Effect of Deposition Pressure on the Properties of Silicon Thin Films

Abstract

Hydrogenated silicon thin film was prepared by plasma enhanced chemical vapor deposition (PECVD). The effects of the deposition pressure on the growth rate, the photoelectronic and microstructure properties of the thin films were investigated via transmission, photo/dark conductivity, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) measurements. The results indicate that the increase of the deposition pressure increases the bandgap and the growth rate, while makes the photosensitivity get worse, decreasing from more than ~103to ~102. And at the same time, the crystalline volume fraction (Xc) in the film decreases from 70% to 61%, when the deposition pressure increases from 100 Pa to 500 Pa. The order degree of the microstructure was deteriorated with pressure increasing.