Manufacturable Nanometer Designs using Standard Cells with Regular Layout

Kasyab Parmesh Subramaniyan and Per Larsson-Edefors
Chalmers University of Technology


Abstract

In addition to performance considerations, designing VLSI circuits at nanometer-scale process technology nodes demands considerations related to manufacturability and cost. Regular layout patterns are known to enhance resilience to random as well as certain types of systematic variations. In this contribution we assess the implications of this layout regularity using design automation for Critical Feature Analysis (CFA) and raw metrics, such as via count. Using the ISCAS'89 benchmark suite, for each benchmark circuit we compare place-and-route implementations that are based on semi-regular and ultra-regular cell layouts. While the CFA counter-intuitively suggests that implementations using ultra-regular layouts have lower Design for Manufacturability (DFM) scores than those using semi-regular layouts, we find that ultra-regular layouts yield implementations with an average of 22% fewer vias at the cost of a small wire length increase.