Patent ID: 7989234

Claim:
A method for manufacturing a thin film transistor, comprising the steps of: stacking a light-blocking film, a base film, a first conductive film, a first insulating film, a semiconductor film, an impurity semiconductor film, and a second conductive film in this order; forming a first resist mask over the second conductive film; performing first etching on the second conductive film, the impurity semiconductor film, the semiconductor film, the first insulating film, the first conductive film, the base film, and the light-blocking film using the first resist mask; performing second etching in which part of the first conductive film is side-etched to form a gate electrode layer; forming a second resist mask over the second conductive film; and performing third etching on the second conductive film, the impurity semiconductor film, and part of the semiconductor film using the second resist mask to form a source and drain electrode layer, a source and drain region, and a semiconductor layer.