an automatic optical-simulation-based lithography hotspot fix flow for post-route optimization
In this paper, an automatic lithography hotspot fix guidance generation method based on optical simulation engine and a fix flow utilizing this method are proposed. We find that subject to shape changes of original layout, there is strong correlation between the optical intensity maps of pre-OPC and post-OPC layouts. From this fact, we develop a fix action generation method by optimizing optical intensity in terms of polygon changes near a litho hotspot in a pre-OPC layout. Fix guidances as a subset of fix actions of a hotspot can be selected by a greedy method. The fix guidances are used as input to router to fix the hotspots. We integrate this fix guidance generation method with commercial lithography hotspot detection tool to create a post-route lithography hotspot fixing flow and test with industry 65nm designs. Compared with commercial flow, our method has 1.4X~1.9X fix rate with similar run time. The circuit timing impact is negligible in both our flow and industry flow. And our flow will not introduce any new design rule check (DRC) violation.
lithography hotspot routing opc