• 한국전기전자재료학회논문지
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• 제16권4호
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• pp.292-297
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• 2003

We fabricated a single crystal silicon thin film transistor for active matrix organic light emitting displays(AMOLEDs) using silicon on insulator wafer (SOI wafer). Poly crystal silicon thin film transistor(poly-Si TFT) Is actively researched and developed nowsdays for a pixel switching devices of AMOLEDs. However, poly-Si TFT has some disadvantages such as high off-state leakage currents and low field-effect mobility due to a trap of grain boundary in active channel. While single crystal silicon TFT has many advantages such as high field effect mobility, low off-state leakage currents, low power consumption because of the low threshold voltage and simultaneous integration of driving ICs on a substrate. In our experiment, we compared the property of poly-Si TFT with that of SOI TFT. Poly-Si TFT exhibited a field effect mobility of 34 $\textrm{cm}^2$/Vs, an off-state leakage current of about l${\times}$10$\^$-9/ A at the gate voltage of 10 V, a subthreshold slope of 0.5 V/dec and on/off ratio of 10$\^$-4/, a threshold voltage of 7.8 V. Otherwise, single crystal silicon TFT on SOI wafer exhibited a field effect mobility of 750 $\textrm{cm}^2$/Vs, an off-state leakage current of about 1${\times}$10$\^$-10/ A at the gate voltage of 10 V, a subthreshold slope of 0.59 V/dec and on/off ratio of 10$\^$7/, a threshold voltage of 6.75 V. So, we observed that the properties of single crystal silicon TFT using SOI wafer are better than those of Poly Si TFT. For the pixel driver in AMOLEDs, the best suitable pixel driver is single crystal silicon TFT using SOI wafer.

• 센서학회지
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• 제22권5호
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• pp.369-373
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• 2013

In this paper, we developed contact type temperature sensor with single crystal silicon strip thermopile. This sensor consists of 15 p-type single crystal silicon strips, 17 n-types and contact electrodes on silicon dioxide silicon membrane. The result of electromotive force measuring showed very good characteristic as $15.18mV/^{\circ}C$ when temperature difference between the two ends of the thermopile occurs by applying thermal contact on the thermopile which was fabricated with silicon strip of $200{\mu}m$ length, $20{\mu}m$ width, $1{\mu}m$ thickness.

• 한국결정성장학회지
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• 제4권2호
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• pp.111-118
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• 1994

Crystal growth chamber 상부에 있는 reservoir에서 polycrystalline silicon powder를 연속적으로 feeding하면서 도가니 하부에 용융대를 형성시키고 seed를 meed를 dipping하여 회전시키면서 하부로 끌어내려 단결정을 성장시키는 연속성장법의 기본 원리를 확립하였고, 직접 고안 설계 제작한 연속성장 장치로 silicon 단결정을 성장시켰다. 본 연속성장법은 melt에 미치는 중력, 진동, melt의 표면장력, melt와 solid의 계면 장력, seed의 회전에 따른 원심력 등의 힘들이서로 상쇄되고 power, feeding양과 성장속도가 비례하여 적당한 조합을 이룰 때 안정한 연속성장을 할 수있다.

• 한국결정성장학회지
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• 제19권6호
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• pp.293-297
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• 2009

본 연구에서는 p형 단결정 규소 기판을 에칭시켜 다층구조를 갖는 DBR 및 Microcavity 다공질규소를 제작하고, 그 반사율 스펙트럼을 조사하였다. 그 결과 다층구조를 갖는 다공질규소의 반사율 스펙트럼에서 프린지 패턴의 수는 단일층 다공질규소의 경우보다 상대적으로 많았으며, 특정 파장에서 반사율은 90 % 이상으로 나타났다. 그리고 DBR 다공질규소에서 최대 반사율 봉우리의 FWHM 값은 33 nm로 매우 좁게 나타났다.

• 한국결정성장학회지
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• 제15권4호
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• pp.129-134
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• 2005

초크랄스키 단결정장치내 실리콘 유동의 자기장효과에 대한 수치해석을 하였다. 8" 단결정 성장과정에서 난류 모형을 사용하여 수송현상을 계산하였다. 도가니 회전수가 작으면 자연대류가 지배적이었다. 도가니 회전수가 증가할수록 강제대류가 증가되며 온도 분포는 더 넓어진다. cusp 자기장을 인가하면 도가니근처의 유동이 크게 감소하며 온도분포는 전도의 경우와 비슷해진다.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.39-43
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• 2012

This paper presents a study on the design of a pulling module for silicon ingot and an apparatus of manufacturing silicon single crystal ingot using the same method. The pulling module is conceptually designed by using TRIZ. Czochralski method(CZ) is representative way to manufacture single crystal ingot for wafers. The seed can be broken by high tension which is caused by large weight of a silicon ingot. The solution of this problem has been derived using 6SC(6 steps creativity)TRIZ. The pulling module is actuated by DC motor and rollers. High tension in the seed is removed by the rotate-elevate motion of rollers in the pulling module. A rubber belt is included in the rotate-elevate mechanism for increasing friction between rollers and silicon ingot.

• 한국생산제조학회지
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• 제20권4호
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• pp.395-400
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• 2011

Scanning Probe Lithography is a method to localized oxidation on single crystal silicon wafer surface. This study demonstrates nanometer scale non contact lithography process on (100) silicon (p-type) wafer surface using AFM(Atomic force microscope) apparatuses and pulse controlling methods. AFM-based experimental apparatuses are connected the DC pulse generator that supplies ultra short pulses between conductive tip and single crystal silicon wafer surface maintaining constant humidity during processes. Then ultra short pulse durations are controlled according to various experimental conditions. Non contact lithography of using ultra short pulse induces electrochemical reaction between micro-scale tip and silicon wafer surface. Various growths of oxides can be created by ultra short pulse non contact lithography modification according to various pulse durations and applied constant humidity environment.

• 소성∙가공
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• 제12권7호
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• pp.623-630
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• 2003

Nanomachining process, static nanoplowing, is one of the most promising lithographic technologies in terms of the low cost of operation and variety of workable materials. In nanomachining process, chemical effects are more dominant factor compared with those by physical deformation or fracture. For example, during the nanoscratch on a silicon surface in the atmosphere, micro protuberances are formed due to the mechanochemical reaction between diamond tip and the surfaces. On the contrary, in case of chemically stable materials, such as ceramic or glass, surface protuberances are not formed. The purpose of this study is to understand effects of the mechanochemical reaction between tip and surfaces on deformation behaviors of hard-brittle materials. Nanometerscale elasoplastic deformation behavior of single crystal silicon (100) was characterized with micro protuberance phenomena, and compared with that of borosilicate (Pyrex glass 7740). In addition, effects of the silicon protuberances on nanoscratch test results were discussed.

• 비파괴검사학회지
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• 제36권1호
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• pp.1-8
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• 2016

Single crystalline silicon wafers having (100), (110), and (111) directions are employed as specimens for obtaining slowness profiles. Leaky Lamb waves (LLW) from immersed wafers were detected by varying the incident angles of the specimens and rotating the specimens. From an analysis of LLW signals for different propagation directions and phase velocities of each specimen, slowness profiles were obtained, which showed a unique symmetry with different symmetric axes. Slowness profiles were compared with elastic moduli of each wafer. They showed the same symmetries as crystal structures. In addition, slowness profiles showed expected patterns and values that can be inferred from elastic moduli. This implies that slowness profiles can be used to examine crystal structures of anisotropic solids.

• 비파괴검사학회지
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• 제35권6호
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• pp.381-388
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• 2015

The speed and oscillation directions of elastic waves propagating in the [ab0] direction of a silicon single crystal were obtained by solving Christoffel's equation. It was found that the quasi waves propagate in the off-principal axis, and hence, the directions of the phase and group velocities are not the same. The maximum deviation of the two directions was $7.2^{\circ}$. Two modes of the pure transverse waves propagate in the [110] direction with different speeds, and hence, two peaks were observed in the pulse echo signal. The amplitude ratio of the two peaks was dependent on the initial oscillating direction of the incident wave. The pure and quasi-transverse waves propagate in the [210] direction, and the oscillation directions of these waves are perpendicular to each other. The skewing angle of the quasi wave was calculated as $7.14^{\circ}$, and it was measured as $9.76^{\circ}$. The amplitude decomposition in the [210] direction was similar to that in the [110] direction, since the oscillation directions of these waves are perpendicular to each other. These results offer useful information in measuring the crystal orientation of the silicon single crystal.