• 한국전기전자재료학회논문지
• /
• 제17권7호
• /
• pp.760-763
• /
• 2004

We studied the nematic liquid crystaL(NLC) aligning capabilities using the new alignment material of a nitrogenated diamond-like carbon(NDLC) thin film. The NDLC thin film exhibits high electrical resistivity and thermal conductivity that are similar to the properties shown by diamond-like carbon (DLC) thin films. The diamond-like properties and nondiamond-like bonding make NDLC an attractive candidate for applications. A high pretilt angle of about 9.9$^{\circ}$ by ion beam(IB) exposure on the NDLC thin film surface was measured. A good LC alignment is achieved by the IB alignment method on the NDLC thin films surface at annealing temperature of 200 $^{\circ}C$. The alignment defect of the NLC was observed above annealing temperature of 250 $^{\circ}C$. Consequently, the high pretilt angle and the good LC alignment by the IB alignment method on the NDLC thin film surface can be achieved.

• 한국진공학회지
• /
• 제12권1호
• /
• pp.25-34
• /
• 2003

탄소 원자 간의 interaction potential로서 Tersoff에 의해 제안된 반 경험적인 potential을 이용하여 고경질 탄소박막의 합성 거동을 전산 모사하였다. 고에너지의 탄소익사를 diamond (100) 표면에 충돌시켜 고밀도의 비정질 탄소박막을 만들 수 있었으며, 전산모사에 의해 합성된 탄소 박막의 물성과 Shin 등이 발표한 filtered cathodic arc 공정에 의해 합성된 탄소의 물성을 비교하였다. ta-C 합성 실험에서 관찰된 바와 같이 최적의 에너지 영역에서 다이아몬드에 가장 유사한 물성의 필름이 합성되었으며, 이때의 입사원자 에너지인 50 eV 는 실험적으로 최적의 필름이 얻어지는 조건에서의 탄소이온 에너지와 유사하였다. 전산모사에 의해 합성된 박막은 비정질이었으며, 다이아몬드 lattice에 해당하는 short range order를 가지긴 있었다. 그러나, 최적의 에너지 조건에서는 2.1 $\AA$의 거리의 준안정 site에 탄소들이 많이 존재하는 것을 알 수 있었는데, 이는 필름 표면의 국부적 급냉효과가 최대가 되는 조건과 일치하였다. 이러한 결과는 다이아몬드상 카본필름의 합성에 있어서, 고 에너지의 탄소인자가 충돌하면서 발생하는 국소적인 열에너지의 증가가 가장 빨리 제거되는 조건에서 최적의 물성을 가지는 경질탄소 필름이 형성되는 것을 보여주고 있다.

• Corrosion Science and Technology
• /
• 제4권6호
• /
• pp.226-230
• /
• 2005

Si incorporated diamond-like carbon (Si-DLC) films ranging from 0 to 2 at.% contents were deposited on STS 316L substrates for orthopedic implants by means of r.f. plasma-assisted chemical vapor deposition (r.f. PACVD) technique, using mixtures of benzene ($C_6H_6$) and silane ($SiH_4$) as the precursor gases. This study provides the reliable and quantitative data for assessment of the effect of Si incorporation on corrosion property in the simulated body fluid environment through the electrochemical test. It was found that corrosion to resistance of Si-DLC coatings with increasing Si content are improved owing to high $sp^3$ bonding.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권6호
• /
• pp.403-409
• /
• 1999

We fabricated diamond like carbon (DLC) thin films using pulsed laser deposition (PLD) method. Among many deposition parameters, the effects of the deposition temperature and the laser energy density were investigated. Structural properties of the films were studied by Raman spectroscopy. The surface morphologies and cross-section imagies of the films were investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM) respctively. DLC thin films fabricated at $12 J/cm^2$ of a laser energy density and $300^{\circ}C$ of a deposition temperature showed the best quality.

• Transactions on Electrical and Electronic Materials
• /
• 제3권2호
• /
• pp.1-5
• /
• 2002

Alignment effects for nematic liquid crystal (NLC) and electro-optical (EO) characteristics of the ion beam (IB) aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the diamond-like carbon (DLC) thin film surface were studied. A high pretilt angle of 3.5$^{\circ}$ in NLC by ion beam exposure on the DLC thin film layer can be measured. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the DLC thin film surface for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved.

• The Korean Journal of Ceramics
• /
• 제4권1호
• /
• 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.

• The Korean Journal of Ceramics
• /
• 제4권1호
• /
• pp.20-24
• /
• 1998

Thin films of diamond-like carbon(DLC) can be successfully deposited by using a magnetron plasma chemical vapor deposition (CVD) method with an rf(13.56 MHz) plasma of $C_dH_8$. Plasma characteristics are analyzed as a function of the magnetic field. As the magnetic field increases, both electron temperature ($T_e$) and density ($n_e$)increase, but the negative dc self-bias voltage (-$V_{ab}$) decreases, irrespective of gas pressures in the range of 1~7 mTorr. High deposition rates have been obtained even at low gas pressures, which may be attributed to the increased mean free path of electrons in the magentron plasma. Effects of rf power and additive gas on the structural properties of DLC films aer also examined by using various technique namely, TED(transmissio electron diffraction) microanalysis, FTIR, and Raman spectroscopies.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1999년도 제30회 추계학술대회
• /
• pp.42-48
• /
• 1999

An experimental study was performed to discover the effect of environment on the tribological behavior of Si-incorporated diamond-like carbon(Si-DLC) film slid on a steel ball. The films were deposited on Si(100) wafers from radio-frequency glow discharge of mixtures of benzene and dilute silane gases. Experiments using a ball-on-disk test-rig was performed under vacuum, dry air and ambient air conditions. It was observed that coefficient of friction was decreased as the environmental condition changes from vacuum, to dry air. It was also observed that the coefficient of friction decreased with increasing silicon concentration in the film. Chemical analyses of debris suggested that the low and stable friction coefficient is closely related to the silicon rich oxide debris and the rolling action.

• 한국전기전자재료학회논문지
• /
• 제19권11호
• /
• pp.1010-1013
• /
• 2006

Hydrogenated Diamond-like carbon (DLC) films were Prepared by the radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method on silicon substrates using methane $(CH_4)$ and hydrogen $(H_2)$ gas for the application to solid lubricant of MEMS devices. We have checked the influence of varying RF power on tribological properties of DLC film. We have checked their performance as two kinds of method such as FFM (Friction Force Microscope) and BOD (Ball-on Disk) measurement. The friction coefficients and the contact number of cycles to steady state decreased as the increase of RF power with FFM and BOD measurement, respectively.

• 산업기술연구
• /
• 제32권A호
• /
• pp.119-123
• /
• 2012

Diamond-like carbon(DLC) thin films with interlayer were deposited on silicon substrate using a reactive sputtering method. The thermal stability of the films was investigated by annealing the films for 1hr in air in the range of 100 to $500^{\circ}C$. The $I_D/I_G$ ratio increased with increasing temperature as related to the $sp^3-to-sp^2$transition. Accordingly, G-position shifting started from $150^{\circ}C$ in the DLC films and from $270^{\circ}C$ in the a-Si/DLC films. Moreover, in the case of the a-Si/DLC films the film still observed even after annealing at $500^{\circ}C$. The thermal stability of the reactive sputtered DLC films appeared to be improved by the a-Si interlayer.