• KIEE International Transactions on Electrophysics and Applications
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• 제3C권2호
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• pp.43-47
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• 2003

Lead zirconate titanate (PZT) thin films were fabricated by the pulsed laser ablation deposition (PLAD) method onto Pt/Ti/SiO$_2$/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The well-crystallized perovskite phase and the (101) preferred orientation were obtained by two-step annealing at the conditions of $650^{\circ}C$, 1 hour. It was found that the temperature for the pulsed laser ablated PZT films annealed via a two-step annealing process can be reduced 20$0^{\circ}C$ compared to that of the conventional three-step annealing temperature profile for enhancing the transformation of the perovskite phase. The remanent polarization and the coercive field of this film were about 20 $\mu$C/$\textrm{cm}^2$ and 46 kV/cm, while the dielectric constant and loss values measured at 1 KHz were approximately 860 and 0.04, respectively. The interesting phenomena of this film, such as vertical shift in hysteresis curve, are also discussed.

• E2M - 전기 전자와 첨단 소재
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• 제9권2호
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• pp.196-203
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• 1996

The highly c-axis oriented zinc oxide thin films were deposited on Sapphire(0001) substrates by reactive RF magnetron sputtering. The characteristics of zinc oxide thin films on RF power, substrate-target distance, and substrate temperature were investigated by XRD, SEM and EDX analyses. The physical characteristics of zinc oxide thin films changed with various deposition conditions. The higher substrate temperatures were, The better crystallinity of zinc oxide thin films. The highly c-axis oriented zinc oxide thin films were obtained at sputter pressure 5mTorr, rf power 200W, substrate temperature 350.deg. C, substrate-target distance 5.5cm. In these conditions, the resistivity of zinc oxide thin films deposited on pt/sapphire was 12.196*10$^{9}$ [.ohm.cm].

• Journal of information and communication convergence engineering
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• 제3권3호
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• pp.131-136
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• 2005

The effects of the deposition temperature on the growth characteristics of the ZnO films were studied for film bulk acoustic wave resonator (FBAR) device applications. All films were deposited using a radio frequency (RF) magnetron sputtering technique. It was found that the growth characteristics of the ZnO films have a strong dependence on the deposition temperature from 25 to $350^{\circ}C$. The ZnO films deposited below $200^{\circ}C$ exhibited reasonably good columnar grain structures with a highly preferred c-axis orientation while those above 200°C showed very poor columnar grain structures with a mixed-axis orientation. This study seems very useful for the future FBAR device applications.

• 한국표면공학회지
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• 제36권2호
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• pp.141-147
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• 2003

Silicon carbide thin film was deposited in APCVD and LPCVD system with 1,3-DSB precursor 1,3-DSB is the single precursor to deposit SiC on Si at low temperature. SiC film was deposited at $850^{\circ}C$ lower than ordinary temperature ($1000~1200^{\circ}C$) in CVD process. SiC thin film glowed to high oriented (111) plane in APCVD system. In LPCVD system, SiC film groved to preferred (220) plane at same temperature. This discrepancy between preferred planes can be described by the difference of deposition mechanism. Amorphous phase and crystal defect were observed in APCVD system with the main growth mechanism of mass transport limited region. But in LPCVD system, we got the SIC film of uniform, faceted structure and high quality.

• 한국재료학회지
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• 제27권2호
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• pp.69-75
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• 2017

To establish low-temperature process conditions, process-property correlation has been investigated for Ga-doped ZnO (GZO) thin films deposited by pulsed DC magnetron sputtering. Thickness of GZO films and deposition temperature were varied from 50 to 500 nm and from room temperature to $250^{\circ}C$, respectively. Electrical properties of the GZO films initially improved with increase of temperature to $150^{\circ}C$, but deteriorated subsequently with further increase of the temperature. At lower temperatures, the electrical properties improved with increasing thickness; however, at higher temperatures, increasing thickness resulted in deteriorated electrical properties. Such changes in electrical properties were correlated to the microstructural evolution, which is dependent on the deposition temperature and the film thickness. While the GZO films had c-axis preferred orientation due to preferred nucleation, structural disordering with increasing deposition temperature and film thickness promoted grain growth with a-axis orientation. Consequently, it was possible to obtain a good electrical property at relatively low deposition temperature with small thickness.

• 감성과학
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• 제9권4호
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• pp.353-366
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• 2006

이 연구의 목적은 백색 LED 조명의 광학적 특성을 분석하고 그 특성에 따라 반응하는 학생과 교사들의 감성 반응을 평가하는 데 있다. 이를 위해 이 연구에서는 백색 LED모듈 5개를 시제품으로 만들어 광학적 특성을 측정하고 감성 평가용 모형을 제작하여 감성 반응을 평가하여 분석하였다. 감성 평가에 이용된 평가 방법은 의미미분법이고 선정된 문항은 16문항이며, 이 문항의 신뢰성과 타당성을 검증하기 위하여 예비 실험을 통하여 신뢰도 분석과 타당도 분석을 하였다. 이 과정에서 4가지 요인을 추출하였는데 제 1요인은 활동성, 제 2요인은 안정감, 제 3요인은 역량성, 제 4요인은 감성이미지 요인이라고 명명하였다. 색온도에 따른 감성 평가의 결과는 활동성과 역량성 요인에서는 색온도가 높은 조명을 선호하였으며 , 안정감 요인에서는 색온도가 낮은 조명을 선호하였다. 감성이미지 요인에서는 색온도와 관련 없이 5800K인 청색 계통의 조명을 선호하였다. 연색지수에 따른 감성 평가의 결과는 활동성, 안정감, 감성이미지 요인에서는 고연색 조명을 선호하였으며, 역량성 요인에서는 중 연색 조명을 선호하였다.

• 패션비즈니스
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• 제3권2호
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• pp.31-36
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• 1999

This study is to examine personal color - preferred color, well-matched color and the relations between preferred color and the well-matched color. Focus is also placed on how sexual difference influences color temperature preference. For data collection, a questionnaire including color stimulus was employed. The subjects of this study were the male and female college students who lived in Pusan. The results of the research are summarized as the following : In view of preferred color, male subjects preferred KEY2 color(warm) in red, pink, and yellow, and preferred KEY1(cool) in green and blue. While most subjects showed the same signal, in green, male preferred KEY1 color and female preferred KEY2 color. Concerning preferred personal color type, KEY1 type person liked KEY1 color except red, and KEY2 type person liked KEY2 color except blue. This shows that people prefer the focused color presenting its own traits. In view of well-matched color, most subjects liked KEY2 color in red, yellow, pink, and they selected KEY1 color in blue as the well-matched color. However, in green, each sex showed different preferences; while male subjects selected KEY1 color as the well-matched color, female ones selected KEY2 color. In each personal color type, KEY1 type male evaluated KEY1 color as the well-matched color, KEY2 type male evaluated KEY2 color except blue. KEY1 type female chose all the KEY1 color as well-matched colors, and KEY2 type female chose KEY2 color. The well-matched colors are similar between male and female subjects. In over 80 percentage of the answers, the preferred colors coincided with well-matched colors. KEY1 type persons chose KEY1 color, and KEY2 type person chose KEY2 color as the well-matched color. These results show that there is a meaningful relationship between the preferred color and well-matched color.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.88-92
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• 2003

본 논문에서는 Al 하부전극 상에서 RF magnetron sputtering 기술을 이용한 ZnO 박막 증착 및 공정온도가 ZnO 결정성장에 미치는 영향을 고려하여 제작한 FBAR 소자에 대한 연구를 발표한다. 결과적으로, 20$0^{\circ}C$의 공정온도에서 주상형 결정립(columnar grain)을 가지고 c축 우선 배향된 ZnO 박막을 얻을 수 있었다. 이렇게 얻은 ZnO 박막을 FBAR 소자에 적용하여 제작한 결과, 2.05GHz의 공진 주파수에서 ~19.5dB의 반사손실을 보였다.

• Nuclear Engineering and Technology
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• 제29권6호
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• pp.488-499
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• 1997

The measurements of the moderator temperature coefficient (MTC) are performed to demonstrate that the calculational model produces results that are consistent with the measurements. Since negative MTC is also a technical specification value that may limit the cycle length, it is important to measure it as accurately as possible. In this report, preferred choice of test method depending on the time in cycle, best power indication and temperature definition in MTC calculation were determined based on the MTC test results taken during initial startup testing and at 2/3 cycle burnup in the Yonggwang nuclear power plant. The results show that the ratio and rodded methods provided good agreement with the predictions during initial startup testing. However, near end-of-cycle the depletion method gives better results, and so is suggested to be used in the MTC measurements at 2/3 cycle burnup. The use of primary Delta T power as a power indicator in the MTC calculations is highly advisable since it responds with good consistent results very quickly to changes unlike secondary calorimetric power. For the appropriate temperature definitions used in the MTC calculations, it is considered that the arithmetic average temperature measured simply by inlet and outlet thermocouples is preferred. Although volumetric average temperature provides better results, the improvement is not sufficient to compensate for the simplicity of calculations by arithmetic average temperature.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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• pp.89-92
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• 2005

The AIN/AI thin films were prepared at various conditions, such as $N_2$ gas flow rate [$N_2(N_2+Ar)$] from 0.6 to 0.9, a substrate temperature ranging from room temperature to $300^{\circ}C$ and working pressure 1mTorr. We estimated crystallographic characteristics and c-axis preferred orientations of AIN/AI thin films as function of AI electrode surface roughness. The optimal processing conditions for AI electrode were found at substrate temperature of $300^{\circ}C$ sputtering power of 100W and a working pressure of 2mTorr. In these conditions, we obtained the c-axis preferred orientation of $AIN/AI/SiO_2/Si$ thin film about 4 degree.