| AVS 57th International Symposium & Exhibition | |
| Energy Frontiers Topical Conference | Tuesday Sessions |
| Session EN+TF-TuA |
| Session: | Thin Films for Photovoltaics |
| Presenter: | A.C. Bronneberg, Eindhoven University of Technology, the Netherlands |
| Authors: | A.C. Bronneberg, Eindhoven University of Technology, the Netherlands A.M. Creatore, Eindhoven University of Technology, the Netherlands M.C.M. van de Sanden, Eindhoven University of Technology, the Netherlands |
| Correspondent: | email address not available |
The transition from amorphous (a-Si:H) to microcrystalline (µc-Si:H) silicon film growth has been ascribed to the interaction of atomic hydrogen with the (sub)surface of the growing film [1]. To gain more insight into the formation of microcrystalline silicon and to the role of atomic hydrogen, several studies have been dedicated to hydrogen treatment of a-Si:H films [2,3,4,5]. However, the observed film crystallization is often wrongly ascribed to the impinging hydrogen atoms. What tended to be overlooked, is that the counter electrode is covered with an a-Si:H film during the deposition step. Interaction of the H2 plasma with the coated electrode will result in formation of molecules and radicals originating from silane [4]. Hence, the resulting plasma conditions are similar to those used for µc-Si:H, which explains the observed crystal formation.
Here, we show that this is not only true for direct plasmas, but that also in remote plasmas the reactor wall has big influences on the growth process. By using in situ spectroscopic ellipsometry and ex situ Raman spectroscopy, we show that H2 plasma treatment of a-Si:H only results in the formation of crystals when there is a source of silicon-based molecules and radicals. Together with a plasma study, comprising mass spectrometry and ion probe measurements, we address the origin and kinetics of the crystal formation and discuss the implications for µc-Si:H growth.
1. A. Matsuda, Journal of Non-Crystalline Solids 338, 1-12 (2004).
2. A. F. I. Morral, J. Bertomeu, and P. R. I. Cabarrocas, Materials Science and Engineering B-Solid State Materials for Advanced Technology 69, 559-563 (2000).
3. A. F. I. Morral and P. R. I. Cabarrocas, Journal of Non-Crystalline Solids 299, 196-200 (2002).
4. K. Saitoh, M. Kondo, M. Fukawa, T. Nishimiya, A. Matsuda, W. Futako, and I. Shimizu, Applied Physics Letters 71, 3403-3405 (1997).