Tailored Si-Layers on Silicon Oxide Obtained by Thermal CVD

In this paper, a method to obtain by CVD Si layers on silicon oxide with the desired grain size is described, involving nucleation control through the growth parameters. Nucleation experiments are carried out with a hydrogen - dichlorosilane - HCl ambient at high temperature. The nucleus density is observed to drop to low values at a threshold HCl-flow. A qualitative explanation using concepts from atomistic nucleation theory is proposed. The effect of addition of diborane to the gas flow is investigated and appears to be small or non-existent . Finally, preliminary results of a thin-film crystalline silicon solar cell process applied on such layers are given to illustrate the potential of such layers.