• 한국재료학회지
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• 제27권2호
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• pp.69-75
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• 2017

To establish low-temperature process conditions, process-property correlation has been investigated for Ga-doped ZnO (GZO) thin films deposited by pulsed DC magnetron sputtering. Thickness of GZO films and deposition temperature were varied from 50 to 500 nm and from room temperature to $250^{\circ}C$, respectively. Electrical properties of the GZO films initially improved with increase of temperature to $150^{\circ}C$, but deteriorated subsequently with further increase of the temperature. At lower temperatures, the electrical properties improved with increasing thickness; however, at higher temperatures, increasing thickness resulted in deteriorated electrical properties. Such changes in electrical properties were correlated to the microstructural evolution, which is dependent on the deposition temperature and the film thickness. While the GZO films had c-axis preferred orientation due to preferred nucleation, structural disordering with increasing deposition temperature and film thickness promoted grain growth with a-axis orientation. Consequently, it was possible to obtain a good electrical property at relatively low deposition temperature with small thickness.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.181.2-181.2
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• 2015

Sputtering is one of the most popular physical deposition methods due to their versatility and reproducibility. Synthesis of Cr thin films by DC magnetron sputtering using glancing angle deposition (GLAD) has been reported. Chromium thin films have been prepared at two different working pressure($2.0{\times}10-2$, 30, $3.3{\times}10-3torr$) on Si-wafer substrate using magnetron sputtering with glancing angle deposition (GLAD) technique. The thickness of Cr thin films on the substrate was adjusted about 1 mm. The electrical property was measured by four-point probe method. For the measurement of density in the films, an X-ray reflectivity (XRR) was carried out. The sheet resistance and column angle increased with the increase of glancing angle. However, nanohardness and density of Cr thin films decreased as the glancing angle increased. The measured density for the Cr thin films decreased from 6.1 to 3.8 g/cc as the glancing angle increased from $0^{\circ}$ to $90^{\circ}$ degree. The low density of Cr thin films is resulted from the isolated columnar structure of samples. The evolution of the isolated columnar structure was enhanced at the conditions of low sputter pressure and high glancing angle. This GLAD technique can be potentially applied to the synthesis of thin films requiring porous and uniform coating such as thin film catalysts or gas sensors.

• 한국세라믹학회지
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• 제33권5호
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• pp.514-518
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• 1996

Sb doped SnO2(ATO: Antinomy doped Tin Oxide) thin films were prepared by a DC magnetron spttuering method using an oxide target and the electrical characteristics of ATO films were investigated. The experimen-tal conditions are as follows :Ar flow rate ; 0~100 sccm deposition tempera-ture ; 250~40$0^{\circ}C$ DC sputter powder ; 150~550W and sputteing pressure ; 2~7 mTorr, The thickness of depositied ATO films were 600$\AA$~1100 $\AA$ ranges. The resistivity of ATO films was decreased due to the increase of the crystallinity of ATO films with deposition temperature. The decrease of carrier concentration of films with the increase of oxygen flow rate and working pressure is responsible for the increase of resistivity. Increasing of sputtering power raised the resistivity of films by decreasing the carrier mobility.

• 한국표면공학회지
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• 제49권5호
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• pp.461-466
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• 2016

Nanocrystalline vanadium nitride (VN) coatings were deposited using asymmetric bipolar pulsed dc sputtering to further understand the influence of the pulsed plasmas on the crystal structure, microstructure and mechanical properties. Properties of VN coatings were investigated with FE-SEM, XRD and nanoindentation. The results show that, with the increasing pulse frequency and decreasing duty cycle, the coating morphology changed from a porous columnar to a dense structure, with finer grains. Asymmetric bipolar pulsed dc sputtered VN coatings showed higher hardness, elastic modulus and residual compressive stress than dc sputtered VN coatings. The results suggest that asymmetric bipolar pulsed dc sputtering technique is very beneficial for the reactive sputtering deposition of VN coatings.

• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.44-48
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• 2013

Niobium oxide($Nb_2O_5$) films were deposited on p-type Si wafers at room temperature using in-line pulsed-DC magnetron sputtering system with various frequencies. The different duty ratios were obtained by varying the frequency of pulsed DC power from 100 to 300 kHz at the fixed reverse time of $1.5{\mu}s$. From the thickness of the sputtered $NbO_x$ films, it was possible to obtain much higher deposition rate in case of pulsed-DC sputtering than RF sputtering. However, the similar leakage currents and structural characteristics were obtained from the metal-insulator-semiconductor(MIS) structure fabricated with the $NbO_x$ films and the x-ray photoelectron spectroscopy(XPS) results in spite of the different deposition rates. From the experimental results, the $NbO_x$ films sputtered by pulsed-DC sputtering are expected to be used in the fabrication process instead of RF sputtering.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.427-431
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• 2000

ITO (indium tin oxide) thin films on PET (polyethylene terephthalate) and glass substrates have been deposited by a dc magnetron sputtering without heat treatments such as substrate heater and post heat treatment. Each sputtering parameter during the sputtering deposition is an important factor for the high quality of ITO thin films deposited on polymeric substrate. Particularly, the material, electrical and optical properties of as-deposited ITO oxide films are dominated by sputtering power, oxygen partial pressure and films thickness. As the experimental results, the XRD patters of ITO films are influenced by sputtering power and pressure. As the power and pressure are increased, (411) peak is grown suddenly. the electrical resistivity is also increased, as the sputteing power and pressure are increased. Transmittance of ITO thin films in visible light ranges is lowered with increasing the sputtering power and film thickness. Reflectance of ITO films in infia-red region is decreased, as the power and pressure is increased.

• 한국표면공학회지
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• 제37권1호
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• pp.5-12
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• 2004

The enhancement of adhesion for Cu film on polycarbonate (PC) surface with the $Ar/O_2$ gas plasma treatment and dc-bias sputtering was studied. The plasma treatment with this reactive mixture changes the chemical property of PC surface into hydrophllic one, which is shown by the variation of contact angle with surface modification. The micro surface roughness that also gives the high adhesive environment is increased by the $Ar/O_2$ gas plasma treatment. These results were observed distinctly from the atomic force microscopy (AFM). The negative substrate dc-bias effect for the Cu adhesion on PC was also investifated. Accelerated $Ar^{+}$ lons in sheath area of anode bombard the bare surface of PC during initial stage of dc bias sputtering. PC substrate. therefore, has severe roughen and hydrophilic surface due to the physical etching process with more activated functional group. As dc-bias sputtering process proceeds, morphology of Cu film shows better step coverage and dense layer. The results of peel test show the evidence of superiority of bias sputtering for the adhesion between metal Cu and PC.C.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 추계학술발표회초록집
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• pp.114-115
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• 2003

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.254-257
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• 2008

We have investigated the effect of source/drain electrode deposition method on a performance of top gate structured ZnO TFT performance. TFT using S/D of ITO film, consisted of bi-layer which deposited by ion beam assisted sputtering at the initial stage then deposited by DC magnetron sputtering, showed better performance compared to that using S/D of ITO deposited by just DC magnetron sputtering. Two ITO films exhibited different grain shapes and these resulted in different etching properties. We also suspect that charge trapping on the glass substrate (back channel) during the ITO film deposition may influence the characteristics of top gate structured ZnO TFT.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.149-149
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• 2009

실제 산업에서 가장 많이 사용하고 있는 in-line type system에서 Al-doped ZnO (AZO) 막을 bipolar pulsed DC sputtering을 이용해 증착하였다. 약 30 nm/sec의 속도로 기판을 타겟 좌우로 swing 하면서 동적 증착 공정을 한 AZO 박막의 columnar structure가 정적 증착일 때와 다른 형태의 zigzag-type columnar structure가 형성되었다. 투명전도막의 가장 중요한 특성인 비저항과 투과도가 동적 증착 공정일 때의 박막과 정적 증착 공정일 때의 박막이 각각 $2.5{\times}10^{-3}{\Omega}{\cdot}cm$, 78.5%와 $1.65{\times}10^{-3}{\Omega}{\cdot}cm$, 83.9% 였다. 이렇게 성장하는 막의 구조 형태에 따라 달라지는 특성 변화는 양산하는 현장에서 매우 중요한 것이며, 동적 증착 공정에서의 박막 특성 개선에 정적 증착 공정과는 다른 방법의 연구가 필요할 것이다.