The present disclosure describes a semiconductor device having a contact structure isolated from a source/drain structure. The semiconductor structure includes a gate structure on a substrate, first and second source/drain (S/D) structures on opposite sides of the gate structure, an isolation layer on the second S/D structure, a third S/D structure adjacent to and separate from the second S/D structure, and a S/D contact structure on the isolation layer and the third S/D structure. The isolation layer separates the S/D contact structure from the second S/D structure.