Semiconductor device comprising both amorphous and crystalline semiconductor oxide

摘要

A semiconductor device for high power application in which a novel semiconductor material having high mass productivity is provided. An oxide semiconductor film is formed, and then, first heat treatment is performed on the exposed oxide semiconductor film in order to reduce impurities such as moisture or hydrogen in the oxide semiconductor film. Next, in order to further reduce impurities such as moisture or hydrogen in the oxide semiconductor film, oxygen is added to the oxide semiconductor film by an ion implantation method, an ion doping method, or the like, and after that, second heat treatment is performed on the exposed oxide semiconductor film.

主权项

1. A semiconductor device comprising:
a gate electrode; a gate insulating film over the gate electrode; an oxide semiconductor layer over the gate insulating film; a source electrode and a drain electrode over the oxide semiconductor layer; and an insulating film over the oxide semiconductor layer, the source electrode, and the drain electrode, wherein a portion of the oxide semiconductor layer located between the source electrode and the drain electrode is thinner than portions of the oxide semiconductor layer below the source electrode and the drain electrode, wherein the portion of the oxide semiconductor layer located between the source electrode and the drain electrode includes a crystal region, wherein a c axis of the crystal region is aligned in a direction which is substantially perpendicular to a top surface of the oxide semiconductor layer, and wherein the oxide semiconductor layer includes indium, gallium, and zinc.