In double patterning lithography (DPL) layout decomposition for 45nm and below process nodes, two featuresmust be assigned opposite colors (corresponding to different exposures) if their spacing is less than the minimumcoloring spacing.~(5,11,14)However, there exist pattern configurations for which features separated byless than the minimum coloring spacing cannot be assigned different colors. In such cases, DPL requires thata layout feature be split into two parts. We address this problem using a layout decomposition algorithm thatincorporates integer linear programming (ILP), phase conflict detection (PCD), and node-deletion bipartization(NDB) methods. We evaluate our approach on both real-world and artificially generated testcases in 45nmtechnology. Experimental results show that our proposed layout decomposition method effectively decomposesgiven layouts to satisfy the key goals of minimized line-ends and maximized overlap margin. There are no designrule violations in the final decomposed layout. While we have previously reported other facets of our researchon DPL pattern decomposition,~6the present paper differs from that work in the following key respects: (1)instead of detecting conflict cycles and splitting nodes in conflict cycles to achieve graph bipartization,~6we splitall nodes of the conflict graph at all feasible dividing points and then formulate a problem of bipartization byILP, PCD~8 and NDB~9methods; and (2) instead of reporting unresolvable conflict cycles, we report the numberof deleted conflict edges to more accurately capture the needed design changes in the experimental results.
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