Wide Bandgap Fluorinated Silicon-Carbide-Nitride Films Using NF3

1991 ◽  
Vol 219 ◽  
Author(s):  
H. C. Goh ◽  
S. M. Tan ◽  
H. A. Naseem ◽  
S. S. Ang ◽  
W. D. Brown
Keyword(s):  
Silicon Carbide ◽  
Refractive Index ◽  
Carbon Content ◽  
Power Density ◽  
Deposition Rate ◽  
Gas Flow ◽  
Substantial Reduction ◽  
Wide Bandgap ◽  
Amorphous Hydrogenated Silicon ◽  
Stainless Steel Reactor

ABSTRACTAmorphous hydrogenated silicon carbide has been studied extensively because of its properties as a wide bandgap material. However, a large amount of methane is needed to deposit the material. Also, the high carbon content of these films poses some problems. The addition of NF3 to the gas stream results in wide bandgap films with a substantial reduction in the required CH4 flow for deposition. Amorphous SiCx Ny :H:F films were prepared using rf glow discharge decomposition of silane, methane, and nitrogen trifluoride in a parallel-plate stainless steel reactor. Gas flow rate and power density were varied. For a gas mixture containing 6% NF3 and 78% CH4, FTIR measurements reveal a reduction in C-H peak heights at 2960 cm-1 and 2880 cm-1 with respect to the Si-H peak at 2080 cm-1 indicating a smaller carbon content in the film. The C-H peaks shift to higher wavenumbers with increasing NF3. The use of NF3 increases the bandgap from 2.6 to 3.14 eV while reducing the refractive index from 2.12. to 1.87. A maximum deposition rate of 625 A/min was achieved. This should be compared to the very low deposition rate of 18 A/min for comparable bandgap Si-C films deposited using 97% methane in silane. Increasing the deposition power density resulted in a larger bandgap and a smaller refractive index.

The Effects of Deposition Parameters on the Properties of SiO2 Films Deposited by Microwave Ecr Plasmas

1993 ◽  
Vol 334 ◽  
Author(s):  
T. T. Chau ◽  
P. M. Lam ◽  
K. C. Kao
Keyword(s):  
Refractive Index ◽  
Deposition Rate ◽  
Gas Flow ◽  
High Pressures ◽  
Thermally Grown Oxide ◽  
Film Deposition ◽  
Flow Ratio ◽  
Gas Flow Ratio ◽  
Film Deposition Rate ◽  
Thermally Grown

AbstractElectronic and physical properties of SiO2 films deposited by microwave ECR plasmas of the mixtures of SiH4 and N2O have been measured as functions of the pressure and the gas-flow ratio of N2O to SiH4 gases in the processing chamber. Experimental results show that the film deposition rate increases with increasing SiH4 concentration, that is, with decreasing gas-flow ratio. The films deposited at N2O/SiH4 gas-flow ratios smaller than 10 tend to have a refractive index higher than the thermally grown oxide. However, for the N2O/SiH4 gas-flow ratios between 10 and 20, the films have the refractive index close to that of thermally grown oxide, which is about 1.45-1.46. The film deposition rate increases linearly with increasing pressure. In general, the films deposited at high pressures (>100 mTorr) have a higher refractive index as compared with the thermally grown oxide; also films deposited at high pressures have more electron traps. Good quality SiO2 films can be deposited at pressures with the range of 20 -50 mTorr and the N2O/SiH4 gas-flow ratio of 10.

Amorphous Hydrogenated Silicon Carbide Prepared from DC-Biased RF-Plasma-Enhanced Chemical Vapor Deposition

1991 ◽  
Vol 219 ◽  
Author(s):  
Hsueh Yi Lu ◽  
Mark A. Petrich
Keyword(s):  
Silicon Carbide ◽  
Carbon Content ◽  
Plasma Deposition ◽  
Chemical Vapor ◽  
Plasma Potential ◽  
Rf Plasma ◽  
Hydrogenated Silicon ◽  
Optical Band Gaps ◽  
Amorphous Hydrogenated Silicon ◽  
Dc Bias

ABSTRACTWe present evidence that an independently applied dc bias voltage has a significant effect on the plasma deposition of amorphous hydrogenated silicon carbide. Deposition rates increase with either positive or negative dc voltages applied to the powered rf electrode. The microstructure of the films (as determined by infrared absorption) can be reduced by increasing the plasma potential (positive dc bias voltages). Negative dc biases, or excessively high positive biases, result in increased amounts of film microstructure. Film carbon content is increased when positive biases are applied, but the optical band gaps decrease suggesting increased amounts of graphitic bonding configurations. Negative biases do not change the carbon content of the films, but do increase both deposition rate and microstructure.

scholarly journals Interleaved, Switched Inductor and High-Gain Wide Bandgap Based Boost Converter Proposal

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 800
Author(s):  
David Marroqui ◽  
Ausias Garrigós ◽  
Cristian Torres ◽  
Carlos Orts ◽  
Jose M. Blanes ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
Low Voltage ◽  
High Gain ◽  
Wide Bandgap ◽  
High Power Density ◽  
Boost Converters ◽  
Proposal A ◽  
Current Ripples ◽  
Current Ripple

Many applications (electric vehicles, renewable energies, low-voltage DC grids) require simple, high-power density and low-current ripple-boost converters. Traditional step-up converters are limited when large transformation ratios are involved. In this work is proposed a step-up converter that brings together the characteristics of high gain, low ripple, and high-power density. From the converter proposal, a mathematical analysis of its operation is first performed, including its static transfer function, stress of components, and voltage and current ripples. Furthermore, it provides a design example for an application of Vin = 48 V to Vo = 270 V and 500 W. For its implementation, two different wide bandgap (WBG) semiconductor models have been used, hybrid GaN cascodes and SiC MOSFETs. Finally, the experimental results of the produced prototypes are shown, and the results are discussed.

Initial results and long-term clinical follow-up of an amorphous hydrogenated silicon-carbide-coated stent in daily practice

1998 ◽  
Vol 1 (2) ◽  
pp. 81-85
Author(s):  
Clara EE Hanekamp ◽  
Hans JRM Bonnier ◽  
Rolf H Michels ◽  
Kathinka H Peels ◽  
Eric PCM Heijmen ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Daily Practice ◽  
Hydrogenated Silicon ◽  
Amorphous Hydrogenated Silicon ◽  
Initial Results

Influence of Carbon Content on Ceramic Injection Molding of Reaction-Bonded Silicon Carbide

2016 ◽  
Vol 13 (5) ◽  
pp. 838-843 ◽  
Author(s):  
Zhao Zhang ◽  
Yujun Zhang ◽  
Hongyu Gong ◽  
Xue Guo ◽  
Yubai Zhang ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Injection Molding ◽  
Carbon Content ◽  
Ceramic Injection Molding

Surface Characterization of Silicon Carbide Following Shallow Implantation of Palladium Ions

2005 ◽  
Vol 900 ◽  
Author(s):  
Claudiu I. Muntele ◽  
Sergey Sarkisov ◽  
Iulia Muntele ◽  
Daryush Ila
Keyword(s):  
Silicon Carbide ◽  
Surface Characterization ◽  
Wide Bandgap ◽  
Electrical Contacts ◽  
Temperature Dependent ◽  
Wide Bandgap Semiconductor ◽  
Hydrogen Sensing ◽  
Fast Switching ◽  
Sensing Applications

ABSTRACTSilicon carbide is a promising wide-bandgap semiconductor intended for use in fabrication of high temperature, high power, and fast switching microelectronics components running without cooling. For hydrogen sensing applications, silicon carbide is generally used in conjunction with either palladium or platinum, both of them being good catalysts for hydrogen. Here we are reporting on the temperature-dependent surface morphology and depth profile modifications of Au, Ti, and W electrical contacts deposited on silicon carbide substrates implanted with 20 keV Pd ions.

DEPOSITION-AND-SUBSTRATE TUNABLE PHOTONIC BANDGAP IN OPTICAL RESPONSES OF HYDROGENATED AMORPHOUS SILICON CARBIDE THIN FILMS

2003 ◽  
Vol 17 (09) ◽  
pp. 387-392 ◽  
Author(s):  
NIKIFOR RAKOV ◽  
ARSHAD MAHMOOD ◽  
MUFEI XIAO
Keyword(s):  
Thin Films ◽  
Silicon Carbide ◽  
Photonic Bandgap ◽  
Visible Spectrum ◽  
Incoherent Light ◽  
Hydrogenated Silicon ◽  
Optical Responses ◽  
Amorphous Hydrogenated Silicon ◽  
The Status ◽  
Two Parameters

Amorphous hydrogenated silicon carbide (a-SiC:H) thin films have been prepared by the RF reactive magnetron sputtering technique. The optical properties of the films have been studied by optical spectroscopy with an incoherent light source. The material is commonly regarded as a dielectric. We have discovered however that some films that were prepared under certain deposition conditions and on certain substrates may respond to external light as a metallic thin film, i.e. there are strongly enhanced reflection peaks in the optical spectrum. We have further discovered that some films may have a strong and broadened absorption peak at about 590 nm, which is an apparent photonic bandgap in the visible spectrum. The appearance of the photonic bandgap is very sensitive to two parameters: the substrate and the deposition gas. By changing the two parameters, one shifts the status of the film from with and without the photonic bandgap.

scholarly journals Potential of using inert gas flows for controlling the quality of as-grown silicon single crystal

2020 ◽  
Vol 6 (1) ◽  
pp. 1-7
Author(s):  
Tatyana V. Kritskaya ◽  
Vladimir N. Zhuravlev ◽  
Vladimir S. Berdnikov
Keyword(s):  
Single Crystal ◽  
Carbon Content ◽  
Single Crystals ◽  
Gas Flow ◽  
Thermal Stresses ◽  
Crystal Surface ◽  
Gas Flows ◽  
Reaction Products ◽  
Crystal Silicon ◽  
Argon Gas

We have improved the well-known Czochralski single crystal silicon growth method by using two argon gas flows. One flow is the main one (15–20 nl/min) and is directed from top to bottom along the growing single crystal. This flow entrains reaction products of melt and quartz crucible (mainly SiO), removes them from the growth chamber through a port in the bottom of the chamber and provides for the growth of dislocation-free single crystals from large weight charge. Similar processes are well known and have been generally used since the 1970s world over. The second additional gas flow (1.5–2 nl/min) is directed at a 45 arc deg angle to the melt surface in the form of jets emitted from circularly arranged nozzles. This second gas flow initiates the formation of a turbulent melt flow region which separates the crystallization front from oxygen-rich convective flows and accelerates carbon evaporation from the melt. It has been confirmed that oxygen evaporated from the melt (in the form of SiO) acts as transport agent for nonvolatile carbon. Commercial process implementation has shown that carbon content in as-grown single crystals can be reduced to below the carbon content in the charge. Single crystals grown with two argon gas flows have also proven to have highly macro- and micro-homogeneous oxygen distributions, with much greater lengths of single crystal portions in which the oxygen concentration is constant and below the preset limit. Carbon contents of 5–10 times lower than carbon content in the charge can be achieved with low argon gas consumption per one growth process (15–20 nl/min vs 50–80 nl/min for conventional processes). The use of an additional argon gas flow with a 10 times lower flowrate than that of the main flow does not distort the pattern of main (axial) flow circumvention around single crystal surface, does not hamper the “dislocation-free growth” of crystals and does not increase the density of microdefects. This suggests that the new method does not change temperature gradients and does not produce thermal shocks that may generate thermal stresses in single crystals.

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