In this paper, we present ELIAD, an efficient lithography aware detailed router to optimize silicon image after optical proximity correction (OPC) in a correct-by-construction manner. We first propose a compact post-OPC litho-metric for a detailed router based on statistical characterization. We characterize the interferences among weak grids filled with one of predefined litho-prone shapes (e.g., jog-corner, via, line-end). Our litho-metric derived from the characterization shows high fidelity to total edge placement error (EPE) in large scale, compared with Calibre-OPC/ORC. As a chip itself is in the largest scale, ELIAD powered by the proposed metric can enhance the overall post-OPC printed silicon image. Experimental results on 65nm industrial circuits show that ELIAD outperforms a ripup/rerouting approach such as RADAR [17] with 8x more EPE hotspot reduction and 12x speedup. Also, compared with a conventional detailed router, ELIAD is only about 50% slower. Categories and Subject...
Minsik Cho, Kun Yuan, Yongchan Ban, David Z. Pan