Semiconductor device and manufacturing method thereof

The method for forming a semiconductor device includes forming gate spacers on a substrate; forming a gate structure on the substrate and laterally between the gate spacers; forming a protective cap over the gate structure and laterally between the gate spacers; forming source/drain structures over the substrate and on opposite sides of the gate structure; depositing a dielectric layer over the protective cap, the gate spacers, and the source/drain structures; performing an etching process on the dielectric layer to form an opening exposing one of the source/drain structures, the etching process further etching a first one of the gate spacers to expose the protective cap; selectively depositing a capping material on the exposed protective cap; forming a source/drain contact in the opening.