Electronic transport properties of polycrystalline silicon films deposited on ceramic substrates

In this paper we first present our results on growth of silicon onto silicon oxide and ceramic (alumina, mullite) substrates in three chemical vapor deposition (CVD) reactors using chlorosilanes as precursor gases. The effect of operational parameters (substrate temperature and gas concentration) on growth rate and grain size were analyzed using scanning electron microscopy (SEM) technique. We show that deposition rates up to 5 mu m/min can be reached. Furthermore, preferential(up to 80%) (220) oriented structure with grain size ranging from 0.5 to 10 mu m can be generated for a 10 mu m thick Si film. In the second part we report on electronic properties of the deposited poly-Si films through the layer resistivity, open-circuit voltage of photovoltaic devices, minority carrier diffusion length and spectral response data. We show that the grain size and the post-hydrogenation treatment affect mostly the open-circuit voltage and weakly the spectral response. (C) 1999 Elsevier Science B.V. All rights reserved.