EUV NTD resist modeling and mechanisms of deformation

Precondition for successful application of NTD resists in EUV is the model-ability so that resist induced EPE can be compensated by model based OPC. The strongest NTD specific modeling challenge is the deformation of the resist material, its experimental characterization and calibration. We performed a detailed experimental characterization of EUV NTD resist shrinkage after each lithographic process step using DRM (development rate monitors) to identify deformation root causes and observed multiple deformation mechanisms. All mechanisms could be captured by process step specific model components. In a second experiment, we investigate the impact of deformation on multiple lithographic pattern profiles measured by SEM from wafer cross sections. Comparison to simulation results shows that also EPE critical lateral deformation is captured by the model. Finally, and in preparation of OPC we validate model-ability with contours of complex and deformation sensitive patterns.