Semiconductor device

摘要

Provided is a structure of a transistor, which enables a so-called normally-off switching element, and a manufacturing method thereof. Provided is a structure of a semiconductor device which achieves high-speed response and high-speed operation by improving on characteristics of a transistor, and a manufacturing method thereof. Provided is a highly reliable semiconductor device. In the transistor in which a semiconductor layer, source and drain electrode layers, a gate insulating layer, and a gate electrode layer are stacked in that order. As the semiconductor layer, an oxide semiconductor layer which contains at least four kinds of elements of indium, gallium, zinc, and oxygen, and has a composition ratio (atomic percentage) of indium as twice or more as a composition ratio of gallium and a composition ratio of zinc, is used.

主权项

1. A semiconductor device comprising:
an oxide semiconductor layer including a channel formation region, a first region, and a second region; a source electrode layer and a drain electrode layer over the oxide semiconductor layer; and a gate electrode layer over the oxide semiconductor layer with a gate insulating film interposed therebetween, wherein the first region is not overlapped with the gate electrode layer, the source electrode layer and the drain electrode layer, wherein the second region is overlapped with the source electrode layer or the drain electrode layer, and wherein a resistance in the second region is higher than a resistance in the first region.