In-situ silicon cap for metal gate electrode

A method comprising:

• providing a substrate;
• depositing a dielectric layer on the substrate;
• heating the substrate and the dielectric layer in an inert gas environment;
• cooling the substrate and the dielectric layer in the inert gas environment,
• wherein the heating and cooling drives off absorbed oxygen containing species on the substrate;
• depositing a metal layer on the dielectric layer;
• depositing a silicon (Si) cap on the metal layer;
• wherein the Si cap has a thickness of approximately 25-200 angstrom (Å), and wherein the Si cap is deposited without a vacuum break from the heating, cooling or metal deposition processes;
• removing the substrate, dielectric layer, metal layer, and Si cap from the vacuum break;
• and
• depositing an additional Si layer on the Si cap layer to achieve a desired thickness.