Semiconductor device including oxide semiconductor

摘要

A more convenient and highly reliable semiconductor device which has a transistor including an oxide semiconductor with higher impact resistance used for a variety of applications is provided. A semiconductor device has a bottom-gate transistor including a gate electrode layer, a gate insulating layer, and an oxide semiconductor layer over a substrate, an insulating layer over the transistor, and a conductive layer over the insulating layer. The insulating layer covers the oxide semiconductor layer and is in contact with the gate insulating layer. In a channel width direction of the oxide semiconductor layer, end portions of the gate insulating layer and the insulating layer are aligned with each other over the gate electrode layer, and the conductive layer covers a channel formation region of the oxide semiconductor layer and the end portions of the gate insulating layer and the insulating layer and is in contact with the gate electrode layer.

主权项

1. A semiconductor device comprising a transistor, the transistor comprising:
a gate electrode; a first insulating layer over the gate electrode; an oxide semiconductor layer over the gate electrode with the first insulating layer therebetween; a second insulating layer over the oxide semiconductor layer; and a conductive layer over the oxide semiconductor layer with the second insulating layer therebetween, wherein the conductive layer is overlapped with the gate electrode, wherein each of the gate electrode and the conductive layer extends beyond both side edges of the oxide semiconductor layer in a channel width direction of the transistor so that the oxide semiconductor layer is surrounded by the gate electrode, the first insulating layer, the second insulating layer and the conductive layer, wherein the first insulating layer is in contact with a bottom surface of the oxide semiconductor layer, wherein the second insulating layer is in contact with a top surface of the oxide semiconductor layer, wherein the first insulating layer comprises silicon oxide, wherein the second insulating layer comprises silicon oxide, wherein the oxide semiconductor layer comprises a portion overlapping with the conductive layer, and wherein a length of the portion in the channel width direction of the transistor is larger than a length of the portion in a channel length direction of the transistor.