Initial Stage of Microcrystalline Silicon Growth by Plasma-Enhanced Chemical Vapor Deposition

Abstract
We report the initial stage of growth of hydrogenated microcrystalline silicon (µ c-Si:H) film with less than 500 Å thick by conventional rf plasma-enhanced chemical vapor deposition (PECVD). Through studies of film deposited on thermally grown SiO2 with various types of morphology and film grown by a layer-by-layer (LbL) technique, it was found that the crystallinity strongly influenced on the induced surface roughness and it correlated with the SiH2/SiH intensity ratio. The thin film transistor (TFT) characteristics are determined not only by the film crystallinity but alsso by the morphology of SiO2 substrate, which suggest that the formation of the crystallite phase at the early stage of growth without increasing the interface roughness is essential for further improvement of the carrier transport properties.