Semiconductor device with work function layer

Abstract

The present application discloses a semiconductor device. The semiconductor device includes a substrate; a peripheral gate structure including: a peripheral gate insulating layer inwardly positioned in the substrate and including a U-shaped cross-sectional profile, a peripheral work function layer positioned on the peripheral gate insulating layer and including a recess, a first peripheral interconnect layer positioned on the peripheral work function layer, a first peripheral liner layer positioned between the peripheral work function layer and the first peripheral interconnect layer, and a peripheral capping layer positioned on the first peripheral interconnect layer. The peripheral work function layer includes titanium, titanium nitride, silicon, silicon germanium, or a combination thereof. The first peripheral liner layer includes graphene. The first peripheral interconnect layer includes tungsten, tungsten nitride, or a combination thereof.