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Evolution of Structural and Electronic Properties in Boron-doped Nanocrystalline Silicon Thin Films

Published online by Cambridge University Press:  01 February 2011

Hyun Jung Lee ,
Andrei Sazonov  and
Arokia Nathan
Hyun Jung Lee
Affiliation:
[email protected], University of Waterloo, Department of Electrical and Computer Engineering, 200 University Avenue West, Waterloo, N2L 3G1, Canada
Andrei Sazonov
Affiliation:
[email protected], University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, Ontario, N2L 3G1, Canada
Arokia Nathan
Affiliation:
[email protected], University College Lodon, London Centre for Nanotechnology, London, WC1H 0AH, United Kingdom
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Abstract

We report on the boron-doping dependence of the structural and electronic properties in nanocrystalline silicon (nc-Si:H) films directly deposited by plasma- enhanced chemical vapor deposition (PECVD). The crystallinity, micro-structure, and dark conductivity of the films were investigated by gradually varying the ratio of trimethylboron [B(CH3)3 or TMB] to silane (SiH4) from 0.1 to 2 %. It was found that the low level of boron doping (< 0.2 %) first compensated the nc-Si:H material which demonstrates slightly n-type properties. As the doping increased up to 0.5 %, the maximum dark conductivity (ód) of 1.11 S/cm was obtained while high crystalline fraction (Xc) of the films (over 70 %) was maintained. However, further increase in a TMB-to-SiH4 ratio reduced ód to the order of 10-7 S/cm due to a phase transition of the films from nanocrystalline to amorphous, which was indicated by Raman spectra measurements.

P-channel nc-Si:H thin film transistors (TFTs) with top gate and staggered source/drain contacts were fabricated using the developed p+ nc-Si:H layer. The fabricated TFT exhibits a threshold voltage (VTp) of -26.2 V and field effective mobility of holes (μp) of 0.24 cm2/V·s.

Keywords

thin filmplasma-enhanced CVD (PECVD) (deposition)electronic structure
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 989: Symposium A – Amorphous and Polycrystalline Thin-Film Silicon Science and Technology-2007 , 2007 , 0989-A21-07
Copyright
Copyright © Materials Research Society 2007

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References

1 Wang, A. W. and Saraswat, K. C., IEEE Trans. Elec. Dev., 47, 1035 (2000).Google Scholar
2 Cheng, I.-C. and Wagner, S., MRS Symp. Proc., 808, A4.6 (2004).Google Scholar
3 Alpuim, P., Chu, V., and Conde, J. P., J. Vac. Sci. Technol. A, 19. 2328 (2001).Google Scholar
4 Panda, D. P. and Dalal, V., MRS Symp. Proc., 910, A8.3 (2006).Google Scholar
5 Tarui, H., Matsuyama, T., Okamoto, S., Dohjoh, H., Hishikawa, Y., Nakamura, N., Tsuda, S., Nakano, S., Ohnishi, M., and Kuwano, Y., Jpn. J. Appl. Phys., 28, 2436 (1989).Google Scholar
6 Okada, T., Iwaki, T., Karasawa, H., and Yamamoto, K., Jpn. J. Appl. Phys., 24, 161 (1985).Google Scholar
7 Matsui, T., Kondo, M., and Matsuda, A., J. Non-Cryst. Sol. 338–340, 646 (2004).Google Scholar
8 Perrin, J., Takeda, Y., Hirano, N., Takeuchi, Y., and Matsuda, A., Surf. Sci., 210, 114 (1989).Google Scholar
9 Kumar, P., Kupich, M., Grunsky, D., and Schroeder, B., Thin Solid Films, 501, 260 (2006).Google Scholar
10 Flückiger, R., Meier, J., Goetz, M., and Shah, A., J. Appl. Phys., 77, 712 (1995).Google Scholar