• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.33-36
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• 1999

In this paper, $Ba_{0.5}$Sr$_{0.5}$TiO$_3$ thin-films were prepared on Pt/Ti/Si0$_2$/Si substrates by RF magnetron sp-uttering method. We investigated electric and dielectric properties of BST thin-films with various ann-ealing temperature using in-sute RTA. Deposition conditions of BST films were set substrate temperat-ure, 30$0^{\circ}C$ and working gas ratio, Ar:O$_2$=90:10. After BST films deposited, we fabricated a capacitor of MIM structure with Al top electrode for measurement. Post-annealing using RTA performed at 40$0^{\circ}C$, $600^{\circ}C$, 80$0^{\circ}C$ for 60 sec, respectively. Also we exacted crystallization and composition of BST thin-films by XRD analysis. In measurement result, this capacitors showed a dielectric constant of about 200 at 1MHz and leakage current density of 5$\times$10$^{-8}$ A/$\textrm{cm}^2$ at 1.5V Microstructure of BST thin-films exhibited effective quality in low-temperature annealed 71ms than high-temperature annealed 71ms.s.s.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.55-56
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• 2005

The properties of phosphorus doped ZnO thin films deposited on (001) sapphire substrates by pulsed laser deposition (PLD) were investigated depending on various deposition conditions. The phosphorus (P) doped ZnO target was composed of ZnO + x wt% Al (x=1, 3, 5). The structural, electrical and optical properties of the ZnO thin films were measured by X-ray diffraction (XRD), Hall measurements and photoluminescence (PL). As the deposition temperature optimized, the electrical properties of the phosphorus doped ZnO (ZnO:P) layer showed a electron concentration of $7.76\times10^{16}/cm^3$, a mobility of 10.225 $cm^2/Vs$, a resistivity of 7.932 $\Omega$cm. It was observed the electrical property of the film was changed by dopant activation effect as target variations and deposition conditions.

• 한국세라믹학회지
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• 제48권4호
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• pp.328-333
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• 2011

The influence of Al-doped ZnO (AZO) thin films degraded under high temperature and damp heat on the performance deterioration of Cu(In,Ga)$Se_2$ (CIGS) solar cells was investigated. CIGS solar cells with AZO/CdS/CIGS/Mo structure were prepared on glass substrate and exposed to high temperature ($85^{\circ}C$) and damp heat ($85^{\circ}C$/85% RH) for 1000 h. As-prepared CIGS solar cells had 64.91% in fill factor (FF) and 12.04% in conversion efficiency. After exposed to high temperature, CIGS solar cell had 59.14% in FF and 9.78% in efficiency, while after exposed to damp heat, it had 54.00% in FF and 8.78% in efficiency. AZO thin films in the deteriorated CIGS solar cells showed increases in resistivity up to 3.1 times and 4.4 times compared to their initial resistivity after 1000 h of high temperature and damp heat exposure, respectively. These results can be explained by the decreases in carrier concentration and mobility due to diffusion or adsorption of oxygen and moisture in AZO thin films. It can be inferred that decreases in FF and conversion efficiency were caused by an increase in series resistance, which resulted from an increase in resistivity of AZO thin films degraded under high temperature and damp heat.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.568-573
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• 2011

AZO (Al doped ZnO) thin films were deposited on the quartz substrates with thickness variation from 25 to 300 nm by using PLD (pulsed laser deposition). XRD (x-ray diffractometer), SPM (scanning probe microscopy), Hall effect measurement and uv-visible spectrophotometer were employed to investigate the structural, morphological, electrical and optical properties of the thin films. XRD results demonstrated that films were preferrentially oriented along the c-axis and crystallinity of film was improved with increase of film thickness. As for the surface morphologies, the mean diameter and root mean square of grains were increased as the film thickness was increased. When the film thickness was 200 nm, the lowest resistivity of $4.25{\times}10^{-4}\;{\Omega}cm$ obtained with carrier concentration of $6.84{\times}10^{20}\;cm^{-3}$ and mobility of $21.4\;cm^2/V{\cdot}S$. All samples showed more than 80% of transmittance in the visible range. Upon these results, it is found that the samples thickness can affect their structural, morphological, optical and electrical properties. This study suggests that the resistivity can be improved by controlling film thickness.

• 한국재료학회지
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• 제20권1호
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• pp.47-50
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• 2010

Various thicknesses of Al-doped ZnO (AZO) films were deposited on glass substrate using pulsed dc magnetron sputtering with a cylindrical target designed for large-area high-speed deposition. The structural, electrical, and optical properties of the films of various thicknesses were characterized. All deposited AZO films have (0002) preferred orientation with the c-axis perpendicular to the substrate. Crystal quality and surface morphology of the films changed according to the film thickness. The samples with higher surface roughness exhibited lower Hall mobility. Analysis of the measured data of the optical band gap and the carrier concentration revealed that there were no changes for all the film thicknesses. The optical transmittances were more than 85% regardless of film thickness within the visible wavelength region. The lowest resistivity, $4.13\times10^{-4}\Omega{\cdot}cm^{-1}$ was found in 750 nm films with an electron mobility $(\mu)$ of $10.6 cm^2V^{-1} s^{-1}$ and a carrier concentration (n) of $1.42\times10^{21} cm^{-3}$.

• 한국세라믹학회지
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• 제50권6호
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• pp.551-556
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• 2013

AlN films with c-axis orientation and thermal conductivity characteristics were deposited by using Pulsed Laser Deposition and the films were characterized by changing the deposition conditions. In particular, we investigated the optimal conditions for the application of a heat sinking plane AlN thin film. Epitaxial AlN films were deposited on sapphire ($c-Al_2O_3$) single crystals by pulsed laser deposition (PLD) with an AlN target. AlN films were deposited at a fixed pressure of $2{\times}10^{-5}$ Torr, while the substrate temperature was varied from 500 to $700^{\circ}C$. According to the experimental results of the growth temperature of the thin film, AlN thin films were confirmed with a highly c-axis orientation, maximum grain size, and high thermal conductivity at $650^{\circ}C$. The thermal conductivity of the AlN thin film was found to increase compared to bulk AlN near the band gap value of 6.2 eV.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.319.2-319.2
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• 2014

휴대기기 발전과 사용 증가로 인해 배터리의 고용량화와 소형화가 요구되고 있으며, 특히 의료용 센서 기기 같은 health care device에서 소형화에 대한 관심이 증가하였다. 박막 이차 전지는 박막형태로 배터리의 구성요소를 한층씩 쌓아 올린 형태이므로 소형화가 가능하며, 내부에 액체전해질이 없어 누액으로 인한 폭발등의 염려가 없다. 또한 Si 반도체 소자에 integration 할 수 있어 다양한 분야에 적용할 수 있다. 하지만 Si 소자에 integration시 리튬이 기판으로 확산되어 배터리 용량이 감소하거나 Si 소자에 악영향을 미칠 수 있다. 따라서 본 연구에서는 리튬의 확산 여부를 민감하게 평가할 수 있는 방법 및 리튬 확산을 억제할 수 있는 확산방지막에 대한 연구를 진행하였다. 리튬의 확산을 평가하는 방법으로는 물리적 분석 방법 및 전기적 분석 방법을 평가하여 가장 민감한 방법을 선정하였다. 또한 확산방지막으로는 반도체 배선공정에서 Cu 확산 방지막으로 사용되고 있는 Ta, TaN 등과 함께 Na 확산 방지막으로 알려진 $Al_2O_3$ [1]등을 평가하였다.

• 한국전기전자재료학회논문지
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• 제27권7호
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• pp.433-437
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• 2014

Transparent thin film transistors were fabricated on $n^+$-Si wafers coated by $Al_2O_3/SiO_2$. Zinc tin oxide (ZTO) films deposited by rf magnetron sputtering were employed for active layers. The mobility (${\mu}s$), threshold voltage ($V_T$), and subthreshold swing (SS) dependances on ZTO thickness were analyzed. The $V_T$ decreased with increasing ZTO thickness. The ${\mu}s$ raised from $5.1cm^2/Vsec$ to $27.0cm^2/Vsec$ by increasing ZTO thickness from 7 nm to 12 nm, and then decreased with ZTO thickness above 12 nm. The SS was proportional to ZTO thickness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1756-1758
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• 1999

As new gas sensing material with high cata activity for NO decomposition and for CO oxid $LaFeO_3$ thin films with different thicknesses fabricated by the R.F. magnetron sputtering m on an $Al_2O_3$ substrates with Ag electrodes. The sensing characteristics of the $LaFeO_3$ thin films studied as a function of annealing temperature film thickness. The thin film annealed at showed the highest sensitivity of 110% for CO 60% for NO.

• 센서학회지
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• 제6권1호
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• pp.6-15
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• 1997

이 논문은 빔의 구조를 갖거나 멤브레인의 구조를 갖는 써모파일 센서의 다목적 최적설계에 관한 연구이다. 연구대상의 써모파일 센서는 $Si_{3}N_{4}/SiO_{2}$ 박막위에 알루미늄과 다결정 실리콘을 사용하여 열전쌍을 형성하고, 박막중심부에 $RuO_{2}$를 사용하여 적외선 흡수부를 만들어 중심부와 실리콘림부 사이의 온도차이에 따른 Seebeck 효과에 의한 유기전압을 감지하는 센서를 대상으로 하였다. 최적설계의 목적함수는 센서의 감도, 검출능 (detectivity) 및 열시정수를 대상으로 하였다. 패키지를 고려하여 모델링을 하였으며, 기존의 식의 고찰에 의한 단순 설계방법이 아닌 수학적 계획법을 사용한 다목적 최적화 방법을 이용하여 최적해를 구하였다. 최종적인 최적설계 수식화에는 퍼지계획법에서 사용되는 소속함수를 정의하여 설계자가 우선적으로 신뢰할 수 있는 해를 구 할 수 있도록 하였다. 또한, 제한조건으로서 주위 온도변화에 따른 센서의 출력전압변화를 포함시켜 실제 사용되는 환경을 고려하였다.