After an interlayer insulation film (1) and a CMP stopper film are formed, wiring trenches are formed. Next, after a barrier metal film (4) and a Cu film (5) are buried in the wiring trenches, the Cu film (5) and the barrier metal film (4) are planarized by CMP or the like until the CMP stopper film is exposed, whereby lower wirings (17) are formed. Next, the CMP stopper film is removed by dry etching, so that surfaces of the lower wirings (17) relatively protrude from their surrounding area. Su...







