Nanocrystalline Silicon Thin-Film Transistor Fabricated without Substrate Heating for Flexible Display

We fabricated nanocrystalline silicon (nc-Si) thin film transistors (TFTs) without any substrate heating. High quality nc-Si and silicon dioxide films were deposited at room temperature employing an inductively coupled plasma chemical vapour deposition (ICP-CVD) system. For the nc-Si film a crystalline phase was grown as a columnar structure and the crystalline volume fraction was 27%. On the silicon dioixide film, hydrogen plasma post-treatment was performed, and the electrical characteristics of silicon dioxide film improved owing to charge reduction the annealing effect. The nc-Si and silicon dioxide films were used for the fabrication nc-Si TFTs without substrate heating. Although there was no external heating, a mobility of 6.42 cm(-1).V-1.s(-1) was achieved. This result indicates that nc-Si TFTs fabricated without substrate heating may be a suitable devices for a flexible display. (C) 2009 The Japan Society of Applied Physics.