The present invention provides a method for forming interconnection structures, including the following steps: providing a semiconductor wafer with a dielectric layer; forming a first recessed area for forming the interconnection structures and a non-recessed area on the dielectric layer; forming a second recessed area for forming dummy structures on the dielectric layer; depositing a barrier layer to cover the first and second recessed areas and the non-recessed area; depositing a metal layer to fill the first and second recessed areas and cover the non-recessed area; removing the metal layer on the non-recessed area to expose the barrier layer; and removing the barrier layer on the non-recessed area to expose the dielectric layer.