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Mask synthesis and correction flows are becoming increasingly complex in order to deal with increasingly smaller lithography, resist, and etch effects that also increase in importance with increasingly smaller feature sizes. Time-to-mask is also a significant factor in production environments which leads tapeout teams to adopt correction strategies that usually only address effects at the best process condition. As a result, users frequently find hotspots, or process failures, when performing a final lithography verification step using multiple process conditions. In many cases, under production pressure to decrease time-to-mask, tapeout teams choose to correct these hotspots in the fastest manner possible. Performing rule-based fixes to the post-correction layout is usually the fastest method available. This paper will explore using rule-based, post-correction hotspot fixes in a flow using pattern matching. Pattern matching will be used to cluster the post-correction patterns into similar types which will be fixed by different algorithms for each type. Further, pattern matching will be used to find all instances of each pattern to mark for fixing along any similar patterns that may have been missed by the lithography check, or those that received asymmetrical correction.
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