Influence of CVD Parameter on Structure of Graded SiC-C Coating

2014 ◽  
Vol 488-489 ◽  
pp. 53-56
Author(s):  
Yan Li Yu ◽  
Zhi Qiang Fu ◽  
Cheng Biao Wang
Keyword(s):  
Process Parameters ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Molar Ratio ◽  
Gas Composition ◽  
High Concentration ◽  
Carrier Gas ◽  
High Deposition Temperature ◽  
Graded Coating

The influence of chemical vapor deposition process parameters including carrier gas composition, deposition temperature, and content of reactants on the structure of graded SiC-C coating is discussed on the basis of thermodynamic calculation in this paper. The addition of enough hydrogen into carrier gas is necessary for the fabrication graded SiC-C coating. The increase of deposition temperature benefits the control of composition in graded coating but the concentration of free Si and free C becomes high at a too high deposition temperature. A high concentration of reactants is preferred while more defects are apt to exist in coatings if the concentration of reactants is too high. The optimum CVD process parameters for graded SiC-C coating are: gradually changing the molar ratio of SiCl4 and CH4 from 0 to 1 when the concentration of CH4 in hydrogen is 1-2 vol%, and the deposition temperature is 1200-1500 °C.

Effect of Chemical Vapor Deposition Process Parameters on Graded SiC-SiO2 Coating

2014 ◽  
Vol 575 ◽  
pp. 134-137
Author(s):  
Zhi Qiang Fu ◽  
Yan Li Yu ◽  
Wen Yue ◽  
Cheng Biao Wang ◽  
Chun He Tang
Keyword(s):  
Chemical Vapor Deposition ◽  
Process Parameters ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Flow Rate Ratio ◽  
Carrier Gas ◽  
Low Concentration ◽  
Thermodynamic Computation

The effect of the chemical vapor deposition (CVD) process parameters on the structure of graded SiC-SiO2coating was studied through thermodynamic computation. The addition of enough hydrogen into the carrier gas is necessary for the synthesis of the graded SiC-SiO2coating. Both high deposition temperature and low deposition temperature make the change of the composition of the coating abrupt with the change of the composition of CVD atmosphere, which is harmful to the process control of the coating. A low concentration of reactants is preferred according to the thermodynamic computation but the deposition rate is too low at a low concentration of reactants. When hydrogen is the carrier gas and the concentration of SiCl4is between 1 – 2 vol%, the graded SiC-SiO2coating with a suitably graded distribution of SiC and SiO2can be easily obtained through gradually changing the flow rate ratio of methane and water vapor at 1100 - 1200 °C.

scholarly journals Effect of PECVD SiNx deposition process parameters on electrical properties of SiNx/AlGaN/GaN structures

2021 ◽  
Vol 7 (2) ◽  
pp. 63-71
Author(s):  
Kira L. Enisherlova ◽  
Lev A. Seidman ◽  
Ella M. Temper ◽  
Yuliy A. Kontsevoy
Keyword(s):  
Process Parameters ◽  
Surface Preparation ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Nitrogen Plasma ◽  
Fixed Charge ◽  
Electrical Parameters ◽  
High Oxygen Content ◽  
Gas Channel ◽  
Process Mode

The effect of parameters of plasma enhanced chemical vapor deposition (PECVD) processes for SiNx film fabrication on the electrical parameters of dielectric/АlGaN/GaN structures has been studied. The effect of growing film composition, additional heterostructure surface treatment with nitrogen plasma before dielectric deposition and HF biasing during treatment on the parameters of the С–V and I–V curves of SiNx/АlGaN/GaN structures has been analyzed. We show that films with nitrogen to silicon concentration ratios of 60 and 40% and a high oxygen content exhibit a decrease in the positive fixed charge in the structures although the I–V curves of the structures exhibit current oscillations. Information has been reported on the effect of PECVD process mode on current oscillation parameters, e.g. period and amplitude, and length of I–V curve section in which oscillations occur. Possible explanation of these oscillations has been suggested. Additional nitrogen plasma treatment of heterostructure surface before monosilane supply to the chamber changes the magnitude and sign of fixed charge and reduces the free carrier concentration in the 2D gas channel of SiNx/АlGaN/GaN heterostructures. Experimental evidence has been provided for the effect of PECVD process parameters and surface preparation on the electrical parameters of the heterostructures grown.

The Study of Boron-Doped Nanocrystalline Silicon Film with High Conductivity

2009 ◽  
Vol 610-613 ◽  
pp. 367-371
Author(s):  
Hao Liu ◽  
Wei Jia Zhang ◽  
Shi Liang Jia ◽  
Wei Guo ◽  
Jin Wu
Keyword(s):  
Silicon Substrate ◽  
Electron Probe ◽  
Deposition Temperature ◽  
Silicon Film ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Deposition Pressure ◽  
Boron Doped ◽  
High Deposition Temperature ◽  
Electron Probe Microanalyser

Boron-doped nanocrystalline silicon film was prepared through plasma enhanced chemical vapor deposition (PECVD) on silicon substrate and glass substrate under the high deposition pressure (332.5-399Pa) and the high deposition temperature (320-360°C). The film was investigated by Raman, electron probe microanalyser, conductivity and mobility experimenting techniques. The conductivity of the boron-doped nanocrystalline silicon film was 2.97×102Ω-1cm-1. The results showed that the interface between the film and the silicon substrate might have quantum spot and small size effect, causing the increasing of conductivity.

Finite Element Simulation of Effects of Process Parameters on Deposition Rate of SiC by Chemical Vapor Deposition

2009 ◽  
Vol 610-613 ◽  
pp. 635-640 ◽  
Author(s):  
Guo Dong Sun ◽  
He Jun Li ◽  
Shou Yang Zhang ◽  
Qian Gang Fu ◽  
Wei Cao ◽  
...  
Keyword(s):  
Finite Element ◽  
Deposition Rate ◽  
Process Parameters ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Volume Ratio ◽  
Chemical Vapor ◽  
Deposition Behavior ◽  
Element Simulation ◽  
Mixed Gases

A two-dimensional mathematical model for deposition behavior of SiC coating on C/C composites in a hot-wall CVD reactor was developed. Deposition rate of SiC was calculated by finite element method and optimized by using an orthogonal L9(3)4 test. The single and coupling effects of process parameters on deposition rate of SiC, including deposition temperature, the flux of mixed gases, the volume ratio of H2 and Ar, and that of MTS and mixed gases, were calculated and discussed. The optimal deposition rate of SiC was obtained.

scholarly journals Selective Growth ofα-Al2O3Nanowires and Nanobelts

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Zhang ◽  
Ruying Li ◽  
Xiaorong Zhou ◽  
Mei Cai ◽  
Xueliang Sun
Keyword(s):  
Gas Flow ◽  
Ambient Pressure ◽  
Chemical Vapor ◽  
High Growth ◽  
Deposition Process ◽  
Selective Growth ◽  
Diameter Distribution ◽  
High Yield ◽  
Flow Rates ◽  
Carrier Gas

We report the selective growth ofα-Al2O3nanowires and nanobelts via a catalyst-free chemical vapor deposition process under ambient pressure. By controlling the flow rates of the carrier gas, high-yield production of uniform alumina nanowires with diameter distribution (100 nm–200 nm) was achieved at a high growth rate over 200 μm/hour. Alumina nanobelts with variable width were also synthesized by modulating the carrier gas purge process. Further, the effects of temperatures and carrier gas flow rates on the growth of alumina nanostructures were also investigated. Oxygen partial pressure and supersaturation level of the aluminum suboxide are thought to be important factors in the formation process of the alumina nanowires or nanobelts. The typical growth of the alumina nanowires and nanobelts can be ascribed to vapor-solid (VS) mechanism.

scholarly journals Stability Analysis of Multi Process Parameters for Metal-Organic Chemical Vapor Deposition Reaction Cavity

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 876 ◽  
Author(s):  
Jian Li ◽  
Ziling Wu ◽  
Yifeng Xu ◽  
Yanli Pei ◽  
Gang Wang
Keyword(s):  
Chemical Vapor Deposition ◽  
Process Parameters ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Reaction Chamber ◽  
Operating Conditions ◽  
Organic Chemical ◽  
Carrier Gas ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

The parameters for metal-organic chemical vapor deposition (MOCVD) processes significantly influence the properties of ZnO films, especially the flow stability of the chamber, which is caused by process parameters such as the shape of reaction chamber, the working pressure, the growth temperature, the susceptor rotational speed, the gas flow rate, and the nature of the carrier gas at inlet temperature. These parameters are the preconditions for the formation of high-quality film. Therefore, this study uses Ar as a carrier gas, diethylzinc (DEZn) as a Zn source, and H2O as an oxygen source and adopts the reaction mechanism calculated by quantum chemistry, which includes ten gas reactions and eight surface reactions. The process parameters of a specific reaction chamber model were analyzed based on the computational fluid dynamics method. This study also presents an accurate prediction of the flow regime in the reactor chamber under any operating conditions, without additional experiments, based on an analysis of a great quantity of simulation data. Such research is also significant for selecting the growth parameters relevant to production, providing a specific process growth window, narrowing the debugging scope, and providing a theoretical basis for the development of MOCVD equipment and process debugging.

Highly (004)-Oriented Texture of γ-LiAlO2 Films by Laser Chemical Vapor Deposition

2014 ◽  
Vol 616 ◽  
pp. 141-144
Author(s):  
Chen Chi ◽  
Hirokazu Katsui ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Total Pressure ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Columnar Structure ◽  
Molar Ratio ◽  
Laser Chemical Vapor Deposition ◽  
Oriented Texture

(004)-oriented γ-LiAlO2films were prepared on poly-crystalline AlN substrates by laser chemical vapor deposition at deposition temperature (Tdep) of 1100–1250 K, molar ratio of Li/Al (RLi/Al) of 1.0–10 and low total pressure (Ptot) of 100–200 Pa. The (004)-oriented γ-LiAlO2films consisted of pyramidal grains with a columnar structure. The deposition rate of (004)-oriented γ-LiAlO2films reached to 65–72 μm h-1.

Design and Deposition of Infrared Antireflection Protection Film on Magnesium Fluoride Substrate for 3~5 μm

2014 ◽  
Vol 609-610 ◽  
pp. 94-99
Author(s):  
Lin Li ◽  
Da Xing Wang ◽  
Xiu Hua Fu ◽  
Dong Mei Liu ◽  
Yang Kou
Keyword(s):  
Flow Rate ◽  
Deposition Temperature ◽  
Gas Flow ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Magnesium Fluoride ◽  
Infrared Band ◽  
Key Words Magnesium ◽  
Protection Coating

The infrared antireflection protection film is designed and deposited on magnesium fluoride substrate for 3~5 μm. The multilayer antireflection film is designed and prepared by ion beam assisted electron-beam deposition. After repeated experiments, the absorption peak of SiO2 is found at 3000nm,using MgF2 and SiO2 as the low-index materials to reduce the absorption. The coating structure is Sub|1.46H1.37L2.19H1.45L2.49M|Air. DLC (diamond-like carbon) protection coating is deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). Through contrast tests, the best deposition process is obtained (the butane flow rate is 5sccm/s, deposition temperature is 80°C) by setting deposition time as invariant, the reaction gas flow rate and deposition temperature as variables. Meanwhile the problem of associativity between antireflection film and DLC protection coating is solved by adding a Si transition layer. The result shows that the average transmittance of this film in 3~5μm is 95.5%, and this film can withstands harsh environment tests. Key words: Magnesium fluoride substrate; Antireflection protection film; 3~5 μm infrared band Document Code: A Article ID: DIO

Growth and Physical Properties of MOCVD-Deposited Hafnium Oxide Films and Their Properties on Silicon

2002 ◽  
Vol 745 ◽  
Author(s):  
S. Van Elshocht ◽  
M. Caymax ◽  
S. De Gendt ◽  
T. Conard ◽  
J. Pétry ◽  
...  
Keyword(s):  
Physical Properties ◽  
Hafnium Oxide ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Oxide Thickness ◽  
State Density ◽  
Organic Chemical ◽  
Organic Contamination ◽  
Metal Organic

ABSTRACTThis paper discusses metal organic chemical vapor deposited (MOCVD) HfO2 layers using tetrakis(diethylamido)hafnium (TDEAH) as precursor. We have studied the influence of the starting surface and deposition temperature on the growth kinetics and physical properties of the HfO2 layers. Important characteristics such as crystalline state, density, and organic contamination in the layers were found to be dependent on these parameters.Typical for this deposition process is the formation of an interfacial layer underneath the high-k layer. Its composition and thickness, affecting scaling of the equivalent oxide thickness, are shown to be closely related to the HfO2 process parameters mentioned above.Finally, we will show electrical results for HfO2/polySi gate stacks indicating the effect for deposition temperature.

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