US 8,709,922 B2 · Semiconductor device

Abstract

A highly reliable semiconductor device which is formed using an oxide semiconductor and has stable electric characteristics is provided. A semiconductor device which includes an amorphous oxide semiconductor layer including a region containing oxygen in a proportion higher than that in the stoichiometric composition, and an aluminum oxide film provided over the amorphous oxide semiconductor layer is provided. The amorphous oxide semiconductor layer is formed as follows: oxygen implantation treatment is performed on a crystalline or amorphous oxide semiconductor layer which has been subjected to dehydration or dehydrogenation treatment, and then thermal treatment is performed on the oxide semiconductor layer provided with an aluminum oxide film at a temperature lower than or equal to 450° C.

Claims11

Dependent claims

A method for manufacturing a transistor, the method comprising the steps of:

forming an amorphous oxide semiconductor layer;
heating the amorphous oxide semiconductor layer to form a crystalline region in the amorphous oxide semiconductor layer;
forming a gate insulating layer over and in contact with the heated amorphous oxide semiconductor layer;
implanting oxygen to the amorphous oxide semiconductor layer so that the amorphous oxide semiconductor layer comprises a region having stoichiometrically excessive oxygen and the crystalline region is transformed to an amorphous structure;
forming a gate electrode over the gate insulating layer;
and
forming an insulating layer over the gate electrode, the insulating layer comprising aluminum oxide.

4 more elements

Dependencies are inferred from the claim text.

Semiconductor device

Life of this patent

Semiconductor device

Life of this patent

Abstract

Claims11