Display device comprising an oxide semiconductor

摘要

A pixel portion and a driver circuit driving the pixel portion are formed over the same substrate. At least a part of the driver circuit is formed using an inverted staggered thin film transistor in which an oxide semiconductor layer is used and a channel protective layer is provided over the oxide semiconductor layer serving as a channel formation region which is overlapped with the gate electrode. The driver circuit as well as the pixel portion is provided over the same substrate to reduce manufacturing costs.

主权项

1. A display device comprising a pixel portion and a driver circuit,
wherein the pixel portion comprises a first thin film transistor including a first oxide semiconductor layer and a first channel protective layer in contact with the first oxide semiconductor layer, wherein the driver circuit comprises:
a second thin film transistor including a gate insulating layer, a second oxide semiconductor layer and a second channel protective layer in contact with the second oxide semiconductor layer;a third thin film transistor including a third oxide semiconductor layer and a third channel protective layer in contact with the third oxide semiconductor layer;a first conductive layer including a first portion over and in electrical contact with the third oxide semiconductor layer and a second portion over and in electrical contact with the second oxide semiconductor layer, wherein the first portion serves as one of source and drain electrodes of the third thin film transistor and the second portion serves as one of source and drain electrodes of the second thin film transistor; anda second conductive layer including a third portion over and in direct contact with a vertical side surface of the second oxide semiconductor layer and a fourth portion over and in direct contact with a gate electrode of the second thin film transistor, wherein the third portion serves as the other of the source and drain electrodes of the second thin film transistor, and wherein the third portion and the gate electrode of the second thin film transistor overlap each other.