Method of manufacturing interconnect structure

A manufacturing method of an interconnect structure including the following steps is provided. A dielectric layer is formed on a silicon layer, wherein an opening exposing the silicon layer is in the dielectric layer. A metal layer is formed on the surface of the opening. A stress adjustment layer is formed on the metal layer. A thermal process is performed to react the metal layer with the silicon layer to form a metal silicide layer on the silicon layer. The stress adjustment layer is removed after the thermal process is performed. A barrier layer is formed on the surface of the opening.