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Korean Journal of Materials Research, Vol.24, No.9, 443-450, September, 2014
Silicide-Enhanced Rapid Thermal Annealing을 이용한 다결정 Si 박막의 제조 및 다결정 Si 박막 트랜지스터에의 응용
Fabrication of Polycrystalline Si Films by Silicide-Enhanced Rapid Thermal Annealing and Their Application to Thin Film Transistors
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Amorphous (a-Si) films were epitaxially crystallized on a very thin large-grained poly-Si seed layer by a silicideenhanced rapid thermal annealing (SERTA) process. The poly-Si seed layer contained a small amount of nickel silicide which can enhance crystallization of the upper layer of the a-Si film at lower temperature. A 5-nm thick poly-Si seed layer was then prepared by the crystallization of an a-Si film using the vapor-induced crystallization process in a NiCl2 environment. After removing surface oxide on the seed layer, a 45-nm thick a-Si film was deposited on the poly-Si seed layer by hot-wire chemical vapor deposition at 200 oC. The epitaxial crystallization of the top a-Si layer was performed by the rapid thermal annealing
(RTA) process at 730 oC for 5 min in Ar as an ambient atmosphere. Considering the needle-like grains as well as the crystallization temperature of the top layer as produced by the SERTA process, it was thought that the top a-Si layer was epitaxially crystallized with the help of NiSi2 precipitates that originated from the poly-Si seed layer. The crystallinity of the SERTA processed poly-Si thin films was better than the other crystallization process, due to the high-temperature RTA process. The Ni concentration in the poly-Si film fabricated by the SERTA process was reduced to 1 × 1018 cm.3. The maximum fieldeffect mobility and substrate swing of the p-channel poly-Si thin-film transistors (TFTs) using the poly-Si film prepared by the SERTA process were 85 cm2/V·s and 1.23 V/decade at Vds = .3 V, respectively. The off current was little increased under reverse bias from 1.0 × 10.11 A. Our results showed that the SERTA process is a promising technology for high quality poly- Si film, which enables the fabrication of high mobility TFTs. In addition, it is expected that poly-Si TFTs with low leakage current can be fabricated with more precise experiments.
Keywords:thin film transistor;poly-Si film;crystallization of a-Si film;vapor-induced crystallization;rapid thermal annealing
- Seto JYW, J. Appl. Phys., 46, 5247 (1975)
- Baccarani G, Ricco B, Spandini G, J. Appl. Phys., 49, 5565 (1978)
- Zhang H, Kusumoto N, Imushima T, Yamazaki S, IEEE Electron Device Lett., 13, 297 (1992)
- Cammarata RC, Thompson CV, Hayzelden C, Tu KN, J. Mater. Res., 10, 2133 (1990)
- Hayzelden C, Batstone JL, J. Appl. Phys., 73, 8279 (1993)
- Lee SW, Joo SK, IEEE Electron Dev. Lett., 17, 160 (1996)
- Sohn DK, Lee JN, Kang SW, Ahn BT, Jap. J. Appl. Phys., 35, 1005 (1996)
- Jang J, Oh JY, Kim SK, Choi YJ, Yoon SY, Kim CO, Nature, 395(6701), 481 (1998)
- Jun SI, Yang YH, Lee JB, Choi DK, Appl. Phys. Lett., 75, 2235 (1999)
- Lee JN, Choi YW, Lee BJ, Ahn BT, J. Appl. Phys, 82, 2918 (1997)
- Eom JH, Lee KU, Ahn BT, Electrochem. Solid State Lett., 8(3), G65 (2005)
- Eom JH, Lee KU, Ahn BT, J. Electrochem. Soc., 154(3), H194 (2007)
- Choi JH, Kim DY, Choo BK, Sohn WS, Jang J, Electrochem. Solid State Lett., 6(1), G16 (2003)
- Kang SM, Ahn KM, Ahn BT, J. Electrochem. Soc., 159(1), H29 (2012)
- Ahn KM, Kang SM, Ahn BT, Curr. Appl. Phys., 12(6), 1454 (2012)
- Yang YH, Ahn KM, Ahn BT, Electrochem. Solid State Lett., 13(8), J92 (2010)
- Yang YK, Ahn KM, Kang SM, Moon SH, Ahn BT, Kwon HS, Electron. Mater. Lett., in publication
- Gordon I, Van Gestel D, Van Nieuwenhuysen K, Carnel L, Beaucarne G, Poortmans J, Thin Solid Films, 487(1-2), 113 (2005)
- Marmorstein A, Voutsas AT, Solanki R, J. Appl. Phys., 82, 4303 (1997)
- Ahn JH, Ahn BT, J. Electrochem. Soc., 148(9), H115 (2001)