Patent ID: 8372700

Claim:
A method for manufacturing a thin film transistor, comprising the steps of: stacking a first conductive film, an insulating film, and a first semiconductor film in this order; crystallizing the first semiconductor film to form a second semiconductor film; stacking an impurity semiconductor film and a second conductive film in this order over the second semiconductor film; forming a first resist mask having a recessed portion over the second conductive film; performing first etching on at least the second conductive film, the impurity semiconductor film, the second semiconductor film, and the insulating film with the use of the first resist mask; performing second etching in which the first conductive film is side-etched to form a first wiring layer; reducing the first resist mask to expose a part of the second conductive film which overlaps with the recessed portion of the first resist mask to form a second resist mask after performing the second etching; and performing third etching on the second conductive film, the impurity semiconductor film, and the second semiconductor film with the use of the second resist mask to form a second wiring layer, an impurity semiconductor layer, and the second semiconductor film whose upper part is etched.