Feature grouping to enable edge placement error-aware process control in multi-feature logic use case

Abstract

The grouping method assisted EPE-aware control method is being explored in a multi-feature dual layer Logic use case. EPE metric is estimated using angle resolved optical Scatterometry based overlay and electron beam-based metrology (large field of view SEM) for the reconstruction of edge-to-edge distance between the Metal and Via pattern. In the setup phase, EPE sensitivities to dose and focus have been derived using data from a FEM wafer. EPE-aware optimization, using scanner dose and overlay control sub-recipes, outperforms traditional optimization in simulations showing reduced EPE max per die. This improvement suggests a potential increase in device yield through the adoption of EPE-aware control strategies. To verify this performance improvement on wafers, an experiment is needed with minimal wafer to wafer and lot to lot variations which can be achieved by reducing time between lots and increasing the number of wafers measured.