Mask shot count reduction strategies in the OPC flow

Increasing pattern density and the higher complexity of advanced OPC and RET technologies have lead to an explosion in mask data volume. This increased data volume leads to increased mask write times, inspection times, and costs. In the past, several techniques for reducing the mask shot count have been proposed, including OPC fragment alignment, jog alignment, jog smoothing, and design intent-aware layout fragmentation among others. This paper will explore the tradeoffs between mask shot count and simulated print quality for various shot count reduction strategies.