METHOD OF EVALUATING POLYSILICON, THIN FILM TRANSISTOR MANUFACTURING SYSTEM, AND METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain an evaluation result without fail when evaluating a crystal condition of a polysilicon film formed by a low temperature polycrystallizing process. SOLUTION: Linearity or periodicity appear in a spatial structure on a film surface of the polysilicon film, which has been formed according to an energy density applied to amorphous silicon, during the low temperature polycrystallizing process by excimer laser. A surface image of the polysilicon film is photographed by ultraviolet light, and the periodicity of the film surface is digitized (transformed into AC values) from the image utilizing an autocorrelation function. The film condition is evaluated based on the AC value to set an excimer laser power. In the present invention, the surface of the amorphous silicon film is oxidized after the substrate has been cleaned by rare HF and before a laser anneal processing, and a natural oxide film is formed.