Assist Feature aware Double Patterning Decomposition

摘要

Double patterning has gained prominence as the most likely lithographic methodology to help keep Moore's law goingtowards 32nm 1/2 pitch lithography. While solutions, to date, have focused mainly on gap splitting to avoid minimumspacing violations, the decomposition should, ideally, also attempt to optimize the process window of the decomposedmasks. A major contributor to process window sensitivity is the correct placement of sub-resolvable assist features.These features are placed once the polygons of each mask are defined, i.e. post decomposition. If some awareness of thisdownstream process step is made available to the double patterning decomposition stage, then a more robustdecomposition can be achieved.