Patent ID: 8716133

Claim:
A method, comprising: using a first photomask, defining a set of mandrels on a hardmask layer on a substrate; forming sidewall spacers on sidewalls of said mandrels, said sidewall spacers spaced apart; removing said set of mandrels; using a second photomask, removing regions of said sidewall spacers forming trimmed sidewall spacers and defining a pattern of first features; forming a pattern transfer layer on said trimmed sidewall spacers and said hardmask layer not covered by said trimmed sidewall spacers; using a third photomask, defining a pattern of second features in said transfer layer, at least one of said second features abutting at least one feature of said pattern of first features; and simultaneously transferring said pattern of first features and said pattern of second features into said hardmask layer thereby forming a patterned hardmask layer.