Timing-Driven Redundant Contact Insertion for Standard Cell Yield Enhancement

This paper proposes an automatic redundant contact insertion method under timing constraints for standard cell yield enhancement. Contact failure is one of the most dominant yield loss reasons and redundant contact insertion is highly recommended to improve the yield. The proposed method inserts the redundant contacts as many as possible under given timing constraints using a linear Programming. The area constraint can be given during redundant contact insertion simultaneously. Experimental results show that we can analyze the trade-off between performance and the number of the redundant contacts, and can pick up the yield variants from the trade-off curve. These yield variants of the original cells are used as a yield-enhanced cell library which is essential to realize yield-aware VLSI design flows.