2 layer, whereas some intermixing was observed at 800 °C. We use the observed microstructures to estimate equivalent oxide thicknesses. The results demonstrate that oxygen partial pressures and initial SiO2 thickness need to be carefully controlled to control SiO2 formation at the Si interface and to achieve target equivalent oxide thickness.}, number={1}, journal={APPLIED PHYSICS LETTERS}, author={Stemmer, S and Maria, JP and Kingon, AI}, year={2001}, month={Jul}, pages={102–104} }
 @article{letendu_hugon_agius_aubert_coindeau_kingon_2001, title={Study of TaSiN diffusion barrier}, volume={38}, number={1-4}, journal={Integrated Ferroelectrics}, author={Letendu, F. and Hugon, M. C. and Agius, B. and Aubert, P. and Coindeau, S. and Kingon, A. I.}, year={2001}, pages={865–872} }
 @article{kim_park_woo_lee_ha_hwang_jeong_kingon_2001, title={The low-voltage-switching behavior of sol-gel-derived Pb(Zr,Ti)O-3 thin film capacitors}, volume={39}, number={1-4}, journal={Integrated Ferroelectrics}, author={Kim, S. H. and Park, D. Y. and Woo, H. J. and Lee, D. S. and Ha, J. W. and Hwang, C. S. and Jeong, S. and Kingon, A. I.}, year={2001}, pages={963–972} }
 @article{stauf_ragaglia_roeder_vestyck_maria_ayguavives_kingon_mortazawi_tombak_2001, title={Thick electrodes for high frequency high Q tunable ferroelectric thin film varactors}, volume={39}, DOI={10.1080/10584580108011955}, abstractNote={Abstract Thin film barium strontium titanate (BST) shows great promise for voltage tunable dielectric devices for use at RF and microwave frequencies. An MOCVD process has been developed for production of BST, resulting in films with very low losses (as low as 0.002–0.004) and tunabilities over 50% at low operation voltages. With these values of BST loss, overall device quality factors at RF (100 MHz+) frequencies are primarily limited by losses in the thin metal electrodes, such as Pt, normally used for ferroelectric thin films. The bottom electrode in parallel plate capacitor structures is particularly challenging, since it must provide a good growth surface for BST and be stable at high (>600 °C) growth temperatures in an oxidizing atmosphere yet have high conductivity and compatibility with Si or SiO2/Si substrates. These challenges have previously prevented use of Pt thicknesses over 0.1–0.2 urn. Our solution to this problem, involves combinations of adhesion layers at the Pt/SiO2 interface and embedded stabilization layers to make functioning Pt bottom electrodes as thick as 2 μm. Devices with dielectric Q factors over 150 at 100 MHz (tan δ ∼ 0.006 as measured and modeled by S-parameters) and overall device Q factors over 50 at 30 MHz are described. We have also inserted these devices into tunable filters, achieving tunabilities of 50% and low insertion losses (0.3 dB) at RF frequencies.}, number={1-4}, journal={Integrated Ferroelectrics}, author={Stauf, G. T. and Ragaglia, C. and Roeder, J. F. and Vestyck, D. and Maria, J. P. and Ayguavives, T. and Kingon, A. and Mortazawi, A. and Tombak, A.}, year={2001}, pages={1271–1280} }
 @article{kim_woo_ha_hwang_kim_kingon_2001, title={Thickness effects on imprint in chemical-solution-derived (Pb, La)(Zr, Ti)O-3 thin films}, volume={78}, ISSN={["1077-3118"]}, DOI={10.1063/1.1370989}, abstractNote={The film thickness-dependent imprinting behavior (voltage shift) of (Pb, La)(Zr, Ti)O3 capacitors was evaluated by a thermal stress process under a remanence bias. The remanent polarization (Pr) was found to be almost independent of the film thickness whereas in the 50–300 nm range the relative dielectric constant (εr) increased linearly with the square root of the film thickness. It was found that the voltage shift, which was attributed to the accumulation of charged defects near the electrode interface, also increased linearly with increasing film thickness. In addition, the charge accumulated thickness varied with the square root of the film thickness. This was established from a simple assumption that the level of charge accumulation is determined by the product of the total amount of charged defects (total film thickness×charged defect density) and the internal field that is generated by the Pr. Therefore, the imprint is much more a bulk-related degradation phenomenon compared to the fatigue.}, number={19}, journal={APPLIED PHYSICS LETTERS}, author={Kim, SH and Woo, HJ and Ha, J and Hwang, CS and Kim, HR and Kingon, AI}, year={2001}, month={May}, pages={2885–2887} }
 @misc{kingon_maria_streiffer_2000, title={Alternative dielectrics to silicon dioxide for memory and logic devices}, volume={406}, ISSN={["1476-4687"]}, DOI={10.1038/35023243}, abstractNote={The silicon-based microelectronics industry is rapidly approaching a point where device fabrication can no longer be simply scaled to progressively smaller sizes. Technological decisions must now be made that will substantially alter the directions along which silicon devices continue to develop. One such challenge is the need for higher permittivity dielectrics to replace silicon dioxide, the properties of which have hitherto been instrumental to the industry's success. Considerable efforts have already been made to develop replacement dielectrics for dynamic random-access memories. These developments serve to illustrate the magnitude of the now urgent problem of identifying alternatives to silicon dioxide for the gate dielectric in logic devices, such as the ubiquitous field-effect transistor.}, number={6799}, journal={NATURE}, author={Kingon, AI and Maria, JP and Streiffer, SK}, year={2000}, month={Aug}, pages={1032–1038} }
 @article{stemmer_streiffer_browning_basceri_kingon_2000, title={Grain boundaries in barium strontium titanate thin films: Structure, chemistry and influence on electronic properties}, volume={8}, ISSN={["0927-7056"]}, DOI={10.1023/A:1008794520909}, number={2-3}, journal={INTERFACE SCIENCE}, author={Stemmer, S and Streiffer, SK and Browning, ND and Basceri, C and Kingon, AI}, year={2000}, month={Aug}, pages={209–221} }
 @article{kim_kim_maria_kingon_streiffer_im_auciello_krauss_2000, title={Influence of Pt heterostructure bottom electrodes on SrBi2Ta2O9 thin film properties}, volume={76}, ISSN={["1077-3118"]}, DOI={10.1063/1.125799}, abstractNote={The properties of SrBi2Ta2O9 (SBT) films, such as remanent polarization and leakage current density, are closely related to the film/electrode interface and surface roughness of the underlying electrode. SBT films grown on stable Pt/TiO2/SiO2/Si and Pt/ZrO2/SiO2/Si substrates exhibit high remanent polarization, low leakage current density, and low voltage saturation as compared to SBT films synthesized on Pt/Ti/SiO2/Si. It is shown that severe diffusion of Ti from the Ti interlayer onto the surface of the Pt bottom electrode and the increased surface roughness of this electrode stack play key roles in degradation of SBT properties.}, number={4}, journal={APPLIED PHYSICS LETTERS}, author={Kim, SH and Kim, DJ and Maria, JP and Kingon, AI and Streiffer, SK and Im, J and Auciello, O and Krauss, AR}, year={2000}, month={Jan}, pages={496–498} }
 @article{hugon_desvignes_agius_vickridge_kim_kingon_2000, title={Narrow resonance profiling study of the oxidation of reactively sputtered Ti1-xAlxN thin films}, volume={161}, ISSN={["0168-583X"]}, DOI={10.1016/S0168-583X(99)00953-2}, abstractNote={The bottom electrode structure used with ferroelectric (FE) and high dielectric constant (HDC) materials requires a material to promote FE or HDC cristallisation (Pt or IrO2) and a material with diffusion barrier properties; this last material being between Pt (or IrO2) film and Si substrate. TiN, TiAlN and TaSiN have been proposed for diffusion applications. Ti1−xAlxN films have drawn much attention as alternatives to TiN diffusion barriers. In this paper we have investigated the effect of Al content on the oxidation resistance of Ti1−xAlxN films prepared by radio frequency reactive sputtering in a mixed Ar+N2 discharge. The concentration depth profiles of both 18O and 27Al were measured before and after the rapid thermal annealing of samples at 750°C for 30 s in 18O2, via the narrow resonances of 18O(p,α)15N at 151 keV (fwhm=100 eV) and 27Al(p,γ)28Si at 992 keV (fwhm=100 eV). It was found that Al incorporation in the films reduces oxide growth. The Al excitation curves indicate a uniform Al content for as deposited Ti1−xAlxN, and reveal Al diffusion to the surface during oxidation, which indicates the formation of an Al rich oxide layer at the Ti1−xAlxN surface. The results suggest that Ti1−xAlxN films with x>0.39 are promising candidates as electrically conductive diffusion barrier layers.}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS}, author={Hugon, MC and Desvignes, JM and Agius, B and Vickridge, IC and Kim, DJ and Kingon, AI}, year={2000}, month={Mar}, pages={578–583} }
 @article{letendu_hugon_desvignes_agius_vickridge_kim_kingon_2000, title={Oxidation resistance of TaSiN diffusion barriers}, volume={31}, number={1-4}, journal={Integrated Ferroelectrics}, author={Letendu, F. and Hugon, M. C. and Desvignes, J. M. and Agius, B. and Vickridge, I. and Kim, D. J. and Kingon, A. I.}, year={2000}, pages={315–322} }
 @article{yoon_kingon_kim_2000, title={Relaxation and leakage current characteristics of Pb1-xLax(ZryTi1-y)(1-x/4)O3 thin films with various Ir-based top electrodes}, volume={88}, ISSN={["1089-7550"]}, DOI={10.1063/1.1325382}, abstractNote={The dielectric relaxation and leakage current characteristics were studied for Pb1−xLax(ZryTi1−y)1−x/4O3 (PLZT) capacitors with various iridium-based top electrodes. The dielectric relaxation current behavior of PLZT capacitors obeys the well-known Curie–von Schweidler law independent of various Ir-based top electrodes including Pt and shows surprisingly little impact of various atmospheres such as Ar, O2, and H2. Electrical charge hopping, bulk effect, is the dominant mechanism of ac electric conduction which exhibits a linear relationship with frequency at room temperature. The true leakage current was separated definitively from the dielectric relaxation contributions. The PLZT capacitors with Pt or IrO2 top electrodes contacted with PLZT films show strong time dependence of true leakage current, resulting in consistence with space-charge influenced injection model. On the other hand, true leakage current of capacitors with Ir or IrO2/Ir top electrodes is independent of time, resulting in contradiction to the space-charge injection model. The IrPb, conducting phase, at interface between Ir top electrode and PLZT induces a steady state current behavior without the contribution of relaxation current. The second phase formed at interface modified the Schottky barrier height and increases the leakage current density.}, number={11}, journal={JOURNAL OF APPLIED PHYSICS}, author={Yoon, SG and Kingon, AI and Kim, SH}, year={2000}, month={Dec}, pages={6690–6695} }
 @article{christman_kim_maiwa_maria_rodriguez_kingon_nemanich_2000, title={Spatial variation of ferroelectric properties in Pb(Zr-0.3, Ti-0.7)O-3 thin films studied by atomic force microscopy}, volume={87}, ISSN={["0021-8979"]}, DOI={10.1063/1.373492}, abstractNote={Imaging of the phase and magnitude of the piezoelectric strain in Pb(Zr0.3, Ti0.7)O3 (PZT) capacitors is performed with an atomic force microscope. The imaging reveals a significant spatial dependence of the ferroelectric properties of both fatigued and unfatigued PZT films. We propose that the variation is related to the domain structure of the PZT. Through the measurement of local piezoelectric hysteresis loops and imaging of the piezoelectric strain, areas are observed in fatigued PZT that exhibit hysteresis loops shifted along the polarization axis. In some regions of fatigued samples, the hysteresis loops are shifted such that both remanent points of the hysteresis curve have the same polarization direction. These results have important implications for the scalability of nonvolatile ferroelectric random access memory to higher device densities.}, number={11}, journal={JOURNAL OF APPLIED PHYSICS}, author={Christman, JA and Kim, SH and Maiwa, H and Maria, JP and Rodriguez, BJ and Kingon, AI and Nemanich, RJ}, year={2000}, month={Jun}, pages={8031–8034} }
 @article{kim_lee_hwang_kim_kingon_2000, title={Thermally induced voltage offsets in Pb(Zr,Ti)O-3 thin films}, volume={77}, ISSN={["1077-3118"]}, DOI={10.1063/1.1324001}, abstractNote={Voltage offset in the polarization-voltage characteristics of Pb(Zr,Ti)O3 (PZT) capacitors was evaluated by a thermal stress process. A thermally induced voltage shift occurs when heating the sample under either remanence or a saturating bias. It was found that the voltage shifts can, to a large extent, be attributed to the role of charged defects and the defect-dipole alignment throughout the films. PZT film with a high Zr/Ti ratio, i.e., rhombohedral compositions exhibited the best imprint resistance. When these films were doped wit up to 6% La, the imprint resistance was further improved. It was also found that B-site donors were more effective in minimizing the voltage shift than A-site donors. However, dopants with the same charge value as Pb, for example, Ca and Sr, did not affect the thermally induced voltage shifts of the films since they could not reduce the charged defects in the films.}, number={19}, journal={APPLIED PHYSICS LETTERS}, author={Kim, SH and Lee, DS and Hwang, CS and Kim, DJ and Kingon, AI}, year={2000}, month={Nov}, pages={3036–3038} }
 @article{stemmer_streiffer_browning_kingon_1999, title={Accommodation of nonstoichiometry in (100) fiber-textured (BaxSr1-x)Ti1-yO3+z thin films grown by chemical vapor deposition}, volume={74}, ISSN={["1077-3118"]}, DOI={10.1063/1.123871}, abstractNote={We have investigated the microstructural accommodation of nonstoichiometry in (BaxSr1−x)Ti1+yO3+z thin films grown by chemical vapor deposition. Films with y=0.04 and y=0.15 were studied by high-spatial resolution electron energy-loss spectroscopy, revealing changes in chemistry and local atomic environment both at grain boundaries and within grains as a function of titanium content. We find that excess titanium in the samples with y=0.15 segregates to the grain boundaries in addition to being partially accommodated in the grain interior.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Stemmer, S and Streiffer, SK and Browning, ND and Kingon, AI}, year={1999}, month={Apr}, pages={2432–2434} }
 @article{kim_kim_lee_park_kingon_nemanich_im_streiffer_1999, title={An optimized process for fabrication of SrBi2Ta2O9 thin films using a novel chemical solution deposition technique}, volume={14}, ISSN={["0884-2914"]}, DOI={10.1557/JMR.1999.0594}, abstractNote={Ferroelectric SrBi2Ta2O9 (SBT) thin films on Pt/ZrO2/SiO2/Si were successfully prepared by using an alkanolamine-modified chemical solution deposition method. It was observed that alkanolamine provided stability to the SBT solution by retarding the hydrolysis and condensation rates. The crystallinity and the microstructure of the SBT thin films improved with increasing annealing temperature and were strongly correlated with the ferroelectric properties of the SBT thin films. The films annealed at 800 °C exhibited low leakage current density, low voltage saturation, high remanent polarization, and good fatigue characteristics at least up to 1010 switching cycles, indicating favorable behavior for memory applications.}, number={11}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Kim, SH and Kim, DJ and Lee, KM and Park, M and Kingon, AI and Nemanich, RJ and Im, J and Streiffer, SK}, year={1999}, month={Nov}, pages={4395–4401} }
 @article{kingon_1999, title={Device physics - Memories are made of ...}, volume={401}, ISSN={["0028-0836"]}, DOI={10.1038/44307}, abstractNote={One elusive goal in semiconductor technology is realizing the ideal nonvolatile memory -- that is, one that retains information when the power is switched off without battery back-up. In this context, so-called ferroelectric random access memories are promising. Work on a particular form of ferroelectric material provides encouraging evidence that it has the desired properties for nonvolatile memory.}, number={6754}, journal={NATURE}, author={Kingon, A}, year={1999}, month={Oct}, pages={658–659} }
 @misc{kingon_streiffer_1999, title={Ferroelectric films and devices}, volume={4}, number={1}, journal={Current Opinion in Solid State and Materials Science}, author={Kingon, A. I. and Streiffer, S. K.}, year={1999}, pages={39–44} }
 @article{kim_kim_im_kim_kingon_1999, title={Ferroelectric properties of new chemical solution derived SBT thin films for non-volatile memory devices}, volume={16}, ISSN={["1573-4846"]}, DOI={10.1023/A:1008748718231}, number={1-2}, journal={JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY}, author={Kim, SH and Kim, DJ and Im, J and Kim, CE and Kingon, AI}, year={1999}, month={Oct}, pages={57–63} }
 @article{streiffer_basceri_parker_lash_kingon_1999, title={Ferroelectricity in thin films: The dielectric response of fiber-textured (BaxSr1-x)Ti1+yO3+z thin films grown by chemical vapor deposition}, volume={86}, ISSN={["1089-7550"]}, DOI={10.1063/1.371404}, abstractNote={We have investigated the dielectric response of a series of {100} fiber-textured (BaxSr1−x)Ti1+yO3+z samples deposited by liquid-source metalorganic chemical vapor deposition onto Pt/SiO2/Si, as a function of the two most commonly varied microstructural parameters: film thickness and Ti nonstoichiometry y. We find that the overall behavior of these samples is adequately described by mean-field, Landau–Ginzburg–Devonshire theory as for bulk ferroelectrics. However, we quantify the impact of three separable factors for these films that greatly alter the dielectric susceptibility as a function of temperature, compared to that found for bulk ceramic samples at the same Ba/Sr ratio of 70/30: (i) Ti nonstoichiometry; (ii) the apparent interface effect; and (iii) the plane equibiaxial stress state resulting from thermal expansion mismatch strains. When these factors are properly taken into consideration, we show that these fine grained thin films behave in a manner entirely consistent with expectations based on bulk behavior. Implications can therefore be drawn concerning the nature of size effects in this ferroelectric system.}, number={8}, journal={JOURNAL OF APPLIED PHYSICS}, author={Streiffer, SK and Basceri, C and Parker, CB and Lash, SE and Kingon, AI}, year={1999}, month={Oct}, pages={4565–4575} }
 @article{kim_kim_im_streiffer_auciello_maria_kingon_1999, title={Impact of changes in the Pt heterostructure bottom electrodes on the ferroelectric properties of SBT thin films}, volume={26}, DOI={10.1080/10584589908215626}, abstractNote={Abstract The crystallinity and the microstructure of Sr0.8Bi2.3Ta2O9 (SBT) thin films improved with increasing annealing temperature, and strongly influenced the ferroelectric properties. In addition, the properties of SBT films, such as remanent polarization and leakage current density, are closely related to the film/electrode interface and surface roughness of the underlying electrode. SBT films on Pt/TiO2/SiO2/Si and Pt/ZrO2/SiO2/Si substrates exhibited high remanent polarization, low leakage current density, and low voltage saturation as compared to SBT films on Pt/Ti/SiO2/Si substrates. This is deduced to be related to differences in film orientation, electrode roughness, and out-diffusion of Ti onto the surface of the bottom electrode.}, number={1-4}, journal={Integrated Ferroelectrics}, author={Kim, S. H. and Kim, D. J. and Im, J. and Streiffer, S. K. and Auciello, O. and Maria, J. P. and Kingon, A. I.}, year={1999}, pages={955–970} }
 @article{kim_kim_hong_streiffer_kingon_1999, title={Imprint and fatigue properties of chemical solution derived Pb1-xLax(ZryTi1-y)(1-x/4)O-3 thin films}, volume={14}, ISSN={["2044-5326"]}, DOI={10.1557/JMR.1999.0187}, abstractNote={We have investigated the effect of oxygen vacancies on imprint and fatigue behavior of the PLZT thin films. It is found that the compensation of oxygen vacancies with various dopant concentrations and electrode structures is an important process parameter in determining the tendency to imprint and fatigue. In the case of PLZT thin films, the voltage shifts related to imprint are attributed to the trapping of electrons at ionic defect sites such as oxygen vacancies near the film/electrode interface, the magnitude of polarization, and concentration of defect-dipole complexes involving oxygen vacancies such as V′Pb–V••o. The strong dependence of fatigue rate on electrode material for PLZT thin films is due to the effect of the ferroelectric/electrode interaction on the pinning and/or unpinning rate involving the accumulation of oxygen vacancies near the film/electrode interface during fatigue cycling. By using RuO2 as the top and/or bottom electrode instead of Pt, improved fatigue properties are obtained compared to Pt/PLZT/Pt capacitors. This is because a reduced accumulation of oxygen vacancies near the interface by the oxide electrode such as RuO2 may reduce the electronic charge trapping and, consequently, lead to less domain wall pinning.}, number={4}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Kim, SH and Kim, DJ and Hong, J and Streiffer, SK and Kingon, AI}, year={1999}, month={Apr}, pages={1371–1377} }
 @article{kim_kim_maria_kingon_1999, title={Influences on imprint failure of SrBi2Ta2O9 thin film capacitors}, volume={25}, number={1-4}, journal={Integrated Ferroelectrics}, author={Kim, D. J. and Kim, S. H. and Maria, J. P. and Kingon, A. I.}, year={1999}, pages={691–701} }
 @article{maiwa_maria_christman_kim_streiffer_kingon_1999, title={Measurement and calculation of PZT thin film longitudinal piezoelectric coefficients}, volume={24}, ISSN={["1058-4587"]}, DOI={10.1080/10584589908215586}, abstractNote={The ferroelectric and piezoelectric properties of 2000 {angstrom} thick chemical solution deposited Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT) thin films were investigated. Several Zr/Ti ratios were studied: 30/70, 50/50 and 65/35, which correspond to tetragonal, near-morphotropic, and rhombohedral symmetries. In all samples, a {l_brace}111{r_brace}-texture is predominant. Longitudinal piezoelectric coefficients and their dc field dependence were measured using the contact AFM method. The expected trend of a maximum piezoelectric coefficient at or near to the MPB was not observed. The composition dependence was small, with the maximum d{sub 33} occurring in the tetragonal material. To explain the results, crystallographic texture and film thickness effects are suggested. Using a modified phenomenological approach, derived electrostrictive coefficients, and experimental data, d{sub 33} values were calculated. Qualitative agreement was observed between the measured and calculated coefficients. Justifications of modifications to the calculations are discussed.}, number={1-4}, journal={INTEGRATED FERROELECTRICS}, author={Maiwa, H and Maria, JP and Christman, JA and Kim, SH and Streiffer, K and Kingon, AI}, year={1999}, pages={139–146} }
 @article{maiwa_christman_kim_kim_maria_chen_streiffer_kingon_1999, title={Measurement of piezoelectric displacements of Pb(Zr, Ti)O-3 thin films using a double-beam interferometer}, volume={38}, ISSN={["0021-4922"]}, DOI={10.1143/jjap.38.5402}, abstractNote={ 
  The double-beam interferometric method is applied to measure the field-induced  
  displacement of Pb(Zr, Ti)O3 thin films. The dc electric field dependence of the  
  longitudinal piezoelectric coefficient (d
                  33) response of Pb(Zr, Ti)O3 thin films deposited  
  by metal organic chemical vapor deposition (MOCVD) was measured. Experimental d
                  33  
  values were compared with coefficients calculated using a phenomenological approach  
  and bulk parameters. Qualitative agreement was obtained between measured and  
  calculated coefficients. 
  }, number={9B}, journal={JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS}, author={Maiwa, H and Christman, JA and Kim, SH and Kim, DJ and Maria, JP and Chen, B and Streiffer, SK and Kingon, AI}, year={1999}, month={Sep}, pages={5402–5405} }
 @article{kim_kim_streiffer_kingon_1999, title={Preparation and ferroelectric properties of mixed composition layered lead zirconate titanate thin films for nonvolatile memory applications}, volume={14}, ISSN={["0884-2914"]}, DOI={10.1557/JMR.1999.0332}, abstractNote={Mixed composition layered lead zirconate titanate (PZT) films sZr/Ti ratio = 30/70 + 65/35d with stoichiometric lead containing PZT thin layer at the film/electrode interface were successfully fabricated by a modified chemical solution deposition method. These modified PZT thin films are highly (111) textured, and have square-shaped P-E hysteresis loops with large remanent polarization and low coercive field, as well as low saturation voltage. In addition, these films show good fatigue and imprint behavior with Pt electrodes; the retained polarization of the modified film was above 50% after fatigue testing to 109 cycles, and the thermally induced voltage shifts (ΔV) were 0.51 V after heating at 150 °C for 4410 s, two times lower than for films without a stoichiometric thin layer.}, number={6}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Kim, SH and Kim, DJ and Streiffer, SK and Kingon, AI}, year={1999}, month={Jun}, pages={2476–2483} }
 @article{im_auciello_krauss_gruen_chang_kim_kingon_1999, title={Studies of hydrogen-induced degradation processes in SrBi2Ta2O9 ferroelectric film-based capacitors}, volume={74}, ISSN={["0003-6951"]}, DOI={10.1063/1.123474}, abstractNote={It is known that the forming gas (N2–H2 mixture) annealing process required for microcircuit fabrication results in an unacceptable electrical degradation of SrBi2Ta2O9 (SBT) ferroelectric capacitors due mainly to the interaction of H2 with the ferroelectric layer of the capacitor. We have found a strong relationship between changes in the surface composition of the ferroelectric layer and the electrical properties of SBT capacitors as a result of hydrogen annealing. Mass spectroscopy of recoiled ions (MSRI) analysis revealed a strong reduction in the Bi signal as a function of exposure to hydrogen at high temperatures (∼500 °C). The Bi signal reduction correlates with Bi depletion in the SBT surface region. Subsequent annealing in oxygen at temperatures in the range of 700–800 °C resulted in the recovery of the MSRI Bi signal, corresponding to the replenishment of Bi in the previously Bi-depleted surface region. X-ray diffraction (XRD) analysis (probing the whole SBT film thickness) showed little difference in the XRD spectra of the SBT films before and after hydrogen and oxygen-recovery annealing. The combined results of the MSRI and XRD analyses can be interpreted as an indication that the degradation of the electrical properties of the SBT capacitors, after hydrogen annealing, is mainly due to the degradation of the near surface region of the SBT layer.}, number={8}, journal={APPLIED PHYSICS LETTERS}, author={Im, J and Auciello, O and Krauss, AR and Gruen, DM and Chang, RPH and Kim, SH and Kingon, AI}, year={1999}, month={Feb}, pages={1162–1164} }
 @article{kim_hong_streiffer_kingon_1999, title={The effect of RuO2/Pt hybrid bottom electrode structure on the leakage and fatigue properties of chemical solution derived Pb(ZrxTi1-x)O-3 thin films}, volume={14}, ISSN={["0884-2914"]}, DOI={10.1557/JMR.1999.0135}, abstractNote={We have investigated the effect of RuO2 (10, 30, 50 nm)/Pt layered hybrid bottom electrode structure and film composition on the leakage and fatigue properties of chemical solution derived Pb(ZrxTi1−x)O3 (PZT) thin films. It was observed that the use of high Ti content (Zr: Ti = 30: 70) films with control of excess PbO at the thin RuO2 (10 nm)/Pt bottom electrode surface reduced leakage current and showed good fatigue properties with high remanent polarization compared to the use of high Zr films (Zr: Ti = 50: 50) or thicker RuO2 (30, 50 nm)/Pt bottom electrodes. Typical P-E hysteresis behavior of PZT films was observed even at an applied voltage of 3 V, demonstrating greatly improved remanence and coercivity. Fatigue and breakdown characteristics of these modified PZT thin films (Zr: Ti = 30: 70) on RuO2 (10 nm)/Pt, measured at 5 V, showed stable behavior, and less than 15% fatigue degradation was observed up to 1010 cycles.}, number={3}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Kim, SH and Hong, JG and Streiffer, SK and Kingon, AI}, year={1999}, month={Mar}, pages={1018–1025} }
 @article{bilodeau_carl_vanbuskirk_roeder_basceri_lash_parker_streiffer_kingon_1998, title={Dielectric properties and microstructure of thin BST films}, volume={32 pt.4}, number={suppl.}, journal={Journal of the Korean Physical Society}, author={Bilodeau, S. M. and Carl, R. and VanBuskirk, P. C. and Roeder, J. F. and Basceri, C. and Lash, S. E. and Parker, C. B. and Streiffer, S. K. and Kingon, A. I.}, year={1998}, pages={1591–1594} }
 @article{lee_woolcott_basceri_lee_streiffer_kingon_yang_1998, title={Electrical properties of (Ba, Sr)TiO3 thin films prepared by liquid delivery MOCVD}, volume={32 pt.4}, number={suppl.}, journal={Journal of the Korean Physical Society}, author={Lee, W. J. and Woolcott, R. R. and Basceri, C. and Lee, H. Y. and Streiffer, S. K. and Kingon, A. I. and Yang, D. Y.}, year={1998}, pages={1652–1656} }
 @article{lee_basceri_streiffer_kingon_yang_park_kim_1998, title={Ir and Ru bottom electrodes for (Ba, Sr) TiO3 thin films deposited by liquid delivery source chemical vapor deposition}, volume={323}, ISSN={["0040-6090"]}, DOI={10.1016/S0040-6090(97)01043-2}, abstractNote={The electrical properties and surface morphologies of (Ba, Sr)TiO3 thin films, with various bottom electrode structures, deposited by liquid delivery metal organic chemical vapor deposition were investigated. Ir and Ru films as a bottom electrode with varying deposition temperatures were prepared onto SiO2 and polySi substrate structures using ion beam sputtering technique. It is observed that electrical properties of BST films deposited by liquid delivery MOCVD was changed with the deposition temperatures of Ir and Ru as well as substrate structures. Furthermore, it is revealed that these variations in leakage current could be strongly related with the roughness of BST films.}, number={1-2}, journal={THIN SOLID FILMS}, author={Lee, WJ and Basceri, C and Streiffer, SK and Kingon, AI and Yang, DY and Park, Y and Kim, HG}, year={1998}, month={Jun}, pages={285–290} }
 @article{saleh_schindler_sarma_haase_koch_kingon_1998, title={Isolation techniques and electrical characterization of single grain boundaries of Bi2Sr2CaCu2O2 high-temperature superconductor}, volume={295}, ISSN={["0921-4534"]}, DOI={10.1016/s0921-4534(97)01762-0}, abstractNote={We have isolated single grain boundaries of a bulk material of polycrystalline high-temperature superconductor Bi2Sr2CaCu2O2 (Bi-2212) tapes. The tapes were grown on a single crystal of MgO or Ag-foil by partial melting of the superconductor. The isolation techniques consisted of fabricating metal micro-contact pads, wire bonding, and laser patterning of the Bi-2212 superconductor. Results of electrical and magnetic measurements of single grain boundaries suggested a possible existence of Josephson-like junctions coexisting with flux flow junctions. In contrast to bulk samples, Tc of a single grain boundary did not change by applying magnetic field. Jc and Tc were found to be greatly dependent on heat treatment and growth conditions. The current–voltage characteristics of a single patterned bridge followed a relation of the form V∼(I−Ic)n for I>Ic with n∼1.2.}, number={3-4}, journal={PHYSICA C}, author={Saleh, AM and Schindler, G and Sarma, C and Haase, DG and Koch, CC and Kingon, AI}, year={1998}, month={Feb}, pages={225–234} }
 @misc{varsheny_kingon_1998, title={Modulated-structure of PZT/PT ferroelectric thin films for non-volatile random access memories}, volume={5,850,089}, number={1998 Dec. 15}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Varsheny, U. and Kingon, A. I.}, year={1998} }
 @article{christman_woolcott_kingon_nemanich_1998, title={Piezoelectric measurements with atomic force microscopy}, volume={73}, ISSN={["0003-6951"]}, DOI={10.1063/1.122914}, abstractNote={An atomic force microscope (AFM) is used to measure the magnitude of the effective longitudinal piezoelectric constant (d33) of thin films. Measurements are performed with a conducting diamond AFM tip in contact with a top electrode. The interaction between the tip and electric field present is a potentially large source of error that is eliminated through the use of this configuration and the conducting diamond tips. Measurements yielded reasonable piezoelectric constants of X-cut single-crystal quartz, thin film ZnO, and nonpiezoelectric SiO2 thin films.}, number={26}, journal={APPLIED PHYSICS LETTERS}, author={Christman, JA and Woolcott, RR and Kingon, AI and Nemanich, RJ}, year={1998}, month={Dec}, pages={3851–3853} }
 @article{fujimura_thomas_streiffer_kingon_1998, title={Preferred orientation, phase formation and the electrical properties of pulsed laser deposited SrBi2Ta2O9 thin films}, volume={37}, ISSN={["0021-4922"]}, DOI={10.1143/JJAP.37.5185}, abstractNote={ 
  Systematic studies on the preferred orientation, phase formation and the  
  electrical properties of pulsed laser deposited SrBi2Ta2O9 (SBT) have been performed.  
  At a substrate temperature of 600°C, the film on SiO2 was not crystallized. Above 650°C,  
  very strong diffraction from a non-ferroelectric, (111)-oriented fluorite phase was  
  obtained. Its crystallinity increased with increasing Bi content in the target. The fluorite  
  phase was also observed in the film on Pt deposited below 600°C, which together with  
  the pyrochlore phase resulted in the formation of an interfacial reaction product, Bi2Pt.  
  Above 650°C, the films tend to grow as the perovskite SBT phase with a c-axis  
  orientation which is not the polarization axis. In contrast, the formation of the fluorite  
  and pyrochlore phases can be suppressed on Ir electrodes. 
  }, number={9B}, journal={JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS}, author={Fujimura, N and Thomas, DT and Streiffer, SK and Kingon, AJ}, year={1998}, month={Sep}, pages={5185–5188} }
 @article{grossmann_hoffmann_gusowski_waser_streiffer_basceri_parker_lash_kingon_1998, title={Resistance degradation behavior of Ba0.7Sr0.3TiO3 thin films compared to mechanisms found in titanate ceramics and single crystals}, volume={22}, number={1-4}, journal={Integrated Ferroelectrics}, author={Grossmann, M. and Hoffmann, S. and Gusowski, S. and Waser, R. and Streiffer, S. K. and Basceri, C. and Parker, C. B. and Lash, S. E. and Kingon, A. I.}, year={1998}, pages={603–614} }
 @article{kim_kim_hong_streiffer_kingon_1998, title={Thermally induced imprint properties of chemical solution derived PLZT thin films}, volume={22}, number={1-4}, journal={Integrated Ferroelectrics}, author={Kim, S. H. and Kim, D. J. and Hong, J. G. and Streiffer, S. K. and Kingon, A. I.}, year={1998}, pages={653–662} }
 @article{dietz_schumacher_waser_streiffer_basceri_kingon_1997, title={Leakage currents in Ba0.7Sr0.3TiO3 thin films for ultrahigh-density dynamic random access memories}, volume={82}, ISSN={["0021-8979"]}, DOI={10.1063/1.366045}, abstractNote={(Ba,Sr)TiO3 (BST) thin films grown by chemical vapor deposition and with platinum (Pt) top and bottom electrodes have been characterized with respect to the leakage current as a function of temperature and applied voltage. The data can be interpreted via a thermionic emission model. The Schottky approximation accounts for superohmic behavior at higher fields, but the barrier lowering is stronger than expected from this theory. While the leakage mechanism is comparable to SrTiO3 thin films prepared by chemical solution deposition, the absolute values of the leakage current are significantly lower for the metalorganic chemical vapor deposition (MOCVD) prepared BST film. This is presumably due to a more homogeneous microstructure of the latter and may also be due to different electrode processing. The influence of the film thickness on the leakage in combination with additional findings is used to discuss the field distribution in the films under a dc voltage stress.}, number={5}, journal={JOURNAL OF APPLIED PHYSICS}, author={Dietz, GW and Schumacher, M and Waser, R and Streiffer, SK and Basceri, C and Kingon, AI}, year={1997}, month={Sep}, pages={2359–2364} }
 @misc{varshney_kingon_1997, title={Method for producing low thermal budget ferroelectric thin films for integrated device structures using laser-crystallization of spin-on sol-gel films}, volume={5,626,670}, number={1997 May 6}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Varshney, U. and Kingon, A. I.}, year={1997} }
 @article{thomas_kingon_auciello_waser_schumacher_1997, title={Pulsed laser ablation synthesis and characterization of layered SrBi2Ta2O9 films and integration into capacitors for non-volatile memories}, volume={14}, ISSN={["1058-4587"]}, DOI={10.1080/10584589708019976}, abstractNote={Abstract Pulsed laser ablation deposition (PLAD) was used to synthesize SrBi2Ta2O9 (SBT) layered ferroelectric thin films to integrate them into capacitors with top and bottom Pt electrodes produce by an ion beam sputter-deposition technique. SBT layers produced by laser ablation of stoichiometric and Bi-rich SBT targets exhibited marked different orientations. In addition, Pt/SBT/Pt capacitors fabricated with the distinctly oriented SBT layers exhibited substantial difference in the shape and parameters of polarization hysteresis loops, although they exhibited practically no polarization fatigue. The results presented in this paper indicate that the composition, microstructure and properties of SBT layers and SBT-based capacitors depend on the target composition and more studies are needed to understand these dependencies.}, number={1-4}, journal={INTEGRATED FERROELECTRICS}, author={Thomas, D and Kingon, AI and Auciello, O and Waser, R and Schumacher, M}, year={1997}, pages={51–57} }
 @article{basceri_streiffer_kingon_waser_1997, title={The dielectric response as a function of temperature and film thickness of fiber-textured (Ba,Sr)TiO3 thin films grown by chemical vapor deposition}, volume={82}, ISSN={["0021-8979"]}, DOI={10.1063/1.366062}, abstractNote={The temperature- and field-dependent permittivities of fiber-textured Ba0.7Sr0.3TiO3 thin films grown by liquid-source metalorganic chemical vapor deposition were investigated as a function of film thickness. These films display a nonlinear dielectric response under conditions representative of those encountered in dynamic random access memories or other integrated capacitor applications. This behavior has the exact form expected for a classical nonlinear, nonhysteretic dielectric, as described in terms of a power series expansion of the free energy in the polarization as in the Landau–Ginzburg–Devonshire approach. Curie–Weiss-like behavior is exhibited above the bulk Curie point (∼300 K), although the ferroelectric phase transition appears frustrated. Small-signal capacitance measurements of films with different thicknesses (24–160 nm) indicate that only the first term in the power series expansion varies significantly with film thickness or temperature. Possible origins for this thickness dependence are discussed.}, number={5}, journal={JOURNAL OF APPLIED PHYSICS}, author={Basceri, C and Streiffer, SK and Kingon, AI and Waser, R}, year={1997}, month={Sep}, pages={2497–2504} }
 @misc{kingon_al-shareef_auciello_gifford_lichtenwalner_dat_1996, title={Hybrid metal/metal oxide electrodes for ferroelectric capacitors}, volume={5,555,486}, number={1996 Sep. 10}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Kingon, A. I. and Al-Shareef, H. N. and Auciello, O. H. and Gifford, K. D. and Lichtenwalner, D. J. and Dat, R.}, year={1996} }
 @article{dat_lee_auciello_kingon_1995, title={Pulsed-laser ablation synthesis and characterization of layered pt/srbi2ta2o9/pt ferroelectric capacitors with practically no polarization fatigue}, volume={67}, number={4}, journal={Applied Physics Letters}, author={Dat, R. and Lee, J. K. and Auciello, O. and Kingon, A. I.}, year={1995}, pages={572–574} }
 @misc{sonnenberg_kingon_paterson_1991, title={Sintered ceramic product}, volume={5,017,532}, number={1991 May 21}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Sonnenberg, N. and Kingon, A. I. and Paterson, A. W.}, year={1991} }
 @misc{duncan_barrow_van zyl_kingon_1988, title={Method of making beta"-alumina}, volume={4,732,741}, number={1988 Mar. 22}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Duncan, J. H. and Barrow, P. and Van Zyl, A. and Kingon, A. I.}, year={1988} }