Router and cell library co-development for improving redundant via insertion at pins

In this paper we propose a synergetic approach that integrates router design and cell library engineering for improving post-routing via1 (via between M1 and M2) doubling rate at pins. We develop a double-via (DV) aware multilevel router to exploit the via1 doubling possibilities provided to the cells in a conventional as well as a DV-driven cell library. Compared to a non-DV-aware router using a conventional cell library, our approach using a DV-driven library can on average raise via1 doubling rate by 34%, raise total via doubling rate by 11%, reduce the total number of vias by 3%, and reduce the total number of via1s by 8%. All this can be achieved without incurring any performance and area penalties.