The influence of SiN_x substrate on crystallinity of μc-Si film used in thin film transistors

This paper found that the crystalline volume ratio (X_c) of \muc-Si deposited on SiN_x substrate is higher than that on 7059 glass. At the same silane concentration (SC) (for example, at SC=2%), the X_c of \muc-Si deposited on SiN_x is more than 64%, but just 44% if deposited on Conning 7059. It considered that the `hills' on SiN_x substrate would promote the crystalline growth of \muc-Si thin film, which has been confirmed by atomic force microscope (AFM) observation. Comparing several thin film transistor (TFT) samples whose active-layer were deposited under various SC, this paper found that the appropriate SC for the \muc-Si thin film used in TFT as active layer should be more than 2%, and X_c should be around 50%. Additionally, the stability comparison of \muc-Si TFT and a-Si TFT is shown in this paper.