Patent ID: 6806146
Filing Date: 2004-10-19
Classification: H01L,Y10S

Abstract:
A method for making a semiconductor device comprising:forming a high-k gate dielectric layer on a substrate, the high-k gate dielectric layer including impurities, 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; forming a silicon containing sacrificial layer on the high-k gate dielectric layer; removing the silicon containing sacrificial layer after the silicon containing sacrificial layer has gettered the impurities from the high-k gate dielectric layer; exposing the high-k gate dielectric layer to a silicic acid containing solution until a silicon dioxide capping layer forms on the high-k gate dielectric layer; forming a layer that comprises polysilicon on the silicon dioxide capping layer; and etching the polysilicon containing layer, the silicon dioxide capping layer and the high-h gate dielectric layer.