Double patterning lithography (DPL) is a likely resolution enhancement technique for IC production in 32nm and below technology nodes. However, DPL gives rise to two independent, uncorrelated distributions of linewidth on a chip, resulting in a `bimodal' linewidth distribution and an increase in performance variation. [13] suggested that new physical design mechanisms could reduce harmful covariance terms that contribute to this performance variation. In this paper, we propose new bimodal-aware timing analysis and optimization methods to improve timing yield of standardcell based designs that are manufactured using DPL. Our first contribution is a DPL-aware approach to timing modeling, based on detailed analysis of cell layouts. Our second contribution is an ILP-based maximization of `alternate' mask coloring of instances in timing-critical paths, to minimize harmful covariance and performance variation. Third, we propose a dynamic programming-based detailed placement algori...
Mohit Gupta, Kwangok Jeong, Andrew B. Kahng