FABRICATION OF THIN FILM TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To provide a method for fabricating a thin film transistor in which a polysilicon thin film is deposited such that the drain current is normal even under low gate voltage. SOLUTION: A thin film 125 of amorphous silicon is deposited and patterned insularly to form a substantially flat part 125P and a tapered circumferential fringe part 125S. The thin film 125 of amorphous silicon is then irradiated with an excimer laser beam of specified intensity and annealed to form a thin film 110 of polysilicon. Consequently, mean silicon grain size of the polisilicon thin film 110 becomes smaller at the circumferential fringe part 110S as compared with the flat part 110P.