Patent attributes
A method includes forming an etching mask to cover a mandrel, a first spacer, and a second spacer, and the first spacer and the second spacer are in contact with opposing sidewalls of the mandrel. The etching mask is then patterned, and includes 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. The bridge portion has first sidewalls. A first etching process is performed on the mandrel using the etching mask to define pattern, and after the first etching process, the mandrel includes a second bridge portion having second sidewalls vertically aligned to corresponding ones of the first sidewalls. After the mandrel is etched-through, a second etching process is performed to laterally recess the second bridge portion of the mandrel.
