The Poly-Si Thin Film Transistor for Large-area TFT-LCD

대면적 TFT-LCD를 위한 다결정 실리콘 박막 트랜지스터

  • 이정석 (동의대학교 전기전자공학부 정회원) ;
  • 이용재 (동의대학교 전기전자공학부 정회원)
  • Published : 1999.12.01

Abstract

In this paper, the n-channel poly-Si thin-film transistors (poly-Si TFT's) formed by solid phase crystallization (SPC) on glass were investigated by measuring the electrical properties of poly-Si films, such as I-V characteristics, mobility, leakage current, threshold voltage, and subthreshold slope. It is done to decide to be applied on TFT-LCD with large-size and high density. In n-channel poly-Si TFT with 2, 10, 25$\mu\textrm{m}$ of channel length, the field effect mobilities are 111, 126 and 125 $\textrm{cm}^2$/V-s and leakage currents are 0.6, 0.1, and 0.02 pA/$\mu\textrm{m}$, respectively. Low threshold voltage and subthreshold slope, and good ON-OFF ratio are shown, as well. Thus, the poly-Si TFT’s used by SPC are expected to be applied on TFT-LCD with large-size and high density, which can integrate display panel and peripheral circuit on a large glass substrate.

본 논문에서는 유리기판 위에 고상결정화(SPC)로 제작된 n-채널 다결정 박막 트랜지스터(poly-Si TFT's)에 대해 전류-전압 특성, 이동도, 누설전류, 문턱전압, 그리고 부임계 기울기 등과 같은 전기적 특성을 측정함으로서 대면적, 고밀도 TFT-LCD에의 적용 가능성을 조사하였다. 채널 길이가 각각 2, 10, 25$\mu\textrm{m}$로 제작된 n-채널 poly-Si TFT에서, 전계 효과 이동도는 각각 11, 125, 116 $\textrm{cm}^2$/V-s이었으며, 누설전류는 각각 0.6, 0.1, 0.02 pA/$\mu\textrm{m}$로 나타났다. 또한 낮은 문턱전압과 q임계 기울기 그리고 양호한 ON-OFF ratio이 나타났다. 따라서, SPC로 제작된 poly-Si TFT는 대형유리기판에 디스플레이 패널과 구동시스템을 동시에 집적하는 대면적, 고밀도 TFT-LCD에 적용 가능한 것으로 판단된다.

Keywords

References

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