Semiconductor device and method of manufacturing the same

摘要

A semiconductor device, which uses a crystalline silicon film having high crystallinity and a flat surface with few ridges and has high characteristics, and a method of manufacturing the semiconductor device are provided. According to the manufacturing method, a first amorphous silicon film is crystallized by using a heat treatment. A second amorphous silicon film is formed on a first crystalline silicon film thus obtained as an under film, and the second amorphous silicon film is crystallized by irradiation of laser light, so that a silicon film having excellent crystallinity and a surface with few ridges is obtained. The first crystalline silicon film and the second crystalline silicon film having different crystal structures are used as an active layer of a thin film transistor.