Ultrahigh-Temperature Oxidation of 4H-SiC(0001) and an Impact of Cooling Process on SiO2/SiC Interface Properties

2017 ◽  
Vol 897 ◽  
pp. 323-326 ◽  
Author(s):  
Takuji Hosoi ◽  
Daisuke Nagai ◽  
Mitsuru Sometani ◽  
Takayoshi Shimura ◽  
Manabu Takei ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Linear Growth ◽  
State Density ◽  
Oxidation Temperature ◽  
Linear Growth Rate ◽  
Oxide Growth ◽  
Interface Properties ◽  
Cooling Process ◽  
Temperature Oxidation ◽  
Ultrahigh Temperature

This paper reviews our recent work on ultrahigh-temperature oxidation of 4H-SiC(0001) surfaces. Our rapid thermal oxidation experiments demonstrated the reaction-limited linear growth at temperatures ranging from 1200 to 1600°C. The Arrhenius plot of linear growth rate of thermal oxidation can be fitted by a linear line, and the activation energy of oxide growth in dry O2 oxidation was estimated to be 2.9 eV. We also found that unintentional oxidation during the cooling down process severely degrades SiO2/SiC interface properties, resulting in positive flatband voltage shift (VFB) and hysteresis in capacitance-voltage (C-V) characteristics regardless of oxidation temperature. By effectively suppressing oxide growth during the cooling process, we have clarified that SiO2/SiC interface properties depend on oxidation temperature and the lowest interface state density was obtained for the oxide formed at 1450°C.

Ultrahigh-temperature rapid thermal oxidation of 4H-SiC(0001) surfaces and oxidation temperature dependence of SiO2/SiC interface properties

2016 ◽  
Vol 109 (18) ◽  
pp. 182114 ◽  
Author(s):  
Takuji Hosoi ◽  
Daisuke Nagai ◽  
Mitsuru Sometani ◽  
Yoshihito Katsu ◽  
Hironori Takeda ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Thermal Oxidation ◽  
Oxidation Temperature ◽  
Interface Properties ◽  
Rapid Thermal Oxidation ◽  
Ultrahigh Temperature

Improved Electrical Properties of 4H-SiC MOS Devices with High Temperature Thermal Oxidation

2019 ◽  
Vol 954 ◽  
pp. 99-103
Author(s):  
Heng Yu Xu ◽  
Cai Ping Wan ◽  
Jin Ping Ao
Keyword(s):  
High Temperature ◽  
Thermal Oxidation ◽  
High Temperature Oxidation ◽  
Oxidation Temperature ◽  
Nitrogen Gas ◽  
Mos Capacitors ◽  
Temperature Oxidation ◽  
Mos Devices ◽  
Device Reliability ◽  
Nitrogen Ions

We reported that high oxidation temperature is attributed to break Si-C bond and release nitrogen gas to nitrogen ions over 1350°C. The capacitance-voltage characteristics of SiO2/4H-SiC (0001) MOS capacitors fabricated under different thermal oxidation conditions are compared. The dependence of oxidation temperature on device characteristics (such as VFB and ΔVFB) is also analyzed. After a high temperature oxidation, the device reliability of SiC MOS is improved. Such behavior can be attributed to the reduction of the interface traps during high temperature oxidation.

Improving Interface Quality of 4H-SiC MOS Devices with High Temperature Oxidation Process in Mass Produce Furnace

2015 ◽  
Vol 821-823 ◽  
pp. 484-487
Author(s):  
Heng Yu Xu ◽  
Qian Yang ◽  
Xiao Lei Wang ◽  
Xin Yu Liu ◽  
Yan Li Zhao ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Process ◽  
Interface State ◽  
State Density ◽  
Oxidation Temperature ◽  
Interface Quality ◽  
Temperature Oxidation ◽  
Mos Devices ◽  
High Temperature Process

A high-temperature process is used to enhance the COxdesorption rate to reduce trap density in SiC/SiO2interface for SiC MOSFETs. Interface state density as measured by Terman method and C-ψs method for the oxidation processes at a high temperature of 1350°C show significant improvement compared to traditional Si thermal oxidation temperature of 1200°C. The higher oxidation temperature led to a much faster growth rate and some observable hysteresis in the CV curves, which could be due to electron trap and can be resolved by NOxpost oxidation anneal (POA).

Impact of rapid cooling process in ultrahigh-temperature oxidation of 4H-SiC(0001)

2017 ◽  
Vol 56 (4S) ◽  
pp. 04CR04 ◽  
Author(s):  
Mitsuru Sometani ◽  
Daisuke Nagai ◽  
Yoshihito Katsu ◽  
Takuji Hosoi ◽  
Takayoshi Shimura ◽  
...  
Keyword(s):  
Cooling Process ◽  
Rapid Cooling ◽  
Temperature Oxidation ◽  
Ultrahigh Temperature

scholarly journals Friction and Wear of Oxide Scale Obtained on Pure Titanium after High-Temperature Oxidation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3764
Author(s):  
Krzysztof Aniołek ◽  
Adrian Barylski ◽  
Marian Kupka
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Friction And Wear ◽  
High Carbon Steel ◽  
Oxide Films ◽  
Oxidation Temperature ◽  
Temperature Oxidation ◽  
Wear Ratio ◽  
Steel Balls

High-temperature oxidation was performed at temperatures from 600 to 750 °C over a period of 24 h and 72 h. It was shown in the study that the oxide scale became more homogeneous and covered the entire surface as the oxidation temperature increased. After oxidation over a period of 24 h, the hardness of the produced layers increased as the oxidation temperature increased (from 892.4 to 1146.6 kgf/mm2). During oxidation in a longer time variant (72 h), layers with a higher hardness were obtained (1260 kgf/mm2). Studies on friction and wear characteristics of titanium were conducted using couples with ceramic balls (Al2O3, ZrO2) and with high-carbon steel (100Cr6) balls. The oxide films produced at a temperature range of 600–750 °C led to a reduction of the wear ratio value, with the lowest one obtained in tests with the 100Cr6 steel balls. Frictional contact of Al2O3 balls with an oxidized titanium disc resulted in a reduction of the wear ratio, but only for the oxide scales produced at 600 °C (24 h, 72 h) and 650 °C (24 h). For the ZrO2 balls, an increase in the wear ratio was observed, especially when interacting with the oxide films obtained after high-temperature oxidation at 650 °C or higher temperatures. The increase in wear intensity after titanium oxidation was also observed for the 100Cr6 steel balls.

A Perspective on Modeling Materials in Extreme Environments: Oxidation of Ultrahigh-Temperature Ceramics

MRS Bulletin ◽  
2006 ◽  
Vol 31 (5) ◽  
pp. 410-418 ◽  
Author(s):  
Angelo Bongiorno ◽  
Clemens J. Först ◽  
Rajiv K. Kalia ◽  
Ju Li ◽  
Jochen Marschall ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Atomistic Simulation ◽  
Extreme Environments ◽  
Protective Layer ◽  
Ceramic Composites ◽  
Atomistic Modeling ◽  
Temperature Oxidation ◽  
Simulation Techniques ◽  
Oxidation Resistant ◽  
Ultrahigh Temperature

AbstractThe broader context of this discussion, based on a workshop where materials technologists and computational scientists engaged in a dialogue, is an awareness that modeling and simulation techniques and computational capabilities may have matured sufficiently to provide heretofore unavailable insights into the complex microstructural evolution of materials in extreme environments.As an example, this article examines the study of ultrahigh-temperature oxidation-resistant ceramics, through the combination of atomistic simulation and selected experiments.We describe a strategy to investigate oxygen transport through a multi-oxide scale—the protective layer of ultrahigh-temperature ceramic composites ZrB2-SiC and HfB2-SiC—by combining first-principles and atomistic modeling and simulation with selected experiments.

Microborings and growth in Late Ordovician halysitids and other corals

1993 ◽  
Vol 67 (6) ◽  
pp. 922-934 ◽  
Author(s):  
Robert J. Elias ◽  
Dong-Jin Lee
Keyword(s):  
Growth Rate ◽  
Linear Growth ◽  
Inverse Correlation ◽  
Weight Percent ◽  
Late Ordovician ◽  
Coral Growth ◽  
Linear Growth Rate ◽  
Skeletal Density ◽  
Rugose Coral ◽  
Endolithic Algae

Microborings in the Late Ordovician tabulate corals Catenipora rubra (a halysitid) and Manipora amicarum (a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulate Quepora ?agglomeratiformis (a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings in Catenipora rubra and Manipora amicarum is comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.

A linear and quasi-linear investigation of the crossfield current-driven ion-acoustic instability

1982 ◽  
Vol 28 (2) ◽  
pp. 267-279 ◽  
Author(s):  
R. Bharuthram ◽  
M. A. Hellberg
Keyword(s):  
Linear Growth ◽  
Velocity Distribution Function ◽  
Linear Growth Rate ◽  
Particle Diffusion ◽  
Anomalous Resistivity ◽  
Heating Rates ◽  
Ion Heating ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Drift Instability

The linear growth rate of the crossfield current-driven ion-acoustic instability is obtained for any equilibrium particle velocity distribution function of the type . Quasi-linear theory is then used to investigate the saturation of the instability. Several associated features, namely, particle diffusion in velocity space, anomalous resistivity, energy distribution and electron and ion heating rates are evaluated for a Maxwellian distribution. Finally, a brief comparison is made with the heating rates associated with the electron cyclotron drift instability.

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