Multiple patterning with late lithographically-defined mandrel cuts

Abstract

Methods of self-aligned multiple patterning. A mandrel is formed over a hardmask, and a planarizing layer is formed over the mandrel and the hardmask. The planarizing layer is patterned to form first and second trenches exposing respective first and second lengthwise sections of the mandrel. A portion of the patterned planarizing layer covers a third lengthwise section of the mandrel arranged between the first and second lengthwise sections of the mandrel. After patterning the planarizing layer, the first and second lengthwise sections of the mandrel are removed with an etching process to define a pattern including a mandrel line exposing respective first portions of the hardmask. The third lengthwise section of the mandrel is masked by the portion of the planarizing layer during the etching process, and the third lengthwise section covers a second portion of the hardmask arranged along the mandrel line between the first portions of the hardmask.