Introduction 11
RoI)of yield optimization may take the company out of business. A subcat-
egory of yield, called the rst-pass yield (FPY) [11], may be a more relevant
measure of DfM, but a high FPY can result from the extra engineering effort
during processing of the prototyping material. Therefore, for IC DfM, sup-
plementary metrics are required, such as the following:
Mask ratio (MR). This metric is dened as the total number of masks
taped out to adjust product performance to the minimum mask
count required for product functionality, and is well understood by
the design community, reecting product evolution in time. One can
correlate the total design cost to the mask ratio based on the average
redesign time and resources per mask la