Scavenging metal stack for a high-k gate dielectric

Abstract

A semiconductor structure is provided. The structure includes a semiconductor substrate of a semiconductor material and a gate dielectric having a high dielectric constant dielectric layer with a dielectric constant greater than silicon. The gate dielectric is located on the semiconductor substrate. A gate electrode abuts the gate dielectric. The gate electrodes includes a lower metal layer abutting the gate dielectric, a scavenging metal layer abutting the lower metal layer, an upper metal layer abutting the scavenging metal layer, and a silicon layer abutting the upper metal layer. The scavenging metal layer reduces an oxidized layer at an interface between the upper metal layer and the silicon layer responsive to annealing.

Dependencies are inferred from the claim text.