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Better control over the onset of microcrystallinity in fast-growing silicon network

Published online by Cambridge University Press:  03 March 2011

Sumita Mukhopadhyay
Affiliation:
Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
Debajyoti Das
Affiliation:
Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
Swati Ray*
Affiliation:
Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

In view of obtaining a Si:H network at the onset of microcrystallinity at a high deposition rate, we have adopted an intelligent approach to find out a tricky plasma condition in radio frequency (rf) plasma-enhanced chemical vapordeposition that provides a better control on growth introducing retarded microcrystallization. The deposition parameter includes a combination of high electrical power applied to the (SiH4+H2)-plasma and high gas pressure in thereaction chamber. High rf power increases the number density of film-forming precursors as well as atomic H density in the plasma, which helps to increase thefilm deposition rate and to promote microcrystallinity, respectively. In addition,high pressure helps not only to increase the film-growth rate by producing a dense plasma but also retards the microcrystallization process by increasing significantlythe gas phase collision frequency and consequently reducing the effective reactivityof atomic H on the surface of a fast-growing Si:H network. A combination of high-power and high-pressure plasma conditions provides a reasonably wide rangeof H2 dilution to work with and better control in producing a Si:H network at theonset of microcrystallinity, while increasing the film-growth rate.

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Articles
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1.Yang, L., Chen, L., Wiedemann, S. andCatalano, A.: In Microcrystalline Semiconductors: Materials Science & Devices, edited by Fauchet, P.M., Tsai, C.C., Canham, L.T., Shimizu, I., and Aoyagi, Y. (Mater. Res. Soc. Symp. Proc. 283, Pittsburgh, PA, 1993), p. 462.Google Scholar
2.Tsu, D.V., Chao, B.S., Ovshinsky, S.R., Guha, S. andYang, J.: Effect of hydrogen dilution on structure of amorphous silicon alloys. Appl. Phys. Lett. 71, 1317 (1997).CrossRefGoogle Scholar
3.Das, D.: Microphotoluminescence and micro Raman studies near the amorphous-to-microcrystalline transition in Si:H. Solid State Commun. 127, 453 (2003).CrossRefGoogle Scholar
4.Das, C. andRay, S.: Onset of microcrystallinity in silicon thin films. Thin Solid Films 403–404, 81 (2002).CrossRefGoogle Scholar
5.Ray, S., Das, C., Mukhopadhyay, S. andSaha, S.C.: Substrate temperature and hydrogen dilution: Parameters for amorphous to microcrystalline phase transition in silicon thin films. Sol. Energy Mater. Sol. Cells 74, 393 (2002).CrossRefGoogle Scholar
6.Sauvain, E.V., Kroll, U., Meier, J., Shah, A. andPohl, J.: Evolution of the microstructure in microcrystalline Si prepared by VHF glow-discharge using hydrogen dilution. J. Appl. Phys. 87, 3137 (2000).CrossRefGoogle Scholar
7.Ferlauto, A.S., Rovira, P.I., Koval, R.J., Wronski, C.R. andCollins, W.: in Amorphous and Heterogeneous Silicon Thin Films–2000, edited by Collins, R.W., Branz, H.M., Stutzman, M., Guha, S., and Okamoto, H. (Mater. Res. Soc. Symp. Proc. 609, Warrendale, PA, 2001).Google Scholar
8.Ray, S., Mukhopadhyay, S., Jana, T. andCarius, R.: Transition from amorphous to microcrystalline Si:H: Effects of substrate temperature and hydrogen dilution. J. Non-Cryst. Solids 299–302, 761 (2002).CrossRefGoogle Scholar
9.Mavi, H.S., Shukla, A.K., Abbi, S.C. andJain, K.P.: Raman study of amorphous to microcrystalline phase transition in CW laser annealed a-Si:H films. J. Appl. Phys. 66, 5322 (1989).CrossRefGoogle Scholar
10.He, Y., Wei, Y., Zheng, G., Yu, M. andLiu, M.: An exploratory study of the conduction mechanism of hydrogenated nanocrystalline Si films. J. Appl. Phys. 82, 3407 (1997).CrossRefGoogle Scholar
11.Veprek, S., Sarott, F.A. andIqbal, Z.: Effect of grain boundaries on Raman spectra, optical absorption & elastic light scattering in nanometer-sized crystalline silicon. Phys. Rev. B 36, 3344 (1987).CrossRefGoogle ScholarPubMed
12.Yue, G., Lorentzen, J.D., Lin, J., Han, D. andWang, Q.: Photoluminescence & Raman studies in thin film materials: Transition from amorphous to microcrystalline silicon. Appl. Phys. Lett. 75, 492 (1999).CrossRefGoogle Scholar
13.Chou, J.S., Sah, W.J., Lee, S.C., Chang, T.C. andWang, J.C.: Mater. Chem. Phys. 32, 273 (1992).Google Scholar
14.Das, D.Plasma kinetics, surface phenomena and growth mechanism in hydrogenated amorphous silicon: Transition from amorphous to micro- and nano-crystalline Si:H. Solid State Phenomena (Scitec Publication, Switzerland) 227, 44–46 (1995).Google Scholar