• 한국세라믹학회지
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• 제32권3호
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• pp.371-377
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• 1995

Silicon oxide films were grown on single-crystal silicon substrates at low temperatures (25~205$^{\circ}C$) in a low pressure electron cyclotron resonance (ECR) oxygen plasma. The growth rate of the silicon oxide film increased as the temperature increased or the pressure decreased. Also, the thickness of the silicon oxide film increased at negative bias voltage, but not changed at positive bias voltage. The growth law of the silicon oxide film was approximated to the parabolic form. Capacitance-voltage (C-V) and current density-electric field (J-E) characteristics were studied using Al/SiO2/p-Si MOS structures. For a 10.2 nm thick silicon oxide film, the leakage current density at the electric field of 1 MVcm-1 was less than 1.0$\times$10-8Acm-2 and the breakdown field was higher than 10 MVcm-1. The flat band voltage of Al/SiO2/p-Si MOS capacitor was varied in the range of -2~-3 V and the effective dielectric constant was 3.85. These results indicate that high quality oxide films with properties that are similar to those of thermal oxide film can be fastly grown at low temperature using the ECR oxygen plasma.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.688-688
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• 2013

Al-doped ZnO (AZO) thin films have attracted a lot of attention as a cheap transparent conducting oxide (TCO) material that can replace the expensive Sn-doped In2O3. In particular, AZO thin films are widely used as a window layer of chalcogenide-based thin film solar cells such as Cu(In,Ga)Se2 and Cu2ZnSnS4 (CZTS). Mostly important requirements for the window layer material of the thin film solar cells are the high transparency and the low sheet resistance, because they influence the light absorption by the activelayer and the electron collection from the active layer, respectively. In this study, we prepared the AZO thin films by RF magnetron sputtering using a ZnO/Al2O3 (98：2wt%) ceramic target, and the effect of the sputtering condition such as the working pressure, RF power, and the working distance on the optical, electrical, and crystallographic properties of the AZO thin films was investigated. The AZO thin films with optimized properties were used as a window layer of CZTS thin film solar cells. The CZTS active layers were prepared by the electrochemical deposition and the subsequent sulfurization process, which is also one of the cost-effective synthetic approaches. In addition, the solar cell properties of the CZTS thin film solar cells, such as the photocurrent density-voltage (J-V) characteristics and the external quantum efficiency (EQE) were investigated.

• 한국세라믹학회지
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• 제50권1호
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• pp.50-56
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• 2013

Phosphorescent materials coated with titanium dioxide were fabricated and photocatalytic reactions between these materials and VOCs gases were examined. A thin film (approx. 100 nm) of nanosized $TiO_2$ was deposited on the $Sr_4Al_{14}O_{25}$ : $Eu^{2+}$, $Dy^{3+}$, $Ag^+$ phosphor using low-pressure chemical vapor deposition (LPCVD). The characteristics of the photocatalytic reaction were examined in terms of the decomposition of benzene gas using a gas chromatography (GC) system under ultraviolet (${\lambda}$ = 365 nm) and visible light (${\lambda}$ > 420 nm) irradiation. $TiO_2$-coated $Sr_4Al_{14}O_{25}$ : $Eu^{2+}$, $Dy^{3+}$, $Ag^+$ phosphor showed different photocatalytic behavior compared with pure $TiO_2$. $TiO_2$-coated phosphorescent materials showed a much faster photocatalytic decomposition of benzene gas under visible irradiation compared to the pure $TiO_2$ for which the result was practically negligible. This suggests that the extension of the absorption wavelength to visible light occurred through energy band bending by a heterojunction at the interface of the $Sr_4Al_{14}O_{25}-TiO_2$ composite. Also, the $Sr_4Al_{14}O_{25}-TiO_2$ composite showed the photocatalytic decomposition of benzene in darkness due to the photon light emitted from the $Sr_4Al_{14}O_{25}$ phosphors.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.932-934
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• 2003

For the insulator of inorganic thin film electroluminescent (TFEL), devices AlON combined with TiON was used and it exhibits higher luminance than AlON as well as $Al_{2}O_{3}$ insulator. Furthermore, using AlON with TiON film show better stability and higher luminance than that with $TiO_{2}$ grown by conventional atomic layer deposition (ALD) for the application of the insulator of ZnS:Mn TFEL device.

• 한국표면공학회지
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• 제42권3호
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• pp.122-127
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• 2009

Ga/Al doped ZnO (GAZO) thin films were prepared on non-alkali glass substrate by co-sputtering system using two DC cathodes equipped with AZO ($Al_2O_3$:2.0 wt%) target and GZO ($Ga_2O_3$:6.65 wt%) target. This study examined the influence of Al/Ga concentration and substrate temperature on the electrical, structural and optical properties of GAZO films. The lowest resistivity $1.95{\times}10^{-3}{\Omega}cm$ was obtained at room temperature. With increasing substrate temperature, resistivity of GAZO film decreased to a minimum value of $7.47{\times}10^{-4}{\Omega}cm$ at below $300^{\circ}C$. Furthermore, when 0.05% $H_2$ gas was introduced, resistivity of GAZO film decreased to $6.69{\times}10^{-4}{\Omega}cm$. All the films had a preferred orientation along the (002) direction, indicating that the deposited films have hexagonal wurtzite structure formed by the textured growth along the c-axis. The average transmittance of the films was more than 85% in the visible light range.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.137-137
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• 2003

Optical amplificator have been used to compensate the losses in the optical signal transmission and processing. Today, there has been increasing demand for the very low cost optical amplifier. Sol-gel offers considerable potential both low cost manufacture, and for great flexibility in materials composition and structure. In addition, the sol-gel process is a very attractive method for producing porous materials with controlled structure. In this work, we present the potoluminescence properties of Er doped A1$_2$O$_3$/SiO$_2$ films. Erbium doped alumina nano sol was prepared by Al(NO$_3$)$_3$.9$H_2O$ and Er(NO$_3$)$_3$.5$H_2O$ through hydrolysis and peptization, and then GPS (3-Glycidoxypropyltrimethoxysilane) was added into Er doped alumina nano sol for organic- inorganic hybridization. Er doped A1$_2$O$_3$/SiO$_2$ film was obtained by spin coating, dip coating and thermal treatment from 30$0^{\circ}C$~120$0^{\circ}C$, and there were crack-free after thermal treatment. The thickness of film was measured SEM, and the porosity of film was characterized by BET and TGA. The crystal phase of Er doped A1$_2$O$_3$/SiO$_2$ were determined by XRD. Finally, the photoluminescence properties of Er doped A1$_2$O$_3$/SiO$_2$ films will be discuss with the consideration of porosity and crystallity.

• 한국전기전자재료학회논문지
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• 제26권3호
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• pp.177-182
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• 2013

Transparent thin film transistors (TTFT) were fabricated on $N^+$ Si wafers. $SiO_2$, $Si_3N_4/SiO_2$ and $Al_2O_3/SiO_2$ grown on the wafers were used as gate insulators. The rf magnetron sputtered zinc tin oxide (ZTO) films were adopted as active layers. $N^+$ Si wafers were wet-oxidized to grow $SiO_2$. $Si_3N_4$ and $Al_2O_3$ films were deposited on the $SiO_2$ by plasma enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD), respectively. The mobility, $I_{on}/I_{off}$ and subthreshold swing (SS) were obtained from the transfer characteristics of TTFTs. The properties of gate insulators were analyzed by comparing the characteristics of TTFTs. The property variation of the ZTO TTFTs with time were observed.

• 한국분말재료학회지
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• 제22권6호
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• pp.438-442
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• 2015

Porous thick film of alumina which is fabricated by freeze tape casting using a camphene-camphor-acrylate vehicle. Alumina slurry is mixed above the melting point of the camphene-camphor solvent. Upon cooling, the camphene-camphor crystallizes from the solution as particle-free dendrites, with the $Al_2O_3$ powder and acrylate liquid in the interdendritic spaces. Subsequently, the acrylate liquid is solidified by photopolymerization to offer mechanical properties for handling. The microstructure of the porous alumina film is characterized for systems with different cooling rate around the melting temperature of camphor-camphene. The structure of the dendritic porosity is compared as a function of ratio of camphene-camphor solvent and acrylate content, and $Al_2O_3$ powder volume fraction in acrylate in terms of the dendrite arm width.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1057-1061
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• 2007

본 연구에서는 AlAs와 ZnO target을 사용하여 RF magnetron sputtering 시스템에서 layer-by-layer 방법으로 증착한 ZnO 박막의 특성에 대하여 조사하였다. 또한 열처리 전에 $H_2O_2$용액을 사용한 처리가 박막 특성에 미치는 영향도 조사하였다. 연구 결과 열처리 조건에 따라 n-형 또는 p-형 박막이 형성되는 것으로 관찰되었다. 이러한 결과는 박막의 전도 형태를 임의로 수정할 수 있음을 의미하는 동시에 박막 특성의 열적 불안정성을 암시하는 것이기도 하다. 144시간까지 스트레스를 인가한 후 측정한 박막 특성 결과 열처리 과정 중 발생하는 이러한 박막 특성 변화는 열처리 전 박막을 30% $H_2O_2$용액에 1분간 처리함으로써 억제할 수 있는 것으로 관찰되었다.

• 마이크로전자및패키징학회지
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• 제7권2호
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• pp.29-36
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• 2000

후막 페이스트용 glass frit의 내산성에 영향을 미치는 프릿트 제조방법 및 첨가제의 영향을 연구하였다. 프릿트 제조 방법에 따른 내산성을 관찰하기 위하여 $PbO-SiO_2-B_2O_3$기본 조성을 습식 및 건식 등의 흔합 방법 및 용융 횟수를 변수로 연구하였고, 첨가제에 의한 내산성 연구를 위하여 첨가제로 $ZrO_2$, $Al_2O_3$, $TiO_2$등을 0-l0wt% 첨가하여 첨가제에 따른 내산성 변화를 관찰하였다.