Patent ID: 7605023

Claim:
A manufacturing method for a semiconductor device, comprising: forming at least first and second semiconductor layers that are divided from each other in an island-like shape over a substrate having an insulating surface, wherein each of said first and second semiconductor layers includes a region to become at least a channel region of a thin film transistor; forming a conductive layer covering an entire surface of each of the first and second semiconductor layers with an insulating layer interposed therebetween; selectively heating the first and second semiconductor layers by irradiating an incoherent electromagnetic wave within a wavelength band ranging at least from a visible light band to an infrared band to thereby conduct heat treatment on each of the first and second semiconductor layers and the insulating layer; and etching said conductive layer after the selective heating of the first and second semiconductor layers to form at least first and second gate electrodes over the first and second semiconductor layers, respectively, wherein said conductive layer extends beyond each periphery of the first and second semiconductor layers at least when the selective heating of the first and second semiconductor layers is performed.