• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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• pp.97-101
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• 2005

The ZnO:Al thin films were prepared on glass by Facing Target Sputtering (FTS) system. We investigated electrical, optical, and structural properties of AZO thin film with sputter ins current 0.1[A]-0.6[A]. We obtained the lowest resistivity $2.3{\times}\;10^{-4}[{\Omega}-cm]$ at sputtering current 0.6[A] from the 4-point probe and the strong (002) peak at sputtering current 0.3[A] from the X-ray Diffractometer (XRD). The optical transmittance of AZO thin films show a very high transmittance of $80\~95\%$ in the visible range and exhibit the absorpt ion edge of about 350 nm.

• 전자공학회논문지D
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• 제34D권12호
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• pp.46-53
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• 1997

The TMA gas sensors are fabricated with the ZnO-based thin films grown by a RF magnetron sputtering method. The hall effect measurement and AES analysis are carried out to investigate the effects of the sputtering gases and dopants which effect on the electrical resistivity and sensitivity to TMA gas. We measure the cfhanges of the surface carrier concentration, haall electron mobility, electrical resistivity, surface condition, and depth profile of the films. The ZnO-based thin film sensors sputtered in oxygen, or added with dopants showed a high sruface carrier concentration, film sensors sputtered in oxygen and doped with 4.0 wt.% $Al_{2}$O$_{3}$, 1.0 wt.% TiO$_{2}$, and 0.2 wt% v$_{2}$O$_{5}$ showed the highest surface carrier concentration of 5.952 * 10$^{20}$ cm$^{-3}$ , hall electron mobility of 176.7 cm$^{2}$/V.s, lowest electrical resistivity of 6*10$^{-5}$ .ohm.cm and highest sensitivity of 12. These results were measured at a working temperature of 300.deg. C to 8 ppm TMA gas.

• 반도체디스플레이기술학회지
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• 제9권3호
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• pp.75-78
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• 2010

In this study we investigated the electrical properties of ZnO-based MOS capacitor with $HfO_2$ as the gate dielectric. MIM capacitor, which uses either $HfO_2$ or $Al_2O_3$ as the dielectric layer, is also studied to understand the dependency of the dielectrics on the preparation conditions. It was found that thinner $HfO_2$ films yield better electrical properties, namely lower leakage current and higher breakdown electric field. These properties were observed to deteriorate when subsequently annealed. Capacitance in the depletion region of MOS capacitor was found to increase with UV ozone treatment time up to 60min. However, when the treatment time was extended to 120min, the trend is reversed. The 'threshold voltage' was also observed to positively shift with UV ozone treatment time up to 60min. The shift apparently saturated for longer treatment.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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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).

• Transactions on Electrical and Electronic Materials
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• 제15권1호
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• pp.24-27
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• 2014

In this study, the effects of Mn-doping and the electrode materials on the memory characteristics of $ZnO_xS_{1-x}$ resistive random access memory (ReRAM) devices on plastic are investigated. Compared with the undoped Al/$ZnO_xS_{1-x}$/Au and Al/$ZnO_xS_{1-x}$/Cu devices, the Mn-doped ones show a relatively higher ratio of the high resistance state (HRS) to low resistance state (LRS), and narrower resistance distributions in both states. For the $ZnO_xS_{1-x}$ devices with bottom electrodes of Cu, more stable conducting filament paths are formed near these electrodes, due to the relatively higher affinity of copper to sulfur, compared with the devices with bottom electrodes of Au, so that the distributions of the set and reset voltages get narrower. For the Al/$ZnO_xS_{1-x}$/Cu device, the ratio of the HRS to LRS is above $10^6$, and the memory characteristics are maintained for $10^4$ sec, which values are comparable to those of ReRAM devices on Si or glass substrates.

• Transactions on Electrical and Electronic Materials
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• 제10권2호
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• pp.58-61
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• 2009

The electrical stability of ZnO: Al thin films deposited on glass substrate by the RF magnetron sputtering method have been modified by a hydrogen annealing treatment and $SiO_2$ protection layer. AZO thin films were deposited at room temperature and different RF powers of 50, 100, 150, and 200 W to optimize the AZO film growth condition. The lowest value of resistivity of $9.44{\times}10^{-4}{\Omega}cm$ was obtained at 2 mtorr, room temperature, and a power level of 150 W. Then, the AZO thin films were annealed at $250-400^{\circ}C$ for 1 h in hydrogen ambient. The minimum resistivity obtained was $8.32{\times}10^{-4}{\Omega}cm$ as-annealed at $300^{\circ}C$. The electrical properties were enhanced by the hydrogen annealing treatment. After a 72 h damp-heat treatment in harsh conditions of a water steam at $110^{\circ}C$ for four representative samples, a degradation of electrical properties was observed. The sample of hydrogen-annealed AZO thin films with $SiO_2$ protection layer showed a slight degradation ratio(17%) of electrical properties and a preferable transmittance of 90%. The electrical stability of AZO thin films had been modified by hydrogen annealing treatment and $SiO_2$ protection layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.322-323
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• 2005

We deposited Zinc oxide (ZnO) thin films on Ru buffer layer in order to protect the amorphous layer between ZnO and Al interface. In X-ray diffraction (XRD) pattern, it was observed that increase of (002)-orientation by the variation of annealing treatment temperature. Also, surface roughness and specific resistance were increased by annealing treatment but full width at half maximum (FWHM) was decreased. In film bulk acoustic resonators (FBARs) fabricated from these results, we finally confirmed that the resonant frequency of 0.89 GHz without its shift was measured.

• 한국진공학회지
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• 제18권5호
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• pp.377-383
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• 2009

라디오파 마그네트론 스퍼터링 방법을 사용하여 사파이어 기판 위에 Al 도핑된 ZnO (AZO) 박막을 성장시킨 후에 온도 범위 $600-900^{\circ}C$에서 급속 열처리를 수행하였다. 박막의 결정 구조와 표면 형상은 각각 X-선 회절법과 주사전자현미경으로 조사하였다. 급속 열처리 온도가 증가함에 따라 박막의 결정성은 향상되었고, 평균 50 nm의 크기를 갖는 육각형 형태의 결정 입자가 관측되었다. 증착된 모든 박막은 파장 영역 400-1100 nm에서 92%의 평균 투과율을 나타내었다. 열처리 온도가 증가함에 따라 박막의 밴드갭 에너지는 감소하였고, 광여기 발광 신호의 경우에 자외선 발광 신호의 세기가 감소하면서 400 nm에 중심을 둔 보라색 발광 신호가 주된 피크를 형성하였다. 박막의 전기적 특성은 열처리 온도에 현저한 의존성을 보였다.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1072-1076
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• 2007

We prepared the Al doped ZnO (AZO) thin film on polyethersulfon (PES) without any substrate heating by Facing Targets Sputtering (FTS) system. FTS system has two different facing targets. One is ZnO doped the content of Al 2 wt% and the other is Zn in order to decrease resistivity. The electrical, structural and optical properties of AZO thin films were investigated. To evaluate the as-deposited thin film properties, we employed four-point probe (CMT-R100nw, Changmin), Surface profiler (Alpha-step, Tencor), UV/VIS spectrometer (HP), X-ray diffractometer (XRD, Rigaku) and Field Emission Scanning Electron Microscopy (FESEM, Hitachi S-4700). As a result, We obtained that AZO thin film deposited on PES substrate at a DC Power of 150 W, working pressure of 1 mTorr and $O_2$ gas flow ratio of 0.2 exhibited the resistivity of $4.2{\times}10^{-4}\;[{\Omega}cm]$ and the optical transmittance of about 85 % in the visible range.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.67-68
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• 2006

We prepared the AZO thin film with different $O_2$ gas flow rate. the AZO thin films were deposited on glass substrate at room temperature, working gas pressure of 1mTorr. the electrical, structural and optical properties of AZO thin films were investigated by using Hall Effect measurement system, X-ray Diffractometer (XRD) and UV-VIS spectrometer. From the results, we could obtain that AZO thin film with low resistivity of $8.5{\times}10^{-4}{\Omega}cm$ was exhibited in specific $O_2$ gas flow rate. Also, the transmittance of over 80% in visible range was observed in specific $O_2$ gas flow rate. In all of the AZO thin film with the transmittance of over 80%, diffraction peak of (002) direction was observed, while amorphous peak was observed in the AZO thin film with the low transmittance.