• 한국전기전자재료학회논문지
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• 제17권7호
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• pp.738-746
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• 2004

Recently zinc oxide(ZnO) has emerged as one of the most promising transparent conducting films with a strong demand of low cost and high performance optoelectronic devices, ZnO film has many advantages such as high chemical and mechanical stabilities, and abundance in nature. In this paper, in order to obtain the excellent transparent conducting film with low resistivity and high optical transmittance for Plasma Display Pannel(PDP), aluminium doped zinc oxide films were deposited on Corning glass substrate by dc magnetron sputtering method. The effects of the discharge power and doping amounts of $Al_2$$O_3$ on the electrical and optical properties were investigated experimentally. Particularly in order to lower the electrical resistivity, positive and negative bias voltages were applied on the substrate, and the effect of bias voltage on the electrical properties of ZnO:Al thin film were also studied and discussed. Films with lowest resistivity of $4.3 \times 10 ^{-4} \Omega-cm$ and good transmittance of 91.46 % have been achieved for the films deposited at 1 mtorr, $400^{\circ}C$, 40 W, Al content of 2 wt% with a substrate bias of +30 V for about 800 nm in film thickness.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.278-282
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• 2004

The Hydrogenated amorphous carbon(a-C:H) thin films are deposited on silicon with a close field unbalanced magnetron(CFUBM) sputtering systems. The experimental data are obtained on the depositon rate and physical properties of a-C:H films using DC bias voltage and Ar/C$_2$H$_2$ pressure. The depostion rate and the surface roughness decrease with DC bias voltage, but the hardness of the thin films increases with DC bias voltage. And the position of G-peak moves to lower wavenumber indicating an increase in diamond-like carbon characteristics with the lower Ar/C$_2$H$_2$ pressure.

• Journal of Magnetics
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• 제15권3호
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• pp.132-137
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• 2010

Plasma etching of $SiO_2$ contact holes was statistically analyzed by a fractional factorial experimental design. The analysis revealed the dependence of the etch rate and DC self-bias voltage on the input factors of the magnetically enhanced reactive ion etching reactor, including gas pressure, magnetic field, and the gas flow rates of $CHF_3$, $CF_4$, and Ar. Empirical models of the DC self-bias voltage and etch rate were obtained. The DC self-bias voltage was found to be determined mainly by the operating pressure and the magnetic field, and the etch rate was related mainly to the pressure and the flow rates of Ar and $CHF_3$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.513-514
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• 2005

In plasma processing reactors, it is common practice to control plasma density and ion bombardment energy by manipulating excitation voltage and frequency. In this paper, a dually excited capacitively coupled rf plasma reactor is self-consistently simulated with a three moment model. Effects of phase differences between primary and secondary voltage waves, simultaneously modulated at various combination of commensurate frequencies, on plasma properties are investigated. The simulation results show that plasma potential and density as well as primary self-dc bias are nearly unaffected by the phase lag between the primary and the secondary voltage waves. The results also show that, with the secondary frequency substantially lower than the primary frequency, secondary self-dc bias remains constant regardless of the phase lag. As the secondary frequency approaches to the primary frequency, however, the secondary self-dc bias becomes greatly altered by the phase lag, and so does the ion bombardment energy at the secondary electrode. These results demonstrate that ion bombardment energy can be more carefully controlled through plasma simulation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.35-38
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• 2018

본 논문에서는 DC 유형의 에너지 하베스팅을 위한 저전력 MPPT 인터페이스 회로를 설계하였다. 제안된 회로는 크게 MPPT controller, bias generator, voltage detector로 구성된다. MPPT controller는 schmitt trigger로 구성된 MPG(MPPT Pulse Generator)와 에너지 유형(빛, 열)에 따라 동작하는 logic gate와 sample/hold 회로로 구성된다. Bias generator는 beta multiplier 구조를 적용하여 설계되었으며, voltage detector는 bulk-driven comparator와 2단 buffer를 이용하여 설계되었다. 제안된 회로는 $0.35{\mu}m$ CMOS 공정으로 설계하였다. 모의실험 결과 설계된 회로는 3V 이내의 입력전압에서 100nA보다 작은 전류를 소모하며, 최대 전력효율은 99.7%이다. 설계된 회로의 칩 면적은 $1151{\mu}m{\times}940{\mu}m$이다.

• Transactions on Electrical and Electronic Materials
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• 제5권4호
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• pp.153-157
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• 2004

ITO thin films were deposited on PET and soda-lime glass substrates by a dc reactive magnetron sputtering of In-Sn alloy metal target without substrate heater and post-deposition thermal treatment. The dependency of rf-bias voltage and substrate power during deposition processing was investigated to control the electrical and optical properties of ITO films. The range of rf bias voltage is from 0 to -80 V and the substrate power is applied from 10 to 50 W. The minimum resistivity of ITO film is 5.4${\times}$10$^{-4}$ $\Omega$cm at 50 W power and rf-bias voltage of -20 V. The best transmittance of ITO films at 550 nm wavelength is 91 % in the substrate power of 30 W and rf-bias voltage of -80 V.

• E2M - 전기 전자와 첨단 소재
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• 제10권7호
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• pp.692-699
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• 1997

The silicon doped $Al_{0.33}$G $a_{0.67}$As were grown by molecular beam epitaxy. The electroreflectance(ER) spectra of Schottky barrier Au/n-Al/suu x/G $a_{1-x}$ As have been measured at various modulation voltage( $V_{ac}$ ) and dc bias voltage( $V_{bias}$). From the observed Franz-Keldysh oscillations(FKO) peak, the band gap energy of the $Al_{x}$G $a_{1-x}$ As is 1.91 eV which corresponds to an Al composition of 33%. The internal electric field( $E_{i}$)of this sample is 2.96$\times$10$^{5}$ V/cm. As the modulation voltage( $V_{ac}$ ) is changed, the line shape of ER signal does not change but its amplitude varies linearly. The amplitude as a function of modulation voltage has saturated at 0.8 V. The internal electric field has decreased from 6.47$\times$10$^{5}$ V/cm to 2.00$\times$10$^{5}$ V/cm as the dc bias voltage( $V_{bias}$) increases from -3.5 V to +0.8 V. The values of built-in voltage( $V_{bi}$ ) and carrier concentration(N) determined from the plot of $V_{bias}$ from the plot of $V_{bias}$ versus $E_{i}$$^{2}$ are 0.855 V and 3.83$\times$10$^{17}$ c $m^{-3}$ , respectively.ively.y.y.y.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1739-1741
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• 2000

DC current density-voltage and impedance spectroscopy studies have been performed on indium-tin-oxide(ITO)/para-sexiphenyl(6p)/aluminium organic electroluminescent device. The device exhibited a blue color emission, The turn-on voltage of the device is observed at 5V from the current density-voltage measurements. The impedance spectroscopy measurements show that a resonance frequency shift with applied DC bias is observed and a single semi-circle Cole-Cole plot is confirmed. The bias-dependent bulk resistance and bias-independent bulk capacitance is observed.

• 공업화학
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• 제17권3호
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• pp.327-330
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• 2006

Si nanodot 배열을 형성하기 위하여 $NbO_{x}$ nanopillar를 건식식각 공정의 식각마스크로써 이용하기 위한 가능성이 조사되었다. $NbO_{x}$ nanopillar는 Al과 Nb의 양극산화 공정을 이용하여 준비되었다. $NbO_{x}$ nanopillar의 식각속도와 식각프로파일은 고밀도 플라즈마를 이용한 반응성 이온 식각법에 의해서 식각가스의 농도와 coil rf power, 그리고 dc bias voltage를 각각 변화시키면서 조사 되었다. $Cl_{2}$ 가스의 농도가 증가할수록 $NbO_{x}$ nanopillar의 식각속도는 감소하였고 coil rf power와 dc bias voltage의 증가는 식각속도의 상승을 초래했다. 선택된 식각조건에서 식각시간을 변화하여 $NbO_{x}$ nanopillar의 식각특성 및 식각메커니즘이 조사되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.472-474
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• 1995

A Sputter ion Plating(SIP) system with a r.f. coil electrode and the Facing Target Sputter(FTS) source was designed for high-quality thin film formation. The rf discharge was combined with DC facing target sputtering in order to enhance ionization degree of a sputtered atoms. The energy of ions incident on the substrate depended on the health potential of DC biased substrate. The mean impact ion energy increased with negative bias voltage and rf power. The adhesive force of the TiN film formed was in the range of 30$\sim$50N, and markedly influenced by substrate bias voltage.