• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.403-406
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• 1999

The influence of temperature variation (25～125$^{\circ}C$) on poly-Si thin-film transistors (TFT's) was investigated by examining the electrical properties change of poly-Si films formed by solid phase crystallization (SPC). The n-channel poly-Si TFT's fabricated by SPC with channel length of 1.5 and loon ,respectively, exhibit good characteristics with a high ${\mu}$$\sub$FE/ ($\geq$82 and $\geq$60$\textrm{cm}^2$/V-s in 1.5 and 10$\mu\textrm{m}$, respectively), low V$\sub$t/, ($\leq$1.52 and $\leq$ 2.75V in 1.5 and 10$\mu\textrm{m}$, respectively), low S$\sub$t/, and good ON-OFF characteristics in spite of temperature variation. Thus, poly-Si films formed by SPC can be applied for the application to poly-Si TFT liquid crystal display with peripheral integrated circuits.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.324-331
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• 1995

The leakage current characteristics of the low temperature processed LDD structure poly-Si TFT is analyzed. The excimer laser technology was applied to the recrystallization process of poly-Si film and the maximum processing temperature was retained under 600.deg.C. From the fabricated LDD space 0.3.mu.m to 3$\mu$m, the best on/off current ration could be obtained with the 1.3$\mu$m LDD space. And the threshold voltage did not increase more than 4V over 0.8$\mu$m LDD space. The characteristics of leakage current was compared to non-LDD structure TFT to analyze the mechanism of leakage current. Consequently, it could be concluded that the leakage current is strongly affected by the trap states as well as high electric field between gate and drain.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.48-53
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• 1998

Poly-Si TFT's could be fabricated on glass substrates by metal induced lateral crystallization (MILC) method at 450.deg. C. Channel area of the poly-Si TFT's was laterally crystallized from source and drain areas, where a thn nickel film was deposited. Dopants activation for the formation of source and drain region could be achieved by thermal annealing at 450.deg. C after the ion mass doping of phosphorus. The field effect mobility of thus formed N-channel poly-Si TFT's was 76cm$^{2}$/Vs, and the on/off current ratio was higher than 7E6.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.409-409
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• 2012

모바일 및 TV, 모니터 부분에서 AMOLED의 비약적인 시장 점유율 확대와 더불어 TFT 소자 부문에서도 많은 집중과 연구개발이 이루어지고 있다. 높은 이동도를 필요로 하는 AMOLED의 구동 회로에 채널층으로서 a-Si이 낮은 이동도로 인한 한계에 부딪히며 더 이상 쓰일 수 없게 되었고, 현재 우수한 이동도와 균일성, 제조 원가 절감의 효과 등 많은 장점을 보유한 산화물 TFT가 접목되고 있다. 현재까지 IGZO, ZnO 등이 많이 연구되며 실제로 AMOLED 용 TFT 소자에 적용 되고 있다. 본 연구에서는 산화물질인 ZTO (Zinc-Tin-Oxide)를 이용하여 TFT를 제작하였다. n-type 웨이퍼에 PECVD를 이용하여 $SiO_2$를 100 nm 증착한 뒤 spin coater로 ZTO용액을 30 nm 증착하였다. ZTO의 최적화된 열처리 온도인 $450^{\circ}C$에서 annealing을 해준 다음에 thermal evaporator로 source와 drain을 증착하였다. Gate 컨택을 위하여 웨이퍼 후면에 silver paste를 이용해 소자를 완성하였다. 산화물질 특성상 환경변화에 민감한 경향성을 보이기 때문에 현재 산화물 TFT는 신뢰성 분석에 많은 연구가 진행되고 있다. 완성된 ZTO TFT 소자를 빛과 수분에 일정한 시간 노출시킨 뒤 I-V 측정을 통하여 소자 열화를 분석하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.597-600
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• 2006

The silver gate and source/drain electrodes for an a-Si thin film transistor were fabricated by the selective electroless plating (SELP) process. Relevant physical properties including taper angle, uniformity and resistivity are investigated. The Ag layer was about 150nm to 250nm thick, the resistivity less than $3{\times}10^{-6}$ Ohm-cm and the taper angle 45'-60' and the nonuniformity less than 10% on G2 substrates. The transfer characteristics with the Ag gate, and source/drain electrodes respectively possessed good field effect mobility similar to conventionally fabricated a-Si TFTs. This process provided low resistivity, low cost and ease of processing.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.190-190
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• 2003

현재 a-Si TFT는 평판 디스플레이 소자로서 주로 사용되고 있으나 점차 고속응답속도 특성, 고화질이 요구됨에 따라 높은 전계효과 이동도를 가진 poly-Si TFT로 대체하기 위한 연구가 진행되고 있으며 특히 poly-Si TFT를 상용 유리 기판에 적용하기 위해 비정질 실리콘의 저온 결정화에 대한 연구가 활발히 진행 되고 있다. 본 연구에서는 극박막의 Ni을 선택적으로 증착하여 전계 유도방향성 결정화 (Field Aided Lateral Crystallization : FALC) 공정을 이용하여 결정화를 진행하였으며 전계를 인가하지 않은 경우와 전계를 인가한 경우, 전계 세기에 따른 결정화에 대하여 비교하였다.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.933-936
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• 2000

N-channel poly-Si TFT, processed by Solid Phase Crystalline(SPC) on a glass substrate, has been investigated by measuring its electrical properties before and after stressing. It is observed that the threshold voltage shift due to electrical stress varies with various stress conditions. Threshold voltages measured in 1.5um and 3um poly-Si TFT’s are 3.3V, 37V respectively. With the threshold voltage shift, the degradation of transconductance and subthreshold swing is also observed.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.625-631
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• 2023

The important requirement of industrial dynamic X-ray detector operating under high tube voltage up to 450 kVp for 24 hours and 7 days is to obtain significantly high radiation resistance. This study presents the radiation resistance characteristics of various thin film transistors (TFTs) with a-Si, poly-Si and IGZO semiconducting layers. IGZO TFT offering dozens of times higher field effect mobility than a-Si TFT was processed with highly hydrogenated plasma in between IGZO semiconducting layer and inter-layered dielectric. The hydrogenated IGZO TFT showed most sustainable radiation resistance up to 10,000Gy accumulated, thus, concluded that it is a sole switching device in X-ray imaging sensor offering dynamic X-ray imaging at high frame rate under extremely severe radiation environment such as automated X-ray inspection.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.178-178
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• 1999