Patent ID: 7625786

Claim:
A method of manufacturing a semiconductor device comprising: forming a semiconductor film comprising silicon over a substrate; providing the semiconductor film with a catalytic element that accelerates a crystallization of a semiconductor film; crystallizing the semiconductor film provided with the catalytic element by a heat treatment; etching the crystallized semiconductor film into a first semiconductor layer and a second semiconductor layer; forming a first gate electrode and a second gate electrode each adjacent to the first and second semiconductor layers with a gate insulating film interposed therebetween; doping an n-type impurity element into a first portion of the first semiconductor layer and a second portion of the second semiconductor layer using the first and second gate electrodes as masks; doping a p-type impurity element into the second portion of the second semiconductor layer, and a third portion apart from a channel region of the first semiconductor layer and in contact with the first portion of the first semiconductor layer using a resist pattern; and reducing a concentration of the catalytic element in at least the channel region by gettering the catalytic element into the first and the third portions by a heat treatment.