@article{lucovsky_rayner_kang_hinkle_hong_2004, title={A spectroscopic phase separation study distinguishing between chemical with different degrees of crystallinity in Zr(Hf) silicate alloys}, volume={566}, ISSN={["0039-6028"]}, DOI={10.1016/j.susc.2004.06.010}, abstractNote={Abstract Chemical phase separation at device processing temperatures is an important issue for integration of Zr and Hf silicates alloys into advanced CMOS devices. Chemical phase separation into ZrO 2 and SiO 2 has been detected by different spectroscopic techniques, including Fourier transform infra red, X-ray photoelectron, and X-ray absorption spectroscopy, as well as X-ray diffraction and high resolution transmission electron microscopy imaging as well. Comparisons between these techniques for Zr silicates identify an unambiguous approach to distinguishing between chemical phase separation with different degrees of micro- and nano-crystallinity.}, journal={SURFACE SCIENCE}, author={Lucovsky, G and Rayner, GB and Kang, D and Hinkle, CL and Hong, JG}, year={2004}, month={Sep}, pages={772–776} }
 @article{lucovsky_rayner_kang_hinkle_hong_2004, title={A spectroscopic study distinguishing between chemical phase separation with different degrees of crystallinity in Hf(Zr) silicate alloys}, volume={234}, ISSN={["0169-4332"]}, DOI={10.1016/j.apsusc.2004.05.075}, abstractNote={Abstract Chemical phase separation at device processing temperatures is an important issue for integration of Zr and Hf silicates alloys into advanced complementary metal oxide semiconductor (CMOS) devices. Chemical phase separation into ZrO 2 and SiO 2 has been detected by different spectroscopic techniques, including Fourier transform infrared, X-ray photoelectron, and X-ray absorption spectroscopy, as well as X-ray diffraction and high resolution transmission electron microscopy imaging as well. Comparisons between these techniques for Zr silicates identify an unambiguous approach to distinguishing between chemical phase separation with different degrees of micro- and nano-crystallinity.}, number={1-4}, journal={APPLIED SURFACE SCIENCE}, author={Lucovsky, G and Rayner, GB and Kang, D and Hinkle, CL and Hong, JG}, year={2004}, month={Jul}, pages={429–433} }
 @article{rayner_kang_hinkle_hong_lucovsky_2004, title={Chemical phase separation in Zr silicate alloys: a spectroscopic study distinguishing between chemical phase separation with different degree of micro- and nano-crystallinity}, volume={72}, ISSN={["1873-5568"]}, DOI={10.1016/j.mee.2004.01.008}, abstractNote={Chemical phase separation at processing temperatures is an important issue for integration of Zr and Hf silicates alloys into advanced CMOS devices. Chemical phase separation into ZrO2 and SiO2 has been detected by different spectroscopic techniques, including Fourier transform infrared, X-ray photoelectron, and X-ray absorption spectroscopy, as well as X-ray diffraction and high resolution transmission electron microscopy imaging as well. Comparisons between techniques for Zr silicates identify an unambiguous approach to distinguishing between chemical phase separation with different degrees of micro- and nano-crystallinity. This is important since all modes of chemical separation degrade dielectric properties required for high-K applications.}, number={1-4}, journal={MICROELECTRONIC ENGINEERING}, author={Rayner, GB and Kang, D and Hinkle, CL and Hong, JG and Lucovsky, G}, year={2004}, month={Apr}, pages={304–309} }
 @article{rayner_kang_lucovsky_2004, title={Chemical phase separation in Zr silicate alloys: a spectroscopic study distinguishing between chemical phase separation with different degrees of micro- and nano-crystallinity}, volume={338}, ISSN={["1873-4812"]}, DOI={10.1016/j.jnoncrysol.2004.02.042}, abstractNote={Chemical phase separation is an important issue for process integration of non-crystalline Zr and Hf silicate alloys into advanced microelectronic devices. Chemical phase separation of Zr silicates into ZrO2 and SiO2 has been detected by different spectroscopic techniques, including Fourier transform infrared, X-ray photoelectron, X-ray absorption, and extended X-ray absorption fine structure spectroscopies, as well as X-ray diffraction and high resolution transmission electron microscopy imaging. This combination of techniques identifies an unambiguous way to distinguish between chemical phase separation with different degrees of micro- and nano-crystallinity. This is important since all modes of chemical separation degrade dielectric properties required for device applications.}, journal={JOURNAL OF NON-CRYSTALLINE SOLIDS}, author={Rayner, GB and Kang, D and Lucovsky, G}, year={2004}, month={Jun}, pages={151–154} }
 @article{lucovsky_rayner_zhang_appel_whitten_2003, title={Band offset energies in zirconium silicate Si alloys}, volume={216}, ISSN={["0169-4332"]}, DOI={10.1016/S0169-4332(03)00429-X}, abstractNote={Transition metal silicates, (ZrO2)x(SiO2)1−x, with dielectric constants, k>10 have been proposed as alternative dielectrics for advanced Si devices. Studies by X-ray absorption, X-ray photoelectron and Auger electron spectroscopy are combined to identify the compositional variation of the valence and conduction band offset energies with respect to Si in Zr silicate alloys. The minimum conduction band offset energy, associated with localized Zr 4d∗-states, is ∼1.4 eV, and is independent of alloy composition, while valence band offsets decrease monotonically with increasing ZrO2 content. Differences between the coupling of tunneling electrons to localized Zr 4d∗ and extended Si 3s∗ states, characterized by respective tunneling masses of ∼0.5mo and ∼0.2mo, combine to contribute to a minimum in the direct tunneling current in the mid-silicate-alloy composition range, x∼0.4–0.6.}, number={1-4}, journal={APPLIED SURFACE SCIENCE}, author={Lucovsky, G and Rayner, B and Zhang, Y and Appel, G and Whitten, J}, year={2003}, month={Jun}, pages={215–222} }
 @article{bae_rayner_lucovsky_2003, title={Device-quality GaN-dielectric interfaces by 300 degrees C remote plasma processing}, volume={216}, ISSN={["1873-5584"]}, DOI={10.1016/S0169-4332(03)00497-5}, abstractNote={In previous studies, device-quality Si–SiO2 interfaces and dielectric bulk films (SiO2) were prepared using a two-step process; (i) remote plasma-assisted oxidation (RPAO) to form a superficially interfacial oxide (∼0.6 nm) and (ii) remote plasma enhanced chemical vapor deposition (RPECVD) to deposit the oxide film. The same approach has been applied to GaN–SiO2 system. Low-temperature (300 °C) remote N2/He plasma cleaning of the GaN surface, and the kinetics of GaN oxidation using RPAO process and subcutaneous oxidation during the SiO2 deposition using an RPECVD process have been investigated from analysis of on-line Auger electron spectroscopy (AES) features associated N and O. Compared to single-step SiO2 deposition, significantly reduced defect state densities are obtained at the GaN–dielectric interfaces by independent control of GaN–GaOx (x∼1.5) interface formation by RPAO, and SiO2 deposition by RPECVD.}, number={1-4}, journal={APPLIED SURFACE SCIENCE}, author={Bae, C and Rayner, GB and Lucovsky, G}, year={2003}, month={Jun}, pages={119–123} }
 @article{lucovsky_zhang_rayner_appel_ade_whitten_2002, title={Electronic structure of high-k transition metal oxides and their silicate and aluminate alloys}, volume={20}, number={4}, journal={Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures}, author={Lucovsky, G. and Zhang, Y. and Rayner, G. B. and Appel, G. and Ade, H. and Whitten, J. L.}, year={2002}, pages={1739–1747} }
 @article{rayner_kang_zhang_lucovsky_2002, title={Nonlinear composition dependence of x-ray photoelectron spectroscopy and Auger electron spectroscopy features in plasma-deposited zirconium silicate alloy thin films}, volume={20}, ISSN={["2166-2746"]}, DOI={10.1116/1.1493788}, abstractNote={The local bonding of Zr, Si, and O atoms in plasma-deposited, and post-deposition annealed Zr silicate pseudobinary alloys [(ZrO2)x(SiO2)1−x] was studied by x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Systematic decreases in XPS binding energies, and increases in AES kinetic energies with alloy composition x are consistent with an empirical chemical bonding model based on electronegativity equalization; however, there are significant departures from the predicted linear composition dependencies of that model. Deviations from linearity in the XPS compositional dependencies are correlated with dipolar network atom fields as determined from ab initio calculations. The nonlinearities in the x dependence of ZrMVV and OKVV AES spectral features are determined primarily by oxygen–atom coordination dependent shifts in valence band offset energies. The energy spread in the compositional dependence of binding energies (∼1.85 eV) for the XPS Zr 3d5/2 and Si 2p features combined with x-ray absorption spectroscopy data indicates that the conduction band offset energies between the Si substrate and Zr silicate dielectrics are alloy composition independent. Changes in O 1s XPS features in alloys with x∼0.3 to 0.6 as function of annealing temperature are consistent with a previously identified chemical phase separation that occurs after 60 s anneals at 900 °C in a nonoxidizing ambient, Ar.}, number={4}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Rayner, GB and Kang, D and Zhang, Y and Lucovsky, G}, year={2002}, pages={1748–1758} }
 @article{lucovsky_rayner_johnson_2001, title={Chemical and physical limits on the performance of metal silicate high-k gate dielectrics}, volume={41}, ISSN={["0026-2714"]}, DOI={10.1016/S0026-2714(01)00046-4}, abstractNote={This research identifies four significant limitations on the performance of high-k alternative gate dielectrics that derive from inherent relationships between (i) chemical bonding and physical properties, and (ii) device operation. These include interfacial band offset energies, thermal stability against chemical phase separation, coordination dependent dielectric constants, and interfacial fixed charge. Then these are applied to transition metal silicate alloys, e.g., (ZrO2)x(SiO2)1−x. The paper also includes results for other high-k oxides, Al2O3 and Ta2O5, and their alloys that relate to the issues addressed in this paper, and in particular help to put the results on the silicate alloys into a better perspective. This portion of the paper provides additional perspective with regard to the differences in the chemical and physical limitations of elemental oxides and binary oxide alloys.}, number={7}, journal={MICROELECTRONICS RELIABILITY}, author={Lucovsky, G and Rayner, GB and Johnson, RS}, year={2001}, month={Jul}, pages={937–945} }
 @article{lucovsky_rayner_kang_appel_johnson_zhang_sayers_ade_whitten_2001, title={Electronic structure of noncrystalline transition metal silicate and aluminate alloys}, volume={79}, ISSN={["0003-6951"]}, DOI={10.1063/1.1404997}, abstractNote={A localized molecular orbital description (LMO) for the electronic states of transition metal (TM) noncrystalline silicate and aluminate alloys establishes that the lowest conduction band states are derived from d states of TM atoms. The relative energies of these states are in agreement with the LMO approach, and have been measured by x-ray absorption spectroscopy for ZrO2–SiO2 alloys, and deduced from an interpretation of capacitance–voltage and current–voltage data for capacitors with Al2O3–Ta2O5 alloy dielectrics. The LMO model yields a scaling relationship for band offset energies providing a guideline for selection of gate dielectrics for advanced Si devices.}, number={12}, journal={APPLIED PHYSICS LETTERS}, author={Lucovsky, G and Rayner, GB and Kang, D and Appel, G and Johnson, RS and Zhang, Y and Sayers, DE and Ade, H and Whitten, JL}, year={2001}, month={Sep}, pages={1775–1777} }
 @article{lucovsky_rayner_2000, title={Microscopic model for enhanced dielectric constants in low concentration SiO2-rich noncrystalline Zr and Hf silicate alloys}, volume={77}, ISSN={["0003-6951"]}, DOI={10.1063/1.1320860}, abstractNote={Dielectric constants, k, of Zr(Hf) silicate alloy gate dielectrics obtained from analysis of capacitance–voltage curves of metal–oxide–semiconductor capacitors with 3–6 at. % Zr(Hf) are significantly larger than estimates of k based on linear extrapolations between SiO2 and compound silicates, Zr(Hf)SiO4. Analysis of infrared spectra of Zr silicate alloys with 3–16 at. % Zr indicates increases in the coordination of Zr to O atoms from 4 to approximately 8 with increasing Zr content. The major contributions to enhancements in k in these low Zr(Hf) content alloys are explained by a transverse infrared effective charge that scales inversely with increasing Zr–O bond coordination.}, number={18}, journal={APPLIED PHYSICS LETTERS}, author={Lucovsky, G and Rayner, GB}, year={2000}, month={Oct}, pages={2912–2914} }