A scoring methodology for quantitatively evaluating the quality of double patterning technology-compliant layouts

A Double Patterning Technology (DPT)-aware scoring methodology that systematically quantifies the quality of DPTcompliant layout designs is described. The methodology evaluates layouts based on a set of DPT-specific metrics that characterizes layout-induced process variation. Specific metrics include: the spacing variability between two adjacent oppositely-colored features, the density differences between the two exposure masks, and the stitching area's sensitivity to mask misalignment. These metrics are abstracted to a scoring scale from 0 to 1 such that 1 is the optimum. This methodology provides guidance for opportunistic layout modifications so that DPT manufacturability-related issues are mitigated earlier in design. Results show that by using this methodology, a DPT-compliant layout improved from a composite score of 0.66 and 0.78 by merely changing the decomposition solution so that the density distribution between the two exposure masks is relatively equal.