• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.84-95
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• 2001

Titanium is widely used in dentistry for its low density, high strength, fatigue resistance, corrosion resistance, and biocompatibility. But it has a tendency of surface damage under circumstance of friction and impact for its low hardness of the surface. Coating is one of methods fir increasing surface hardness. Its effect is to improve surface physical characteristics without change of titanium. Diamond-like carbon and titanium nitride are known for its high hardness of the surface. So that this study was aimed at the wear test and the cytotoxicity test of the commercially pure titanium and Ti-6Al-4V alloy which were deposited by diamond-like carbon film or titanium nitride film to acertain improvement of the surface hardness and the biocompatibility. A disk (25mm diameter, 2mm thickness) was made of commercially pure titanium and Ti-6Al-4V alloy and these substrates were deposited by diamond-like carbon film or titanium nitride film. Diamond-like carbon film was deposited by the method of radiofrequency plasma assisted chemical vapor deposition and titanium nitride film was deposited by the method of reactive arc ion plating. Then these substrates were tested about wear characteristics by the pin-on-disk type wear tester in which ruby ball was used as a wear causer under the load of 32N, The fracture cycles were measured by rotating the substrates until their films were fractured. The wear volume was measured after 150 cycles and 3,000 cycles using surface profiler. The cytotoxicity test was peformed by the method of the MTT assay. The results were as follows : 1. In the results of the wear volume test, commercially pure titanium and titanium alloy which were coated by diamond-like carbon film or titanium nitride aim had higher resistance against wear than the substrates which were not coated by any films (P<0.05). 2. In the results of the fracture cycle test and the wear volume test, diamond-like carbon film had higher resistance against wear than titanium nitride film (P<0.05). 3. In both coatings of diamond-like carbon aim and titanium nitride film, Ti-6Al-4V alloy had higher resistance against wear than commercially pure titanium (P<0.05) 4. In the results of the cytotoxicity test, diamond-like carbon film and titanium nitride film had little cytotoxicity as like commercially pure titanium or Ti-6Al-4V alloy (P>0.05).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.247-248
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• 2006

Carbon nitride films were evaluated that they had many advantages for miniature micro-humidity-sensors using the standard CMOS technology humidity sensing properties and CV characteristics of the carbon nitride films have been investigated for fabricating one chip HUSFET(Humidity Sensitive Field Effect Transistor) humidity sensors Carbon nitride films were deposited on silicon substrate with meshed electrodes by reactive RF magnetron sputtering system. The capacitor-type humidity sensor revealed good humidity-impedance characteristics with a wide range of relative humidity changes, decreasing $254k{\Omega}$ to $16k{\Omega}$ according to increase of relative humidity between 5% ~ 95% and the films were very stable on the Si wafer. These results reveal that $CN_x$ thin films can be used for Si based or HUSFET structure one chip micro-humidity sensors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.872-875
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• 2003

Carbon nitride($CN_x$) thin films were deposited on quartz substrates using reactive RF magnetron sputtering system at uarious deposition conditions and investigated dielectric characteristics. Samples for capacitance measurements were of the MIM(Metal-Insulator-Metal) type devices. Aluminum film electrodes were prepared by a vacuum thermal evaporation method before and after the deposition of carbon nitride films. Capacitances were measured by a FLUKE PM6306 RCL Meter at room temperature. Current-voltage(I-V) characteristics and resistivity were measured by a CATS CA-EDA semiconductor test and analyzer. The carbon nitride films showed ${\alpha}-C_3N_4$ and ${\beta}-C_3N_4$ etc. peaks through Raman and FTIR. Observed surface of film and side structure using SEM(Scanning Electron Microscope), and measured thickness of film by ${\alpha}-step$. We can find that the dielectric constant was the lowest value in 50% nitrogen ratio and the resistivity was the highest value in 70% nitrogen ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.152-155
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• 2006

Carbon nitride ($CN_X$) films were prepared by reactive RF magnetron sputtering system at various deposition conditions and the C-V characteristics of MIS(metal - insulator - semiconductor) capacitors that have the structures of Al/$CN_x$/p-Si/Al and Al/$CN_x$/$Si_3N_4$/p-Si/Al were investigated. The resistivity of carbon nitride was above $2.40{\times}10^8{\Omega}{\cdot}cm$ at room temperature. The C-V plot showed a typical capacitance-voltage characteristics of semiconductor insulating layers, while it showed hysterisis due to interface charges. Amorphous carbon nitride (a-$CN_x$) films, that have relatively high resistivity and low dielectric constant could be useful as interlayer insulator materials of VLSI(very large-scale integration) and ULSI(ultra large-scale integration).

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.856-857
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• 1998

Hydrogenated amorphous carbon nitride [a-C:H(N)] films were deposited on pretreated silicon(100) substrate in activated gas phase using. RF plasma-assisted CVD. We measured the FT-IR spectrum to investigate $C{\equiv}N$ stretching mode(nitrile), C-H stretching mode, C-H bending mode, C=C stretching mode C=N(imino) mode, and the EDX to investigate the ratio of N to C(0.25). By the results of FT-IR and EDX spectrum, We confirmed that hydrogenated amorphous carbon nitride films successfully were synthesized by RF-PACVD

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.521-525
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• 2004

Crystalline carbon nitride films were attempted for an application of humidity sensors. The films were deposited on $Al_2$O$_3$substrate having intermigrated electrodes by reactive rf magnetron sputtering system. The film revealed a good humidity-resistance characteristics as well as humidity-capacitance ones in the humidity range of 10∼95 RH(%). Temperature dependence was also investigated. These results suggest that the carbon nitride film has a possibility for new humidity-sensitive material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.406-408
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• 1999

Amorphous carbon nitride thin films were prepared on pretreated silicon(100) substrate in sputtering graphite target by activated gas phase using RF reactively sputtering. We measured the FT-IR spectrum to identify C=N(nitrile)stretching mode(2200cm$\^$-1/), C-H stretching mode(2800cm$\^$-1/), C-H bending mode, C=C stretching mode C=N(imino) mode(1680cm$\^$-1/ ), and the XPS to investigate chemical structure of surface. By the results of FT-H and XPS spectrum, We confirmed that amorphous carbon nitride films with typel (C(1s): 285.9[eV], N(1s): 398.5[ev]) and type 2(C1s): 287.5[eV, N(1s): 400.2[eV]) successfully were synthesized by RF reactively sputtering

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.84-87
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• 2003

Carbon nitride ($CN_x$) films were prepared by reactive RF magnetron sputtering system with DC bias at various deposition conditions and the electrical properties were investigated. The films were characterized by fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The metal-insulator-semiconductor (MIS) capacitor which has $Al/CN_x/Si$ structure was designed and fabricated to investigate the capacitance-voltage (C-V) characteristics. Dielectric constant of carbon nitride films is very small.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.243-247
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• 1999

Carbon nitride coatings on the substrates of 0.55wt% C - 1.68wt% Mn induction-hardened rolling elements were prepared by ion beam assisted deposition. It was found through metallographic observation that the carbon nitride coatings appeared lamellar-type repeated layers parallel to the surface of substrate. Surface roughness of the coated specimens was improved in comparison with that of the substrates. Wear resistance of the coatings was evaluated using Polymet RCF-1 machine with a constant supply of lubricant followed by Weibull statistical analysis and scanning electron microscopy. the results indicated failure due to old-age wear-out of the coatings was mainly caused by numerous micropits formed on the wear track during repeated rolling contact.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.49-49
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• 1996