• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.138-138
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• 2009

Al, Ga and In doped ZnO thin film were prepared by faing targets sputtering as a function of oxygen gas contents at R.T. Base pressure was $2{\times}10^{-6}torr$, and working pressure was 1mTorr. The properties of thin films on the electrical and optical properties of the deposited films were investigated by using a four-point probe (Chang-min), a Hall Effect measurement (Ecopia) and an UV/VIS spectrometer (HP). The minimum resistivities of AZO, GZO and IZO thin film were $6.5{times}10^{-4}[{\Omega}-cm],5.5{\times}10^{-4}[{\Omega}-cm]$ and $4.29{\times}10^{-4}[{\Omega}-cm]$. The average transmittance of over 80% was seen in the visible range.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1546-1549
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• 2005

Al-doped ZnO (ZnO:Al) thin films were grown on corning 1737 glass substrates by dc magnetron sputtering. The structural, electrical and optical properties of the films were investigated as a function of various discharge power. The obtained films were polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The lowest resistivity is $6.0{\times}10^{-4}$ Ocm with the carrier concentration of $2.694{\times}10^{20}$ $cm^{-3}$ and Hall mobility of $20.426cm^2/Vs$. The average transmittance in the visible range was above 90%.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.316-316
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• 2014

Two different transparent conducting oxide (TCO) layers of Al-doped ZnO (AZO) and $WO_3$ were prepared by a rf sputtering process. Working pressure, deposition time, and target-to-substrate distance were varied for the sputtering process to improve electrical properties of the resulting layer. Thickness of the TCO layers was measured by a profile meter of ${\alpha}$-step. To evaluate the electrical conductivity, surface resistivity of the TCO layers was measured by a four-point probe technique. Decrease of the working pressure resulted in increase of deposition rate and decrease of surface resistivity of the resulting layer. Increase of the layer thickness due to increased deposition time resulted in decrease of surface resistivity of the resulting layer. The shorter the target-to-substrate distance was, the lower was the surface resistivity of the resulting layer.

• Applied Science and Convergence Technology
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• v.26 no.4
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• pp.66-69
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• 2017

Physically implanted surface islands of Nano Carbon Tube (NCT) and ${\alpha}-F_2O_3$ particles have been produced on Al-doped ZnO (AZO)/glass surfaces by simple and direct ND:YAG laser beam irradiation. Sheet resistance of the reconstructed surface increased by about 3.6% of over AZO. Minimal surface damage can be repaired by ND:YAG laser beam irradiation in conjunction with proper impurities. Implanted islands of NCT, which are considered to be a good conductive impurity, on AZO increased the sheet resistance by about 1.8%, while implanted islands of ${\alpha}-F_2O_3$, an insulating impurity, on AZO increased sheet resistance by about 129% compared with a laser beam treated AZO. This study provides insight regarding surface implantations of nanowires and micro-circuits, doping effects for semiconductors and optical devices, surface area and impurity effects for catalysis.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.36-40
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• 2016

The 2 wt.% Al-doped ZnO(AZO) thin films were fabricated on PET substrates with various RF power 20, 35, 50, 65, and 80W by using RF magnetron sputtering in order to investigate the structure, electrical and optical properties of AZO thin films in this study. The XRD measurements showed that AZO films exhibit c-axis orientation. At a RF power of 80W, the AZO films showed the highest (002) diffraction peak with a FWHM of 0.42. At a RF power of 65W, the lowest electrical resistivity was about $1.64{\times}[10]$ ^(-4) ${\Omega}-cm$ and the average transmittance of all films including substrates was over 80% in visible range. Good transparence and conducting properties were obtained due to RF power control. The obtained results indicate that it is acceptable for applications as transparent conductive electrodes.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.124.2-124.2
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• 2011

현재 박막형 태양전지는 실리콘계가 주류를 이루고 있으며, 유리기판 또는 유연성 기판에 비정질 실리콘 박막을 형성시킨 태양전지와 실리콘 기판 양면에 태양전지를 형성하는 방법 등 효율을 극대화시킨 이종접합 태양전지 등이 연구되고 있다. 예컨대 밴드갭이 서로 다른 박막들 간의 이종접합을 이용한 tandem 구조 및 triple 구조의 Si 박막 태양전지의 경우 13%대 변환효율을 나타낸다고 보고된 바 있다. 본 연구에서는 비정질 Si 박막 태양전지 내 흡수층의 효율을 최대화하기 위하여 AZO/Ag 이중구조 박막의 특성에 관한 연구를 수행하고자 한다. combinatorial sputtering system을 이용하여 AZO/Ag 이중구조 박막을 제작하였으며 타겟으로는 4-inch target(Ag, 2wt% Al2O3 doped ZnO)이 사용되었다. 유리기판 상에 combinatorial sputter system으로 상온에서 제작된 Ag 박막의 두께는 25nm로 성장시켰으며 연속공정으로 AZO 박막을 제작하였고, AZO 박막은 100~500nm의 두께경사를 나타내었다. 이 때 유리기판상에 성장된 Ag/AZO 박막의 면저항은 약 $2{\Omega}/{\Box}$ 값을 나타내었다. 본 발표에서는 AZO/Ag 이중 구조 박막의 우수한 전기적 특성을 기반으로 표면 거칠기 및 반사도 특성 등에 관하여 추가적으로 토론한다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.77.1-77.1
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• 2012

Zn 기반 산화물 반도체는 기존의 비정질 Si에 비해 저온공정에도 불구하고 높은 이동도, 투명하다는 장점으로 인해 차세대 디스플레이용 백플레인 소자로 주목받고 있다. 산화물 트랜지스터는 우수한 소자특성을 보여주고 있지만, 온도, 빛, 그리고 게이트 바이어스 스트레스에 의한 문턱전압의 불안정성이 문제의 문제를 해결해야한다. 산화물 반도체의 문턱전압의 불안정성은 유전체와 채널층의 계면 혹은 채널에서의 charge trap, photo-generated carrier, ads-/desorption of molecular 등의 원인으로 보고되고 있어, 고신뢰성의 산화물 채널층을 성장하기 위한 노력이 이루어지고 있다. 최근, 산화물 트랜지스터의 다양한 조건에서의 문턱전압의 불안정성을 해결하기 위해 산화물의 주된 결함으로 일컬어지고 있는 산소결핍을 억제하기 위해 성장공정의 제어 그리고, 산소와의 높은 binding energy를 같은 Al, Hf, Si 등과 같은 원소를 첨가하여 향상된 소자의 특성이 보고되고 있지만, 줄어든 산소공공으로 인해 이동도가 저하되는 문제점이 야기되고 있다. 이러한 문제점을 해결하기 위해, 최근에는 Buried layer의 삽입 혹은 bi-channel 등과 같은 방안들이 제안되고 있다. 본 연구는 atomic layer deposition을 이용하여 AZO bureid layer가 적용된 ZnO 트랜지스터의 특성과 안정성에 대한 연구를 하였다. 다결정 ZnO 채널은 유전체와의 계면에 많은 interface trap density로 인해 positive gate bias stress에 의한 문턱전압의 불안정성을 보였지만, AZO층이 적용된 ZnO 트랜지스터는 줄어든 interface trap density로 인해 향산된 stability를 보였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1343_1344
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• 2009

In this work, transparent conducting Al-doped zinc oxide (AZO) films were prepared on Corning glass substrate by RF magnetron sputtering using an Al-doped ZnO target (Al: 2 wt.%) at room temperature and all films were deposited with athickness of 150 nm. We investigated the effects of the post-annealing temperature and the annealing ambient on structural, electrical and optical properties of AZO films. The films were annealed at temperatures ranging from 300 to $500^{\circ}C$ in steps of $100^{\circ}C$ using rapid thermal annealing equipment in oxygen. The thickness of the film was observed by field emission scanning electron microscopy (FE-SEM) and grain size was calculated from the XRD spectra using the Scherrer equation and their electrical properties were investigated using a hole measurement and the reflectance of AZO films was investigated by UV-VIS spectrometry.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.154-159
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• 2005

Low RF power density was used for preparing transparent conducting AI-doped ZnO (AZO) thin films by RF Magnetron Sputtering on Corning 1737 glass. The dependence of films' structural, optical and electrical properties on sputtering gas, film's thickness and substrate temperature were investigated. Low percent of incorporated H2 in Ar sputtering gas has proven to reduce film's resistivity and sheet resistance as low as $4.1\times10^{-3}{\Omega}.cm$. It also formed new preferred peaks orientation of (101) and (100) which indicated that the c-axis of AZO films was parallel to the substrate. From UN-VIS-NIR Spectrophotometer analysis, it further showed high optical transmittance at about $\~ 90\%$ at visible light spectra (400-700nm).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.39-40
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• 2006

We prepared ZnO:Al (AZO) thin films on polycarbonate (Pc) and polyethersulfon (PES). Because the polymer substrate has weak thermal resistance. The AZO thin films were deposited at room temperature by facing targets sputtering (FTS) method In the work, AZO thin films were deposited with different thickness in 1mTorr and $O_2$ gas flow rate 0.05. The electrical, optical and crystallographic properties were measured From the results, the resistivity of $7.3{\times}10^{-4}{\Omega}cm$ and transmittance of over 80% in visible range were obtained.