Patent ID: 8048811

Claim:
A method, comprising: forming a stack of layers on a low-k dielectric layer formed above a substrate of a semiconductor device, said stack of layers comprising a hardmask layer formed above said low-k dielectric layer and a first cap layer formed on said hardmask layer; forming a first opening in said stack of layers corresponding to a via opening to be formed in said low-k dielectric layer; forming a first portion of said via opening in said low-k dielectric layer after forming said first opening using said hardmask layer as a first etch mask; forming a trench etch mask by forming a second opening in said hardmask layer after forming said first portion of said via opening; and performing an etching process to form a second portion of said via opening and to form a trench in said low-k dielectric layer on the basis of said trench etch mask, wherein said cap layer is removed from above said hardmask layer during said etching process.