Patent ID: 8906802

Claim:
A method, comprising: performing a directed self-assembly process to form a DSA masking layer, said DSA masking layer being comprised of a first plurality of openings and a first plurality of features that define said first plurality of openings in said DSA masking layer; performing at least one process operation to remove at least one of said first plurality of features so as to thereby define a patterned DSA masking layer with a DSA masking pattern comprised of at least some of said first plurality of openings; performing at least one process operation to form a patterned transfer masking layer having a transfer masking pattern comprised of a second plurality of openings and a second plurality of features that define said second plurality of openings in said transfer masking layer, wherein said transfer masking pattern is the inverse of said DSA masking pattern; and performing at least one etching process through said patterned transfer masking layer on a layer of material to form a plurality of trench/via features in said layer of material.