Graph-Based Simultaneous Placement and Routing for Two-Dimensional Directed Self-Assembly Technology

Two-dimensional directed self-assembly (2D-DSA) is an emerging lithography technology for advanced process nodes. We can determine the orientations of double posts to guide block copolymers to form feasible 2D guiding template patterns by the 2D-DSA process. This paper presents the first work to handle the 2D-DSA simultaneous placement and routing problem. We first propose a novel graph to model feasible guiding templates with a constant-time update scheme for each double-post assignment. Based on a graph model, we then present an algorithm for 2D-DSA simultaneous placement and routing, with a broadcast-based cost function for 2D-DSA cell placement and a graph-based scheme for DSA-compliant routing. Finally, we employ a strongly effective region property to minimize the cuts in the final layout. Experimental results show that our algorithm can efficiently generate a 2D-DSA placement and routing solution with high routability and a low cut number.