• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.448-451
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• 2004

Vanadium oxides have been widely used in a variety of technological applications such electrochromic devices as infrared detectors and are expected as a material suitable for gas sensing applications. Thin films of Vanadium oxide (VOx) have been deposited by r.f magnetron sputtering under different oxygen partial pressure ratios and substrate temperatures. Humidity-sensitive properties of resistive sensors having interdigitated electrode structure are characterized. Our sensors show good response to humidity over 20%RH to 80%RH. Vanadium oxide films deposited with 0% $O_2$ partial pressure at foot exhibit greater sensitivity to humidity change than others.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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• pp.106-109
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• 2005

The ITO thin films for Top-Emitting Organic Light Emitting Devices (TOLEDs) were prepared on cell(LiF/Organic Layer/Bottom Electrode : ITO ) by FTS (Facing Targets Sputtering) system under different sputtering conditions which were varying gas pressure, input current and distance of target to target($D_{T-T}$). As a function of sputtering conditions, I-V characteristics of prepared ITO thin films on cell were measured by 4156A (HP). In the results, when the In thin films were deposited at $D_{T-T}$ 70mm and working pressure 1mTorr, the leakage current of ITO/cell was about 11[V] and 5E-6[$mA/cm^2$].

• 한국재료학회지
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• 제7권2호
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• pp.102-106
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• 1997

박막형 접촉연소식을 포함한 마이크로 가스센서에서 membrane은 Si식각시 식각정지용으로서 또 센서 소자를 지지하는 층으로서 응력이 없어야 하며 이는 응력이 membrane파괴의 주 원인으로 작용하기 때문이다. 이에 따라 본 연구에서는 증착조건이 low pressure chemical vapor deposition(LPCVD)법과 sputtering법으로 제작된 $SiN_{x}$과 $SiN_{x}/SiO_{x}/(NON)$막의 응력고 굴절율 변화에 미치는 효과에 대한 실험을 행하였다. LPCVD의 경우 단일막인 $SiN_{x}$의 압축응력 및 굴절율을 나타내었다. Sputtering의 경우 $SiN_{x}$는 공정압력이 1mtorr에서 30torr까지 증가할수록 인가전력밀도가 $2.74W/cm^2$에서 $1.10W/cm^2$으로 감소할수록 응력값은 압축에서 인장으로 전환되었으며 본 실험에서 응력이 가장 낮게 나온 시편의경우 압축응력으로 $1.2{\times}10^{9}dyne/cm^2$가 공정압력 10mtorr, 인가전력밀도 $1.37W/cm^2$에서 얻어졌다. 굴절율은 공정압력이 1motorr에서 30motorr까지 증가할수혹 인가전력밀도가 $2.74W/cm^2$에서 $1.10W/cm^2$으로 감소할수록 감소하여 2.05에서 1.89의 변화를 보였다. LPCVD와 sputtering으로 증착된 막들은 모두 온도가 증가함에 따라 응력이 감소하였으며 온도감소시 소성적인 특성을 나타내었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.901-904
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• 2001

For the c-axis oriented epitaxial YBa$_2$Cu$_3$O$_{7-{\delta}}$ thin film on r-cut sapphire substrate it is necessary to deposit buffer layers. The CeO$_2$buffer layer was deposited on sapphire substrate using RF magnetron sputtering system. We investigated XRD pattern of CeO$_2$thin films at various sputtering conditions such as sputtering gas ratio, sputtering power, target to substrate distance, sputtering pressure and substrate temperature. The optimum condition was 15 mTorr with deposition pressure, 1:1.2 with $O_2$and Ar ratio and 9cm with target to substrate distance. The CeO$_2$(200) peak was notable for a deposition temperature above 75$0^{\circ}C$. The YBa$_2$Cu$_3$O$_{7-{\delta}}$ was deposited on CeO$_2$buffered r-cut sapphire substrate using pulsed laser ablation. The YBa$_2$Cu$_3$O$_{7-{\delta}}$CeO$_2$(200)/A1$_2$O$_3$thin film was exhibited a critical temperature of 89K.xhibited a critical temperature of 89K.

• 한국자기학회지
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• 제10권5호
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• pp.232-236
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• 2000

Cr을 하지층으로 사용한 CoSm 박막은 고기록밀도 수평 자기기록 매체로 가능성이 커 이에 대한 관심이 집중되고 있다. 본 연구에서는 dc 마그네트론 스퍼터링법으로 제작한 CoSm 박막의 자기적 성질의 Ar 가스 스퍼터링 압력 의존성을 조사하였다. 특히 고기록밀도 자기기록 매체에서 magnetic switching volume V＊은 자기기록 매체에 기록된 정보의 열적 안정성, 자화반전 및 잡음을 이해하는데 중요한 자료가 된다. 따라서 본 연구에서는 동일 조건에서 제작한 하지층 Cr위에 스퍼터링 압력을 달리하여 자성층 CoSm을 성장시켜 switching volume의 스퍼터링 압력 의존성을 규명하도록 하였다. 연구 결과 switching volume은 스퍼터링 압력이 증가할수록 감소하며, 그 크기는 9.0-5.2$\times$$10^{-18}$ $cm^3$ 범위 내에 있었다. Switching volume V＊를 이용하여 계산한 switching 단위의 크기는 22 nm 보다 작으며, 이 크기는 고기록 밀도수평 자기기록매체의 열적 안정성에 대한 Sharrock 조건을 만족한다.

• 대한전자공학회논문지SD
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• 제47권2호
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• pp.15-20
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• 2010

본 연구에서는 RF magnetron sputtering법으로 기판온도 $200^{\circ}C$에서 공정 압력 (5~20 mTorr)과 산소 가스비 (0~3%)를 변화시켜가며 PES 플라스틱 기판 위에 AZO (Al:3wt%) 박막을 제작하여 광학적 및 전기적 특성을 조사하였다. XRD 측정을 통해 공정 조건에 관계없이 모든 AZO박막이 c 축으로 우선 성장함을 확인할 수 있었다. 박막의 표면을 AFM 으로 조사한 결과, 표면 거칠기 값은 공정압력 5 mTorr, 산소 가스비 3%에서 제작한 박막에서 가장 낮은 값 (3.49 nm) 을 나타내었다. 모든 AZO 박막이 가시광 영역에서 80% 정도의 투과율을 보였으며, 공정 압력과 산소 가스비가 감소할수록 에너지 밴드갭이 증가하는 Burstein-Moss 효과를 관찰할 수 있었다. Hall 측정 결과, 공정 압력 5 mTorr와 산소 가스비 0%에서 제작한 AZO 박막에서 가장 높은 캐리어 농도 $2.63\;{\times}\;10^{20}\;cm^{-3}$ 값과 가장 낮은 비저항 $4.35\;{\times}\;10^{-3}\;{\Omega}cm$ 값을 나타내었다.

• 한국전기전자재료학회논문지
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• 제22권7호
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• pp.595-601
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• 2009

For the silicon oxide $(SiO_x)$ films prepared by using the facing target sputtering (FTS) apparatus that was manufactured to enhance the preciseness of the fabricated thin-film and sputtering yield rate by forming a higher-density plasma in the electrical discharge space for using it as a thin-film passivation system for flexible organic light emitting devices (FOLEDs). The deposition characteristics were investigated under various process conditions, such as array of the cathode magnets, oxygen concentration$(O_2/Ar+O_2)$ introduced during deposition, and variations of distance between two targets and working pressure. We report that the optimum conditions for our FTS apparatus for the deposition of the $SiO_x$ films are as follows: $d_{TS}\;and\;d_{TT}$ are 90mm and 120mm, respectively and the maximum deposition rate is obtained under a gas pressure of 2 mTorr with an oxygen concentration of 3.3%. Under this optimum conditions, it was found that the $SiO_x$ film was grown with a very high deposition rate of $250{\AA}$/min by rf-power of $4.4W/cm^2$, which was significantly enhanced as compared with a deposition rate (${\sim}55{\AA})$/min) of the conventional sputtering system. We also reported that the FTS system is a suitable method for the high speed and the low temperature deposition, the plasma free deposition, and the mass-production.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.28.1-28.1
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• 2009

The superior properties of ZnO such as high exciton binding energy, high thermal and chemical stability, low growth temperature and possibility of wet etching process in ZnO have great interest for applications ranging from optoelectronics to chemical sensor. Particularly, vertically well-aligned ZnO nanorods on large areas with good optical and structural properties are of special interest for the fabrication of electronic and optical nanodevices. Currently, low-dimensional ZnO is synthesized by metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), thermal evaporation, and sol.gel growth. Recently, our group has been reported about achievement the growth of Ga-doped ZnO nanorods using ZnO seed layer on p-type Si substrate by RF magnetron sputtering system at high rf power and high growth temperature. However, the crystallinity of nanorods deteriorates due to lattice mismatch between nanorods and Si substrate. Also, in the growth of oxide using sputtering, the oxygen flow ratio relative to argon gas flow is an important growth parameter and significantly affects the structural properties. In this study, Phosphorus (P) doped ZnO nanorods were grown on c-sapphire substrates without seed layer by radio frequency magnetron sputtering with various argon/oxygen gas ratios. The layer change films into nanorods with decreasing oxygen partial pressure. The diameter and length of vertically well-aligned on the c-sapphire substrate are in the range of 51-103 nm and about 725 nm, respectively. The photoluminescence spectra of the nanorods are dominated by intense near band-edge emission with weak deep-level emission.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.574-577
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• 2011

In this study, we use the $2.5cm{\times}7.5cm$ soda lime glass as the substrate. We used the ultrasonicator. Glass was dipped in the acetone, methanol and DI water respectively for 10 minutes. Ar(99.99%)gas was used as the sputtering gas. We varied the RF power between 100~175 W with 25 W steps. Base pressure was kept by turbo molecular pump at $3.0{\times}10^{-6}$ torr. Working pressure was kept by injection of Ar gas. ZnS thin films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers. It is also clearly observed that, the intensity of the (111) XRD peak increases with increasing the RF power. Electrical properties were measured by hall effect methods at room temperature. The resistivity, carrier concentration, and hall mobility of ZnS deposited on glass substrate as a function of sputtering power. It can be seen that as the sputtering power increase from 100 to 175 W, the resistivity of the films on glass decreased significantly from $8.1{\times}10^{-2}$ to $1.2{\times}10^{-3}\;{\Omega}{\cdot}cm$. This behavior could be explained by the effect of the sputtering power on the mobility and carrier concentration. When the RF power increases, the carrier concentration increases slightly while the resistivity decreases significantly. These variation originate from improved crystallinity and enhanced substitutional doping as the sputtering power increases.

• 열처리공학회지
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• 제22권3호
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• pp.143-148
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• 2009

We have fabricated Ti metal films on Cu wire substrates by using a RF magnetron sputtering method at different RF powers (0, 30 and 60 W) in a high vacuum, and we have investigated the thin film characteristics and resistivity. The ion bombardment effect is increased by the method to superimpose RF power to DC power applied to two poles of the base; thus, the thin film is deposited at sputtering gas pressures below 1 Pa. Moreover, the thin film formation of the multilayer structure becomes possible by gradually injecting the RF power, and the thin film quality is improved.