Patent ID: 8907458

Claim:
A semiconductor device comprising: a semiconductor structure; a plurality of dielectric layers on top of said semiconductor structure and being separated by at least a first etch-stop layer; a second etch-stop layer underneath said first etch-stop layer and being separated from said first etch-stop layer; at least a first via, inside said plurality of dielectric layers, having a height crossing at least two of said plurality of dielectric layers and a depth below said first etch-stop layer; a second via having a height crossing at least two of said plurality of dielectric layers and a depth below said second etch-stop layer; and one or more trenches, inside said plurality of dielectric layers, whose depth are defined by said first etch-stop layer, wherein said second via has a uniform width that is wider than that of said first via, and a depth deeper than that of said first via.