SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

摘要

A highly reliable semiconductor device having stable electric characteristics is provided by suppressing, in a transistor including an oxide semiconductor film, diffusion of indium into an insulating film in contact with the oxide semiconductor film and improving the characteristics of the interface between the oxide semiconductor film and the insulating film. In an oxide semiconductor film containing indium, the indium concentration at a surface is decreased, thereby preventing diffusion of indium into an insulating film on and in contact with the oxide semiconductor film. By decreasing the indium concentration at the surface of the oxide semiconductor film, a layer which does not substantially contain indium can be formed at the surface. By using this layer as part of the insulating film, the characteristics of the interface between the oxide semiconductor film and the insulating film in contact with the oxide semiconductor film are improved.

主权项

1. A semiconductor device comprising:
an oxide semiconductor film containing indium; a first insulating film in contact with a bottom surface of the oxide semiconductor film; a second insulating film in contact with a top surface of the oxide semiconductor film; a gate electrode overlapping with the oxide semiconductor film with the first insulating film or the second insulating film interposed therebetween; and source and drain electrodes in contact with the oxide semiconductor film, wherein the oxide semiconductor film comprises a first region in contact with the first insulating film and a second region in contact with the second insulating film and between the second insulating film and the first region, and wherein a concentration of indium in the second region is lower than a concentration of indium in the first region.