• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.398-401
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• 1999

We prepared diamond thin films on WC-Co substrate in a mixtured $H_2-CH_4-O_2$, gas, using 13.%MHz RF PACVD. Scanning electron microscopy, X-ray diffraction and Rarnan spectroscopy were used to analyze the characteristics of thin film, and tribometer of ball-on-disk type were used to test the wear resistance between thin film and substrate. The good diamond quality and wear resistance was appeared with cemented tungsten carbide substrate treated with oxygen plasma.

• Journal of the Korean Vacuum Society
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• v.2 no.3
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• pp.346-354
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• 1993

The diamond particles and films were deposited on Si and qurtz substrate for $CH_4-H_2$ mixed gas by using RF plasma CVD. The temperature of substrate and the thinkness of films deposited on Si substrate were uniformly kept up by inserting metal plate between substrate and substrate holder. On increasing the reaction pressure in the same discharge power, the morphologies of films were changed from well-defind films to micro-crystal or ball-like. When diamond films were deposited on Si substrate from $CH_4-H_2$ mixed gas, we obtained well-defined diamond films at lower concentration than 0.5 vol% of $CH_4/H_2$. The deposited diamond films were indentified by SEM, XRD and Raman spectroscopy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.5
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• pp.371-377
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• 1998

The plasma chemical vapor deposition is one of the most utilized techniques for the diamond growth. As the applications of diamond thin films prepared by plasma chemical vapor deposition(CVD) techniques become more demanding, improved fine-tuning and control of the process are required. The important parameters in diamond film deposition include the substrate temperature, $CO/H_2$gas flow ratio, total gas pressure, and gas excitation power. With the spectroscopic ellipsometry, the substrate temperature as well as the various parameters of the film can be determined without the physical contact and the destructiveness under the extreme environment associated with the diamond film deposition. Through this paper, the important parameters during the diamond film growth using $CO+H_2$are determined and it is shown that $sp^2$ C in the diamond film is greatly reduced.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.1
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• pp.16-20
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• 2021

In this study, we tried finding new materials to improve the stain resistance properties of polymer insulating materials. Using the filtered vacuum arc source (FVAS) with a graphite target source, DLC thin films were deposited on silicon and polymer insulator substrates depending on their thickness to confirm the surface properties, physical properties, and structural properties of the thin films. Subsequently, the possibility of using a DLC thin film as a protective coating material for polymer insulators was confirmed. DLC thin films manufactured in accordance with the thickness of various thin films exhibited a very smooth and uniform surface. As the thin film thickness increased, the surface roughness value decreased and the contact angle value increased. In addition, the elastic modulus and hardness of the DLC thin film slightly increased, and the maximum values of elastic modulus and hardness were 214.5 GPa and 19.8 GPa, respectively. In addition, the DLC thin film showed a very low leakage current value, thereby exhibiting electrical insulation properties.

• Journal of the Korean Ceramic Society
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• v.28 no.10
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• pp.777-784
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• 1991

Diamond films have been growth by the hot-filament chemical vapor deposition (HFCVD) using CH4 and H2 gaseous mixture on the Si substrate. The experimental results indicated that the deposits were pure diamond and contained no amount of non-diamond phases such as amorphous carbon or graphite. The diamond films were deposited well at the conditions: the filament temperature of 210$0^{\circ}C$, the substrate temperature of 77$0^{\circ}C$, the CH4 concentration of 1.76%, the reactor pressure of 30 torr, and the deposition time of 7 hr. At this growth condition, the maximum deposition rate was 2 ${\mu}{\textrm}{m}$/hr. X-ray diffraction patterns and texture coefficient results showed that preferred orientation of the diamond films was {111} orientation under all experimental conditions.

• Journal of the Korean institute of surface engineering
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• v.35 no.2
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• pp.122-128
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• 2002

This study was conducted to synthesize the diamond like carbon films by plasma enhanced chemical vapor deposition (PECVD). The effects of gas composition on growth and mechanical properties of the films were investigated. A little amount of hydrogen or oxygen were added to base gas mixture of methane and argon. Methane dissociation and diamond like carbon nucleation were enhanced by installing negatively bias grid near substrate. The deposited films were indentified as hard diamond like carbon films by micro-Raman spectroscopy. The surface and fractured cross section of the films which were observed by scanning electron microscopy showed that film growth is very slow as about 0.3$\mu\textrm{m}$/hour, and relatively uniform with hydrogen addition. Vickers hardness of tungsten carbide (WC) cutting tool increased from about 1000 to 1600~1800 by deposition of DLC film, that of commercial TiN coated tool was about 1270. In cutting test of aluminum 6061 alloy, DLC coated cutting tool showed 1/3 or lower crater and flank wear than TiN coated or non-coated WC cutting tools.

• Korean Journal of Materials Research
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• v.31 no.12
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• pp.665-671
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• 2021

A 1.8 ㎛ thick polycrystalline diamond (PCD) thin film layer is prepared on a Si(100) substrate using hot-filament chemical vapor deposition. Thereafter, its thermal conductivity is measured using the conventional laser flash analysis (LFA) method, a LaserPIT-M2 instrument, and the newly proposed light source thermal analysis (LSTA) method. The LSTA method measures the thermal conductivity of the prepared PCD thin film layer using an ultraviolet (UV) lamp with a wavelength of 395 nm as the heat source and a thermocouple installed at a specific distance. In addition, the microstructure and quality of the prepared PCD thin films are evaluated using an optical microscope, a field emission scanning electron microscope, and a micro-Raman spectroscope. The LFA, LaserPIT-M2, and LSTA determine the thermal conductivities of the PCD thin films, which are 1.7, 1430, and 213.43 W/(m·K), respectively, indicating that the LFA method and LaserPIT-M2 are prone to errors. Considering the grain size of PCD, we conclude that the LSTA method is the most reliable one for determining the thermal conductivity of the fabricated PCD thin film layers. Therefore, the proposed LSTA method presents significant potential for the accurate and reliable measurement of the thermal conductivity of PCD thin films.

• Journal of the Korean institute of surface engineering
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• v.31 no.3
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• pp.165-170
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• 1998

Deposition of diamond on silicon substrates has been performed by RF HPCVD (Helicon Plasma Chemical Vapor Deposition) from methane-hydrogen gas mixture. Growth properties and deposition condition conditions have been studies as functions of substrate temperature ($750^{\circ}C$~$850^{\circ}C$). Si p-type (100) wafers were used as a substrate. The chharecterizations of the gaind thin films by SEM, AFM and Raman seattring are diamond crystallites which include disordered graphit.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.11
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• pp.973-976
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• 2008

In addition to its similarity to genuine diamond film, diamond-like carbon (DLC) film has many advantages, including its wide band gap and variable refractive index. In this study, DLC films were prepared by the RF PECVD (Plasma Enhanced Chemical Vapor Deposition) method on silicon substrates using methane ($CH_4$) and hydrogen ($H_2$) gas. We examined the effects of the RF power on the electrical properties of the DLC films. The films were deposited at several RF powers ranging from 50 to 175 W in steps of 25 W. The leakage current of DLC films increased at higher deposition RF power. And the resistivities of DLC films grown at 50 W and 175 W were $5\times10^{11}$ ${\Omega}cm$ and $2.68\times10^{10}$ ${\Omega}cm$, respectively.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.786-788
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• 1998

Synthetic diamond films were deposited on pretreated silicon substrate in activated gas phase using RF plasma-assisted CVD. We investigated the influence of $O_2$ gas on facets of diamond crystal. In $H_2-CH_4-O_2$ gas mixture, the increase of oxygen concentration lead to well-faceted diamond particles and increasing crystallinity of diamond films. The deposited diamond films were analyzed by SEM, XRD, Raman spectroscopy.