Patent ID: 10192780

Abstract:
Methods of self-aligned double patterning and improved interconnect structures formed by self-aligned double patterning. A mandrel line including an upper layer and a lower layer is formed over a hardmask. A non-mandrel cut block is formed over a portion of a non-mandrel line, after which the upper layer of the mandrel line is removed. An etch mask is formed over a first section of the lower layer of the mandrel line defining a mandrel cut block over a first portion of the hardmask. The first section of the lower layer is arranged between adjacent second sections of the lower layer. The second sections of the lower layer of the mandrel line are removed to expose respective second portions of the hardmask, and the second portions of the hardmask are removed to form a trench. The mandrel cut block masks the first portion of the hardmask during the etching process.