Patent ID: 7871829

Claim:
A metal wiring forming method, comprising: forming a first interlayer insulating film on a lower metal wiring, the first interlayer insulating film having a non-planar upper surface; forming a stop layer on the first interlayer insulating film and over the lower metal wiring, wherein an upper surface of the stop layer includes a first portion and a second portion higher than the first portion; forming an interlayer insulating film pattern on the first portion of the upper surface of the stop layer, wherein an upper surface of the interlayer insulating film pattern is substantially coplanar with the second portion of the upper surface of the stop layer beside the interlayer insulating film pattern; removing the second portion of the stop layer and a portion of the first interlayer insulating film to form a via hole exposing the lower metal wiring; and forming a via contact filling the via hole such that an upper surface of the via contact is coplanar with a tip of the first portion of the upper surface of the stop layer and the upper surface of the interlayer insulating film pattern.