The Effects of Different Silicon Oxide Substrates on Amorphous Silicon Thin-Film

In this paper, the influences of different substrates on the performance of amorphous silicon (a-Si) film including thickness, within-wafer uniformity, and roughness were studied. The a-Si films were prepared on three different silicon oxide substrates (Dry Oxide, Wet Oxide and HCl Oxide) under three seeding time split conditions. The results showed that the a-Si deposited on wet oxide substrate presented the thickest film, the best uniformity, and the best roughness in all spilt conditions. The presence of a large number of-OH on wet oxide substrate provide dense and uniform nucleation sites which increase the whole growth rate and reduce the difference of growth rate between different areas. Furthermore, the uniform nucleation sites led to the uniform size of the nucleus, and further obtained good roughness in the continuous films. The addition of seeding significantly optimized the performance of a-Si film, and the a-Si deposited on wet oxide substrate still showed the best uniformity and roughness compared to the other two substrates.