Patent ID: 8440484

Claim:
A method for manufacturing an active matrix display device, comprising the steps of: forming a semiconductor layer over a glass substrate; forming a first insulating film over the semiconductor layer; forming a conductive layer on and in contact with the first insulating film; forming a resist over the conductive layer, the resist having a first width; etching the conductive layer by using the resist so as to form a wiring; adding an element selected from an n-type impurity element and a p-type impurity element into the semiconductor layer at a first concentration rate with the wiring and the resist thereover as a mask; etching both the wiring and the resist so that the resist has a second width, the second width being smaller than the first width; adding the element into the semiconductor layer at a second concentration rate with the wiring and the resist thereover having the second width as a mask, the second concentration rate being smaller than the first concentration rate; removing the resist; forming a second insulating film over the semiconductor layer and the wiring; and forming a pixel electrode electrically connected with the semiconductor layer.