Advanced Application of Pattern-Aware OPC

摘要

For advanced technology nodes, it's critical to address yield issues caused by process specific layout patterns with limited process window. RETs such as Model-Based Sub-Resolution Assist Feature (MB-SRAF) are introduced to guarantee high lithographic margin, but these techniques come with long runtime, especially when applied full-chip. There's also lack of integrated solution to easily identify, define comprehensive patterns and apply different controls and/or constraints over these patterns through different stages of OPC/RET process. In this paper, we introduce a flow that applies advanced RET such as MBSRAF or specific local corrections to layouts with critical and yield limiting patterns. We also introduce in-process pattern match based on Cadence topological Squish pattern. Overall, this new flow of Pattern-Aware OPC (PA-OPC) achieves better margin for hotspots, without sacrificing turnaround time and is able to handle more complex patterns and environment than traditional methods. We demonstrate the benefit of the new flow with finegrained process window control over different patterns.