Nucleation control towards the poly-Si thin films with large grain size utilizing intermittent supply of dichlorosilane

In order to obtain polycrystalline Si (poly-Si) thin films with large grain size, we propose a nucleation control method by intermittent supply of Si source gas in atmospheric pressure chemical vapor deposition. By intermittent supply of dichlorosilane as Si source gas, the nucleus density was controlled in a range from 10/sup 5/ to 10/sup 7/ cm/sup -2/. The maximum grain size of 22 /spl mu/m with the film thickness of 15 /spl mu/m was obtained. By optimizing the conditions of an intermittent ratio and time, relatively high preferential orientation of (220) over 65% was achieved.