Model-based guiding pattern synthesis for on-target and robust assembly of via and contact layers using DSA

Directed Self Assembly (DSA) has emerged as one of the most compelling next generation patterning techniques for sub-7nm via or contact layers. A key issue in enabling DSA as a mainstream patterning technique is the generation of grapho-epitaxy based guiding pattern (GP) shapes to assemble the contact patterns on target with high fidelity and resolution. Current GP generation is mostly empirical, and limited to a very small number of via configurations. In this paper, we propose the first model-based GP synthesis algorithm and methodology for on-target and robust DSA, on general via pattern configurations. The final post-RET printed GPs derived from our original synthesized GPs are resilient to process variations and continue to maintain the same DSA fidelity in terms of placement error and target shape.