• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1121-1124
• /
• 2004

Carbon Nitride exhibits high electrical resistivity and thermal conductivity that are similar to the properties shown by diamond-like carbon (DLC) films. These diamond-like transport properties in Carbon Nitride come in a material consisting of $sp^2$-bonded carbon versus the $sp^3$-carbon of DLC. The diamond-like properties and nondiamond-like bonding make NDLC an attractive candidate for applications. Liquid crystal (LC) alignment capabilities with ion beam exposure on carbon nitride thin films and Electro-Optical (EO) performances of the ion-beam aligned twisted nematic liquid crystal display (TN-LCD) with oblique ion beam exposure on the Carbon Nitride thin film surface were studied. An excellent uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the Carbon Nitride thin films was observed. In addition, the good EO properties of the ion-beam-aligned TN-LCD were achieved. Finally, we achieved the residual DC property of the ion-beam- aligned TN-LCD on the Carbon Nitride thin film.

• Korean Journal of Materials Research
• /
• v.20 no.11
• /
• pp.570-574
• /
• 2010

A diamond-like carbon (DLC) film deposited on a WC disk was investigated to improve disk wear resistance for injection molding of zirconia optical ferrule. The deposition of DLC films was performed using the filtered vacuum arc ion plating (FV-AIP) system with a graphite target. The coating processing was controlled with different deposition times and the other conditions for coating, such as input power, working pressure, substrate temperature, gas flow, and bias voltage, were fixed. The coating layers of DLC were characterized using FE-SEM, AFM, and Raman spectrometry; the mechanical properties were investigated with a scratch tester and a nano-indenter. The friction coefficient of the DLC coated on the WC was obtained using a pin-on-disk, according to the ASTM G163-99. The thickness of DLC films coated for 20 min. and 60 min. was about 750 nm and 300 nm, respectively. The surface roughness of DLC films coated for 60 min. was 5.9 nm. The Raman spectrum revealed that the G peak of DLC film was composed of $sp^3$ amorphous carbon bonds. The critical load (Lc) of DLC film obtained with the scratch tester was 14.6 N. The hardness and elastic modulus of DLC measured with the nano-indenter were 36.9 GPa and 585.5 GPa, respectively. The friction coefficient of DLC coated on WC decreased from 0.2 to 0.01. The wear property of DLC coated on WC was enhanced by a factor of 20.

• Journal of Korean Ophthalmic Optics Society
• /
• v.9 no.2
• /
• pp.291-299
• /
• 2004

DLC films were deposited using the ECR-PECVD method with the fixed deposition condition, such as ECR power, methane and hydrogen gas-flow rates and deposition time, for various substrate bias voltage. We have investigated the ion bombardment effect induced by the substrate bias voltage on films during the deposition of film. The characteristic of the films were analyzed using the FTIR, Raman, and UV/Vis spectroscopy analysis shows that the amount of dehydrogenation in films was increased with the increase of substrate bias voltage and films thickness was decreased. Raman scattering analysis shows that integrated intensity ratio(ID/IG) of the D and G peak was increased as the substrate bias voltage increased and films hardness was increased. Optical transmittances of DLC film were decreased with increasing deposition time and substrate bias voltage. From these results, it can be concluded that films deposited at this experimental have the enhanced characteristics of DLC because of the ion bombardment effect on films during the deposition of film.

• Journal of the Korean Ceramic Society
• /
• v.39 no.5
• /
• pp.467-472
• /
• 2002

Long Carbon Nanotubes(CNTs) were cut by diamond lapping film followed by observation using SEM. The paste was prepared by mixing shortened CNT powder, ${\alpha}$-terpineol used as a solvent, and ethylcellulose as a binder. This paste was deposited on glass substrate by screen printing and extruded by syringe. After screen printing, several post-treatments were performed to control the alignment of CNTs perpendicular to the substrate. The deposited CNTs were scratched by sand paper or diamond lapping film. It was also treated by attachment followed by an immediate detachment using the adhesive tape. SEM observation indicates that excellent vertical alignment of CNTs could be achieved by simple post-treatments from the screen printed-CNTs paste. Similar alignment of CNTs is also observed in the as-extruded CNTs paste.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.11
• /
• pp.97-104
• /
• 1996

Because of the novel characteristics such as chemical stability, hardness, electrical resistivity and thermal conductance, diamond-like carbon (DLC) film is a suitable materials for the passivation layers. For this purpose, DLC films are synthesized under various conditions and are characterized. Adhesive stregth is excellent and increased with the increase of the hydrogen gas flow rate. The resistivity of approximately 5.3X10$^{8}{\Omega}{\cdot}cm$ is measured by automatic spreading resistance probe analysis method. The thermal conductivity of DLC films is superior to that of PSG oxide and improved by increasing the hydrogen gas flow rate. The patterning techniques of the DLC films is developed using the lift-off and RIE methods to form 5${\mu}$m line. Finally, power transistor with the DLC film as passivation layer is fabricated and analyzed. The test result shows the improsved long-term stability and higher breakdown voltage.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.6
• /
• pp.648-654
• /
• 2003

Diamond MIS(Metal-Insulator-Semiconductor) diodes and MISFETs(Metal-Insulator-Semiconductor Field Effect Transistors) were fabricated by employing various fluorides as gate insulator, and their electrical properties were closely investigated by means of C-V measurements. The A1/BaF$_2$/diamond MIS structure exhibited outstanding electrical properties. The MIS diode showed a very low surface state density of ∼10$\^$10//$\textrm{cm}^2$ eV near the valence band edge, and the observed effective mobility(${\mu}$$\_$eff/) of the MISFET was 400 $\textrm{cm}^2$/Vs, which is the highest value obtained until now in the diamond FET. From the chemiphysical point of view, the above result might be explained by the reduction of adsorbed-oxygen on the diamond surface via strong chemical reaction by the constituent Ba atom in the insulator during the film deposition(Oxygen-Gettering Effect).

• Proceedings of the KIEE Conference
• /
• 2001.11a
• /
• pp.12-15
• /
• 2001

Polycrystalline diamond films are deposited by cyclic method. modulating the $H_2$ Plasma and $CH_4+H_2$ plasma during the growth step. Diamond quality is evaluated by FWHM and $I_D/I_G$ ratio obtained from Raman spectroscopic analysis. Structural defects and impurities generated during the growth step are characterized by cathodoluminescence, and the variations between band-A(430 nm) line and nitrogen-related(578 nm) line are investigated as a function of $T_E/T_G$. Furthermore, the correlations between preferential orientation. film morphologies and CL characteristics are also investigated.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.22 no.5
• /
• pp.563-572
• /
• 1998

An experimental study of hot filament chemical vapor deposition(HFCVD) has been carried out for the fabrication of diamond thin film. Of particular interest is the measurement of deposition uniformity on large substrates. Experimental apparatus including a vacuum chamber, heating elements, etc. has been designed and manufactured. Deposition profiles for different pretreatment powders and different flow rates have been measured in conjunction with the measurement of substrate temperature distribution on a large substrate surface. As the flow rate increases, deposition rate increases, however, the crystallinity becomes worse. Higher growth rate has been found on the region closer to the center location where substrate temperature is higher. The crystallinity has been improved as gas flow rate decreases. The growth rate and morphology of deposition were identified by SEM and the existence of diamond phase was proved by Raman spectroscopy.

• The Korean Journal of Ceramics
• /
• v.4 no.1
• /
• pp.9-14
• /
• 1998

Diamond-like carbon(DLC) films were deposited on buffer-layered ZnS substrates by radio frequency plasma enhanced chemical vapor deposition(RF-PECVD) method. Ge and GeC buffer layera were used between DLC and ZnS substrates to promote the adhesion of DLC on ZnS substrates. Ge buffer layers were sputter deposited by RF magnetron sputtering and $GeC^1$ buffer layers were deposited by same method except using acetylene reactive gas. The relatinship between film properties and deposition conditions was investigated using gas pressure, RF power and dc bias voltage as PECVD parameters. The hardness of DLC films were measured by micro Vickers hardness test and the adhesion of DLC films on buffer-layered ZnS substrates were studied by Sebastian V stud pull tester. The optical properties of DLC films on butter-layered ZnS substrates were characterized by ellipsometer and FTIR spectroscopy.

• Transactions on Electrical and Electronic Materials
• /
• v.8 no.1
• /
• pp.15-20
• /
• 2007

Conditioner wear, copper polish rates, pad temperature and coefficient of friction (COF) are measured for two novel Mitsubishi Materials Corporation designs during an extended wear and polishing test. Both designs are coated with a $Teflon^{TM}$ film to reduce substrate wear and chemical attack. Using optical interferometry, changes in the coating that result in gradual changes in diamond exposure are measured. Theories of the COF, conditioning, and polishing are applied to explain the observed performance differences between the designs.