SACRIFICIAL LAYER FOR REPLACEMENT METAL SEMICONDUCTOR ALLOY CONTACT FORMATION

A sacrificial layer is formed on exposed surfaces of source/drain structures that are located at the footprint of a gate stack. A stack of, from bottom to top, a middle-of-the-line (MOL) liner, a MOL dielectric material, and an optional dielectric cap material layer is then formed surrounding the gate stack. A contact opening is then formed that exposes a portion of the sacrificial layer. The entirety of the sacrificial layer is then removed and replaced with a metal semiconductor alloy. A conductive metal structure is then provided in the remaining volume of the contact opening.