Hostname: page-component-848d4c4894-r5zm4 Total loading time: 0 Render date: 2024-06-17T23:31:52.008Z Has data issue: false hasContentIssue false

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
Affiliation:, University of Waterloo, Department of Electrical and Computer Engineering, 200 University Avenue West, Waterloo, N2L 3G1, Canada
Andrei Sazonov
Affiliation:, University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, Ontario, N2L 3G1, Canada
Arokia Nathan
Affiliation:, University College Lodon, London Centre for Nanotechnology, London, WC1H 0AH, United Kingdom
Get access


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.

Research Article
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


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