Detailed routing with advanced flexibility and in compliance with self-aligned double patterning constraints

In this paper, we propose a new flexible routing method for Self-Aligned Double Patterning (SADP). SADP is one of the most promising candidates for patterning sub-20 nm node advanced technology but wafer images must satisfy tighter constraints than litho-etch-litho-etch process. Previous SADP routing methods require strict constraints induced from the relation between mandrel and trim patterns, so design freedom is unexpectedly lost. Also these methods assume to form narrow patterns by trimming process without consideration of resolution limit of optical lithography. The proposed method realizes flexible SADP routing with dynamic coloring requiring no decomposition to extract mandrel patterns and no worries about coloring conflicts. The proposed method uses realizable trimming process only for insulation of patterns. The effectiveness of the proposed method is confirmed in the experimental comparisons.