Patent ID: 7375028

Claim:
A method for manufacturing a semiconductor device, comprising: forming an etch stop layer on the semiconductor substrate; sequentially forming a first interlayer insulating layer, a first diffusion barrier, a second interlayer insulating layer, and a second diffusion barrier on the etch stop layer; forming a via hole exposing the etch stop layer by etching the second diffusion barrier, the second interlayer insulating layer, the first diffusion barrier, and the first interlayer insulating layer; forming a first trench overlapping the via hole by etching the second diffusion barrier and the second interlayer insulating layer; forming a second trench continuous to the first trench by etching the first diffusion barrier and part of the first interlayer insulating layer; and removing the etch stop layer exposed through the via hole, wherein the first and second trenches are etched under different etching conditions.