Self-aligned quadruple patterning process

摘要

Methods for modifying a spacer and/or spaces between spacers to enable a fin cut mask to be dropped between the spacers are provided. A first set of second mandrel structures having a first width is formed on facing sidewall surfaces of a neighboring pair of first mandrel structures and a second set of second mandrel structures having a second width less than the first width are formed on non-facing sidewall surfaces of the neighboring pair of first mandrel structures. Each first mandrel structure is removed and a spacer is formed on a sidewall surface of the first and second sets of second mandrel structures. In the region between the neighboring pair of first mandrel structure, a merged spacer is formed. The first and second sets of second mandrel structures are removed. A portion of an underlying substrate can be patterned utilizing each spacer and the merged spacer as etch masks.

主权项

1. A method of forming a mandrel structure comprising:
forming a plurality of first mandrel structures comprising a neighboring pair of first mandrel structures on a surface of a substrate; forming an additive mask on facing sidewall surfaces of said neighboring pair of first mandrel structures and on said surface of said substrate that is located between said neighboring pair of first mandrel structures; forming a first spacer on said additive mask and exposed surfaces of each first mandrel structure and said exposed surfaces of said substrate; removing portions of each first spacer and said additive mask to provide a first set of second mandrel structures having a first width on said facing sidewall surfaces of said neighboring pair of first mandrel structures and a second set of second mandrel structures having a second width that is less than said first width on non-facing sidewall surfaces of said neighboring pair of first mandrel structures; removing each first mandrel structure; forming a second spacer on a sidewall surface of said first and second sets of second mandrel structures, wherein in a region between said neighboring pair of first mandrel structures a merged spacer is formed; removing said first and second sets of second mandrel structures; and patterning a portion of said substrate utilizing said second spacer and said merged spacer as etch masks.