Patent attributes
A method of fabricating interconnect is described. A first dielectric layer having an opening is formed over a substrate. A metal layer is filled into the opening. A material layer is formed over the first dielectric layer and the metal layer. A surface treatment process is performed to the material layer so as to form a cap layer on the surface of the metal layer. The material layer and a portion of the first dielectric layer are removed. A second dielectric layer is formed over the substrate, and the surface of the second dielectric layer is higher than that of the cap layer. A planarization process is performed at least to remove a portion of the second dielectric layer and a portion of the cap layer so as to expose the top of the opening.