Semiconductor device and method for manufacturing the same

摘要

As a display device has a higher definition, the number of pixels, gate lines, and signal lines are increased. When the number of the gate lines and the signal lines are increased, there occurs a problem that it is difficult to mount an IC chip including a driver circuit for driving the gate and signal lines by bonding or the like, whereby manufacturing cost is increased. A pixel portion and a driver circuit for driving the pixel portion are provided over the same substrate, and at least part of the driver circuit includes a thin film transistor using an oxide semiconductor interposed between gate electrodes provided above and below the oxide semiconductor. Therefore, when the pixel portion and the driver circuit are provided over the same substrate, manufacturing cost can be reduced.

主权项

1. A semiconductor device comprising:
a first gate electrode over an insulating surface; a first insulating layer over the first gate electrode; a first oxide semiconductor layer over the first insulating layer; one of a source electrode and a drain electrode over the first oxide semiconductor layer; a second oxide semiconductor layer over the one of the source electrode and the drain electrode; a second insulating layer over the second oxide semiconductor layer; a second gate electrode over the second insulating layer; and a third oxide semiconductor layer between the first insulating layer and the second insulating layer, wherein the first oxide semiconductor layer has n-type conductivity, and wherein the second oxide semiconductor layer has n-type conductivity.