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Hydrogen-plasma etching of thin amorphous silicon layers for heterojunction interdigitated back-contact solar cells

Published online by Cambridge University Press:  10 May 2013

Stefano. N. Granata ,
Twan Bearda ,
Ivan Gordon ,
Jef Poortmans  and
Robert Mertens
Stefano. N. Granata
Affiliation:
IMEC, Kapledreef 75, B-3001 Heverlee, Belgium KU Leuven ESAT Kasteelpark Arenberg 10 B-3001 Heverlee Belgium
Twan Bearda
Affiliation:
IMEC, Kapledreef 75, B-3001 Heverlee, Belgium
Ivan Gordon
Affiliation:
IMEC, Kapledreef 75, B-3001 Heverlee, Belgium
Jef Poortmans
Affiliation:
IMEC, Kapledreef 75, B-3001 Heverlee, Belgium KU Leuven ESAT Kasteelpark Arenberg 10 B-3001 Heverlee Belgium
Robert Mertens
Affiliation:
IMEC, Kapledreef 75, B-3001 Heverlee, Belgium KU Leuven ESAT Kasteelpark Arenberg 10 B-3001 Heverlee Belgium
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Abstract

In this study, A H2-plasma is studied as a dry method to etch thin layers of amorphous silicon aSi:H(i) deposited on a crystalline wafer. It is found that H2-plasma etches aSi:H(i) selectively toward silicon nitrides hard masks with an etch rate below 3nm/min. Depending on power density and temperature of the substrate during the H2-plasma, the energy bandgap, the hydrides distribution and the void concentration of the aSi:H(i) layers are modified and the amorphous-to-crystalline transition is approached. At high temperature (>250C) and low plasma power (<20mW/cm2), the dihydride (SiH2) content increases and the bandgap widens. The etch rates stays below 0.5 nm/min. At low temperature (<150°C) and high power (>70mW/cm2), the void concentration increases significantly and etch rates up to 3nm/min are recorded.

These findings are supported by a theoretical model that indicates formation of Si-H-Si precursors in the layer during exposure to H2-plasma. According to the experimental conditions, these precursors either diffuses and forms Si-Si strong bonds or are removed from the film, causing layer etching.

Keywords

photovoltaicplasma-enhanced CVD (PECVD) (deposition)Si
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1536: Symposium A – Film Silicon Science and Technology , 2013 , pp. 27 - 32
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Wolf Stefaan, De, Antoine, Descoeudres, Holman Zachary, C., and Christophe, Ballif, Green 2, 7 (2012)Google Scholar
Lu, M., Das, U., Bowden, S., Hegedus, S., and Birkmire, R., Progress in Photovoltaics: Research and Applications 19, 326–338 (2011).CrossRefGoogle Scholar
Mingirulli, N., Haschke, J., Gogolin, R., Ferré, R., Schulze, T.F., Düsterhöft, J., Harder, N.-P., Korte, L., Brendel, R., and Rech, B., Physica Status Solidi (RRL) – Rapid Research Letters 5, 159–161 (2011).CrossRefGoogle Scholar
Verlinden, P.J., Aleman, M., Posthuma, N., Fernandez, J., Pawlak, B., Robbelein, J., Debucquoy, M., Van Wichelen, K., and Poortmans, J., Solar Energy Materials and Solar Cells 106, 37 (2012).CrossRefGoogle Scholar
Aleman, M., Das, J., Janssens, T., Pawlak, B., Posthuma, N., Robbelein, J., Singh, S., Baert, K., Poortmans, J., Fernandez, J., Yoshikawa, K., and Verlinden, P.J., Energy Procedia 27, 638 (2012).CrossRefGoogle Scholar
Kovacs, G.T.A., Maluf, N.I., and Petersen, K.E., Proceedings of the IEEE 86, 1536 (1998).CrossRefGoogle Scholar
Tucci, M., Salurso, E., Roca, F., and Palma, F., Thin Solid Films 403-404, 307 (2002).CrossRefGoogle Scholar
Aspnes, D.E., Theeten, J.B., and Hottier, F., Phys. Rev. B 20, 3292 (1979).CrossRefGoogle Scholar
Mahan, A.H., Menna, P., and Tsu, R., Applied Physics Letters 51, 1167 (1987).CrossRefGoogle Scholar
Boland, J.J. and Parsons, G.N., Science 256, 1304 (1992)CrossRefGoogle Scholar
Chiang, C.-M., Gates, S.M., Lee, S.S., Kong, M., and Bent, S.F., J. Phys. Chem. B 101, 9537 (1997).CrossRefGoogle Scholar
Schulze, T.F., Korte, L., Ruske, F., and Rech, B., Phys. Rev. B 83, 165314 (2011).CrossRefGoogle Scholar
Descoeudres, A., Barraud, L., De Wolf, S., Strahm, B., Lachenal, D., Guérin, C., Holman, Z.C., Zicarelli, F., Demaurex, B., Seif, J., Holovsky, J., and Ballif, C., Applied Physics Letters 99, 123506 (2011).CrossRefGoogle Scholar
Chapman, B.N., Glow Discharge Processes: Sputtering and Plasma Etching (Wiley, 1980).Google Scholar
Van de Walle, C.G. and Street, R.A., Phys. Rev. B 51, 10615–10618 (1995).CrossRefGoogle Scholar