Structure and method of improving the performance of metal gate devices by depositing an in-situ silicon (Si) cap are disclosed. A wafer including a substrate and a dielectric layer is heated through a degas process, and then cooled to approximately room temperature. A metal layer is then deposited, and then an in-situ Si cap is deposited thereon. The Si cap is deposited without vacuum break, i.e., in the same mainframe or in the same chamber, as the heating, cooling and metal deposition processes. As such, the amount of oxygen available for interlayer oxide regrowth during subsequent processing is reduced as well as the amount oxygen trapped in the metal gate.