• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.703-706
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• 2002

Piezoelectric thin film such as ZnO and AlN can be applicable to FBAR (Film Bulk Acoustic Resonator) device of thin film type and FBAR can be applicable to MMIC. The characteristic of FBAR device is variable according to the deposition conditions of piezoelectric thin film when preparation of thin film by sputtering method. In this study, we prepared ZnO thin film for FBAR using Facing Targets Sputtering apparatus which can be deposited fine Quality thin film because temperature increase of substrate due to the bombardment of high-energy particles can be restrained. And crystalline and c-axis preferred orientation of ZnO thin film with deposition conditions was investigated by XRD.

• Current Photovoltaic Research
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• 제8권3호
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• pp.94-101
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• 2020

This study was trying to focus on achieving high efficiency of multi junction solar cell with thin film silicon solar cells. The proposed thin film Si-Ge/c-Si tandem junction solar cell concept with a combination of low-cost thin-film silicon solar cell technology and high-efficiency c-Si cells in a monolithically stacked configuration. The tandem junction solar cells using amorphous silicon germanium (a-SiGe:H) as an absorption layer of upper sub-cell were simulated through ASA (Advanced Semiconductor Analysis) simulator for acquiring the optimum structure. Graded Ge composition - effect of E_g profiling and inserted buffer layer between absorption layer and doped layer showed the improved current density (J_sc) and conversion efficiency (η). 13.11% conversion efficiency of the tandem junction solar cell was observed, which is a result of showing the possibility of thin film Si-Ge/c-Si tandem junction solar cell.

• 한국전기전자재료학회논문지
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• 제17권10호
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• pp.1100-1106
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• 2004

In this paper, we intend to make fringe-field switching (FFS) mode cell by the ion beam (IB) alignment method on the a-C：H thin film, to analyze electro-optical characteristics in this cell. We studied on the suitable inorganic thin film for fringe-field switching (FFS) cell and the aligning capabilities of nematic liquid crystal (NLC) using the alignment material of a-C：H thin film as working gas at 30 W rf bias condition. A high pretilt angle of about 5 $^{\circ}C$ by ion beam (IB) exposure on the a-C：H thin film surface was measured. Consequently, the high pretilt angle and the good thermal stability of LC alignment by the IB alignment method on the a-C：H thin film surface as working gas at 30 W rf bias condition can be achieved. An excellent voltage-transmittance (V -T) and response time curve of the IE-aligned FFS-LCD was observed with oblique IB exposure on the a-C：H thin films. Also, AC V-T hysteresis characteristics of the IB-aligned FFS-LCD with IE exposure on the a-C：H thin films is almost the same as that of the rubbing-aligned FFS cell on a polyimide (PI) surface.

• 한국세라믹학회지
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• 제44권1호
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• pp.32-36
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• 2007

Zinc gallate $(ZnGa_2O_4)$ thin film phosphors have been formed on ITO glass substrates by a sol-gel spinning coating method. For the formation of the film phosphors, the starting materials of zinc acetate dihydrate, gallium nitrate hydrate and 2-methoxyethanol as a solution were used. The thin films deposited were firstly dried at $100^{\circ}C$ and fired at $500^{\circ}C\;or\;600^{\circ}C$ for 30 min and then, annealed $500^{\circ}C\;or\;600^{\circ}C$ at for 30 min under an annealing atmosphere of 3% $H_2/Ar$. The thin films deposited on ITO glass plates showed the (220), (222), (400), (422), (511), and (440) peaks of spinel structure as well as the (311) peak indicating a standard powder diffraction pattern. The surface morphologies of the thin film phosphors were observed with a firing and an annealing condition. The $ZnGa_2O_4$ film phosphors showed the blue emission spectra around 410 nm as well as the emission spectra in the UV region (360-380 nm).

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1859-1862
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• 2004

Europium doped yttrium vanadate ($YVO_4$:Eu) phosphor thin films were grown using a pulsed laser deposition (PLD) technique on silicon substrate. The structural characterization carried out on a series of ($YVO_4$:Eu films at post annealing temperature in the range of 550 $^{\circ}C$-1150 $^{\circ}C$ indicating that films were preferentially (200) oriented at post annealing temperature above 950 $^{\circ}C.$ Photoluminescence of thin film increased with the increase of post annealing temperature and ambient oxygen pressure though the thin film has the powder-like surface morphology at oxygen pressure above 200 mTorr. Photoluminescence decay from $^5D_1$ level of $Eu^{3+}$ show the great concentration dependency, which can be used as a good parameter to control the composition of ($YVO_4$:Eu thin film.

• Elastomers and Composites
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• 제45권4호
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• pp.298-308
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• 2010

패럴린 박막의 기계적 성질과 표면 특성을 개선하기 위해 Xylydene계 다이머(DPX-C, DPX-D, DPX-N)를 사용하여 각각의 다이머에 대한 증착 조건과 투입량에 따른 박막의 두께를 조절함으로써 단일 패럴린-C, D, N 박막과 두 가지 타입이 혼합된 하이브리드 타입의 화학적, 물리적 패럴린 박막을 제조하였다. 패럴린 증착은 화학기상증착법(chemical vapor deposition: CVD)을 이용하였으며, 열분석을 통해 단일 박막과 하이브리드 타입의 박막에 대한 열적 특성을 비교 분석하였다. 인장 강도와 신장율 그리고 인열력 시험을 통해 박막에 대한 기계적 물성을 알아보았으며, 접촉각과 표면 에너지를 측정하여 박막에 대한 표면 특성을 관찰하였다. 두 가지 타입이 혼합된 하이브리드 타입의 화학적 패럴린 박막은 서로 다른 다이머의 장단점을 상호 보완시켜 줄 수 있으며, 물리적 패럴린 박막은 기재에 코팅되는 면과 반대 면의 박막 특성을 자유롭게 조절할 수 있다.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.281-286
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• 2002

In odder to investigate the magnetic properties of CoCr-based bilayered thin films on kind of underlayer, we introduced amorphous Si layer to Co-Cr(-Ta) magnetic layer as underlayer. First, we prepared CoCr and CoCrTa single layer using the Facing Targets Sputtering system to investigate theirs properties. It was revealed that with increasing the film thickness of CoCr, CoCrTa single layer, crystalline orientation and perpendicular coercivity was improved. The CoCrTa thin film showed bettor crystalline and magnetic characteristics than CoCr thin film. As a result of investigating magnetic properties of CoCr and CoCrTa magnetic layer on introducing the Si underlayer, perpendicular coercivity and saturation magnetization of CoCr/Si and CoCrTa/Si bilayered thin film were decreased due to the increased grain size and diffusion of Si atoms to magnetic layer. And they showed constant with increasing the film thickness of Si thin film. However, in case of CoCrTa/Si bilayered thin film, in-plane coercivity was controlled low at about 250Oe. The c-axis orientations of CoCr/si and CoCrTa/Si bilayered thin film showed a good crystalline characteristics as about $2^{\circ}$.

• 한국표면공학회지
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• 제50권5호
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• pp.345-351
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• 2017

A double-layered anti-reflective coating with hydrophilic/abrasion-resistant properties was studied using anatase titanium dioxide($TiO_2$) and silicon oxycarbide($SiO_xC_y$) thin film. $TiO_2$ and $SiO_xC_y$ thin films were sequentially deposited on a glass substrate by DC sputtering and PECVD, respectively. The optical properties were measured by UV-Vis-NIR spectrophotometer. The abrasion-resistance and the hydrophilicity were observed by a taber abrasion tester and a contact angle analyzer, respectively. The $TiO_2/SiO_xC_y$ double-layer thin film had an average transmittance of 91.3%, which was improved by 10% in the visible light region (400 to 800 nm) than that of the $TiO_2$ single-layer thin film. The contact angle of $TiO_2/SiO_xC_y$ film was $6.9^{\circ}$ right after UV exposure. After 9 days from the exposure, the contact angle was $10.2^{\circ}$, which was $33^{\circ}$ lower than that of the $TiO_2$ single-layer film. By the abrasion test, $SiO_xC_y$ film showed a superior abrasion-resistance to the $TiO_2$ film. Consequently, the $TiO_2/SiO_xC_y$ double-layer film has achieved superior anti-reflection, hydrophilicity, and abrasion resistance over the $TiO_2$ or $SiO_xC_y$ single-layer film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.709-712
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• 2001

The effects of post annealing temperature by the Rapid Thermal Annealing(RTA) on the electrical properties of Pb(Zr,Ti)O$_3$(PZT) thin film were investigated. Analyses by the RTA treatments reveled that the leakage current of PZT thin films strongly depend on heating temperature and time. It was found that leakage current properties of PZT capacitor were changed by heating temperature during the RTA annealing. On Pt/Ti/Si substrates, PZT films are deposited at 350 $^{\circ}C$ by rf magnetron sputtering. The X-ray diffusion (XRD) was confirmed the formation of PZT thin film. Leakage current characteristics were improved with decreasing the post annealing temperature of PZT thin film. RTA annealed film on the 700$^{\circ}C$ shows ferroelectric and electrical properties with a remanent polarization of 12.4${\mu}$C/$\textrm{cm}^2$ coercive field of 117kV/cm, leakage current J= 6.2${\times}$10$\^$-6/ A/$\textrm{cm}^2$

• 한국정보통신학회논문지
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• 제7권3호
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• pp.468-473
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• 2003

본 연구에서는 박막트랜지스터의 특성 향상을 위하여 강유전성 박막을 게이트 절연층으로 사용하기 위하여 강유전성 박막과 a-Si:H의 계면특성을 조사하였다. 먼저 강유전성 박막 중에 대표적인 SrTiO$_3$를 I-BEAM 증착기로 박막을 형성시켰다. 형성된 박막은 N2 분위기에서 $150^{\circ}C∼600^{\circ}C$로 1시간 ANNEALING하여 전자현미경으로 표면을 측정하였다. SrTiO$_3$의 유전상수는 50∼100 정도였으며 항복전계는 1∼l.5 MV/cm로 매우 우수한 유전특성을 갖고 있었다. 강유전체 박막 위에 a-SiN:H,a-Si:H(n-type a-Si:H) 등을 PECVD로 증착하여 MFNS구조를 형성하였다. 계면특성을 C-V PLOTTER로 측정한 결과 SrTiO$_3$ 박막은 SiN과의 접합이 매우 안정되어 있었고 C-V특성은 SiN/a-Si:H과 유사하였다. 그러나 FERROELECTRIC/a-S:H의 경우가 훨씬 CAPACITANCE 값이 컸으며, 이는 강유전체 박막의 높은 유전상수에 기인 된 것이라 생각된다.