Abstract
Threshold voltage assignment is a very effective technique to reduce leakage power consumption in modern integrated circuit (IC) design. As feature size continues to decrease, the layout constraints (called MinIA constraints) on the implant area, which determines the threshold voltage of a device, are becoming increasingly difficult to satisfy. It is necessary to take these constraints into consideration during the layout stage. In this paper, we propose to resolve the MinIA constraint violations by a simultaneous detailed placement and threshold voltage refinement approach. We present an optimal and efficient mixed integer-linear programming (MILP)-based algorithm which guarantees to fix all MinIA constraint violations. Experimental results demonstrate that our algorithm only perturbs the original placement and threshold voltage assignment solutions minimally to eliminate all violations and is fast in practice.