In a method for fabricating a semiconductor device, first, a first metal
interconnect is formed in an interconnect formation region, and a second
metal interconnect is formed in a seal ring region. Subsequently, by
chemical mechanical polishing or etching, the upper portions of the first
metal interconnect and the second metal interconnect are recessed to form
recesses. A second insulating film filling the recesses is then formed
above a substrate, and the upper portion of the second insulating film is
planarized. Next, a hole and a trench are formed to extend halfway
through the second insulating film, and ashing and polymer removal are
performed. Subsequently to this, the hole and the trench are allowed to
reach the first metal interconnect and the second metal interconnect.