Semiconductor structure and fabrication method thereof

Abstract

A method for fabricating a semiconductor structure includes providing a dielectric layer on a semiconductor substrate, forming an opening in the dielectric layer to expose a portion of the surface of the semiconductor substrate, forming a metal layer to fill up the opening, and removing the portion of the metal layer formed above the top surface of the dielectric layer by polishing. A metal oxide layer is formed on the surface of the metal layer after polishing. The method further includes removing the metal oxide layer from the top surface of the metal layer, forming a metal barrier layer on the top surface of the metal layer after the removal of the metal oxide layer to provide a more uniform thickness and a denser texture, and converting the metal barrier layer to a metal cap layer by introducing a silicon-containing gas onto a surface of the metal barrier layer.

Dependencies are inferred from the claim text.