An interconnect structure of an integrated circuit having improved reliability and a method for forming the same are provided. The method includes providing a substrate, forming a dielectric layer overlying the substrate, performing a first shrinking process, wherein the dielectric layer shrinks and has a first shrinkage rate, forming a conductive feature in the dielectric layer after the step of performing the first shrinking process, and performing a second shrinking process after the step of forming the conductive feature, wherein the dielectric layer substantially shrinks and has a second shrinkage rate.