CPC H01L 21/3086 (2013.01) [H01L 21/0332 (2013.01); H01L 21/0337 (2013.01); H01L 21/0338 (2013.01); H01L 21/30604 (2013.01); H01L 21/3088 (2013.01); H01L 21/31116 (2013.01); H01L 21/31144 (2013.01); H01L 21/32139 (2013.01); H01L 21/76802 (2013.01); H01L 21/76811 (2013.01); H01L 21/76813 (2013.01); H01L 21/76816 (2013.01)] | 20 Claims |
1. A method comprising:
forming a first etching mask to cover a mandrel, a first spacer, and a second spacer, wherein the first spacer and the second spacer are in contact with opposing sidewalls of the mandrel;
patterning the first etching mask, wherein after the patterning, the first etching mask comprises:
a first portion covering the first spacer;
a second portion covering the second spacer; and
a bridge portion connecting the first portion to the second portion, wherein the bridge portion comprises first sidewalls;
performing a first etching process on the mandrel using the first etching mask to define pattern, wherein after the first etching process, the mandrel comprises a second bridge portion having second sidewalls vertically aligned to corresponding ones of the first sidewalls; and
after the mandrel is etched-through, performing a second etching process to laterally recess the second bridge portion of the mandrel.
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