Semiconductor device and method for manufacturing semiconductor device

摘要

It is an object of the present invention to provide a crystallizing method that can control the orientation with the use of the metal element for promoting the crystallization, wherein the pulsed laser is irradiated once to the crystalline semiconductor film with the orientation aligned to form a crystalline semiconductor film having small crystal grains formed in a grid pattern at regular intervals in which the orientation is aligned in adjacent crystal grains. It is also an object of the present invention to provide a method for manufacturing the crystalline semiconductor film. In view of the above object, the present invention provides a crystalline semiconductor film having the crystal grains formed in a grid pattern in which the orientation is aligned in adjacent crystal grains and also provides a thin film transistor having the crystalline semiconductor film. Particularly in the present invention, in order to form a crystal grain with the orientation aligned in adjacent crystal grains, the metal element for promoting the crystallization is added selectively to form a crystalline semiconductor film and the pulsed laser is preferably irradiated thereafter.