Deposition Mechanism of Tungsten Silicide Films by Low Pressure CVD

1990 ◽  
Vol 181 ◽  
Author(s):  
Jae H. Sone ◽  
Hyeong J. Kim
Keyword(s):  
Mass Transfer ◽  
Deposition Rate ◽  
Flow Rate ◽  
Deposition Temperature ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Deposition Mechanism ◽  
Si Substrates ◽  
Si Content

ABSTRACTWSix thin films were deposited on SiO2/Si substrates by Low Pressure Chemical Vapor Deposition (LPCVD) using WF6 and SiH4 gases. The deposition mechanism has been studied by measuring the thickness, resistivity and composition of the films by varying deposition temperature and gas flow rate at a constant total reactant gas pressure. Below 300°C, the surface chemical reaction was the rate-limiting process and the deposition rate increased exponentially with temperature having a thermal activation energy of 3.2 kcal/mol. Meanwhile, above 300°C the reaction was governed by the mass transfer step in the gas. The deposition rate in this range is insensitive to the deposition temperature but shows dependence of the flow rate of reactant gases. AES and RBS analyses were performed to determine the stoichiometry of WSix thin film. The Si content in film gradually increased as the deposition temperature increased. The resistivity of as-deposited WSix film has dependence on both deposition temperature and Si/W ratio, and exponentially increased with a moderate slope. However, temperature insensitive behavior of resistivity appeared in the mass transfer controlled region. Such resistivity changes with temperature were discussed with the Si/W ratio and the microstructure of films.

Deposition on SS 316 at Different Gas Flow Rates Using Thermal CVD

2012 ◽  
Vol 576 ◽  
pp. 594-597 ◽  
Author(s):  
Mohammad Asaduzzaman Chowdhury ◽  
Dewan Muhammad Nuruzzaman
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Deposition Rate ◽  
Flow Rate ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Gas Flow Rate ◽  
Flow Rates

A hot filament thermal chemical vapor deposition (CVD) reactor was used to deposit solid thin films on stainless steel 316 (SS 316) substrates at different flow rates of natural gas. The variation of thin film deposition rate with the variation of gas flow rate has been investigated experimentally. During experiment, the effect of gap between activation heater and substrate on the deposition rate has also been observed. Results show that deposition rate on SS 316 increases with the increase in gas flow rate. It is also observed that deposition rate increases with the decrease in gap between activation heater and substrate within the observed range. In addition, friction coefficient and wear rate of SS 316 sliding against SS 304 under different normal loads are also investigated before and after deposition. The experimental results reveal that improved friction coefficient and wear rate are obtained after deposition as compared to that of before deposition.

Nitrogen-Doping of Polycrystalline 3C-SiC Films Deposited by Low Pressure Chemical Vapor Deposition

2006 ◽  
Vol 527-529 ◽  
pp. 311-314 ◽  
Author(s):  
Xiao An Fu ◽  
Jacob Trevino ◽  
Mehran Mehregany ◽  
Christian A. Zorman
Keyword(s):  
Residual Stress ◽  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Atom Concentration ◽  
Pressure Chemical ◽  
Sic Films

This paper reports the effect of deposition temperature on the deposition rate, residual stress, and resistivity of in-situ nitrogen-doped (N-doped) polycrystalline 3C-SiC (poly-SiC) films deposited by low pressure chemical vapor deposition (LPCVD). N-doped poly-SiC films were deposited in a high-throughput, resistively-heated, horizontal LPCVD furnace capable of holding up to 150 mm-diameter substrates using SiH2Cl2 (100%) and C2H2 (5% in H2) precursors, with NH3 (5% in H2) as the doping gas. The deposition rate increased, while the residual stress decreased significantly as the deposition temperature increased from 825oC to 900°C. The resistivity of the films decreased significantly from 825°C to 850°C. Above 850°C, although the resistivity still decreased, the change was much smaller than at lower temperatures. XRD patterns indicated a polycrystalline (111) 3C-SiC texture for all films deposited in the temperature range studied. SIMS depth profiles indicated a constant nitrogen atom concentration of 2.6×1020/cm3 in the intentionally doped films deposited at 900°C. The nitrogen concentration of unintentionally doped films (i.e., when NH3 gas flow was zero) deposited at 900°C was on the order of 1017/cm3. The doped films deposited at 900°C exhibited a resistivity of 0.02 -cm and a tensile residual stress of 59 MPa, making them very suitable for use as a mechanical material supporting microelectromechanical systems (MEMS) device development.

Mechanical Properties and Morphology of Polycrystalline 3C-SiC Films Deposited on Si and SiO2 by LPCVD

2003 ◽  
Vol 795 ◽  
Author(s):  
Xiao-an Fu ◽  
Jeremy Dunning ◽  
Srihari Rajgopal ◽  
Ming Zhang ◽  
Christian A. Zorman ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Flow Rate ◽  
Chemical Vapor ◽  
Tem Analysis ◽  
Deposition Rates ◽  
Si Substrates ◽  
Compressive Stresses ◽  
Rate Versus ◽  
Slope Change ◽  
Sic Films

ABSTRACTPoly-SiC films were deposited on Si and SiO2 substrates in a high-throughput, low pressure chemical vapor deposition (LPCVD) furnace using dichlorosilane (DCS) and acetylene precursors. The deposition temperature and pressure were fixed at 900°C and 2 Torr, respectively, while the flow rate of DCS was varied between 18 and 54 sccm. Poly-SiC deposition rates on both Si and SiO2 were nearly identical to each other and increased as a function of DCS flow rate. Consistent with both substrate materials, the following observations were made. A slope change of the deposition rate versus DCS flow rate was observed around a DCS flow rate of 35 sccm. Residual stress varied with respect to the deposition rate, with tensile stresses occurring at lower deposition rates and compressive stresses at higher deposition rates. The tensile-to-compressive stress transition corresponded to the slope change of the deposition rate versus DCS flow rate. The surface morphology consisted of pyramidal grains, as observed under an SEM. TEM analysis for poly-SiC films grown on Si substrates showed that microstructural differences exist for poly-SiC films having tensile and compressive stresses.

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

Study of Factor and Interaction Effects During Programmed Rate Chemical Vapor Deposition of Aluminum

1998 ◽  
Vol 514 ◽  
Author(s):  
D. Yang ◽  
R. Jonnalagaddal ◽  
B. R. Rogers ◽  
J. T. Hillman ◽  
R. F. Foster ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Deposition Rate ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Pulse Time ◽  
Gas Flow Rate ◽  
Initial Substrate ◽  
Rate Interaction

ABSTRACTResults from a statistically designed experiment studying the effects of initial substrate temperature (A), precursor pulse time (B), diluent gas flow rate (C), and their interactions on film properties of programmed rate chemical vapor deposited aluminum are presented. Deposition rate, reflectivity, absolute and normalized roughness, and grain orientation were the response variables investigated. A two level, three factor (23) full factorial experimental design was used. Five center cell replicates were used to estimate cell standard deviations. The experiments were conducted using tri-isobutyl aluminum (TIBA) as the precursor in a lowpressure chemical vapor deposition (LPCVD) cold wall reactor. Effects were considered significant at the 95% confidence level. Initial substrate temperature (A) affected deposition rate and reflectivity. Diluent gas flow rate (C) affected deposition rate, normalized roughness and film texture. The precursor pulse time/diluent gas flow rate interaction (BC) affected film reflectivity and absolute surface roughness, while the initial substrate temperature/diluent gas flow rate interaction (AC) affected film texture.

Kinetics of Chemical Vapor Deposition of Sic Between 750 and 850°C at 1 Bar Total Pressure

1991 ◽  
Vol 250 ◽  
Author(s):  
Dieter Neuschütz ◽  
Farzin Salehomoum
Keyword(s):  
Deposition Rate ◽  
Total Pressure ◽  
Reaction Rate ◽  
Chemical Vapor ◽  
Deposition Mechanism ◽  
Reaction Orders ◽  
Si Content ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Kinetics Of

AbstractThe deposition rate from mixtures of methyltrichlorosilane (MTS), hydrogen and methane was measured thermogravimetrically using a hot wall vertical reactor and planar SiC substrates. Below 850 °C and at sufficiently high gas velocities, the rate of the phase boundary reaction could be determined. In the absence of CH4 and at H2 :MTS=55, Si was deposited together with SiC. Addition of CH4 lowered the Si content, pure SiC being deposited at CH4 :MTS above 10. The deposition rate j in the range 750 to 850 °C follows the equation with E(Si) = 160 and E(SiC) = 300 kJ/mol. Reaction mechanisms are presented to account for the observed reaction orders with respect to MTS. Between 900 and 970 °C, the reaction rate decreased with temperature indicating a change in the deposition mechanism.

Effects of Acetylene on Deposition Rate of Stainless Steels Using Thermal Chemical Vapor Deposition

2016 ◽  
Vol 23 ◽  
pp. 7-12 ◽  
Author(s):  
M. Mostafizur Rahman ◽  
Shaon Talukdar ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Rasel Khan ◽  
Abdullah A. Masum ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Gas Flow Rate ◽  
Thermal Chemical Vapor Deposition

A hot filament thermal chemical vapor deposition (CVD) reactor was used to deposit solid thin films on stainless steel 316 (SS 316) and stainless steel 201 (SS 201) substrates at different flow rates of acetylene (C2H2) gas. The variation of thin film deposition rate with the variation of gas flow rate has been investigated experimentally. During experiments are conducted under gas flow rate (1-5) lit/min gas flow rate, duration of deposition (10-60 min), pressure (0.2-1 bar), average surface roughness (0.3-1.05) µm and temperature 800 °C considered. Experimental results show that deposition rate on SS 316 and SS 201 increases with the increase in gas flow rate. The deposition rate also shows increasing trend with pressure and duration of deposition. Under the above mentioned experimental conditions deposition is found to be maximum of SS-316 compared to SS-201. In relation to roughness the maximum deposition is found at 0.5 microns but comparing the both materials -316 and-201 highest of deposition rate is obtained from SS-316.

The Effect of Gas Flow Rate on the Thin Film Deposition Rate on Carbon Steel Using Thermal CVD

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Mohammad A. Chowdhury ◽  
Dewan M. Nuruzzaman ◽  
Mohammad L. Rahaman
Keyword(s):  
Carbon Steel ◽  
Deposition Rate ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Gas Flow Rate ◽  
Film Deposition Rate

Solid thin films have been deposited on carbon steel substrates in a chemical vapor deposition (CVD) reactor where natural gas, mostly methane (CH4), was used as a precursor gas. The effect of gas flow rate on the thin film deposition rate has been investigated experimentally. The effect of gap between activation heater and substrate on the deposition rate has also been observed. To do so, a hot filament thermal chemical vapor deposition unit is used. The flow rate of natural gas varies from 0.5 to 2 l/min at normal temperature and pressure (NTP) and the gap between activation heater and substrate varies from 4 to 6.5 mm. Results show that the deposition rate on carbon steel increases with the increase of gas flow rate. It is also seen that deposition rate increases with the decrease of gap between activation heater and substrate within the observed range. These results are analyzed by dimensional analysis to correlate the deposition rate with gas flow rate, surface roughness and film thickness. In addition, friction coefficient and wear rate of carbon steel sliding against SS 304 under different normal loads are also investigated before and after deposition. The obtained results reveal that in general, the values of friction coefficient and wear rate are lower after deposition than that of before deposition.

Chemical Vapor Deposition (CVD) of ZrC Coatings from ZrCl4-C3H6-H2

2011 ◽  
Vol 189-193 ◽  
pp. 648-652 ◽  
Author(s):  
Qiao Mu Liu ◽  
Li Tong Zhang ◽  
Zhi Xin Meng ◽  
Lai Fei Cheng
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Content ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Carbon Deposition ◽  
Rough Surfaces ◽  
Chemical Vapor ◽  
Deposition Mechanism ◽  
Spherical Structure

ZrC coatings were prepared by CVD using ZrCl4, C3H6, and H2as the precursors. The mechanisms responsible for the effects of deposition temperature, H2flow rate and inlet C/Zr ratio on the ZrC coatings were studied based on the deposition mechanism of ZrC. The results indicate that the ZrC morphologies change from a loose spherical structure to a cauliflower structure, then to a glassy structure as the deposition temperature increases from 1050°C to 1150°C, then to 1250°C. The carbon content in the ZrC coatings increases with increasing the deposition temperature. Higher inlet C/Zr ratio can lead to rough surfaces and higher carbon content. Reasonable H2concentration can inhibit carbon deposition, and lead to a cauliflower structure.

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