SEMICONDUCTOR STRUCTURE AND FABRICATION METHOD THEREOF

A method is provided for fabricating a semiconductor structure. The method includes providing a substrate having a dielectric layer formed on the substrate, where an opening is formed in the dielectric layer, and bottom of the opening exposes surface of the substrate. The method also includes forming a first metal layer over of the dielectric layer, where a temperature for forming the first metal layer is a first temperature. In addition, the method includes forming a second metal layer filling the opening, where a temperature for forming the second metal layer is a second temperature, and the second temperature is higher than the first temperature. Further, the method includes planarizing the second metal layer and the first metal layer until the top surface of the dielectric layer is exposed.