Method of forming a semiconductor structure including a plurality of fins and an alignment/overlay mark

摘要

A method includes providing a semiconductor structure including a substrate that includes a material to be patterned. First and second mandrels are formed over the substrate using a common photolithography process that defines a position of the first mandrel relative to the substrate and a position of the second mandrel relative to the substrate. A first sidewall spacer is formed adjacent the first mandrel and a second sidewall spacer is formed adjacent the second mandrel. After the formation of the first and the second sidewall spacers, the first mandrel is removed. The second mandrel remains in the semiconductor structure. A first mask element is provided on the basis of the first sidewall spacer. A second mask element is provided on the basis of the second mandrel and the second sidewall spacer. The material to be patterned is patterned on the basis of the first and the second mask elements.

主权项

1. A method, comprising:
providing a semiconductor structure comprising a substrate comprising a material to be patterned; forming a first mandrel and a second mandrel over said substrate, the formation of said first mandrel and said second mandrel comprising a common photolithography process defining a position of said first mandrel relative to said substrate and a position of said second mandrel relative to said substrate; forming a first sidewall spacer adjacent said first mandrel and a second sidewall spacer adjacent said second mandrel; after the formation of said first and the second sidewall spacers, forming a block mask over said semiconductor structure, wherein said second mandrel is covered by said block mask and said first mandrel is not covered by said block mask and wherein forming said block mask comprises:
forming an organic planarization layer over said semiconductor structure;forming an anti-reflective coating over said organic planarization layer;forming a photoresist layer over said anti-reflective coating; andpatterning said photoresist layer by means of a block mask photolithography process, wherein a photoresist mask is formed, portions of said organic planarization layer and said anti-reflective coating over said second mandrel being covered by said photoresist mask, portions of said organic planarization layer and said anti-reflective coating over said first mandrel not being covered by said photoresist mask, with said block mask in position, removing said first mandrel, while leaving said second mandrel remaining in maid semiconductor structure; and providing a first mask element on the basis of said first sidewall spacer and a second mask element on the basis of said second mandrel and said second sidewall spacer and pattering said material to be patterned on the basis of said first and said second mask element, wherein a fin is formed front portions of said material to be patterned below said first mask element and an alignment/overlay mark is formed from portions of said material to be patterned below said second mask element.