A method of forming an interconnect structure for an integrated circuit device is provided. The method includes forming a wiring layer having a metal line, and forming a patterned disposable material layer over the wiring layer and having an opening aligned with the metal line. The method also includes depositing a first dielectric film in the opening and in contact with the metal line, and removing the patterned disposable material layer to leave the first dielectric film. The method further includes depositing a second dielectric film over the first dielectric film, and etching the second dielectric film to form a trench above the first dielectric film. In addition, the method includes removing a portion of the first dielectric film to form a via hole under the trench, and depositing a conductive material in the trench and the via hole.