• Journal of the Korean Vacuum Society
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• v.11 no.4
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• pp.256-260
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• 2002

Carbon nanotubes on metal(SUS304) substrates were synthesized by using micro-wave plasma-enhanced chemical vapor deposition at $650^{\circ}C$ with gas mixture CH$_4$(11%) and H$_2$(89%). Their structure was investigated by scanning electron microscopy and transmission electron microscopy. Raman spectroscopy was also used to justify the structure and crystallinity of graphite sheets. High-resolution transmission electron microscopy images clearly showed carbon nanotubes to be multwalled. The measured turn-on field and current density obtained from I-V measurement were 4.4 V/$\mu \textrm{m}$ and $8.4\times10^1\mu\textrm{A}/\textrm{cm}^2$, respectively.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.7
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• pp.387-394
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• 2004

Diamond films were deposited on the cemented tungsten carbide WC-Co cutting insert substrates by using both microwave plasma chemical vapor deposition(MWPCVD) and radio frequency plasma chemical vapor deposition (RFPCVD) from $CH_4$$-H_2$$-O_2$ gas mixture. Scanning electron microscopy and X-ray diffraction techniques were used to investigate the microstructure and phase analysis of the materials and Raman spectrometry was used to characterize the quality of the diamond coating. Diamond films deposited using MWPCVD from $CH_4$$-H_2$$-O_2$ gas mixture show a dense, uniform, well faceted and polycrystalline morphology. The compressive stress in the diamond film was estimated to be (1.0∼3.6)$\pm$0.9 GPa. Diamond films which were deposited on the WC-Co cutting insert substrates by RFPCVD from $CH_4$$-H_2$$-O_2$ gas mixture show relatively good adhesion, very uniform, dense and polycrystalline morphology.

• Journal of the Korean Ceramic Society
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• v.27 no.4
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• pp.513-520
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• 1990

Diamond film was deposited on Si wafer substrate from a gas mixture of methane, hydrogen and oxygen by microwave plasma-assisted chemical vapor deposition. The effects of the pre-treatments of the substrate and of the oxygen addition on the diamond film synthesis are described. In order to obtain diamond film, the substrate was pre-treated with 3 kinds of methods. When the substrate was ultrasonically vibrated within the ethyl alcohol dispersed with 25${\mu}{\textrm}{m}$ diamond powder, the denset diamond film was deposited. Addition of oxygen in the gas mixture of methane and hydrogen improved the crystallinity of the deposited diamond film and also increased the deposition rate of the diamond film more than two times.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.373-376
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• 1997

Diamond thin films were deposited on P-type(100) Si wafers using MPECVD. Prior to deposition, mechanical scretching was done to improve density of nucleation sites with diamond paste of 0.25${\mu}{\textrm}{m}$ size. Diamond films were deposited under the following conditions : methane concentration of 0.5~5%, oxygen concentration of 0~70%, process pressure of 70Torr, process temperature of 900~95$0^{\circ}C$, and deposition time 5hrs. The changes of the morphology and the growth rates of the deposits with the experimental conditions are expriend by Scanning Electron Microscopy. Raman Spectroscopy and X-ray Diffraction method.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.396-403
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• 1990

We describe how to design and construct a LPCVD (Low Pressure Chemical Vapor Deposition) apparatus which can be applicable to the study of reaction mechanism in general CVD experiments. With this apparatus we have attempted to make diamond like carbon films on the p-type (111) Si wafer from (H$_2$ ＋ CH$_4$) gas mixtures. Two different methods have been tried to get products. (1)The experiment was carried out in the reactor with two different inlet gas tubes. One coated with phosphoric acid was used for supplying microwave discharged hydrogen gas stream, and methane has been passed through the other tube without the microwave discharge. In this method we got only amorphous carbon cluster products. (2) The gas mixture (H$_2$ ＋ CH$_4$) has been passed through the discharge tube with the Si wafer located in and/or near the microwave plasma. In this case diamond-like carbon products could be obtained.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.231-234
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• 2000

Vertically aligned carbon nanotubes were synthesized on Ni-coated Si substrates using microwave plasma-enhanced chemical vapor deposition. The grain size of Ni thin films was varied with the RF power density during the RF magnetron sputtering process. It was found that the diameter, growth rate, and density of carbon nanotubes could be controlled systematically by the grain size of Ni thin films. With decreasing the grain size of Ni thin films, the diameter of the nanotubes decreased, whereas the growth rate and density increased. High-resolution transmission electron microscope images clearly demonstrated synthesized nanotubes to be multiwalled. The number of graphitized wall decreased with decreasing the diameter. Field emission properties will be further presented.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.5
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• pp.239-244
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• 2021

Following Silicon Carbide, single crystal diamond continues to attract attention as a next-generation semiconductor substrate material. In addition to excellent physical properties, large area and productivity are very important for semiconductor substrate materials. Research on the increase in area and productivity of single crystal diamonds has been carried out using various devices such as HPHT (High Pressure High Temperature) and MPECVD (Microwave Plasma Enhanced Chemical Vapor Deposition). We hit the limits of growth rate and internal defects. However, HFCVD (Hot Filament Chemical Vapor Deposition) can be replaced due to the previous problem. In this study, HFCVD confirmed the distance between the substrate and the filament, the accompanying growth rate, the surface shape, and the Raman shift of the substrate after vapor deposition according to the vapor deposition temperature change. As a result, it was confirmed that the difference in the growth rate of the single crystal substrate due to the change in the vapor deposition temperature was gained up to 5 times, and that as the vapor deposition temperature increased, a large amount of polycrystalline diamond tended to be generated on the surface.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.352-359
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• 2017

The growth of nanocrystalline diamond films on a p-type poly silicon substrate was studied using microwave plasma chemical vapor deposition method. A 6 mm thick poly silicon plate was mirror polished and scratched in an ultrasonic bath containing slurries made of 30 cc ethanol and 1 gram of diamond powders having different sizes between 5 and 200 nm. Upon diamond deposition, the specimen scratched in a slurry with the smallest size of diamond powder exhibited the highest diamond particle density and, in turn, fastest diamond film growth rate. Diamond deposition was carried out applying different DC bias voltages (0, -50, -100, -150, -200 V) to the substrate. In the early stage of diamond deposition up to 2 h, the effect of voltage bias was not prominent probably because the diamond nucleation was retarded by ion bombardment onto the substrate. After 4 h of deposition, the film growth rate increased with the modest bias of -100 V and -150 V. With a bigger bias condition(-200 V), the growth rate decreased possibly due to the excessive ion bombardment on the substrate. The film grown under -150V bias exhibited the lowest contact angle and the highest surface roughness, which implied the most hydrophilic surface among the prepared samples. The film growth rate increased with the apparent activation energy of 21.04 kJ/mol as the deposition temperature increased in the range of $300{\sim}600^{\circ}C$.

• Journal of the Korean Vacuum Society
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• v.1 no.2
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• pp.277-285
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• 1992

플라즈마 화학기상증착법과 저압 화학기상증착법을 사용하여 실리콘 기판 위에 텅 스텐 박막을 증착하였다. 반응기체로 WF6를 사용하였으며 환원기체로는 SiH4를 사용하였다. 플라즈마 증착법에 의한 텅스텐 박막의 성장은 환원기체의 유무에 상관없이 주로 기상 반응 에 의한 텅스텐 덩어리들의 증착에 의하여 이루어졌으며 비교적 균일도가 낮은 박막표면을 이루었다. 저압 화학증착법의 경우 환원기체를 사용하지 않았을 때에는 실리콘 기판에 의한 제한된 환원반응에 의해 텅스텐이 증착되었으나, 환원기체를 사용했을 때에는 초기의 실리 콘 기판에 의한 환원반응과 이어 일어나는 SiH4 기체와의 불균일계 환원반응의 두 단계반응 에 의하여 텅스텐 박막 증착이 이루어졌다. 저압 화학증착법의 경우 텅스텐 박막의 특성은 플라즈마 증착법에서 보다 우수하였으며 박막 성장은 island by island 양식을 따르는 것으 로 추정되었다. 박막은 $\alpha$-W의 체심입방 구조로 이루어졌으며 박막이 성장함에 따라 단결정 구조가 증가하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.289-292
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• 1998

The methastable state diamond films have been deposited on Si substrates using MWPCVD. Effects of each experimental parameters of MWPCVD including CH$_4$ concentrations, Oxygen additions, Operating pressure, deposition time, etc. on the growth rate and crystallinity were investigated. The best crystallinity of the finn at 3% methane concentration addition of oxygen to the CH$_4$-$H_2O$ mixture gave an improved film crystallinity at 50% oxygen concentration. Upon increasing the operating pressure and time, the growth rate and crystallinity were increased simultaneously.