Structure and method for replacement gate MOSFET with self-aligned contact using sacrificial mandrel dielectric

摘要

The present disclosure provides a method for forming a semiconductor device that includes forming a replacement gate structure overlying a channel region of a substrate. A mandrel dielectric layer is formed overlying source and drain regions of the substrate. The replacement gate structure is removed to provide an opening exposing the channel region of the substrate. A functional gate structure is formed over the channel region including a work function metal layer. A protective cap structure is formed over the functional gate structure. At least one via is etched through the mandrel dielectric layer selective to the protective cap structure to expose a portion of at least one of the source region and the drain region. A conductive fill is then formed in the vias to provide a contact to the at least one of the source region and the drain region.