• Korean Journal of Materials Research
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• v.14 no.5
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• pp.328-333
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• 2004

Transparent ZnO:Al conductor films for the optoelectronic devices were deposited by using the capacitively coupled DC magnetron sputtering method. The effect of Al doping concentration and discharge power on the electrical and optical properties of the films was studied. The film resistivity of $8.5${\times}$10^{-4}$ $\Omega$-cm was obtained at the discharge power of 40 W with the ZnO target doped with 2 wt% $Al_2$$_O3$. The transmittance of the 840 nm thick film was 91.7% in the visible waves. Increasing doping concentration of 3 wt% $Al_2$$O_3$ in ZnO target results in significant decrease of film resistivity, which may be due to the formation of $Al_2$$O_3$ particles in the as-deposited ZnO:Al film and the reduced ZnO grain sizes. Increasing DC power from 40 to 60 W increases deposition rate by more than 50%, but can induce high defect density in the film, resulting in higher film resistivity.

• Transactions on Electrical and Electronic Materials
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• v.12 no.2
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• pp.76-79
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• 2011

In order to improve efficiency and make a new material thin film, we prepared the Al-In-Sn-ZnO thin film on a glass substrate at room temperature using a Facing Target Sputtering (FTS) system. The FTS system was designed to array two targets that face each other. Two different kinds of targets were installed on the FTS system. We used an ITO ($In_2O_3$ 90wt%, $SnO_2$ 10wt%) target and an AZO (ZnO 98wt%, $Al_2O_3$ 2wt%) target. The AIZTO films were deposited using different applied powers to the targets. The as-deposited AIZTO thin films were investigated using a UV/VIS spectrometer, an X-ray diffratometer (XRD), and Energy Dispersive X-ray spectroscopy (EDX).

• Journal of the Korean Society for Heat Treatment
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• v.21 no.1
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• pp.3-9
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• 2008

Al-Co-N thin films, Al-Co-N/Al-N and Al-Co-N/Al-Co multilayers containing various amounts of Co content were deposited by using a two-facing targets type dc sputtering (TFTS) system. The films were also annealed successively and isothermally at different annealing temperatures. Irrespective of Co content and preparation methods, all the as-deposited films were observed non-magnetized. It was found that annealing conditions can control the magnetic and electrical properties as well as the microstructure of the films.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.207-207
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• 2011

Amorphous transparent oxide semiconductors (a-TOS) have been widely studied for many optoelectronic devices such as AM-OLED (active-matrix organic light emitting diodes). Recently, Nomura et al. demonstrated high performance amorphous IGZO (In-Ga-Zn-O) TFTs.1 Despite the amorphous structure, due to the conduction band minimum (CBM) that made of spherically extended s-orbitals of the constituent metals, an a-IGZO TFT shows high mobility.2,3 But IGZO films contain high cost rare metals. Therefore, we need to investigate the alternatives. Because Aluminum has a high bond enthalpy with oxygen atom and Alumina has a high lattice energy, we try to replace Gallium with Aluminum that is high reserve low cost material. In this study, we focused on the electrical properties of IZO:Al thin films as a channel layer of TFTs. IZO:Al were deposited on unheated non-alkali glass substrates (5 cm ${\times}$ 5 cm) by magnetron co-sputtering system with two cathodes equipped with IZO target and Al target, respectively. The sintered ceramic IZO disc (3 inch ${\phi}$, 5 mm t) and metal Al target (3 inch ${\phi}$, 5 mm t) are used for deposition. The O2 gas was used as the reactive gas to control carrier concentration and mobility. Deposition was carried out under various sputtering conditions to investigate the effect of sputtering process on the characteristics of IZO:Al thin films. Correlation between sputtering factors and electronic properties of the film will be discussed in detail.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.98-101
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• 2004

AZO(ZnO:Al) thin film were prepared by FTS(Facing Target Sputtering) system. Change the sputtering conditions, AZO thin film deposited the lower resistivity(<$10-4{\Omega}cm$) so it can use to be a display application electrode. In this study, the electrical and crystallographic effects of target type have been investigated. The crystal structure was studied by XRD and the resistivity of AZO thin film was obtained by the four-point probe.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.655-658
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• 2007

Characteristics of Al cathode films deposited by using specially designed twin target sputter (TTS) system were investigated. It was found that Al cathode films prepared by TTS were amorphous structure with nanocrystallines due to low substrate temperature and OLEDs fabricated using TTS system have low leakage current density at reverse bias because of effective confinement of energetic particles during sputtering process.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.125.1-125.1
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• 2015

산업 자동화기술이 발달함에 따라 다양한 용도의 부품개발과 산업 장비들의 부품에 대한 수요가 날로 증가하게 되어 산업이 발달하게 된 반면, 장비의 성능을 저하시키는 마모에 대한 문제점이 제기되고 있다. 이에 대한 해결책으로 내열성 및 내마모성을 가지는 박막코팅기술이 요구되고 있다. 특히, Alumina (Al2O3)와 Zirconia (ZrO2)는 내식성과 내열성, 내마모성의 우수한 특성을 지닌 재료이며, 이들을 기어, 베어링, 실린더 등 각종 기계의 부품에 코팅하여 내마모성을 가지게 한다. 본 실험에서는 Al2O3 : ZrO2 = 50 : 50 wt% 의 비율로 혼합한 target이 사용되었다. 그리고 Al2O3-ZrO2 target을 사용하여 RF-magnetron sputtering 방법으로 박막을 제작 하였다. sputter시에 power를 20 W에서 80 W까지 변화를 주었다. AFM, SEM, XRD를 통하여 알루미늄 기판위에 증착된 Al2O3-ZrO2 박막의 구조적 특성을 알아보았으며, 내마모성 테스트 장비를 통하여 박막의 마찰마모 특성에 대하여 조사하였다.

• Korean Journal of Materials Research
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• v.13 no.4
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• pp.205-212
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• 2003

RF sputtering process was applied to produce thin hydroxyapatite［HA, Ca10($PO_4$)$_{6}$ $ (OH)_2$films on Ti-6Al-4V alloy substrates. To make a 101.6 mm dia.${\times}$5 mm HA target, the commercial HA powder was first calcinated for 3h at $200^{\circ}C$. A certain amount of the calcinated HA powder was pressed under a pressure of 20,000 psi by the cold isostatic press(CIP) and the pressed HA target was sintered for 6 h at $1,200^{\circ}C$. The effects of different heat treating conditions on the bonding strength between HA thin films and Ti-6Al-4V alloy substrates were studied. Before deposition, the alloy substrates were annealed for 1 h at $850^{\circ}C$ under $3.0${\times}$10^{-3}$ Xtorr, and after deposition, the hydroxyapatite/Ti-6Al-4V alloy thin films were annealed for 1 h at 400, 600 and $800^{\circ}C$ under the atmosphere, respectively. Experimental results represented that the HA thin films on the annealed substrates had higher hardness than non-heat treated substrates before the deposition.

• Korean Journal of Metals and Materials
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• v.49 no.6
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• pp.493-497
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• 2011

The basic properties and electrical characteristics of sputtering films deposited with a commercial cast target and spark plasma sintering (SPS) were compared and analyzed. The results, revealed that, the Al film prepared by heating at $60^{\circ}C/min$ (SPS process) showed a specific resistance similar to the commercial cast Al film. In addition, the results of XRD, SIMS and TEM, showed that there was not much difference in the crystal structure and impurities between the two films. Consequently, the SPS Al target was found to have properties quite similar to the commercial one and it is expected to be applied in future research to the metal wiring material for semiconductor/display devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.337-337
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• 2014

투명 전도성 산화물(transparent conductive oxide: TCO) 박막은 높은 투과율과 낮은 비저항 덕분에 LCD (liquid crystal display), PDP (plasma display panel), OLED (organic light emitting display) 등 평판 디스플레이에 널리 사용되고 있다. 현재 양산되고 있는 ITO (indium tin oxide)는 90% 이상의 높은 투과율과 우수한 전도성으로 인해 TCO 박막 가운데서 디스플레이 산업에서 가장 널리 쓰이고 있다. 그런데, ITO의 인듐산화물에 의한 간질성 폐렴(interstitial pneumonia)의 유발 위험이 있다든가, 인듐의 매장량이 적어 원자재 가격이 비싼 단점도 가지고 있다. 이에 최근 ITO를 대체할 수 있는 TCO물질로 많은 연구가 이루어지고 있는데, 특히 AZO (aluminum-doped zinc oxide)는 그 중 대표적인 대체물질로서 독성이 없고 가격도 저렴하여 많은 관심이 증폭되고 있다. 현재 AZO는 sol-gel 방법이나 CVD (chemical vapor deposition) 또는 스퍼터링 방법 등으로 증착되고 있다. 본 연구에서는 두 개의 이종타겟(hetero target)을 장착한 대향 타겟 스퍼터링(facing target sputtering: FTS) 장치를 사용하여 AZO 박막을 제작한다. 기존의 여러 증착법과 달리, FTS 장치는 두 타겟 사이에 형성되는 플라즈마 내의 ${\gamma}$-전자를 구속하게 되며, 낮은 가스 압력에서 고밀도 플라즈마가 생성되어 빠른 증착 속도와 안정적인 방전을 유지한 상태에서 박막을 증착할 수가 있다. 또한 기판과 플라즈마가 이격되어 있어 높은 에너지를 갖는 입자들의 기판 충돌을 억제할 수 있는 장점들을 갖는다. 이종 타겟인 ZnO와 Al2O3를 사용하고 각 타겟에 인가되는 파워 변화를 통해 AZO 박막 내 Al2O3의 성분비를 조절하였다. ZnO 타겟의 증착 파워를 100 W로 고정할 경우, Al2O3 타겟의 증착 파워가 (50~90) W으로 실험을 하였으며, Al2O3 타겟의 증착 파워가 70 W일 때 AZO 박막의 Al2O3 성분비는 2.02 wt.%이며 박막의 비저항 값은 $5{\times}10^{-4}{\Omega}{\cdot}cm$로 최소값을 보였다. 이러한 비저항의 변화는 파워에 따른 AZO 박막의 캐리어 이동도(Hall mobility)와 캐리어의 농도(Carrier Concentration)의 변화와 밀접한 관계가 있음을 보여주며, 특히 AZO 박막의 캐리어 농도와 캐리어 이동도는 AZO 박막을 형성하고 있는 결정립의 크기에 의존하는 것이 X-선 회절 패턴과 SEM으로부터 확인되었다. 특히, 본 연구에서는 두 개의 이종 타겟(hetero target) Al2O3와 ZnO를 장착하고 각각의 파워를 변화시켜 도핑 량을 조절할 수는 대향 타겟 스퍼터링(FTS: facing-target sputtering) 방법을 이용하여 제작된 AZO 박막에 대해 전기적, 광학적 및 구조적 특성을 분석하고 ITO의 대체물로서의 가능성을 검토하고자 한다.