• 한국결정성장학회지
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• 제4권1호
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• pp.71-75
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• 1994

본 연구에서는 (100) 배향된 단결정 실리콘 웨이퍼의 열탄성응력지수, 열응력과 임계소성변형 온도와의 관계를 모사하였다. 열탄성웅력지수는 <110> 방향에서 최대값을, <100> 방향에서 최소값을 보여주었다. 그리고, 열탄성응력지수로 부터 유도된 열응력과 임계 소성변형 온도의 모사로 부터, 실리콘 웨이퍼가 1000K 이상에서 소성변형될 수 있음을 예측할 수 있었다.

• Journal of the Optical Society of Korea
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• 제18권5호
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• pp.569-573
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• 2014

We demonstrate a low-cost, superbly efficient way of etching for the nano-, and micro-sized pyramid patterns on (100)-oriented Si wafer surfaces for use as a patterned master. We show a way of producing functional optical films for the viewing angle direction brightness-enhancement of Lambertian LED (light emitting diode)/OLED (organic light emitting diode) planar lighting applications. An optimally formulated KOH (Potassium hydroxide) wet etching process enabled random-positioned, and random size-distributed (within a certain size range) pyramid patterns to be developed over the entire (100) silicon wafer substrates up to 8" and a simple replication process of master patterns onto the PC (poly-carbonate) and PMMA (poly-methyl methacrylate) films were performed. Haze ratio values were measured for several film samples exhibiting excellent values over 90% suitable for LED/OLED lighting purposes. Brightness was also improved by 13~14% toward the viewing angle direction. Computational simulations using LightTools$^{TM}$ were also carried out and turned out to be in strong agreement with experimental data. Finally, we could check the feasibility of fabricating low-cost, large area, high performance optical films for commercialization.

• 한국세라믹학회지
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• 제40권8호
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• pp.770-776
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• 2003

(111) 및 (100) 단결정 실리콘 웨이퍼에 대하여 #140 mesh와 #600 mesh의 연삭숫돌을 사용하여 연삭가공을 행하고 가공에 의한 표면품위의 변화를 관찰하였다. 이를 위하여 Atomic Force Microscope(Am)을 사용하여 미세거칠기를 분석하고 라만 분광법(Raman spectroscopy)을 통하여 결정구조, 상변화 및 잔류응력을 분석하였다. 그 결과 연삭가공 후에 (111) 면에서 미세거칠기가 더 크게 나타났으며 실리콘이 다이아몬드구조의 Si-I에서 Si-III(body centered tetragonal) 및 Si-XII(rhombohedral)로 전이하는 현상을 라만스펙트럼 분석을 통해 확인하였다. 또한 연삭가공에 의하여 패인 구덩이에서는 일반적인 가공표면과 다른 라만스펙트럼이 관찰되어, 표면에 인가된 잔류응력이 새로운 표면생성으로 해소되었음을 알수 있었다. 또한 열처리에 의한 재료의 표면품위개선효과를 분석하기 위하여 대기 중에서 열처리를 시행한 결과 열처리는 잔류응력의 해소와 상전이의 회복에 효과적인 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1988-1990
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• 1996

In this work, we have grown or evaporated thermal oxide and E-beam oxide on the (100) oriented n-type silicon wafers, respectively and they were directly bonded with another silicon wafer after hydrophilization using solutions of three types of $HNO_3$, $H_{2}SO_{4}$ and $NH_{4}OH$. Changes of average surface roughness after hydrophilizations of the single crystalline silicon wafer, thermal oxide and E-beam evaporated silicon oxide were studied using atomic force microscope. Bonding interfaces of the bonded pairs were inspected using scanning electron microscope. Void and non-contact area of the bonded pairs were also inspected using infrared transmission microscope.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.295-298
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• 2007

Reduction of optical losses in crystalline silicon solar cells by surface modification is one of the most important issues of silicon photovoltaics. Porous Si layers on the front surface of textured Si substrates have been investigated with the aim of improving the optical losses of the solar cells, because an anti-reflection coating(ARC) and a surface passivation can be obtained simultaneously in one process. We have demonstrated the feasibility of a very efficient porous Si ARC layer, prepared by a simple, cost effective, electrochemical etching method. Silicon p-type CZ (100) oriented wafers were textured by anisotropic etching in sodium carbonate solution. Then, the porous Si layers were formed by electrochemical etching in HF solutions. After that, the properties of porous Si in terms of morphology, structure and reflectance are summarized. The structure of porous Si layers was investigated with SEM. The formation of a nanoporous Si layer about 100nm thick on the textured silicon wafer result in a reflectance lower than 5% in the wavelength region from 500 to 900nm. Such a surface modification allows improving the Si solar cell characteristics. An efficiency of 13.4% is achieved on a monocrystalline silicon solar cell using the electrochemical technique.

• 한국전기전자재료학회논문지
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• 제22권7호
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• pp.616-621
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• 2009

Reduction of optical losses in crystalline silicon solar cells by surface modification is one of the most important issues of silicon photovoltaics. Porous Si layers on the front surface of textured Si substrates have been investigated with the aim of improving the optical losses of the solar cells, because an anti-reflection coating(ARC) and a surface passivation can be obtained simultaneously in one process. We have demonstrated the feasibility of a very efficient porous Si ARC layer, prepared by a simple, cost effective, electrochemical etching method. Silicon p-type CZ (100) oriented wafers were textured by anisotropic etching in sodium carbonate solution. Then, the porous Si layers were formed by electrochemical etching in HF solutions. After that, the properties of porous Si in terms of morphology, structure and reflectance are summarized. The structure of porous Si layers was investigated with SEM. The formation of a nanoporous Si layer about 100nm thick on the textured silicon wafer result in a reflectance lower than 5% in the wavelength region from 500 to 900nm. Such a surface modification allows improving the Si solar cell characteristics. An efficiency of 13.4% is achieved on a monocrystalline silicon solar cell using the electrochemical technique.

• 신재생에너지
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• 제2권2호
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• pp.4-8
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• 2006

Reduction of optical losses in crystalline silicon solar cells by surface modification is one of the most important issues of silicon photovoltaics. Porous Si layers on the front surface of textured Si substrates have been investigated with the aim of improving the optical losses of the solar cells, because an anti-reflection coating and a surface passivation can be obtained simultaneously in one process. We have demonstrated the feasibility of a very efficient porous Si AR layer, prepared by a simple, cost effective, electrochemical etching method. Silicon p-type CZ (100) oriented wafers were textured by anisotropic etching in sodium carbonate solution. Then, the porous Si layer were formed by electrochemical etching in HF solutions. After that, the properties of porous Si in terms of morphology, structure and reflectance are summarized. The surface morphology of porous Si layers were investigated using SEM. The formation of a porous Si layer about $0.1{\mu}m$ thick on the textured silicon wafer result in an effective reflectance coefficient Reff lower than 5% in the wavelength region from 400 to 1000nm. Such a surface modification allows improving the Si solar cell characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.183-186
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• 2006

Reduction of optical losses in crystalline silicon solar cells by surface modification is one of the most important issues of silicon photovoltaics. Porous Si layers on the front surface of textured Si substrates have been investigated with the aim of improving the optical losses of the solar cells, because an anti-reflection coating and a surface passivation can be obtained simultaneously in one process. We have demonstrated the feasibility of a very efficient porous Si AR layer, prepared by a simple, cost effective, electrochemical etching method. Silicon p-type CZ (100) oriented wafers were textured by anisotropic etching in sodium carbonate solution. Then, the porous Si layer were formed by electrochemical etching in HF solutions. After that, the properties of porous Si in terms of morphology, structure and reflectance are summarized. The surface morphology of porous Si layers were investigated using SEM. The formation of a porous Si layer about $0.1{\mu}m$ thick on the textured silicon wafer result in an effective reflectance coefficient $R_{eff}$ lower than 5% in the wavelength region from 400 to 1000nm. Such a surface modification allows improving the Si solar cell characteristics.

• 한국진공학회지
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• 제9권3호
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• pp.267-272
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• 2000

electroplating(EP)법을 이용하여 ULSI용 Cu 박막을 제조하였다. seed Cu는 sputtering으로 증착하였으며, 확산방지막으로 TaN를 사용하였다. 제작된 EP Cu 박막은 seed Cu의 영향으로 열처리 조건에 관계없이 Cu(111)방향으로 강하게 우선 배향 하였다. 열처리 온도와 시간이 증가함에 따라 Cu박막의 미세조직이 non-columnar structure에서 약 2배 이상 결정립 성장하여 columnar structure로 바뀌었으며, 또한 as-deposit시 관찰되었던 stacking fault, twin, dislocation들이 상당히 줄어드는 것이 관찰되었다. Cu의 확산에 의하여 생기는 copper-silicide는 관찰할 수 없었으며, 이것은 두께 45nm의 TaN막이 $450^{\circ}C$, 30분 열처리시 확산방지막으로 충분한 역할을 한 것으로 판단된다. Cu(111)우선 배향과 열처리에 의한 결정립 성장 및 defect감소는 Cu 박막의 결정립계에서 발생하는 electromigration 현상을 상당히 줄일 수 있을 것으로 판단된다.

• 센서학회지
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• 제6권5호
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• pp.346-355
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• 1997

본 논문에서는 범용 유한요소 구조해석 프로그램인 ANSYS를 이용하여 가속도센서의 미세기계구조부의 스트레스 분포와 주파수특성을 해석하였다. 해석된 결과로 부터 자동차의 에어백 시스템에 들어가는 가속도센서의 사양에 적합한 새로운 형태의 6빔 압저항형 가속도센서의 파라미터 값을 설정하였다. 이때, 설계된 가속도 센서의 매스 패드의 반경 및 빔 길이, 빔 폭, 빔 두께의 각 파라미터 값은 $500{\mu}m$, $350{\mu}m$, $100{\mu}m$, $5{\mu}m$였으며, 그리고 같은 구조의 센서에서 진동질량은 0.4 mg과 0.8mg인 두가지 종류로 정의하였다. 설계된 구조를 가지고 (111)면 n 실리콘웨이퍼에 $n^{+}$ 영역이 선택적으로 확산된 $n/n^{+}/n$ 3층 구조를 사용하여 6빔 압저항형 실리콘 가속도센서를 제조하고, 특성을 조사하였다. 이때, 센서의 미세기계구조를 형성하기 위하여 다공질 실리콘 에칭법을 이용한 마이크로머시닝 기술을 사용하였다.