METHOD FOR FABRICATING POLYSILICON THIN FILM HAVING IMPROVED CRYSTALLIZATION CHARACTERISTICS WITHOUT DIRECTION DEPENDANCE OF GRAIN AND METHOD FOR FABRICATING LCD DEVICE BASED ON THE SAME

摘要

PURPOSE: A method for fabricating a polysilicon thin film is provided to obtain a uniform size of a grain and remove direction dependance of the grain by improving a crystallization method. A method for fabricating an LCD device is provided to improve picture quality by using the polysilicon thin film having improved crystallization characteristics as an active layer. CONSTITUTION: A method for fabricating a polysilicon thin film includes the steps of preparing a substrate, depositing an amorphous polysilicon thin film(220) on the entire surface of the substrate, horizontally crystallizing the amorphous polysilicon thin film in a first direction, and horizontally crystallizing the crystallized polysilicon thin film in a second direction. The amorphous polysilicon thin film is deposited at a thickness of 1000Å to 2000Å. The step of etching the entire surface of the crystallized polysilicon thin film is further be provided to allow the polysilicon thin film to remain at a thickness of 300Å to 600Å after the crystallizing step in the first direction. The amorphous polysilicon thin film is crystallized by sequential horizontal crystallization, and the first direction is vertical to the second direction.