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High Electron Mobility (˜150 cm2/Vs) PECVD Nanocrystalline Silicon Top-Gate TFTs at 260 °C

Published online by Cambridge University Press:  01 February 2011

Czang-Ho Lee
Affiliation:
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
Andrei Sazonov
Affiliation:
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
Arokia Nathan
Affiliation:
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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Abstract

Undoped nanocrystalline silicon (nc-Si:H) films were prepared by conventional 13.56 MHz plasma enhanced chemical vapor deposition (PECVD) at 260 °C, using highly H2-diluted SiH4 plasma. The nc-Si:H films were evaluated using electrical, structural, and chemical measurements. The optimized nc-Si:H film showed an oxygen concentration (CO) of ˜1.5 X 1017 at./cm3 and a dark conductivity (σD) of ˜10-6 S/cm, while the Raman crystalline volume fraction (XC) was ˜85 %. Top-gate staggered TFTs with a ˜100 nm nc-Si:H channel layer and an amorphous silicon oxide (a-SiOx) as the gate dielectric were fabricated. The TFTs showed a field effect mobility (μFE) of ˜150 cm2/Vs, a threshold voltage (VT) of ˜2 V, a subthreshold slope (S) of ˜0.25 V/dec, and an ON/OFF current ratio more than 106. To the best of our knowledge, the TFT mobility reported here is the highest achieved to date using state-of-the-art nc-Si:H films prepared by direct PECVD.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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References

1 Sekiya, M., Hara, M., Sano, N., Kohno, A., and Sameshima, T., IEEE Electron Device Lett. 15, 69 (1994).10.1109/55.285370Google Scholar
2 Jang, J., Oh, J. Y. Kim, S. K. Choi, Y. J. Yoon, S. Y. and Kim, C. O. Nature 395, 481 (1998).10.1038/26711Google Scholar
3 Nagahara, T., Fujimoto, K., Kohno, N., Kashiwagi, Y., and Kakinoki, H., Jan. J. Appl. Phys. 31, 4555 (1992).10.1143/JJAP.31.4555Google Scholar
4 Cheng, I-Chun and Wagner, S., Appl. Phys. Lett. 80, 440 (2002).10.1063/1.1435798Google Scholar
5 Teng, L. and Anderson, W. A. IEEE Electron Device Lett. 15, 399 (2003).10.1109/LED.2003.813364Google Scholar
6 Wang, C., Williams, M. J. and Lucovsky, G., J. Vac. Sci. Technol. A 9, 444 (1991).10.1116/1.577430Google Scholar
7 Torres, P., Meier, J., Flückiger, R., Koll, U., Selvan, J. A. Anna, Keppner, H., Shah, A., Littelwood, S. D., Kelly, I. E. and Giannoulès, P., Appl. Phys. Lett. 69, 1373 (1996).10.1063/1.117440Google Scholar
8 Platz, R. and Wagner, S., Appl. Phys. Lett. 73, 1236 (1998).10.1063/1.122138Google Scholar
9 Kamei, T., Kondo, M., and Matsuda, A., Jan. J. Appl. Phys. 89, 6265 (2001).10.1063/1.1368164Google Scholar
10 Boyce, J. B. and Mei, P., in Technology and Application of Hydrogenated Amorphous Silicon, edited by Street, R. A. (Springer, New York, 2000), ch. 3.Google Scholar
11 Kroll, U., Meier, J., Shah, A., Mikhailov, S., and Weber, J., J. Appl. Phys. 80, 4971 (1996).10.1063/1.363541Google Scholar
12 Tsai, C. C. in Amorphous Silicon and Related Materials, edited by Fritzche, H. (World Scientific, Singapore, 1988), p. 123.Google Scholar
13 Matsuda, A., J. Non-Cryst. Solids 59-60, 767 (1983).10.1016/0022-3093(83)90284-3Google Scholar
14 Nasuno, Y., Knodo, M., and Matsuda, A., Appl. Phys. Lett. 78, 2330 (2001).10.1063/1.1364657Google Scholar
15 Nathan, A., Servati, P., Karim, K. S. Striakhilev, D., and Sazonov, A., in Thin Film Material and Process Volume 1: Amorphous Silicon Thin Film Transistors, edited by Kuo, Y. (Kluwer Academic, Boston, 2004), ch. 3.Google Scholar
16 Greve, D. W. Field Effect Devices and Applications: Devices for Portable, Low-Power, and Imaging Systems (Prentice Hall, New Jersey, 1998), ch. 7.Google Scholar