Interfacial layer regrowth control in high-k gate structure for field effect transistor

Abstract

A field effect transistor having a gate structure comprising a high-K dielectric layer, a gate electrode located on the high-K dielectric layer, and an interfacial layer located in between the high-K dielectric layer and a channel region of the field effect transistor. The interfacial layer comprises a layer of SiOcontaining a regrowth inhibiting agent. A method of forming the gate structure includes forming a gate stack comprising, in order: a SiOlayer adjacent a channel region of the field effect transistor; a high-K dielectric layer on the SiOlayer; and a gate electrode on the high-K dielectric layer. The method also includes introducing a regrowth inhibiting agent into the SiOlayer and then annealing the gate structure. The presence of the regrowth inhibiting agent in the SiOinterfacial layer inhibits regrowth of the SiOlayer into the channel region during the annealing step.