Placement mitigation techniques for power grid electromigration

Abstract

In advanced technology nodes, power grid metal wires are prone to electromigration (EM) failures due to small wire sizes and high unidirectional current densities. Power grid EM failures usually happen around weak power grid connections delivering current to high power-consuming regions. Previously, power grid EM was mostly addressed at the post-routing stage, which may be too late for a large number of EM violations in modern designs. In this paper, we propose a new set of incremental placement techniques to mitigate power grid EM, including cell move, single row placement, and single tile placement. Experimental results demonstrate the proposed placement techniques can effectively reduce EM violations with negligible wirelength and placement density impacts.