Thin film transistor

摘要

A thin film transistor including an oxide semiconductor with favorable electrical characteristics is provided. The thin film transistor includes a gate electrode provided over a substrate, a gate insulating film provided over the gate electrode, an oxide semiconductor film provided over the gate electrode and on the gate insulating film, a metal oxide film provided on the oxide semiconductor film, and a metal film provided on the metal oxide film. The oxide semiconductor film is in contact with the metal oxide film, and includes a region whose concentration of metal is higher than that of any other region in the oxide semiconductor film (a high metal concentration region). In the high metal concentration region, the metal contained in the oxide semiconductor film may be present as a crystal grain or a microcrystal.

主权项

1. A transistor comprising:
a gate electrode; a gate insulating film overlapping with the gate electrode; an oxide semiconductor film overlapping with the gate electrode with the gate insulating film interposed therebetween; and a titanium film overlapping with the oxide semiconductor film, wherein the oxide semiconductor film contains at least one of indium, gallium, and zinc, wherein the oxide semiconductor film includes a first region and a second region, wherein the first region and the second region overlap with the titanium film, wherein the first region is closer to the titanium film than the second region, wherein the first region is in the vicinity of the titanium film, and wherein a concentration of indium in the first region is higher than a concentration of indium in the second region.