Dose map and placement co-optimization for timing yield enhancement and leakage power reduction

In sub-100 nm CMOS processes, delay and leakage power reduction continue to be among the most critical design concerns. We propose to exploit the recent availability of fine-grain exposure dose control in the stepper to achieve both design-time (placement) and manufacturing-time (yield-aware dose mapping) optimizations of timing yield and leakage power. Our placement and dose map co-optimization can simultaneously improve both timing yield and leakage power of a given design. We formulate the placement-aware dose map optimization as a quadratic program, and solve it using an efficient quadratic programming solver. In this paper, we mainly focus on the placement-aware dose map optimization problem; in the Appendix, we describe the complementary but less impactful dose map-aware placement optimization, and an efficient cell swapping heuristic. Experimental results are promising: with typical 90 nm stepper (ASML Dose Mapper) parameters, we achieve more than 8% improvement in minimum cycle time of the circuit without any leakage power degradation.