Patent ID: 7981701

Claim:
A method for manufacturing a semiconductor thin film, comprising: a step of forming an island-shaped region with an approximate band-shaped crystal semiconductor thin film crystallized and modified in film quality so that crystal grains grow laterally in a scanning direction by irradiating a continuous oscillation laser beam in a given region of said semiconductor thin film formed on an insulated substrate while scanning said continuous oscillation laser beam or said insulated substrate; a step of irradiating an inspection beam to an end region of said island-shaped region when said continuous oscillation laser beam is turned off; a step of evaluating the film quality of said semiconductor thin film by detecting an almost linearly-linked protrusion, which is generated when the continuous oscillation laser beam irradiation is switched from on to off in the process conditions on which lateral crystals are to be obtained, in the end region of said island-shaped region using the intensity or the distribution of its scattering light, reflection light, its diffraction light; a step of determining values for the laser energy and substrate scanning speed to form lateral crystals based on scattered light generated from an inspection beam irradiated on the end region of the island-shaped region; and a step of supplying a feedback of the determined laser energy and substrate scanning speed to two controllers.