Dose Map and Placement Co-Optimization for Improved Timing Yield and Leakage Power

Abstract

In sub-100nm 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 step-and-scan tool 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 improve both timing yield and leakage power of a given design. We formulate the placement-aware dose map optimization as quadratic and quadratic constraint programs which are solved using efficient quadratic program solvers. In this paper, we mainly focus on the placement-aware dose map optimization problem; in the Appendix, we describe a complementary but less impactful dose map-aware placement optimization based on an efficient cell swapping heuristic. Experimental results show noticeable improvements in minimum cycle time without leakage power increase, or in leakage power reduction without degradation of circuit performance.