On-Chip Bottom-Gate Polysilicon and Amorphous Silicon Thin-Film Transistors Using Excimer Laser Annealing

Abstract

High-performance bottom-gate thin-film transistors (TFTs) with both polysilicon (poly-Si) and amorphous silicon (a-Si) have been fabricated, for the first time, using chemical-vapor-deposited a-Si film as a starting semiconductor material. The feature of this technology is that both TFTs can be produced in the same process and at the same time on a single substrate except for the local laser crystallization step of the a-Si. The field-effect mobilities were 60 cm 2 /V ·s for the poly-Si TFT and 1.3 cm 2 /V ·s for the a-Si TFT, respectively. Their on-off current ratios were more than 10 6 .