Spacer-is-dielectric-compliant detailed routing for self-aligned double patterning lithography

Self-aligned double patterning (SADP) lithography is a leading technology for 10nm node Metal layer fabrication. In order to achieve successful decomposition, SADP-compliant design becomes a necessity. Spacer-Is-Dielectric (SID) is the most popular flavor of SADP with higher flexibility in design. This paper makes a careful study on the challenges for SID-compliant detailed routing and proposes a graph model to capture the decomposition violations and SID intrinsic residue issues. Then a negotiated congestion based scheme is adopted to solve the overall routing problem. The proposed SID-compliant detailed routing algorithm simultaneously assigns colors to the routed wires, which provides valuable information guiding SID decomposition. In addition, if one pin has multiple candidate locations, the optimal one will be automatically determined during detailed routing. The decomposability of the conflict-free routing layers produced by our detailed router is verified by a commercial SADP decomposition tool.