Method for making a semiconductor device having a high-k gate dielectric
View Patent ↗A method for making a semiconductor device is described. That method comprises forming a high-k gate dielectric layer on a substrate, then forming a capping layer on the high-k gate dielectric layer. After oxidizing the capping layer to form a capping dielectric oxide on the high-k gate dielectric layer, a gate electrode is formed on the capping dielectric oxide.
1. A method for making a semiconductor device comprising:
forming on a substrate a high-k gate dielectric layer;
applying a wet chemical treatment to the high-k gate dielectric layer to remove impurities from that layer and to increase the oxygen content of that layer;
forming a capping layer that comprises silicon and that is less than about five monolayers thick on the high-k gate dielectric layer;
oxidizing the capping layer by exposing the capping layer to a solution that comprises hydrogen peroxide to form a capping dielectric oxide on the high-k gate dielectric layer; and then
forming a gate electrode on the capping dielectric oxide.
2. A method for making a semiconductor device comprising:
forming a high-k gate dielectric layer on a substrate, the high-k gate dielectric layer being less than about 60 angstroms thick and comprising a material selected from the group consisting of hafnium oxide, zirconium oxide, titanium oxide, and aluminum oxide;
applying a wet chemical treatment to the high-k gate dielectric layer to remove impurities from that layer and to increase the oxygen content of that layer;
forming on the high-k gate dielectric layer a silicon containing layer that is less than about five monolayers thick;
oxidizing the silicon containing layer to form a silicon dioxide layer on the high-k gate dielectric layer; and
forming a gate electrode on the silicon dioxide layer.