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Effect of RF or VHF Plasma on Nanocrystalline Silicon Thin Film Structure: Insight from OES and Langmuir Probe Measurements

Published online by Cambridge University Press:  07 August 2013

Lala Zhu ,
Ujjwal K Das ,
Steven S Hegedus  and
Robert W Birkmire
Lala Zhu
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, Delaware, USA 19716; Department of Physics and Astronomy, University of Delaware, Newark, Delaware, USA 19716.
Ujjwal K Das
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, Delaware, USA 19716;
Steven S Hegedus
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, Delaware, USA 19716;
Robert W Birkmire
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, Delaware, USA 19716; Department of Physics and Astronomy, University of Delaware, Newark, Delaware, USA 19716.
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Abstract

Optical emission spectroscopy (OES) and Langmuir Probe were used to characterize RF and VHF plasma properties under conditions leading to nanocrystalline silicon film deposition. Films deposited by RF plasma at low pressure (3 Torr), even with high crystalline volume fraction, show weak X-ray diffraction signals, suggesting small grain size, while RF films at higher pressure (8 Torr) and VHF films at both high and low pressure have larger grain sizes. The preferential growth orientation is controlled by the H2/SiH4 ratio with RF plasma, while the film deposited by VHF shows primarily (220) orientation independent of H-dilution ratio. Langmuir Probe measurements indicate that the high energy electron population is reduced by increasing pressure from 3 Torr to 8 Torr in RF plasma. Compared with RF plasma, the VHF plasma shows higher electron density and sheath potential, but lower average electron energy, which may be responsible for the larger grain size and crystal orientation. The growth rate and crystalline volume fraction of the film is correlated with OES intensity ratio of SiH* and Hα/SiH* for both RF and VHF plasmas.

Keywords

plasma-enhanced CVD (PECVD) (deposition)thin filmSi
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1536: Symposium A – Film Silicon Science and Technology , 2013 , pp. 161 - 166
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Vetterl, O., Finger, F., Carius, R., Hapke, P., Houben, L., Kluth, O., Lambertz, A., Muck, A., Rech, B. and Wagner, H., Solar Energy Materials & Solar Cells 62 (2000) 97–108 10.1016/S0927-0248(99)00140-3CrossRefGoogle Scholar
Saito, K. and Kondo, M., Progress in Photovoltaics: Research and Applications 19 (2010) 858–864 10.1002/pip.1053CrossRefGoogle Scholar
Moiseev, T., Isella, G., Chrastina, D. and Cavallotti, C., Journal of Physics D: Applied Physics 42 (2009) 225202 CrossRefGoogle Scholar
Yan, B., Yue, G., Yang, J. and Guha, S., Applied Physics Letters 85, 1955 (2004)10.1063/1.1788877CrossRefGoogle Scholar
Ross, C., Mai, Y., Carius, R. and Finger, F. Prog. Photovolt: Res. Appl. 2011; 19:715–723 CrossRefGoogle Scholar
Druyvesteyn, M J 1930 Z. Phys. 64 781–98 10.1007/BF01773007CrossRefGoogle Scholar
Ke, W., Feng, X. and Huang, Y., Journal of Applied Physics 109 (2011) 083526 CrossRefGoogle Scholar
Kondo, M., Fukawa, M., Guo, L. and Matsuda, A., Journal of Non-Crystalline Solids 266-269 (2000) 84–89 CrossRefGoogle Scholar