• Journal of the Korean Ceramic Society
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• v.34 no.2
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• pp.209-215
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• 1997

Aluminum nitride(AIN) thin films were deposited by reactive single ion beam sputtering using N2 or NH3 as reactive gas. The structural, compositional and optical properties of AIN thin films were characterized by XRD, GAXRD, TEM, SEM, XPS UV/VIS spectrophotometer, and FT-IR. All the deposited AIN thin films were amorphous by the analysis fo XRD and GAXRD. However, TEM analysis showed that AIN nano-crystallites were uniformly distributed in the films. The presence of Al-N bonds were also confirmed by FT-IR and XPS analyses. The optical bandgap of AIN films increased up to 6.2 eV and the transmittance was a-bout 100% in visible range with approaching the stoichimetric composition. Irrespective of using N2 or NH3 as reactive gas, the deposited AIN thin films had very smooth surface morphologies. Their refractive index ranged from 1.6 to 1.7.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.4121-4124
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• 2011

• Corrosion Science and Technology
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• v.18 no.5
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• pp.206-211
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• 2019

Silicon carbide (SiC) thin films become superhard when they have microstructures of nanocolumnar crystalline grains (NCCG) with an intergranular amorphous SiC matrix. We investigated the role of ion bombardment and deposition temperature in forming the NCCG in SiC thin films. A direct-current (DC) unbalanced magnetron sputtering method was used with pure Ar as sputtering gas to deposit the SiC thin films at fixed target power of 200 W and chamber pressure of 0.4 Pa. The Ar ion bombardment of the deposited films was conducted by applying a negative DC bias voltage 0-100 V to the substrate during deposition. The deposition temperature was varied between room temperature and $450^{\circ}C$. Above a critical bias voltage of -80 V, the NCCG formed, whereas, below it, the SiC films were amorphous. Additionally, a minimum thermal energy (corresponding to a deposition temperature of $450^{\circ}C$ in this study) was required for the NCCG formation. Transmission electron microscopy, Raman spectroscopy, and glancing angle X-ray diffraction analysis (GAXRD) were conducted to probe the samples' structural characteristics. Of those methods, Raman spectroscopy was a particularly efficient non-destructive tool to analyze the formation of the SiC NCCG in the film, whereas GAXRD was insufficiently sensitive.

• Journal of Surface Science and Engineering
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• v.44 no.6
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• pp.246-249
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• 2011

Surface modification before coating nickel by coupling agents and/or etchant of glass did not provide enough adhesive strength of electroless nickel deposits on glass. Effect of heat treatments on hardness as well as adhesion of nickel deposits was studied by using tape test for adhesion, nanoindenter for hardness and glancing angle x-ray diffractometer (GAXRD) for phase characterization. Heat treatment improved hardness as well as adhesion. XRD results give that the improvements of adhesion and hardness are due to the formation of $NiSiO_4$ around the interface between the nickel deposits and the glass and the precipitation of $Ni_3P$ causing precipitation hardening, respectively. The details in effects of heat treatment on adhesion and hardness are described here.

• Journal of Surface Science and Engineering
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• v.34 no.4
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• pp.321-326
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• 2001

The TiCrN Coatings haying three kinds of Compositions of $Ti_{36}$ $Cr_{26}$ $N_{38}$ , $Ti_{31}$ $Cr_{35}$ $N_{34}$ / and $Ti_{14}$ $Cr_{52}$ $N_{34}$ were deposited on STD 61 steel substrate by arc ion plating and were oxidized between 700 and 100$0^{\circ}C$ to identify the oxide scales formed on the coatings. The oxide scales were then analyzed using EPMA, XRD and GAXRD. During oxidation, the coatings consisting of TiN and CrN phases were reduced to TiO2 and $Cr_2$$O_3$, respectively. Titania tended to form at the outer oxide layer, whereas chromia tended to form at the inner oxide layer, owing to the different oxygen affinity. The substrate elements as well as coating elements diffused outwardly toward the oxide layer due to the concentration gradient. The growth of oxide from the TiCrN coatings was schematically expressed on the basis of thickness measurement of the reacted and unreacted coatings. The Cr element showed its stronger role to keep the TiCrN coatings from oxidation, when compared with Ni.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.286-286
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• 2011

최근 폴리머를 기판으로 하는 Flexible TFT (thin film transistor)나 3D-ULSI (three dimensional ultra large-scale integrated circuit)에서 높은 에너지 소비효율과, 빠른 반응 속도를 실현 시키기 위해 낮은 비저항(resistivity)을 가지며, 높은 홀 속도(carrier hall mobility)를 가지는 다결정 반도체 박막(poly-crystalline thin film)을 만들고자 하고 있다. 이를 실현 시키기 위해서는 높은 온도에서 장시간의 열처리가 필요하며, 이는 폴리머 기판의 문제점을 야기시킬 뿐 아니라 공정시간이 길다는 단점이 있었다. 이에 반도체 박막의 재결정화 온도를 낮춰주는 metal (Al, Ni, Co, Cu, Ag, Pd etc.,)을 이용하여 결정화 시키는 방법이 많이 연구 되어지고 있지만, 이 또한 재결정화가 이루어진 반도체 박막 안에 잔여 금속(residual metal)이 존재하게 되어 비저항을 높이고, 홀 속도를 감소시키는 단점이 있다. 이에 본 실험은 HiPIMS (High power impulse magnetron sputtering)와 PIII and D (plasma immersion ion implantation and deposition) 공정을 복합시킨 프로세스로 적은양의 금속이온주입을 통하여 재결정화 온도를 낮췄을 뿐 아니라, 잔여 하는 금속의 양도 매우 적은 다결정 반도체 박막을 만들 수 있었다. 분석 장비로는 박막의 결정화도를 측정하기 위해 GAXRD (glancing angle X-ray diffractometer)를 사용하였고, 잔여 하는 금속의 양과 화학적 결합 상태를 알아보기 위해 XPS를 통해 분석을 하였다. 마지막으로 홀 속도와 비저항을 측정하기 위해 Hall measurement와 Four-point prove를 사용하였다.