Improvement of Channel Mobility in 4H-SiC C-Face MOSFETs by H2 Rich Wet Re-Oxidation

2014 ◽  
Vol 778-780 ◽  
pp. 975-978 ◽  
Author(s):  
Mitsuo Okamoto ◽  
Youichi Makifuchi ◽  
Tsuyoshi Araoka ◽  
Masaki Miyazato ◽  
Yoshiyuki Sugahara ◽  
...  
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Oxidation Rate ◽  
Catalytic Action ◽  
Wet Oxidation ◽  
Interface Traps ◽  
Mos Capacitor ◽  
Channel Mobility ◽  
Vapor Generator ◽  
First Time

4H-SiC(000-1) C-face was oxidized in H2O and H2mixture gas (H2rich wet ambient) for the first time. H2rich wet ambient was formed by the catalytic water vapor generator (WVG) system, where the catalytic action instantaneously enhances the reactivity between H2and O2to produce H2O. The dependence of SiC oxidation rate on the H2O partial pressure was investigated. We fabricated 4H-SiC C-face MOS capacitor and MOSFET by the H2rich wet re-oxidation following the dry O2oxidation. The density of interface traps was reduced and the channel mobility was improved in comparison with the conventional O2rich wet oxidation.

scholarly journals Physical Characterisation of 3C-SiC(001)/SiO2 Interface Using XPS

2017 ◽  
Vol 897 ◽  
pp. 151-154 ◽  
Author(s):  
Fan Li ◽  
Oliver Vavasour ◽  
Marc Walker ◽  
David M. Martin ◽  
Yogesh K. Sharma ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Process ◽  
Wet Oxidation ◽  
Interface Traps ◽  
Xps Analysis ◽  
Channel Mobility

Normally-on MOSFETs were fabricated on 3C-SiC epilayers using high temperature (1300 °C) wet oxidation process. XPS analysis found little carbon at the MOS interface yet the channel mobility (60 cm2/V.s) is considerably low. Si suboxides (SiOx, x<2) exist at the wet oxidised 3C-SiC/SiO2 interface, which may act as interface traps and degrade the conduction performance.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

12 kV 4H-SiC p-IGBTs with Record Low Specific On-Resistance

2008 ◽  
Vol 600-603 ◽  
pp. 1187-1190 ◽  
Author(s):  
Q. Jon Zhang ◽  
Charlotte Jonas ◽  
Joseph J. Sumakeris ◽  
Anant K. Agarwal ◽  
John W. Palmour
Keyword(s):  
Carrier Lifetime ◽  
Drift Region ◽  
Gate Bias ◽  
Enhancement Layer ◽  
Channel Mobility ◽  
Dc Characteristics ◽  
Blocking Voltage ◽  
High Carrier ◽  
P Type ◽  
First Time

DC characteristics of 4H-SiC p-channel IGBTs capable of blocking -12 kV and conducting -0.4 A (-100 A/cm2) at a forward voltage of -5.2 V at 25°C are demonstrated for the first time. A record low differential on-resistance of 14 mW×cm2 was achieved with a gate bias of -20 V indicating a strong conductivity modulation in the p-type drift region. A moderately doped current enhancement layer grown on the lightly doped drift layer effectively reduces the JFET resistance while maintains a high carrier lifetime for conductivity modulation. A hole MOS channel mobility of 12.5 cm2/V-s at -20 V of gate bias was measured with a MOS threshold voltage of -5.8 V. The blocking voltage of -12 kV was achieved by Junction Termination Extension (JTE).

scholarly journals First-time lidar measurement of water vapor flux in a volcanic plume

2011 ◽  
Vol 284 (5) ◽  
pp. 1295-1298 ◽  
Author(s):  
Luca Fiorani ◽  
Francesco Colao ◽  
Antonio Palucci ◽  
Davod Poreh ◽  
Alessandro Aiuppa ◽  
...  
Keyword(s):  
Water Vapor ◽  
Volcanic Plume ◽  
Lidar Measurement ◽  
Water Vapor Flux ◽  
Vapor Flux ◽  
First Time

SiC MOSFET Channel Mobility Dependence on Substrate Doping and Temperature Considering High Density of Interface Traps

2007 ◽  
Vol 556-557 ◽  
pp. 835-838 ◽  
Author(s):  
Amador Pérez-Tomás ◽  
Michael R. Jennings ◽  
Philip A. Mawby ◽  
James A. Covington ◽  
Phillippe Godignon ◽  
...  
Keyword(s):  
Degradation Mechanism ◽  
Mobility Model ◽  
Effect Of Temperature ◽  
Coulomb Scattering ◽  
Interface Traps ◽  
Channel Mobility ◽  
Inversion Channel ◽  
Scattering Effects ◽  
Charge Concentration ◽  
Substrate Doping

In prior work we have proposed a mobility model for describing the mobility degradation observed in SiC MOSFET devices, suitable for being implemented into a commercial simulator, including Coulomb scattering effects at interface traps. In this paper, the effect of temperature and doping on the channel mobility has been modelled. The computation results suggest that the Coulomb scattering at charged interface traps is the dominant degradation mechanism. Simulations also show that a temperature increase implies an improvement in field-effect mobility since the inversion channel concentration increases and the trapped charge is reduced due to bandgap narrowing. In contrast, increasing the substrate impurity concentration further degrades the fieldeffect mobility since the inversion charge concentration decreases for a given gate bias. We have good agreement between the computational results and experimental mobility measurements.

Rapid Thermal Oxidation of Lightly Doped Silicon in N2O

1994 ◽  
Vol 342 ◽  
Author(s):  
S.C. Sun ◽  
L.S. Wang ◽  
F.L. Yeh ◽  
T.S. Lai ◽  
Y.H. Lin
Keyword(s):  
Growth Rate ◽  
Thermal Oxidation ◽  
Charge Trapping ◽  
Interface State ◽  
Constant Current ◽  
Mos Capacitor ◽  
Rapid Thermal Oxidation ◽  
Doped Silicon ◽  
State Generation ◽  
First Time

ABSTRACTIn this paper, a detailed study is presented for the growth kinetics of rapid thermal oxidation of lightly-doped silicon in N2O and O2 on (100), (110), and (111) oriented substrates. It was found that (110)-oriented Si has the highest growth rate in both N2O and dry O2, and (100) Si has the lowest rate. There is no “crossover” on the growth rate of rapid thermal N2O oxidation between (110) Si and (111) Si as compared to oxides grown in furnace N2O. Pressure dependence of rapid thermal N2O oxidation is reported for the first time. MOS capacitor results show that the low-pressure (40 Torr) N2O-grown oxides have much less interface state generation and charge trapping under constant current stress as compared to oxides grown in either 760 Torr N2O or O2 ambient.

Reduction in the Density of Interface States at the SiO2/4H-SiC Interface after Dry Oxidation in the Presence of Potassium

2011 ◽  
Vol 679-680 ◽  
pp. 334-337 ◽  
Author(s):  
Pétur Gordon Hermannsson ◽  
Einar Ö. Sveinbjörnsson
Keyword(s):  
Energy Distribution ◽  
Oxidation Rate ◽  
Alkali Metals ◽  
Interface States ◽  
Significant Enhancement ◽  
Interface Traps ◽  
Strong Reduction ◽  
Dry Oxidation ◽  
Density Of Interface States

We report a strong reduction in the density of near-interface traps (NITs) at the SiO2/4H-SiC interface after dry oxidation in the presence of potassium. This is accompanied by a significant enhancement of the oxidation rate. The results are in line with recent investigations of the effect of sodium on oxidation of 4H-SiC. It is evident that both alkali metals enhance the oxidation rate of SiC and strongly influence the energy distribution of interface states.

Gamma Irradiation Effects on 4H-SiC MOS Capacitors and MOSFETs

2006 ◽  
Vol 527-529 ◽  
pp. 1063-1066 ◽  
Author(s):  
Ayayi Claude Ahyi ◽  
S.R. Wang ◽  
John R. Williams
Keyword(s):  
Field Effect ◽  
Gamma Dose ◽  
Interface Traps ◽  
Valence Band Edge ◽  
Field Effect Mobility ◽  
Irradiation Effects ◽  
Mos Capacitors ◽  
Channel Mobility ◽  
Radiation Induced ◽  
Radiation Tolerant

The effects of gamma radiation on field effect mobility and threshold voltage have been studied for lateral n-channel 4H-SiC MOSFETs passivated with nitric oxide. MOS capacitors (n and p) and n-channel lateral MOSFETs were irradiated unbiased (floating contacts) for a total gamma dose of 6.8Mrad (Si). The MOS capacitors were used to study the radiation-induced interface traps and fixed oxide charge that affect the performance of the MOSFETs. Radiationinduced interface traps were observed near the SiC valence band edge and just above mid-gap, and field effect channel mobility was reduced by 18-20% following irradiation. Even so, 4HMOSFETs appear to be more radiation tolerant than Si devices.

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