Low Temperature Diamond Growth With CF4 Addition in A Hot Filament Reactor

1994 ◽  
Vol 349 ◽  
Author(s):  
Evaldo. J. Corat ◽  
V. J. Trava-Airoldi ◽  
Nélia F. Leite ◽  
Angel F.V. Peña ◽  
Vítor Baranauskas
Keyword(s):  
Growth Rate ◽  
Raman Spectroscopy ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Low Temperatures ◽  
Diamond Growth ◽  
Gas Mixture ◽  
Hot Filament ◽  
Micro Balance

ABSTRACTIn this work we show that the addition of a small amount of CF4 to a regular CH4 -H2 gas mixture allows diamond growth at lower temperatures with reasonable growth rates. We used a hot filament assisted reactor and observed diamond growth with a substrate temperature as low as 390 ଌ. We present a comparative study for the growth dependence on substrate temperature with and without CF4 addition in the gas mixture. The growth rate is measured by post growth weighting with a micro balance. Raman spectroscopy, SEM and AFM images show the good quality of the films grown at low temperatures when CF4 is added to the feeding gas.

Effect of Argon during Diamond Deposition by Hot Filament Chemical Vapor Deposition

2016 ◽  
Vol 869 ◽  
pp. 721-726 ◽  
Author(s):  
Divani C. Barbosa ◽  
Ursula Andréia Mengui ◽  
Mauricio R. Baldan ◽  
Vladimir J. Trava-Airoldi ◽  
Evaldo José Corat
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Gas Mixture ◽  
X Ray Diffraction ◽  
Hot Filament ◽  
Argon Content

The effect of argon content upon the growth rate and the properties of diamond thin films grown with different grains sizes are explored. An argon-free and argon-rich gas mixture of methane and hydrogen is used in a hot filament chemical vapor deposition reactor. Characterization of the films is accomplished by scanning electron microscopy, Raman spectroscopy and high-resolution x-ray diffraction. An extensive comparison of the growth rate values and films morphologies obtained in this study with those found in the literature suggests that there are distinct common trends for microcrystalline and nanocrystalline diamond growth, despite a large variation in the gas mixture composition. Included is a discussion of the possible reasons for these observations.

The Selective Epitaxy of Silicon at Low Temperatures

1991 ◽  
Vol 220 ◽  
Author(s):  
Jen-Chung Lou ◽  
William G. Oldham ◽  
Harry Kawayoshi ◽  
Peiching Ling
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Low Temperatures ◽  
Surface Oxide ◽  
Ex Situ ◽  
Deposition Cycle ◽  
Local Growth ◽  
Selective Epitaxial Growth

ABSTRACTLow-temperature selective epitaxial growth (SEG) of silicon using a dichlorosilane-hydrogen mixture in an LPCVD hot-wall reactor has been discussed with respect to the wafer preparation and the deposition cycle. The surface morphology and the quality of epilayers are strongly affected by residual oxide islands at interface. A reduction of local growth rate near interfacial oxides is attributed to the dissolution of oxide at interface, and this reduction can lead to pits and textured features on the Si epitaxial surface. An ex-situ HF vapor or an HF dip with an in-situ small DCS 900°C prebake step can completely remove surface oxide prior to the deposition and achieve defect-free Si epilayers at the deposition temperatures of 850°C and 800°C. It is also found that fluorine atoms can play a major role in the removal of surface oxide.

Simulation of Substrate Temperature Distribution in Diamond Films Growth on Silicon Wafer by Hot Filament CVD

2011 ◽  
Vol 697-698 ◽  
pp. 454-457 ◽  
Author(s):  
T. Zhang ◽  
Jian Guo Zhang ◽  
Bin Shen ◽  
Fang Hong Sun
Keyword(s):  
Growth Rate ◽  
Temperature Distribution ◽  
Substrate Temperature ◽  
Diamond Films ◽  
Great Influence ◽  
Chemical Vapor ◽  
Deposition Parameters ◽  
Simulation Results ◽  
Hot Filament

The substrate temperature has great influence on the growth rate and quality of diamond films by hot filament chemical vapor deposition (HFCVD). In order to deposit polycrystalline diamond films of uniform thickness over large areas and improve the growth rate of diamond films, the substrate temperature uniformity need to be further improved. Thus three-dimensional finite volume simulation has been developed to predict substrate temperature distribution, and optimize the deposition parameters like the size and arrangement of filaments which have a profound effect on the substrate temperature. Based on the simulation results, the optimum parameters of diamond deposition are found. Subsequently, experiments of depositing diamond films on silicon (100) wafers are done when the deposition parameters are fixed at optimum values gained from the simulation results. According to the results of scanning electron microscopy (SEM) and Raman spectroscopy, the thickness and quality of diamond films are homogeneous, which validate that the simulated deposition parameters are conducive to fabricate the high quality diamond films.

scholarly journals Unusual Dependence of the Diamond Growth Rate on the Methane Concentration in the Hot Filament Chemical Vapor Deposition Process

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 426
Author(s):  
Byeong-Kwan Song ◽  
Hwan-Young Kim ◽  
Kun-Su Kim ◽  
Jeong-Woo Yang ◽  
Nong-Moon Hwang
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Methane Concentration ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Lower Growth ◽  
Filament Temperature ◽  
Diamond Phase ◽  
Hot Filament

Although the growth rate of diamond increased with increasing methane concentration at the filament temperature of 2100 °C during a hot filament chemical vapor deposition (HFCVD), it decreased with increasing methane concentration from 1% CH4 –99% H2 to 3% CH4 –97% H2 at 1900 °C. We investigated this unusual dependence of the growth rate on the methane concentration, which might give insight into the growth mechanism of a diamond. One possibility would be that the high methane concentration increases the non-diamond phase, which is then etched faster by atomic hydrogen, resulting in a decrease in the growth rate with increasing methane concentration. At 3% CH4 –97% H2, the graphite was coated on the hot filament both at 1900 °C and 2100 °C. The graphite coating on the filament decreased the number of electrons emitted from the hot filament. The electron emission at 3% CH4 –97% H2 was 13 times less than that at 1% CH4 –99% H2 at the filament temperature of 1900 °C. The lower number of electrons at 3% CH4 –97% H2 was attributed to the formation of the non-diamond phase, which etched faster than diamond, resulting in a lower growth rate.

Oxygen Effect in Diamond Deposition at Low Temperatures

1989 ◽  
Vol 162 ◽  
Author(s):  
Y. Liou ◽  
A. Inspektor ◽  
R. Weimer ◽  
D. Knight ◽  
R. Messier
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Gas Mixtures ◽  
Diamond Growth ◽  
Oxygen Effect ◽  
Gas Mixture ◽  
Diamond Thin Films ◽  
Deposited Films

ABSTRACTDiamond thin films were deposited on different substrates at low temperatures (lowest temperature∼ 300°C, estimated) in a microwave plasma enhanced chemical vapor deposition (MPCVD) system. The deposited films were amorphous carbon or diamond films depending on the different gas mixtures used. The growth rate of diamond thin films was decreased by adding oxygen to the gas mixture. The addition of oxygen to the gas mixtures was found to be important for diamond growth at low temperatures. Different concentrations of oxygen have been added into the gas mixture. Without oxygen, the deposited films were white soots and easily scratched off. Increasing the oxygen input improved the quality of the Raman peaks and increased the film transpancy. The diamond films were also characterized by scanning electron microscopy (SEM).

Apparatus for low-temperature growth of diamond-containing films

1989 ◽  
Vol 4 (5) ◽  
pp. 1243-1245 ◽  
Author(s):  
P. H. Fang ◽  
J. H. Kinnier
Keyword(s):  
Substrate Temperature ◽  
Electronic Devices ◽  
Silicon Crystal ◽  
Discharge Voltage ◽  
Diamond Growth ◽  
Diamond Like Carbon ◽  
Hydrocarbon Gases ◽  
Temperature Growth ◽  
Hot Filament ◽  
Deposited Film

In current processes of diamond growth, the substrate temperature is in general around 600–900 °C. In the case of diamond-like carbon, the substrate temperature is lower, around 25–200 °C. There are many superior properties of diamond compared with diamond-like carbon; however, the high temperature requirement to grow diamond precludes many technologically important substrate materials such as zinc sulfide for an infrared window or electronic devices on which protective diamond layers are to be coated. The present approach is a hot filament DC glow discharge of hydrocarbon gases. A graphite hot filament cathode is inserted in a discharge cylinder tube anode. The discharge voltage is in the range of 50 to 250 volts at a methane gas pressure of about 100 microns. A negative biased voltage of 100 volts is applied between the cathode and the substrate. A magnetic field of 1 kG is applied near the cathode-anode assembly. At a substrate temperature of 200–400 °C, the deposited film on silicon crystal is confirmed by an electron diffraction pattern to consist of microcrystalline diamond.

Quantitative In Situ Growth Measurements of Chlorine-Activated Homoepitaxial Diamond Cvd

1994 ◽  
Vol 349 ◽  
Author(s):  
Chenyu Pan ◽  
John L. Margrave ◽  
Robert H. Hauge
Keyword(s):  
Growth Rate ◽  
Substrate Temperature ◽  
Growth Rates ◽  
Diamond Growth ◽  
Flow Rates ◽  
Temperature Range ◽  
Quantitative Studies ◽  
Growth Activation ◽  
Lower Temperature

ABSTRACTIn situ quantitative studies of the effects of substrate temperature, methane and chlorine flow rates on homoepitaxial diamond growth rates on (110) surfaces in a chlorine-activated diamond CVD reactor have been carried out using a Fizeau interferometer. The temperature dependence of diamond growth rates was found to display three distinct growth activation energies, ranging from 9±2 kcal/mol in the substrate temperature of 750-950°C, to 3.2±0.2 kcal/mol in the temperature range of 300-650°C, followed by 1.2±0.2 kcal/mol in the temperature range of 102-250°C. Atomic hydrogen is believed to be the dominant activating species in the highest temperature range, and atomic chlorine is believed to be the dominant species in the lower temperature regions. Studies of the methane flow effect on diamond growth rates revealed a linearity, indicating that the diamond growth rate was of the first order in methane flows. Diamond growth rates were also found to increase linearly with the chlorine flow. At high chlorine flow rates, however, an accelerated diamond growth rate was observed. Discussion is given to explain the observed results.

Plasma-Enhanced Atomic Layer Deposition of GaN Thin Film at Low Temperature

2017 ◽  
Vol 727 ◽  
pp. 907-914
Author(s):  
Wen Hui Tang ◽  
Yi Jia ◽  
Bo Cheng Zhang ◽  
Chang Wei Yang ◽  
You Zhi Qu ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Low Temperature ◽  
Atomic Layer Deposition ◽  
Flow Rate ◽  
Nitrogen Sources ◽  
Atomic Layer ◽  
Gas Mixture ◽  
X Ray ◽  
Layer Deposition

Polycrystalline GaN thin films were successfully grown at low temperature (250 °C) by plasma-enhanced atomic layer deposition with NH3, N2, N2/H2 gas mixture and trimethylgallium (TMG) as precusor. The growth rate, crystal structure, surface composition and the valence state of the corresponding element of the GaN thin films using different nitrogen sources were characterized and examined systematically via the spectroscopic ellipsometry, the x-ray diffractometer, the x-ray photoel-ectron spectrometer. It is showed that all the GaN thin films using different nitrogen sources were polycrystalline structure and the preffered orientation were mainly (100). The films using N2 and N2/H2 gas mixture had a higher crystal quality than films using NH3. The GPC (growth rate per cycle) would increase with the increase of the N2 flow rate. The films using a suitable ratio of N2/H2 flow rate had not only a high GPC but a good crystal quality. The ratios of Ga/N element of the films using N2/H2 gas mixture were approximated to 1:1, it would increase with the ratio of the N2/H2 flow rate in the gas mixture, which is showing much effect of the ratios of N2/H2 flow rate on the nitrogen content of the thin films.

scholarly journals EFFECTS OF LONG-TERM RELATIVELY HIGH AND LOW TEMPERATURE USE ON GROWTH PERFORMANCE AND MEAT QUALITY OF BROILERS

2020 ◽  
pp. 12-17
Author(s):  
Yingying Qiao ◽  
Oleksandr Kyselov ◽  
Changzhong Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Growth Performance ◽  
Meat Quality ◽  
Low Temperatures ◽  
Production Performance ◽  
Control Group ◽  
Temperature Group

The experiment aims to study the effects of long-term relatively high and low temperatures on growth performance and meat quality of broiler chickens. The experiment was carried out in Yunnan Academy of Animal Science, for determine the quality of meat used the laboratories of Henan Institute of Science and Technology. A total of experiment use 240 healthy 1-day-old Avian broiler chickens were randomly divided into three groups: relatively high temperature group, low temperature group and control group. The results of the experiment confirm that at low temperatures, when the energy consumption of the animal decreases, it leads to weight loss, which we can see in the low-temperature group, the average daily weight gain in this experiment was significantly lower than in the control group (P <0.05). It was found that low-temperature stress significantly increased the mortality of broilers, at the age of 42 days in the low-temperature group, the mortality of chickens was higher than in the control group, by 71.4%. Among all evaluated groups on the content of unsaturated fatty acids SFA, PUFA, MUFA and EFA in the muscles of the breasts of broilers, the lowest content was in the lower temperature group than in the control group, by 48.3%, 46.9%, 51.5% and 43.9%. Studies have shown that influence of high-temperature above 30°C causes disturbances in poultry behavior and physiology, leading to reduced production performance. Broilers aged 35-40 days experienced 31°C high-temperature stress and found that their performance and immunity decreased. Broilers feed intake and growth rate at 35°C high temperature were reduced by 13% and 32% than at 20°C. The results showed that: ① Relatively high temperature and low temperature for a long time reduced the growth performance and mortality of broilers, and long-term relatively low temperature decreased the slaughter performance of broilers.② Relatively high and low temperatures for a long period of time reduced the levels of serine, glycine, SFA, PUFA, USFA, EFA and MUFA in broiler breast muscles negative effect on meat quality. ③ The long-term relatively low temperature has a greater adverse effect on broilers than the long-term relatively high temperature. The results provided some theoretical basis for accurately setting the broiler breeding environment temperature, improving broiler quality, maximizing broiler production performance, and increasing the economic benefits of the farm.

Homoepitaxial Growth Rate Studies on Diamond (110), (111), and (100) Surfaces in a Hot-Filament Reactor

1992 ◽  
Vol 270 ◽  
Author(s):  
C. Judith Chu ◽  
Benjamin J. Bai ◽  
Norma J. Komplin ◽  
Donald E. Patterson ◽  
Mark P. D'evelyn ◽  
...  
Keyword(s):  
Growth Rate ◽  
Substrate Temperature ◽  
Growth Rates ◽  
Radical Mechanism ◽  
Effective Activation ◽  
Methyl Radical ◽  
Kcal Mole ◽  
Hot Filament ◽  
Substrate Temperatures ◽  
Methane Concentrations

ABSTRACTGrowth rates of homoepitaxial (110), (111), and (100) diamond films were experimentally determined, for the first time, in a hot filament reactor using methane and carbon tetrachloride as the carbon source. Methane concentrations from 0.07 % to 1.03 % in H2 were studied at a substrate temperature of 970°C. Growth rates were found to be crystal-face dependent with respect to methane concentration, being linear or first order for the (100)-orientation, sublinear for (110), and sigmoidal for (111). The observed growth kinetics of (111) suggest the viability of an acetylene mechanism for (111), along with the methyl radical mechanism at methane concentrations above 0.73%. CC14 concentrations from 0.06% to 0.69% in H2 were also investigated at a substrate temperature of 970°C. Growth rate behavior was similar to that of methane for all three crystal faces.The temperature dependence of the growth rates was also crystal-orientation dependent. At substrate temperatures above 730°C, growth rates are thought to be mainly transport limited, yielding effective activation energies of 8±3, 18±2, and 12±4 kcal/mole for (100), (110), and (111) orientations, respectively. At substrate temperatures below 730°C, growth rates are thought to be surface reaction rate-limited, with an overall effective activation energy of 50±19 kcal/mole for the three crystal-orientations studied.

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