The Experts below are selected from a list of 111255 Experts worldwide ranked by ideXlab platform
Koji Kita - One of the best experts on this subject based on the ideXlab platform.
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low temperature wet o2 annealing process for enhancement of inversion channel mobility and suppression of vfb instability on 4h sic 0001 si face
Applied Physics Letters, 2018Co-Authors: Hirohisa Hirai, Koji KitaAbstract:For improvement of 4H-SiC metal-Oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in Oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on Oxide Growth kinetics on 4H-SiC.
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low temperature wet o2 annealing process for enhancement of inversion channel mobility and suppression of vfb instability on 4h sic 0001 si face
Applied Physics Letters, 2018Co-Authors: Hirohisa Hirai, Koji KitaAbstract:For improvement of 4H-SiC metal-Oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in Oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on Oxide Growth kinetics on 4H-SiC.For improvement of 4H-SiC metal-Oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in Oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on Oxide Growth kinetics on 4H-SiC.
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interface reaction limited Growth of thermal Oxides on 4h sic 0001 in nanometer thick region
Applied Physics Letters, 2014Co-Authors: Richard Heihachiro Kikuchi, Koji KitaAbstract:Growth kinetics of nanometer-thick thermal Oxides on 4H-SiC (0001), Si-face, was investigated. A linear Oxide Growth was clearly observed in this thickness region, indicating the Oxide Growth is limited by interface reaction. The activation energy of the interface reaction was estimated to be 3.8 ± 0.1 eV. The rate-limiting step in this reaction was discussed from both the value of activation energy and the oxygen partial pressure dependence of the Growth rate. The enhanced Growth limited only to the initial <2 nm region was also observed, which is suggesting the change of the rate-limiting step for the interface reaction in the ultrathin region.
Hirohisa Hirai - One of the best experts on this subject based on the ideXlab platform.
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low temperature wet o2 annealing process for enhancement of inversion channel mobility and suppression of vfb instability on 4h sic 0001 si face
Applied Physics Letters, 2018Co-Authors: Hirohisa Hirai, Koji KitaAbstract:For improvement of 4H-SiC metal-Oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in Oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on Oxide Growth kinetics on 4H-SiC.For improvement of 4H-SiC metal-Oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in Oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on Oxide Growth kinetics on 4H-SiC.
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low temperature wet o2 annealing process for enhancement of inversion channel mobility and suppression of vfb instability on 4h sic 0001 si face
Applied Physics Letters, 2018Co-Authors: Hirohisa Hirai, Koji KitaAbstract:For improvement of 4H-SiC metal-Oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in Oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on Oxide Growth kinetics on 4H-SiC.
Yves J Chabal - One of the best experts on this subject based on the ideXlab platform.
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in situ infrared spectroscopy of hafnium Oxide Growth on hydrogen terminated silicon surfaces by atomic layer deposition
Applied Physics Letters, 2005Co-Authors: M T Ho, Yves J Chabal, Yu Wang, Rhett T Brewer, L Wielunski, Naim Moumen, Marek P BoleslawskiAbstract:The interface formation between HfO2 and H-terminated Si(111) and Si(100) is studied by in situ infrared absorption spectroscopy during atomic layer deposition using alternating tetrakis-ethylmethylamino hafnium (TEMAH) and deuterium Oxide (D2O) pulses. The HfO2 Growth is initiated by the reaction of TEMAH with Si–H rather than D2O, and there is no evidence for SiO2 formation at moderate Growth temperatures (∼100°C). Although Rutherford backscattering shows a linear increase of Hf coverage, direct observations of Si–H, Si–O–Hf, and HfO2 phonons indicate that five cycles are needed to reach the steady state interface composition of ∼50% reacted sites. The formation of interfacial SiO2 (∼0.7nm) is observed after postdeposition annealing at 700°C in ultrapure nitrogen.
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enhanced initial Growth of atomic layer deposited metal Oxides on hydrogen terminated silicon
Applied Physics Letters, 2003Co-Authors: Martin M Frank, Yves J Chabal, M L Green, Annelies Delabie, Bert Brijs, Glen D Wilk, Munyee Ho, Elisa Brod Oliveira Da Rosa, I J R Baumvol, F C StedileAbstract:A route is presented for activation of hydrogen-terminated Si(100) prior to atomic layer deposition. It is based on our discovery from in situ infrared spectroscopy that organometallic precursors can effectively initiate Oxide Growth. Narrow nuclear resonance profiling and Rutherford backscattering spectrometry show that surface functionalization by pre-exposure to 108 Langmuir trimethylaluminum at 300 °C leads to enhanced nucleation and to nearly linear Growth kinetics of the high-permittivity gate dielectrics aluminum Oxide and hafnium Oxide.
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nucleation and interface formation mechanisms in atomic layer deposition of gate Oxides
Applied Physics Letters, 2003Co-Authors: Martin M Frank, Yves J Chabal, Glen D WilkAbstract:We present an in situ infrared spectroscopic study of the interface formation during atomic layer deposition of alternative high-permittivity (high-κ) gate dielectrics. Layer-by-layer Oxide Growth may be achieved by alternating pulses of a molecular metal precursor (e.g., trimethylaluminum for aluminum Oxide Growth) and water vapor. Contrary to common belief, we find that the metal precursor, not the oxidizing agent, is the key factor to control Al2O3 nucleation on hydrogen-terminated silicon. Metal surface species catalyze subsurface Si oxidation. These findings have direct implications on Growth conditions to optimize semiconductor-dielectric interfaces.
Dan Addison - One of the best experts on this subject based on the ideXlab platform.
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Rechargeable-battery chemistry based on lithium Oxide Growth through nitrate anion redox
Nature Chemistry, 2019Co-Authors: Vincent Giordani, Dylan Tozier, Hongjin Tan, Gregory V. Chase, Betar M Gallant, Jasim Uddin, Bryan D Mccloskey, Julia R Greer, Dan AddisonAbstract:Phase-forming conversion chemistry, like that observed in Li–S and Li–O_2 batteries, shows great promise, but these systems suffer some drawbacks, such as practically low cathode areal capacities and electrolyte decomposition. Now, high-energy conversion battery chemistry—based on nitrate/nitrite redox where one of the products is soluble—has been enabled by using nanoparticulate Ni/NiO electrocatalysts.AbstractNext-generation lithium-battery cathodes often involve the Growth of lithium-rich phases, which enable specific capacities that are 2−3 times higher than insertion cathode materials, such as lithium cobalt Oxide. Here, we investigated battery chemistry previously deemed irreversible in which lithium Oxide, a lithium-rich phase, grows through the reduction of the nitrate anion in a lithium nitrate-based molten salt at 150 °C. Using a suite of independent characterization techniques, we demonstrated that a Ni nanoparticle catalyst enables the reversible Growth and dissolution of micrometre-sized lithium Oxide crystals through the effective catalysis of nitrate reduction and nitrite oxidation, which results in high cathode areal capacities (~12 mAh cm^–2). These results enable a rechargeable battery system that has a full-cell theoretical specific energy of 1,579 Wh kg^–1, in which a molten nitrate salt serves as both an active material and the electrolyte.
M Gell - One of the best experts on this subject based on the ideXlab platform.
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thermally grown Oxide Growth behavior and spallation lives of solution precursor plasma spray thermal barrier coatings
Surface & Coatings Technology, 2008Co-Authors: Fang Wu, Eric H Jordan, M GellAbstract:The effects of thermally grown Oxide (TGO) Growth rate and bond coat oxidation behavior on the spallation lives of thermal barrier coatings (TBCs) have been investigated. Yttria partially stabilized zirconia (7YSZ) coatings have been applied to various bond coat/superalloy substrate combinations using the Solution Precursor Plasma Spray (SPPS) process. The coatings have been furnace thermal cycled at 1121 °C, using one hour cycles. A large variation in the spallation lives, from 125 to 1230 cycles, has been observed and are attributed to (a) the spatially averaged TGO Growth rate, (b) the maximum localized TGO thickness, (c) the formation of non-alumina Oxides with weak interfaces, and (d) the formation of yttrium aluminate stringers in low pressure plasma spray (LPPS) processed bond coat. Of these four factors, the average TGO thickness is the most important. Surprisingly vacuum plasma sprayed bond coated samples consistently had shorter cyclic live compared to air plasma sprayed bond coated samples.
