Patent ID: 8735996
Filing Date: 2014-05-27
Classification: H01L

Abstract:
1. A semiconductor structure, comprising: a semiconductor substrate of a semiconductor material; a gate dielectric comprising a high dielectric constant dielectric layer having a dielectric constant greater than silicon and located on the semiconductor substrate; and a gate electrode abutting the gate dielectric and including 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 reducing an oxidized layer at an interface between the upper metal layer and the silicon layer in response to annealing; wherein the oxidized layer at the interface between the upper metal layer and the silicon layer comprises a metal oxide layer and a silicon dioxide layer; and wherein the scavenging metal layer attracts oxygen atoms from both the metal oxide layer and the silicon dioxide layer.