Patent ID: 8895333
Filing Date: 2014-11-25
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, comprising the steps of: forming a transparent conductive film and a first metal film sequentially over a substrate; forming a first resist by using a first photomask which is a multi-tone mask, the first resist having different thicknesses in a first portion and in a second portion; forming a gate electrode by shaping the transparent conductive film and the first metal film with the first resist so that a stack of the transparent conductive film and the first metal film remains in the first portion and only the transparent conductive film remains in the second portion; forming an insulating film, a first semiconductor film, a second semiconductor film, and a second metal film sequentially over the gate electrode; forming a second resist by using a second photomask which is a multi-tone mask, the second resist having different thicknesses in a channel region formation portion and in a source region formation portion and a drain region formation portion; forming a first semiconductor layer, a second semiconductor layer, and a second metal layer by shaping the first semiconductor film, the second semiconductor film, and the second metal film, respectively, with the second resist; forming a channel region, a drain region, a source region, a drain wiring, and a source wiring of a thin film transistor by etching a part of the first semiconductor layer, the second semiconductor layer, and the second metal layer in the channel region formation portion; forming a protective film over the thin film transistor; and forming a pixel electrode over the protective film.