@misc{herr_zhirnov_2006, title={Deterministically doped field-effect devices and methods of making same}, volume={7,015,546}, number={2006 Mar. 21}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Herr, D. J. C. and Zhirnov, V. V.}, year={2006} } @misc{herr_zhirnov_2005, title={Supermolecular structureS and devices made from same}, volume={6,897,470}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Herr, D. J. C. and Zhirnov, V. V.}, year={2005} } @article{kvit_zhirnov_tyler_hren_2004, title={Aging effect and nitrogen distribution in diamond nanoparticles}, volume={35}, ISSN={["1359-8368"]}, DOI={10.1016/j.compositesb.2003.08.003}, abstractNote={This paper is focused on understanding the behavior of diamond particle aging effect and nitrogen atoms behavior in isolated diamond nanoparticles. Aging is a crucial effect that is observed in as-grown individual nanoparticles only. This effect was investigated for as-grown nanodiamond particles exposed and non-exposed to field emission experiments. It was shown that under field emission exposure the sp2 fraction in as-grown structures starts increasing from the surface of the particles and this process continues up to the whole particle phase transition. Nitrogen is potentially a donor dopant in diamond but there were no experimental results describing the nitrogen behavior in diamond nanoparticles, in large part, due to the nanometer scale of the structures. In this paper the clear indications of nitrogen impurities imbedded in bulk of nanodiamond are presented. By field electron emission measurements it was shown that a single isolated diamond particle on a metal tip substantially increases the emission voltage. The major characterization techniques are Z-contrast imaging using scanning transmission electron microscopy, electron energy loss spectroscopy and high-resolution transmission electron microscopy.}, number={2}, journal={COMPOSITES PART B-ENGINEERING}, author={Kvit, AV and Zhirnov, VV and Tyler, T and Hren, JJ}, year={2004}, pages={163–166} } @article{zhirnov_shenderova_jaeger_tyler_areshkin_brenner_hren_2004, title={Electron emission properties of detonation nanodiamonds}, volume={46}, ISSN={["1063-7834"]}, DOI={10.1134/1.1711444}, number={4}, journal={PHYSICS OF THE SOLID STATE}, author={Zhirnov, VV and Shenderova, OA and Jaeger, DL and Tyler, T and Areshkin, DA and Brenner, DW and Hren, JJ}, year={2004}, pages={657–661} } @article{tyler_zhirnov_kvit_kang_hren_2003, title={Electron emission from diamond nanoparticles on metal tips}, volume={82}, ISSN={["0003-6951"]}, DOI={10.1063/1.1570498}, abstractNote={Single-crystalline diamond nanoparticles (∼5 nm in scale) have been deposited onto molybdenum needles (with radii <100 nm), and their effects on field emission behavior were measured. Combined transmission electron microscopy observations, field emission measurements, and diamond depositions allowed for direct comparison of the effects of various amounts of nanodiamond coating on the field emission properties of a coated metal field emitter. In the limit, field emission from a single isolated diamond nanoparticle is compared here with that from an uncoated metal emitter and from a coating comprised of several layers of nanoparticles.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Tyler, T and Zhirnov, VV and Kvit, AV and Kang, D and Hren, JJ}, year={2003}, month={Apr}, pages={2904–2906} } @article{hajra_chubun_chakhovskoi_hunt_liu_murali_risbud_tyler_zhirnov_2003, title={Field emission characterization of silicon tip arrays coated with GaN and diamond nanoparticle clusters}, volume={21}, ISSN={["1071-1023"]}, DOI={10.1116/1.1540986}, abstractNote={Wide band-gap materials show promise for applications in coating of field emission tips. Recently nanocrystalline hexagonal GaN crystallites as small as 12 nm average diameter have been formed using reactive laser ablation of gallium metal in nitrogenating ambient [T. J. Goodwin et al., Appl. Phys. Lett. 70, 3122 (1997)]. In this article we investigated the performance of ungated emitters with and without surface coating. Silicon tip arrays are coated by dielectrophoresis of gallium nitride nanoparticles or nanocrystalline diamond clusters from an ethanol suspension. The emitters were evaluated and compared before and after the surface treatment using SEM image and I–V measurements in the diode configuration. The results suggest that the emitters benefit from coating the surface with nanocrystalline diamond clusters in terms of reduction in the turn on voltage by 100 V and increase uniformity in emission during low voltage operation. The long-term emission stability for both types of the coated cathodes was studied over a period of 90 h. The emitters coated with GaN nanoparticle clusters show a significant improvement in the current fluctuation from 150% (for untreated cathodes) to 50%.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Hajra, M and Chubun, NN and Chakhovskoi, AG and Hunt, CE and Liu, K and Murali, A and Risbud, SH and Tyler, T and Zhirnov, V}, year={2003}, pages={458–463} } @misc{herr_zhirnov_2003, title={Supermolecular structures and devices made from same}, volume={6,664,559}, number={2003 Dec. 16}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Herr, D. J. C. and Zhirnov, V. V.}, year={2003} } @article{zhirnov_alimova_hren_2002, title={Anomalous field emission from Al2O3 coated Si tips}, volume={191}, ISSN={["0169-4332"]}, DOI={10.1016/S0169-4332(02)00131-9}, abstractNote={Abstract The emission properties of Al 2 O 3 coated Si field emitters were found to be radically different from any others reported to date. Silicon field emitter arrays were coated with ultrafine aluminum oxide powders by dielectrophoresis. The emission threshold, corresponding to a current of 10 pA, was 0.25 V/mm. The current–voltage ( I – V ) plots of the Al 2 O 3 coated Si field emitter arrays were steep, with a distinct deviation from Fowler–Nordheim (F–N) behavior. The emission showed a slow but distinct increase or decrease of current with time depending on the magnitude of the current. This behavior could be approximated with an exponential function. We suggest a tentative explanation in terms of “field emission induced secondary electron emission”, i.e. the generation of a secondary electron cascade by the interaction of the field emitted electrons with crystallites comprising the porous aluminum oxide coating.}, number={1-4}, journal={APPLIED SURFACE SCIENCE}, author={Zhirnov, VV and Alimova, AN and Hren, JJ}, year={2002}, month={May}, pages={20–25} } @misc{shenderova_zhirnov_brenner_2002, title={Carbon nanostructures}, volume={27}, ISSN={["1547-6561"]}, DOI={10.1080/10408430208500497}, abstractNote={ABSTRACT An overview of the various carbon structures with characteristic sizes in the nanoscale region is presented, with special attention devoted to the structures and properties of ‘nanodiamond’ and carbon nanotubes. The term ‘nanodiamond’ is used broadly for a variety of diamond-based materials at the nanoscale ranging from single diamond clusters to bulk nanocrystalline films. Only selected properties of carbon nanotubes are discussed, with an aim to summarize the most recent discoveries. Current and potential applications of carbon nanostructures are critically analyzed.}, number={3-4}, journal={CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES}, author={Shenderova, OA and Zhirnov, VV and Brenner, DW}, year={2002}, pages={227–356} } @article{hutchby_bourianoff_zhirnov_brewer_2002, title={Extending the road beyond CMOS}, volume={18}, ISSN={["8755-3996"]}, DOI={10.1109/101.994856}, abstractNote={The accelerating pace of CMOS scaling is rapidly approaching the fundamental limits of MOSFET performance, even as the projected size of a high-performance and manufacturable MOSFET technology is currently being extended with growing confidence to the 22-nm node (featuring a 9-nm physical gate length). The new 2001 International Technology Roadmap for Semiconductors currently projects the industry to reach this node in 2016. However, this forecast assumes the traditional industry node-cycle cadence of a quadrupling of the number of transistors every three years for DRAMS and a return to the three-year cycle in 2004 for MPUs and ASICs. During the past several years the node cycles for MPUs have been accelerated to occur within two-year periods. This pace will bring the microelectronics industry to the end of silicon CMOS technology scaling sometime not later than 2016, and maybe as soon as 2010. The new Emerging Technologies section of the 2001 ITRS offers guidance on both sides of this problem: nanoelectronics for memory, logic, and information-processing architectures could possibly extend the time frame of the ITRS beyond CMOS.}, number={2}, journal={IEEE CIRCUITS & DEVICES}, author={Hutchby, JA and Bourianoff, GI and Zhirnov, VV and Brewer, JE}, year={2002}, month={Mar}, pages={28–41} } @article{jaeger_hren_zhirnov_2003, title={Local electrostatic effects of surface structure on field emission}, volume={93}, ISSN={["1089-7550"]}, DOI={10.1063/1.1526934}, abstractNote={We examined the classical electrostatic effects due to geometric surface structures on conductive field emission needles numerically using the finite element method and compared our results to several commonly applied analytic relations. Analysis of the morphology of electrochemically prepared Mo needles by high-resolution transmission electron microscopy was incorporated in the numerical analysis in the form of small surface protrusions and gross needle shape. We found that the error between the electrostatic potential defined by popular analytic equations and both analytic equations derived in prolate spheroidal coordinates and finite element method results was significant for ellipsoidal needles with and without surface protrusions. The morphology of the surface protrusion was found to introduce a significant nonlinear potential barrier near the needle surface. Finally we numerically analyzed a nonsymmetric, nonhomogeneous experimental needle indicating that even larger errors in the electrostatic potential can be expected relative to analytic equations.}, number={1}, journal={JOURNAL OF APPLIED PHYSICS}, author={Jaeger, DL and Hren, JJ and Zhirnov, VV}, year={2003}, month={Jan}, pages={691–697} } @article{zhirnov_lizzul-rinne_wojak_sanwald_hren_2001, title={"Standardization" of field emission measurements}, volume={19}, ISSN={["1071-1023"]}, DOI={10.1116/1.1342006}, abstractNote={Interest in field emission and field emission devices has been renewed in the last 5 yr. This increase has been due to work on several new materials systems, which have shown promising field emission (FE) behavior. In turn, this interest gives impetus to the search for new FE sources. In order to move the technology ahead at a faster pace, there is a need for common ground rules and a “standardization” of the data reported so that it can be compared directly in a meaningful way and thereby accelerate the development process. In this article key factors affecting the FE data will be discussed and several parameters are suggested to initiate the process of developing a set of “standardized” FE parameters. A correct, or at least consistent, determination of characteristics such as work function, emission area, and field enhancement form the basis for developing a framework to make meaningful comparisons between different sets of data.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Zhirnov, VV and Lizzul-Rinne, C and Wojak, GJ and Sanwald, RC and Hren, JJ}, year={2001}, pages={87–93} } @article{liu_chiu_morton_kang_zhirnov_hren_cuomo_2001, title={Band gap structure and electron emission property of chemical-vapor-deposited diamond films}, volume={45}, ISSN={["0038-1101"]}, DOI={10.1016/S0038-1101(00)00210-0}, abstractNote={The structures of the band gap and defect states of chemical-vapor-deposited diamond films were investigated by photoluminescence spectroscopy, covering wavelength from visible to vacuum ultraviolet (VUV). Band gaps ranging from 5.5 to 3.2 eV were measured for natural, polycrystalline, and amorphous diamond films. Low voltage field emissions were obtained from wide band gap films with band gap states distributed close to the conduction band and extended deeply into the band gap. Amorphous diamond film with a narrower band gap could not provide low field emission.}, number={6}, journal={SOLID-STATE ELECTRONICS}, author={Liu, JJ and Chiu, DYT and Morton, DC and Kang, DH and Zhirnov, VV and Hren, JJ and Cuomo, JJ}, year={2001}, month={Jun}, pages={915–919} } @article{kang_zhirnov_sanwald_hren_cuomo_2001, title={Field emission from ultrathin coatings of AlN on Mo emitters}, volume={19}, ISSN={["2166-2746"]}, DOI={10.1116/1.1340669}, abstractNote={Experiments characterizing both the physics of emission and the performance of Mo tips coated with ultrathin film of AlN were conducted. Ultrathin films of AlN with thicknesses ranging from 7 to 21 nm in 1.5 nm increments were deposited onto Mo tips by magnetron sputtering. In situ field emission measurements were performed after each deposition step. Tip radius, thickness, and morphology of AlN coating were characterized with the transmission electron microscopy. The effect of the thickness of AlN on emission was determined using a Fowler–Nordheim analysis. Various surface treatment effects were studied and measurements of maximum current and emission stability were performed, e.g., maximum current from a single Mo tip with 15 nm of AlN coating was 52 μA.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Kang, D and Zhirnov, VV and Sanwald, RC and Hren, JJ and Cuomo, JJ}, year={2001}, pages={50–54} } @article{zhirnov_herr_2001, title={New frontiers: Self-assembly and nanoelectronics}, volume={34}, ISSN={["0018-9162"]}, DOI={10.1109/2.895116}, abstractNote={In the quest for new semiconductor materials and processes, researchers focus on self-assembly, a concept that draws from diverse disciplines like chemistry, biology, material science, and electrical engineering. The following areas are examined: information theory; thermodynamics, synergetics and self-assembly; ribosome based lithography; nanofabrication by self-assembly; molecular electronics; and smart matter.}, number={1}, journal={COMPUTER}, author={Zhirnov, VV and Herr, DJC}, year={2001}, month={Jan}, pages={34-+} } @article{zhirnov_lizzul-rinne_wojak_sanwald_cuomo_hren_2001, title={Optimizing high-current yields from diamond coated field emitters}, volume={19}, ISSN={["1071-1023"]}, DOI={10.1116/1.1340009}, abstractNote={The data for the maximum emission currents from needle-shaped emitters with differing diamond coatings were empirically analyzed. The coatings studied were chemical vapor deposition diamond, natural diamond, and nanodiamond. Two parameters were chosen to characterize the emissive properties: (1) the dependence of the maximum current (Imax) on the coating thickness (D), i.e., I(D)=ΔImax/ΔD, and (2) the dependence of the threshold voltage Vth on [(D);ΔVth/ΔD]. The dependence of Imax(D) and Imax/Vmax(D) were determined from the experimental data for the three different diamond coatings. The maximum current Imax is very different for these three different coatings and is also a function of the coating thickness, D. Both the maximum current and the transconductance of field emission tips can be increased significantly by diamond coatings. A strong, nearly linear, dependence of Imax on diamond thickness was found. An empirical estimate of the thermal conductivity of nanodiamond, based on the field emission data, gave 2.71 W/cm K. The maximum current output from multitip arrays was also analyzed and an optimization procedure was devised that suggested a route to “engineered coatings.”}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Zhirnov, VV and Lizzul-Rinne, C and Wojak, GJ and Sanwald, RC and Cuomo, JJ and Hren, JJ}, year={2001}, pages={17–22} } @article{hren_zhirnov_sitar_wojak_2000, title={Characterization of dielectrics on the 'tips of needles'}, volume={30}, number={4}, journal={Electrochemistry}, author={Hren, J. J. and Zhirnov, V. V. and Sitar, Z. and Wojak, G.}, year={2000}, pages={210–215} } @article{park_sowers_rinne_schlesser_bergman_nemanich_sitar_hren_cuomo_zhirnov_et al._1999, title={Effect of nitrogen incorporation on electron emission from chemical vapor deposited diamond}, volume={17}, ISSN={["2166-2746"]}, DOI={10.1116/1.590630}, abstractNote={Two different types of the nitrogen-doped chemical vapor deposited (CVD) diamond films were synthesized with N2 (nitrogen) and C3H6N6 (melamine) as doping sources. The samples were analyzed by scanning electron microscopy, Raman scattering, photoluminescence spectroscopy, and field-emission measurements. More effective substitutional nitrogen doping was achieved with C3H6N6 than with N2. The diamond film doped with N2 contained a significant amount of nondiamond carbon phases. The sample produced with N2 exhibited a lower field emission turn-on field than the sample produced with C3H6N6. It is believed that the presence of the graphitic phases (or amorphous sp2 carbon) at the grain boundaries of the diamond and/or the nanocrystallinity (or microcrystallinity) of the diamond play a significant role in lowering the turn-on field of the film produced using N2. It is speculated that substitutional nitrogen doping plays only a minor role in changing the field emission characteristics of CVD diamond films.}, number={2}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Park, M and Sowers, AT and Rinne, CL and Schlesser, R and Bergman, L and Nemanich, RJ and Sitar, Z and Hren, JJ and Cuomo, JJ and Zhirnov, VV and et al.}, year={1999}, pages={734–739} } @article{kang_zhirnov_wojak_preble_choi_hren_cuomo_1999, title={Investigation of thickness effects on AlN coated metal tips by in situ I-V measurement}, volume={17}, ISSN={["1071-1023"]}, DOI={10.1116/1.590608}, abstractNote={The effects of the aluminum nitride coating thickness on molybdenum emitter tips were investigated by an in situ I–V measurement technique inside a typical magnetron sputtering system. AlN was deposited on Mo tips using a dc-modulated 1 kW power source at 200 °C. Each I/V measurement was carried out immediately following a 15 s AlN deposition. Significantly improved field emission was observed as well as a strong emission thickness dependence, which we attribute to the influence of space charge.}, number={2}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Kang, DH and Zhirnov, VV and Wojak, GJ and Preble, EA and Choi, WB and Hren, JJ and Cuomo, JJ}, year={1999}, pages={632–634} } @article{park_mcgregor_bergman_nemanich_hren_cuomo_choi_zhirnov_1999, title={Raman analysis and field emission study of ion beam etched diamond films}, volume={17}, ISSN={["2166-2746"]}, DOI={10.1116/1.590622}, abstractNote={Discontinuous diamond films were deposited on silicon using a microwave plasma chemical vapor deposition system. The diamond deposits were sharpened by argon ion beam etching. Raman spectroscopy was carried out to study the structural change of the diamond after ion beam bombardment. It was found that amorphous sp2 carbon is produced as diamond is being sputtered by the Ar ion beam. The field emission turn-on field was also drastically lowered after sharpening, which, it is speculated, is caused by field enhancement due to change in geometry and/or structural changes (such as amorphization of crystalline diamond into graphitic or amorphous sp2 carbon) by Ar ion irradiation.}, number={2}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Park, M and McGregor, DR and Bergman, L and Nemanich, RJ and Hren, JJ and Cuomo, JJ and Choi, WB and Zhirnov, VV}, year={1999}, pages={700–704} } @article{zhirnov_hren_1998, title={Electron emission from diamond films}, volume={23}, ISSN={["0883-7694"]}, DOI={10.1557/S0883769400029365}, abstractNote={Diamond always has been considered an exciting material. In addition to its other outstanding properties, diamond's capacity for cold electron emission has become a “hot” topic of research in recent years. The electron emission from diamond films is important for both fundamental and applied purposes, which may be expressed by two questions as follows: “Why does diamond emit electrons?” and “How can an efficient cold cathode be made?”The “diamond-emission era” started in 1991. That year three papers were published, reporting unexpectedly high electron emissivity from diamond. The first paper by Djubua and Chubun was very practical, having been written by device engineers. They tried different materials for the fabrication of pointed field emission cathodes and found that emitters made from diamondlike carbon (DLC) demonstrated a lower emission threshold compared to other materials. A second paper by Wang et al. reported a low emission threshold for chemical-vapor-deposition (CVD) diamond films, whereas a third paper by Geis et al. described the fabrication and operation of diamond cold cathodes.Since 1991 hundreds of papers about electron emission from diamond and diamondlike materials have been published. The motivations for this increasing activity are prospective applications in vacuum microelectronics—that is, vacuum emission devices fabricated by modern microelectronic technologies. Experts expect that combining the physical advantages of emission devices and the technological progress in solid-state microelectronics will result in the development of an entirely new generation of high-performance electronic devices—among them, flat-panel displays and miniature microwave tubes.}, number={9}, journal={MRS BULLETIN}, author={Zhirnov, VV and Hren, JJ}, year={1998}, month={Sep}, pages={42–48} } @article{zhirnov_liu_wojak_cuomo_hren_1998, title={Environmental effect on the electron emission from diamond surfaces}, volume={16}, number={3}, journal={Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures}, author={Zhirnov, V. V. and Liu, J. and Wojak, G. J. and Cuomo, J. J. and Hren, J. J.}, year={1998}, pages={1188–1193} }