• 한국표면공학회지
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• 제28권4호
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• pp.225-235
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• 1995

To investigate the effects of pretreatment and substrate bias on the characteristics of the diamond thin films, the thin films were deposited on the p-type Si(100) wafer by MPECVD using mixtures of $H_2$, $CH_4$, and $O_2$ gases. Deposition was carried out at the substrate temperature of $900^{\circ}C$ and at the pressure of 40torr. The effect of the pretreatment on the film formation was the examined by using SiC and diamond powders as abrasive powders. Furthermore, the substrate bias effect on the formation of the diamond film was also examined. The highest nucleation density was observed for the pretreatment with 40~60$\mu\textrm{m}$ size of diamond powders and a negative bias potential(-50V). Many defects and(111) twins in the diamond films were observed.

• 한국재료학회지
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• 제16권1호
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• pp.25-29
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• 2006

Vertical growth of iridium-catalyzed carbon nanofibers could be selectively grown on the MgO substrate using microwave plasma-enhanced chemical vapor deposition method. Growth positions of the iridium-catalyzed carbon nanofibers on the MgO substrate could be manipulated according to the applied bias voltage. At-150 V, the carbon nanofibers growth was confined only at the corner area of the substrate. Based on these results, we discussed the cause for the confinement of the vertically grown carbon nanofibers on the specific area of the MgO substrate as a function of the applied bias voltage.

• Transactions on Electrical and Electronic Materials
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• 제6권2호
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• pp.57-62
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• 2005

Using intense pulsed ion beam evaporation technique, we have succeeded in the preparation of poly crystalline silicon thin films without impurities on silicon substrate. Good crystallinity and high deposition rate have been achieved without heating the substrate by using lEE. The crystallinity of poly-Si film has been improved with the high density of the ablation plasma. The intense diffraction peaks of poly-Si thin films could be obtained by using the substrate bias system. The crystallinity and the deposition rate of poly-Si thin films were increased by applying (-) bias voltage for the substrate.

• 한국표면공학회지
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• 제32권3호
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• pp.303-306
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• 1999

On the effect of substrate bias at first stage of diamond synthesis at lower substrate temperature(approximately 673K) using microwave plasma CVD and effect of reaction gas system for the bias enhanced nucleation were studied. The reaction gas was mixture of methane and hydrogen or carbon monoxide and hydrogen. The nucleation density of applied bias -150V using $CH_4-H_2$ reaction gas system, significantly higher than that of $C-H_2$ reaction gas system. When the $CH_4-H_2$ reaction was used, nucleation density was increased because of existence of SiC as a interface for diamond nucleation. By use of this negative bias effect for fabrication of CVD diamond film using two-step diamond growth without pre-treatment, fabrication of the diamond film consist of diamond grains $0.2\mu\textrm{m}$ in diameter was demonstrated

• 전기학회논문지
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• 제56권1호
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• pp.132-138
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• 2007

Carbon nanotubes (CNTs) arc grown on Ni catalysts employing an inductively-coupled plasma chemical vapor deposition (ICP-CVD) method. The structural and field-emissive properties of the CNTs grown are characterized in terms of the substrate-bias applied. Characterization using the various techniques, such as field-omission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and Raman spectroscopy, shows that the structural properties of the CNTs, including their physical dimensions and crystal qualities, as well as the nature of vertical growth, are strongly dependent upon the application of substrate bias during CNT growth. It is for the first time observed that the provailing growth mechanism of CNTs, which is either due to tip-driven growth or based-on-catalyst growth, may be influenced by substrate biasing. It is also seen that negatively substrate-biasing would promote the vertical-alignment of the CNTs grown, compared to positively substrate-biasing. However, the CNTs grown under the positively-biased condition display a higher electron-emission capability than those grown under the negatively-biased condition or without any bias applied.

• 한국결정성장학회지
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• 제4권1호
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• pp.92-99
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• 1994

마이크로웨이브 화학 기상 중착법을 이용하여 n 형 Si(100) 기팡위에 다이아몬드 박막을 증착하였다. 다이아몬드의 핵생성 밀도를 향상시키기 위하여 Si 기판을 다이아몬드 분말로 전처리 하거나 negative bias를 인가하여 다이아몬드 박막을 증착하였다. 전처리한 기판에서는 다이아몬드의 순수도가 전체압력이 증가함에 따라 (20~150 Torr)향상되었으며 bias 인가시에는$CH_4$ 농도와 전체압력에 따라 다이아몬드의 생성유무가 결정되었다.플라즈마의 이온에 의해 가판위에 생성되는 전류를 $CH_4$ 농도, bias 전압, 그리고 전체압력에 따라 측정하였으며 그 결과를 다이아몬드 박막의 생성 조건과 관련시켜 검토 하였다.

• 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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• 제21권8호
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• pp.706-710
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• 2008

The substrate bias effect on the current level of SOI-MOSFETs for high temperature operation has been investigated. In this work, we demonstrate the current level of SOI-MOSFETs can be controlled at different temperatures by applying a control bias to the substrate, showing that all current levels below T=150$^{\circ}C$ can be adjusted to a constant current level. 2D numerical simulation results show that substrate bias effectively controls the current conduction; as the substrate bias effectively lower the potential of the channel, inversion carrier generation is effectively controlled and consequently a constant current conduction level is achieved up to T=150$^{\circ}C$. We also demonstrate that the device simulated in this work has same operation at any temperature below T=150$^{\circ}C$ through mixed mode simulation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.302-303
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• 2008

Nominally undoped (intrinsic) ZnO thin films were deposited by magnetron sputtering system with utilization of substrate bias on silicon at $450^{\circ}C$. Oxygen gas was selected as sputtering gas. The deposited thins were evaluated with X-ray diffraction (XRD) for their microstructure analysis and Hall effect in Van der Pauw configuration for their electrical property. The XRD shows that the magnitude and polarity of substrate bias significantly influence the microstructure and electrical properties.

• 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.