Patent ID: 7141491

Claim:
A method for manufacturing a semiconductor device comprising: forming a semiconductor film comprising amorphous silicon over a substrate; providing the semiconductor film with a metal containing material for promoting crystallization of the semiconductor film; crystallizing the semiconductor film by heating; irradiating the crystallized semiconductor film with laser light so as to distribute the metal in the crystallized semiconductor film; removing the distributed metal from the crystallized semiconductor film by gettering after the irradiation of the laser light; forming a semiconductor island having a tapered shape by patterning the crystallized semiconductor film, the tapered shape having an angle within a range of 20° to 50° between a side thereof and an underlying surface; forming a gate insulating film over the semiconductor island; forming a gate electrode over the semiconductor island with the gate insulating film therebetween; and forming at least a source region and a drain region in the semiconductor island.