Mask design and decomposition for sidewall image transfer

摘要

A design level compatible with a sidewall image transfer process employs an alternating grid of mandrel-type line tracks and non-mandrel-type line tracks. Target structure design shapes are formed such that all vertices of the target structure design shapes are on the grid. The target structure design shapes are classified as mandrel-type design shapes and non-mandrel-type design shapes depending on the track type of the overlapping line tracks for lengthwise portions. All mandrel-type line tracks and straps of the mandrel-type design shapes less lateral strap regions of the non-mandrel-type design shapes collectively form mandrel design shapes, which can be employed to generate a first lithographic mask. Sidewall design shapes are generated from the mandrel design shapes. Blocking shapes for a second lithographic mask can be generated by selecting all areas that are not included in the target structure design shapes or the sidewall design shapes.

主权项

1. A method for generating shapes for a plurality of lithographic masks from design shapes for a design level and manufacturing at least one of the plurality of lithographic masks, said method comprising processing steps of:
a first step of providing a design layout for a design level including design shapes, wherein lengthwise portions of said design shapes overlie line tracks extending along a lengthwise direction; a second step of identifying said line tracks as mandrel-type line tracks and non-mandrel-type line tracks; a third step of identifying design shapes as mandrel-type design shapes and non-mandrel-type design shapes, wherein all lengthwise edges of mandrel-type design shapes are within mandrel-type line tracks and all lengthwise edges of non-mandrel-type design shapes are within non-mandrel-type line tracks; a fourth step of generating mandrel design shapes by performing a union of said mandrel-type line tracks and said mandrel-type design shapes and then subtracting areas derived from lateral straps of non-mandrel-type design shapes by expansion by a spacer target width; and a fifth step of manufacturing the at least one of the plurality of lithographic masks by processing at least one physical structure based on the mandrel design shapes generated in the fourth step.