• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.212-216
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• 2007

Although DLC coatings have good tribological properties, these are dependent on the deposition method, property of contact surface, and test condition. Si-DLC/DLC coatings with various Si content were deposited on Si substrates and tested using a reciprocating friction tester against steel balls. The results revealed that the tribological behavior of Si-DLC/DLC coatings was dependent on the Si content. The formation of transfer film and wear particles on the contact surface was greatly influenced by the Si content in DLC coatings. In particular, silicon oxide transfer film formed by tribochemical reaction contributed to reduce wear and friction.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.159-160
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• 2002

To investigate the humidity effect on tribological behaviors of Si-DLC/DLC multi-layers, the samples were prepared using a system consisted of an ion-gun for deposition DLC films and a balanced magnetron sputter for introducing silicon atoms to Si-DLC films. The Si-DLC/DLC multi-layers were composed of pure DLC films and Si-incorporated DLC films alternatively and had different bilayer numbers. Hardness and residual stress were drastically decreased through the formation of Si-DLC/DLC multi-layers compared to those of the pure and Si-incorporated DLC films. Wear results obtained under the various humidity conditions (<10%, $40{\sim}50%$, and >85%) showed that the pure DLC film was largely depended on the humidity while the Si-DLC and the Si-DLC/DLC multi-layers were little affected by the environmental humidity. Although friction coefficients of all samples were increased with the relative humidity, the multi-layer films showed relatively lower friction coefficients that those of the single films.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.169.2-169.2
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• 2013

본 연구에서는 gas를 이용한 PECVD 공법중 이온화 에너지가 높고 대면적 코팅이 용이한 Hybrid 코팅 장비에서 Linear Ion-Gun 이용하여 탄화수소 계열의 gas인 $C_2H_2$ 와 Si을 함유한 TMS (tetramethylsilane, $Si(CH_3)_4)$ gas를 이용하여 저마찰, 고경도 특성을 갖는 Si-DLC 코팅에 대한 연구를 수행하였다. Si-DLC 코팅에 앞서 전처리 공정으로 Linear Ion-Gun에 Ar gas를 주입하고 고전압의 DC 전원을 인가하여 제품 표면의 건식세정 및 표면 활성화를 진행 후, $C_2H_2$ 와 TMS gas를 Linear Ion-Gun에 주입하여 Si-DLC 코팅 공정을 진행하였다. Si-DLC 코팅시 $C_2H_2$ gas 주입량을 고정하고 TMS 가스 유량을 5~20sccm으로 조절하여 Si 함유량에 따른 Si-DLC 코팅막의 특성을 분석하였다. 이렇게 코팅된 Si-DLC의 박막 특성 분석으로 마찰계수 측정을 위해 ball-on-disk 타입의 tribometer를 사용하였으며, 박막 경도 측정은 Nano-indenter를 이용하여 분석을 진행하였다. 그 결과 Si을 포함하지 않는 DLC의 경우 마찰계수가 ~0.2를 가지는 반면, Si-DLC의 경우 Si 함유량이 약 1.5at%일 때, 마찰계수 ~0.04 저마찰의 우수한 특성을 지니며, 박막의 경도는 22[Gpa]로 고경도의 Si-DLC 코팅을 확인할 수 있었다.

• KSTLE International Journal
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• v.10 no.1_2
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• pp.1-5
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• 2009

This paper reports an investigation on nanotribological properties of silicon nanochannels coated by a diamond-like carbon (DLC) film. The nanochannels were fabricated on Si (100) wafers by using photolithography and reactive ion etching (RIE) techniques. The channeled surfaces (Si channels) were then further modified by coating thin DLC film. Water contact angle of the modified and unmodified Si surfaces was examined by an anglemeter using the sessile-drop method. Nanotribological properties, namely friction and adhesion forces, of the Si channels coated with DLC (DLC-coated Si channels) were investigated in comparison with those of the flat Si, DLC-coated flat Si (flat DLC), and Si channels, using an atomic force microscope (AFM). Results showed that the DLC-coated Si channels greatly increased hydrophobicity of silicon surfaces. The DLC coating and Si channels themselves individually reduced adhesion and friction forces of the flat Si. Further, the DLC-coated Si channels exhibited the lowest values of these forces, owing to the combined effect of reduced contact area through the channeling and low surface energy of the DLC. This combined modification could prove a promising method for tribological applications at small scales.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.369.2-369.2
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• 2014

Diamond-like Carbon(DLC) films doping Si were deposited by linear ion source(LIS)-physical vapor deposition method on Si wafer. We have studied the effects of Si content on friction and wear properties of DLC films and the characteristics of the films were investigated using Nano-indentation, Micro raman spectroscopy, Field Emission-Scanning Electron Microscope (FM-SEM) and X-ray Photoelectron Spectroscopy (XPS). The films has been various low-friction and low-stress by varying the flow rates of silane gas. Under the about 2% of Si doping is very suitable for improving the adhesion of films and reducing internal stress while maintaining the surfaces hardness of DLC films. Linear ion source (LIS)를 사용하여 Si wafer위에 Si 이온이 첨가된 DLC 박막을 증착하였다. 참가된Si 이온의 양에 따라 DLC 박막에 미치는 영향을 분석하기 위하여 마찰 계수 및 경도를 비교하였고, Micro raman spectroscopy, Field Emission-Scanning Electron Microscope (FM-SEM) and X-ray Photoelectron Spectroscopy (XPS)를 통하여 표면 상태를 분석하였다. 천체 주입된 가스량의 약 2%까지 Si 이온 주입이 늘어날수록 DLC 박막의 마찰계수는 낮아졌고, 경도는 Si 이온이 주입되지 않았을 경우와 비슷한 값(약 20~23 GPa)을 가졌다. 2% 이상의 주입량에서는 마찰계수는 주입량이 늘어날수록 높아졌으며 경도는 떨어지는 경향을 보였다. 이는 Si이온이 2%이하로 첨가되었을 경우, DLC 박막의 생성시 탄소 이온들의 결합 Stress를 줄여 마찰계수가 줄어든다고 볼 수 있으며, 그 양이 2%이상이 되면 오히려 불순물로 작용하여 DLC 박막의 Stress는 급격히 증가하고 마찰계수도 높아짐을 알 수 있다.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.3
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• pp.27-29
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• 2000

For the DLC-coaled Si-tip FEA, the modified lift off-process, by which DLC coated on both gate electrode surface and gate insulator in the gate aperture could be removed, was proposed. In the process, the Al sacrificial layer was deposited on a tilted and rotated substrate by an e-beam evaporation, and DLC film was coated on the substrate by PA-CVD method. Afterward the DLC was perfectly removed except the DLC films coated on emitter tips by etch-out of Al sacrificial layer. Current-voltage curves and current fluctuation of the DLC-coated Si-tip FEA showed that the proposed lift-off process played an important role in decreasing gate leakage current and stabilizing omission current.

• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.59-65
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• 1998

Multi-layer diamond-like carbon (DLC) films were deposited by 13.56 MHz r.f. PACVD method. Multi-layer DLC film was composed of 2.5 $mu extrm{m}$ thick pure DLC filml and 0.2$\mu\textrm{m}$ thick Si incorporated DLC (Si-DLC) film as a surface layer. Tribological behaviors of the multi-layer DLC film were investigated with a ball-on-disk type tribometer in ambient atmosphere using AISI 52100 steel ball. Low friction coefficient (<0.1) period increased with increasing the Si content in the surface Si-DLC film. The wear rate after 44,000 cycles and 158,400 cycles were the $2.5\times10^{-8}\sim1.8\times10^{-7}\textrm{mm}^3$/rev. and $7.1\times10^{-9}\sim1.8\times10^{-8}\textrm{mm}^3$/rev.,respectively. The wear rate of the multi-layer DLC film after 158,400 cycles was about 2 times smaller than that of pure DLC films of 2.7 $\mu\textrm{m}$ thickness. This high wear resistance and low friction coefficient was caused by the formation of Si oxide layer on the wear scar surface, as confirmed by the debris composition analysis. It was further shown that this si oxide debris layer on the wear scar surface is formed again even after removing the debris of the steel ball, which maintain the low friction coefficient between multi-layer DLC films and steel ball.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.37-37
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• 2008

고온에서 안정적인 DLC막을 성막하기 위해 PECVD공정에서 실리콘을 첨가하여 제조하였다. 기존의 실리콘첨가 DLC막과는 다르게 고온에서 생성됨으로 마이크로 클러스터 형태의 DLC구조로서 disordered 영역이 넓게 존재하고 있어 I(D)/I(G)비에서의 변화가 있는 것이 관찰되었다. 실리콘 양이 증가할수록 값이 낮아지는 것이 관찰되는데 이는 실리콘량이 증가하면서 수소의 위치에 실리콘이 결합하면서 sp3 단일구조형태의 코팅 막을 만드는 것이 관찰된다. 고온 어닐링효과로 내부구조에서 다량의 sp2구조가 관찰되는 것으로서 DLC막이 어느 정도 흑연화되지만, 실리콘이 SiC에서 SiOx로 $SiO_2$와 SiOH막으로 바뀌는 면서 마찰계수가 낮은 DLC막을 유지할 것으로 기대되며, XPS와 FT-IR분석에 의해 이러한 상들의 존재를 관찰할 수 있었다. 특히 공정상 TMS이 증가하면 첨가된 Si에 의해 형성되는 막이 초기부터 OH기를 다량 포함하고 있는 것을 알 수 있었고, 온도 상승에 의해서 실리콘표층에 더욱 많은 SiOx계열의 물질이 생성되는 것이 명확하게 발견되었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.240-240
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• 2012

Linear ion source (LIS)를 사용하여 Si wafer 위에 Si 이온이 첨가된 DLC 박막을 증착하였다. 참가된 Si 이온의 양에 따라 DLC 박막에 미치는 영향을 분석하기 위하여 마찰 계수 및 경도를 비교하였고, Micro raman spectroscopy, Field Emission-Scanning Electron Microscope(FM-SEM) and X-ray Photoelectron Spectroscopy (XPS)를 통하여 표면 상태를 분석하였다. 천체 주입된 가스량의 약 2%까지 Si 이온 주입이 늘어날수록 DLC 박막의 마찰계수는 낮아졌고, 경도는 Si 이온이 주입되지 않았을 경우와 비슷한 값(약 20~23GPa)을 가졌다. 2% 이상의 주입량에서는 마찰계수는 주입량이 늘어날수록 높아졌으며 경도는 떨어지는 경향을 보였다. 이는 Si 이온이 2% 이하로 첨가되었을 경우, DLC 박막의 생성시 탄소 이온들의 결합 Stress를 줄여 마찰계수가 줄어든다고 볼 수 있으며, 그 양이 2% 이상이 되면 오히려 불순물로 작용하여 DLC 박막의 Stress는 급격히 증가하고 마찰계수도 높아짐을 알 수 있다.

• Journal of the Korean institute of surface engineering
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• v.43 no.3
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• pp.127-131
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• 2010

Adhesion of DLC film is very significant property that exhibits wear resistance, chemical inertness and high hardness when being deposited to metal substrate. This study was considered that change adhesion of DLC film produced by Plasma Enhanced Chemical Vapor Deposition can be presented through inserting interlayer (Cr, Si-C:H). The thickness of interlayer was result of changing adhesion and residual stress. It was showed that the maximum 12 N of adhesion is on DLC film of Cr interlayer, and that a tendency is to be increased residual stress depend on the thickness. DLC film of Si-C:H interlayer represented 16 N of adhesion at $1{\mu}m$, whereas adhesion is decreased when the thickness is increased. For the interlayer at multi-layer, it was the best that adhesion of Cr/Si-C:H/DLC film was 33 N. Si-C:H interlayer at DLC film controled adhesion of the whole film. It was relaxed the internal stress of DLC film produced by inserting Cr, Si-C:H interlayer.