Semiconductor device and method for manufacturing the same

摘要

A highly reliable display device which has high aperture ratio and includes a transistor with stable electrical characteristics is manufactured. The display device includes a driver circuit portion and a display portion over the same substrate. The driver circuit portion includes a driver circuit transistor and a driver circuit wiring. A source electrode and a drain electrode of the driver circuit transistor are formed using a metal. A channel layer of the driver circuit transistor is formed using an oxide semiconductor. The driver circuit wiring is formed using a metal. The display portion includes a pixel transistor and a display portion wiring. A source electrode and a drain electrode of the pixel transistor are formed using a transparent oxide conductor. A semiconductor layer of the pixel transistor is formed using the oxide semiconductor. The display portion wiring is formed using a transparent oxide conductor.

主权项

1. A semiconductor device comprising:
a pixel portion formed over a substrate, the pixel portion including a first transistor; and a driver circuit portion formed over the substrate, the driver circuit portion including a second transistor, wherein the first transistor includes:
a first gate electrode layer;a gate insulating layer over the first gate electrode layer;a first source electrode layer and a first drain electrode layer over the gate insulating layer;a first oxide semiconductor layer over the gate insulating layer, the first source electrode layer, and the first drain electrode layer, the first oxide semiconductor layer being in contact with the gate insulating layer and including a channel formation region;an oxide insulating layer over the first oxide semiconductor layer; anda pixel electrode layer over the oxide insulating layer, wherein the second transistor includes:
a second gate electrode layer;the gate insulating layer over the second gate electrode layer;a second oxide semiconductor layer over the second gate electrode layer and the gate insulating layer;a second source electrode layer and a second drain electrode layer over the second oxide semiconductor layer; andthe oxide insulating layer over the second oxide semiconductor layer, the second source electrode layer, and the second drain electrode layer, the oxide insulating layer being in contact with the second oxide semiconductor layer, wherein each of the first gate electrode layer, the first oxide semiconductor layer, the first source electrode layer, and the first drain electrode layer has a light-transmitting property, wherein a material of the second source electrode layer and the second drain electrode layer is different from a material of the first source electrode layer and the first drain electrode layer, wherein the material of the second source electrode layer and the second drain electrode layer is a metal having lower resistance than the material of the first source electrode layer and the first drain electrode layer, and wherein the channel formation region is interposed between the first source electrode layer and the first drain electrode layer.