Fabrication of thin film transistors by chemical mechanical polished polycrystalline silicon films

Abstract

A top-gate p-channel polycrystalline thin film transistor (TFT) has been fabricated using the polycrystalline silicon (poly-Si) film as-deposited by ultrahigh vacuum chemical vapor deposition (UHV/CVD) and polished by chemical mechanical polishing (CMP). In this process, long-term recrystallization in channel films is not needed. A maximum field effect mobility of 58 cm/sup 2//V-s, ON/OFF current ratio of 1.1 10/sup 7/, and threshold voltage of -0.54 V were obtained. The characteristics are not poor. In this work, therefore, we have demonstrated a new method to fabricate poly-Si TFT's.