The effect of SiH/sub 4/ flow and H/sub 2/ dilution on hot-wire /spl mu/c-Si:H and a-Si:H films

Abstract

The effects of SiH/sub 4/ flow and H/sub 2/ dilution on the hot wire silicon films have been studied in this paper. The Si films deposited at low SiH/sub 4/ flow (1 to 7 sccm) have distinct Raman TO mode peak near 520 cm/sup -1/ even at no H/sub 2/ dilution. The microcrystalline to amorphous phase transition, however, occurred at increased SiH/sub 4/ flow above than 10 sccm. The added H/sub 2/ gas does not contribute to the crystallinity improvement of the samples deposited at low SiH/sub 4/ flow while the amorphous films are crystallized as the high H/sub 2/ gases are employed. On the contrary, when the deposition time increased, the crystalline properties are greatly improved; crystalline volume fraction reached up to 75% without H/sub 2/ dilution. The electrical properties and hydrogen bonding configuration as functions of SiH/sub 4/ flow and different dilution conditions are also discussed in the paper.