• 전자공학회논문지D
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• 제36D권1호
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• pp.57-62
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• 1999

유리기판 위에 다결정 실리콘 박막 트랜지스터(Thin Film Transistor, TFT)를 형성하기 위해서 램프 Scanning 열처리 장치를 개발하였다. 선형 램프를 Scanning 함으로써 대면적 유리기판에의 적용 가능성을 높였으며 TFT의 채널 부분은 금속 유도 측면 결정화 방법에 의해 결정화 시켰다. 할로겐 램프에 의한 빛은 투명 유리기판은 가열시키지 않고 ,island 행태의 실리콘 박막만을 가열시킬 수 있었다. 실리콘 산화막으로 이루어진 Capping layer를 적용하였고 이때의 성장 속도는 Capping layer가 없는 경우보다 35배 정도로 빠른 MILC 성장 속도를 나타내었다. 할로겐 램프를 약 1.4mm/sec의 속도록 Scanning한 경우 유리기판의 손상 없이 18-27${\mu}m/scan$ 정도의 결정화를 나타내었다. 이와 같이 제작된 다결정 실리콘 박막으로 제작된 TFT는 전자이동도 130$cm^2/V{\cdot}sec$의 우수한 특성을 나타내었다.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1329-1333
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• 2018

We investigated the mechanism of mobility enhancement after the dehydrogenation process in polycrystalline silicon (poly-Si) thin films. The dehydrogenation process was performed by using an in-situ CVD chamber in a $N_2$ ambient or an ex-situ furnace in air ambient. We observed that the dehydrogenated poly-Si in a $N_2$ ambient had a lower oxygen concentration than the dehydrogenated poly-Si annealed in an air ambient. The in-situ dehydrogenation increased the (111) preferred orientation of poly-Si and reduced the oxygen concentration in poly-Si thin films, leading to a reduction of the trap density near the valence band. This phenomenon gave rise to an increase of the field-effect mobility of the poly-Si thin film transistor.

• 한국레이저가공학회지
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• 제6권2호
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• pp.9-17
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• 2003

Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received an increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM photography. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

• 반도체디스플레이기술학회지
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• 제6권2호
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• pp.15-18
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• 2007

Effects of $O_2$ flow during deposition on Si crystallization at low substrate temperature were studied. Silicon thin films were prepared on $SiO_2$ substrates in a low-pressure chemical vapor deposition chamber using a mixture of $SiH_4$ and $H_2$. In some cases $O_2$ was intentionally introduced during deposition. Growth of poly silicon was observed at the substrate temperature as low as $480^{\circ}C$ when $O_2$ was flowed during deposition implying that crystallization of Si was enhanced by $O_2$ flow. On the other hand, $O_2$ flow did not show any significant effects at higher substrate temperature, where deposition rate is relatively fast. Enhancement mechanism of Si crystallization by $O_2$ flow was suggested from these results.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 한국재료학회 춘계학술발표강연 및 논문개요집
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• pp.114-114
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• 1998

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권5호
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• pp.237-241
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• 2004

Amorphous silicon (a-Si) films are used in a broad range of solar cell, flat panel display, and sensor. Because of the greater ease of deposition and lower processing temperature, thin films are widely used for thin film transistors (TFTs). However, they have lower stability under the exposure of visible light and because of their low field effect mobility ($\mu$$_{FE}$ ) , less than 1 c $m^2$/Vs, they require a driving IC in the external circuits. On the other hand, polycrystalline silicon (poly-Si) thin films have superiority in $\mu$$_{FE}$ and optical stability in comparison to a-Si film. Many researches have been done to obtain high performance poly-Si because conventional methods such as excimer laser annealing, solid phase crystallization and metal induced crystallization have several difficulties to crystallize. In this paper, a new crystallization process using a molybdenum substrate has been proposed. As we use a flexible substrate, high temperature treatment and roll-to-roll process are possible. We have used a high temperature process above 75$0^{\circ}C$ to obtain poly-Si films on molybdenum substrates by a rapid thermal annealing (RTA) of the amorphous silicon (a-Si) layers. The properties of high temperature crystallized poly-Si studied, and poly-Si has been used for the fabrication of TFT. By this method, we are able to achieve high crystal volume fraction as well as high field effect mobility.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.129-130
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• 2008

Polycrystalline silicon (poly-Si) Schottky barrier thin film transistors (SB-TFT) are fabricated by erbium silicided source/drain for n-type SB-TFT. High quality poly-Si film were obtained by crystallizing the amorphous Si film with excimer laser annealing (ELA) or solid phase crystallization (SPC) method. The fabricated poly-Si SB-TFTs have a large on/off current ratio with a low leakage current. Moreover, the electrical characteristics of poly-Si SB TFTs are significantly improved by the additional forming gas annealing in 2 % $H_2/N_2$, because the interface trap states at the poly-Si grain boundaries and at the gate oxide/poly-Si channel decreased.

• 대한기계학회논문집B
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• 제35권3호
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• pp.221-228
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• 2011

대면적 비정질 실리콘 박막의 결정화는 평판 디스플레이 생산에 있어서 핵심 요소로 꼽힌다. 현재 다양한 결정화 기술들이 연구 되고 있으며 그 중 최근에 소개된 줄 가열 유도 결정화는 수십 마이크로초의 짧은 공정 시간, 대면적 결정화 그리고 국부적인 가열로 기판의 열변형 억제 등의 잇점으로 인해 AMOLED 제작에 있어서 기대되는 기술이다. 본 연구에서는 JIC 공정 중 상변화과정에서의 온도를 이론적으로 해석하고 이를 실험과 비교하였다. 이를 통하여 결정화 메커니즘을 결정하는 임계온도를 in-situ 실험과 수치해석을 통해 밝혀내었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2004년도 춘계학술발표대회 및 제6회 신소재 심포지엄
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• pp.62-62
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• 2004

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.89-93
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• 1995

Effects of hydrogenation in amorphous silicon rile growths on Solid Phase Crystallization (SPC) was investigated using x-ray diffractometry, energy dispersive Spectroscopy, and Raman spectrum. Interdiffusion of barium(Ba) and aluminum(Al) compounds of corning substrate was observed in both of rf sputtering and LFCVD films under the low temperature(580$^{\circ}C$) annealing. Low degree of crystallinity resulted from the interdiffusion was obtained. Highly applicable degree of crystallinity was obtained through the mechanical damage induced surface activation on amorphous silicon films. X-ray diffraction intensity of (111) orientation was used to characterize the degree of crystallinity of SPC. Nucleation and growth rate in SPC could be controllable through the employed surface treatment. IIydrogenated LPCVD films showed the superior crystallinity to non-hydrogenated sputtering films. Insignificant effects of activation treatment in sputtered film was of activation treatment in sputtered film was observed on SPC.