DSA-compliant routing for two-dimensional patterns using block copolymer lithography

Two-dimensional (2D) directed self-assembly (DSA) is an emerging lithography for the 5 nm process node and beyond that can substantially increase design flexibility in critical routing layers and reduce the number of cuts for better yield. The state-of-the-art 2D DSA process manipulates the orientation of double posts inside guiding templates to guide block copolymers (BCPs) to form 2D patterns. However, a key challenge arises on how to correctly assign double post orientations and place cut patterns to make desired net connections for a given routing instance. In this paper, we propose a novel 2D DSA-compliant routing framework, named 2D-DCR, to systematically derive feasible orientation assignments for double posts to maximize routability. Specifically, 2D-DCR features a complete set of new routing rules which transform the underlying physical BCP growth principles for large-scale routing, adopts a network-flow-based double-post assignment routing algorithm, and leverages a 2D DSA line-end creation property to maximally reduce line-end cuts. Experimental results show that our 2D-DCR can effectively generate a 2D DSA-compliant routing solution with zero double post conflicts, maximized routability, and minimized the number of cuts.