Wire Density Driven Global Routing for CMP Variation and Timing

We propose the first wire density driven global routing that considers CMP variation and timing optimization. To enable CMP awareness during global routing, we propose a compact predictive CMP model with dummy insertion, and validate it with extensive industry data. While wire density has some correlation and similarity to the conventional congestion metric, they are indeed different in the global routing context. Therefore, wire density rather than congestion should be a unified metric to improve both CMP variation and timing. The proposed wire density driven global routing is implemented in a congestion-driven global router [1] for CMP and timing optimization. The new global router utilizes several novel techniques to reduce the wire density of CMP and timing hotspots. Our experimental results are very encouraging. The proposed algorithm improves CMP variation and timing by over 7% with negligible overhead in wirelength and even slightly better routability, compared to the pure congestion-driven global router [1].

By: Minsik Cho; Hua Xiang; Ruchir Puri; David Z. Pan

Published in: RC23938 in 2006


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