Higher 'k' gate dielectric cap for replacement metal gate (rmg) finfet devices

Abstract

A semiconductor structure includes a semiconductor substrate, n-type and p-type FinFETs on the substrate, each of the n-type and the p-type FinFETs include a channel region and a gate structure surrounding the channel region, each gate structure having a phase-changed high-k gate dielectric layer lining a gate trench thereof, the gate trench defined by a pair of spacers. The semiconductor structure further includes a conformal dielectric capping layer over each phase-changed high-k gate dielectric layer, the conformal dielectric capping layer having a higher dielectric constant than the phase-changed high-k gate dielectric layer. Further included on the n-type FinFETs is a multi-layer replacement gate stack of n-type work function material over the phase-changed high-k gate dielectric layer. A method of fabricating the semiconductor structure is also provided.