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Characteristics of poly-Si TFTs using Excimer Laser Annealing Crystallization and high-k Gate Dielectrics

Excimer Laser Annealing 결정화 방법 및 고유전 게이트 절연막을 사용한 poly-Si TFT의 특성

  • 이우현 (광운대학교 전자재료공학과) ;
  • 조원주 (광운대학교 전자재료공학과)
  • Published : 2008.01.01

Abstract

The electrical characteristics of polycrystalline silicon (poly-Si) thin film transistor (TFT) crystallized by excimer laser annealing (ELA) method were evaluated, The polycrystalline silicon thin-film transistor (poly-Si TFT) has higher electric field-effect-mobility and larger drivability than the amorphous silicon TFT. However, to poly-Si TFT's using conventional processes, the temperature must be very high. For this reason, an amorphous silicon film on a buried oxide was crystallized by annealing with a KrF excimer laser (248 nm)to fabricate a poly-Si film at low temperature. Then, High permittivity $HfO_2$ of 20 nm as the gate-insulator was deposited by atomic layer deposition (ALD) to low temperature process. In addition, the solid phase crystallization (SPC) was compared to the ELA method as a crystallization technique of amorphous-silicon film. As a result, the crystallinity and surface roughness of poly-Si crystallized by ELA method was superior to the SPC method. Also, we obtained excellent device characteristics from the Poly-Si TFT fabricated by the ELA crystallization method.

Keywords

ELA;SLS;SPC;poly-Si TFT;high-k;$HfO_2$

References

  1. 백희원, 변문기, 김영호, 'SOI technology (2) : SOI MOS 트랜지스터의 전기적 특성', 전기전자재료, 12권, 9호, p. 10, 1999
  2. Victor W. C. Chan, Philip C. H. Chan, and Chan M., 'Three dimension CMOS integrated. circuits on large grain polysilicon films', IEEE IEDM Tech Dig., p. 161, 2000
  3. S. Inoue., S. Utsunomiya., T. Saeki, and T. Shimoda., 'Surface-free. technology by laser annealing (SUFTLA) and its application to poly-. Si TFT-LCDs on plastic film with integrated drivers', IEEE Trans. on Electron Device, Vol. 49, No. 8, p. 1353, 2002 https://doi.org/10.1109/TED.2002.801294
  4. A. W. Topol, D. C. La Tulipe, Jr., L. Shi, D. J. Frank, K. Bernstein, S. E. Steen, A. Kumar, G. U. Singco, A. M. Young, K. W. Guarini, and M. Ieong, 'Three-dimensional integrated circuits', IBM J. RES. & DEV., Vol. 50, No. 4/5, p. 491, 2006 https://doi.org/10.1147/rd.504.0491
  5. W.-J. Cho, K.-J. Im, C.-G. Ahn, J.-H. Yang, J.-H. Oh, I.-B. Baek, and S.-J. Lee, 'Plasma doping technology for fabrication of nanoscale metal-oxide-semiconductor devices', J. Vac. Sci. Technol. B, Vol. 22, No. 6, p. 3210, 2004 https://doi.org/10.1116/1.1813461
  6. G. D. Wilk, R. M. Wallace, and J. M. Anthony, 'High-k gate dielectrics: current status and materials properties considerations', J. Appl. Phys., Vol. 89, p. 5243, 2001 https://doi.org/10.1063/1.1361065
  7. 류명관, 손곤, 김천홍, 이정열, 'SLS technology for high performance poly-Si TFTs and Its application to advanced LCD and SOG', 전기전자재료, 19권, 9호, p. 11, 2006