Patent ID: 9569578
Date: 2017-02-14
CPC Classifications: G03F,G06F,H01L

Claim:
1. A computer implemented method of mask decomposition and optimization for directed self assembly (DSA) comprising: inputting design information of an integrated circuit that is to be patterned using a DSA process; mapping the design information into a tree graph comprising nodes and edges; searching the tree graph using a tree graph searching algorithm to identify a longest path through the tree graph; identifying a branch comprising an edge on the tree graph not on the longest path and stemming from one of the nodes on the longest path; outputting the one node on the longest path that connects to the branch as a hot spot; modifying a photomask by removing the branch from the photomask at the hot spot wherein removing the branch comprising separating the branch from the longest path and connecting the removed branch to a via, via array or line on an adjacent layer or a same layer; and further comprising applying a photoresist layer on a substrate of an integrated circuit; exposing the photoresist layer to the modified photomask in a lithographic process; developing and etching the exposed photoresist layer to form a DSA directing pattern; applying a block copolymer over the DSA directing pattern; and etching the block polymer to form the DSA pattern.