Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-24T16:07:05.905Z Has data issue: false hasContentIssue false

Study of Surface Passivation of CZ c-Si by PECVD a-Si:H Films; A Comparison Between Quasi-Steady-State and Transient Photoconductance Decay Measurement

Published online by Cambridge University Press:  13 May 2013

Omid Madani Ghahfarokhi
Affiliation:
NEXT ENERGY ∙ EWE Research Centre for Energy Technology at Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str. 15, 26129 Oldenburg, Germany
Karsten von Maydell
Affiliation:
NEXT ENERGY ∙ EWE Research Centre for Energy Technology at Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str. 15, 26129 Oldenburg, Germany
Carsten Agert
Affiliation:
NEXT ENERGY ∙ EWE Research Centre for Energy Technology at Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky-Str. 15, 26129 Oldenburg, Germany
Get access

Abstract

We have investigated the passivation of low lifetime non-polished Czochralski (CZ) mono-crystalline silicon (c-Si) wafers by hydrogenated amorphous silicon (a-Si:H), deposited by plasma enhanced chemical vapor deposition (PECVD) technique. The dependence of the effective lifetime (τeff) on the deposition parameters including hydrogen gas flow, power and temperature has been studied. Minority carrier lifetime was measured as deposited and also after an annealing step in both quasi-steady-state (QSS) and transient mode of photoconductance decay. By comparison between τeff measured in each of the aforementioned modes, two distinguishable behaviors could be observed. Moreover, to get further insight into the surface passivation mechanism, we have modeled the recombination at a-Si:H/c-Si interface based on the amphoteric nature of dangling bonds. The results of our modeling show that the discrepancy observed between QSS and transient mode is due to the high recombination rate that exists in the bulk of defective CZ wafer and also partly related to the different thicknesses monitored in each mode. So, by comparison between the injection level dependency of τeff measured in QSS and transient modes, we introduce a valuable technique for the evaluation of c-Si bulk lifetime.

Type
Articles
Copyright
Copyright © Materials Research Society 2013 

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.)

References

REFERENCES

Sinton, R. and Cuevas, A., Appl. Phys. Lett. 69, 2510 (1996).CrossRefGoogle Scholar
Nagel, H., Berge, C. and Aberle, A. G., J. Appl. Phys. 86, 6218 (1999).CrossRefGoogle Scholar
Schmidt, J., IEEE Trans. Electron. Dev. 46, 2018 (1999)CrossRefGoogle Scholar
Olibet, S., Sauvain, E. V. and Ballif, C., Phys. Rev. B 76, 035326 (2007).CrossRefGoogle Scholar
De Wolf, S. and Kondo, M., J. Appl. Phys. 90, 042111 (2007).Google Scholar
Descoeudres, A., Barraud, L., Bartlome, R., Choong, G., Wolf, Stefaan De, Zicarelli, F., Ballif, C., Appl. Phys. Lett. 97, 183505 (2010).CrossRefGoogle Scholar
Burrows, M. Z., Das, U. K., Opila, R. L., Wolf, S. De and Birkmire, R. W., J. Vac. Sci. Technol. A 26(4), 683 (2008).CrossRefGoogle Scholar
Street, R. A., Phys. Rev. B 43, 2454 (1991).CrossRefGoogle Scholar
Schulze, T. F., Beushausen, H. N., Leendertz, C., Dobrich, A., Rech, B. and Korte, L., Appl. Phys. Lett. 96, 252102 (2010).CrossRefGoogle Scholar
Jeon, M. S., Kawachi, K., Supajariyawichai, P., Dhamrin, M. and .Kamisako, K, e-J. Surf. Sci. Nanotech. 6, 124 (2008).CrossRefGoogle Scholar
Matsuda, A., Takai, M., Nishimoto, T., Kondo, M., Sol. Energ. Mat. Sol. Cells 78, 3 (2003).CrossRefGoogle Scholar
Biegelsen, D. K., Street, R. A., Tsai, C. C., and Knight, J. C., Phys. Rev. B 20, 4839 (1979).CrossRefGoogle Scholar
Hubin, J., Shah, A.V. and Sauvain, E.. Philosophical Magazine Letters 66, 115 (1992).CrossRefGoogle Scholar