Patent ID: 8524545
Filing Date: 2013-09-03
Classification: H01L

Abstract:
1. A method, comprising: forming trench isolation regions in a silicon layer of a substrate to define a first silicon region and a second silicon region bounded by said trench isolation regions; patterning a first hardmask layer to form a first hardmask island on said first silicon region and a second hardmask island on said second silicon region; patterning a second hardmask layer to form a third hardmask island on said first hardmask island and a fourth hardmask island on said second hardmask island; removing said fourth hardmask island from said second hardmask island; patterning first and second mandrels over said first silicon region and said second silicon region; forming a third hardmask layer over said substrate; removing said first and second mandrels to form openings in said third hardmask layer and to uncover exposed areas of said first silicon region and said second silicon region; etching trenches into said exposed areas of said first silicon region and said second silicon region; and removing said second hardmask island.