Defect printability comparing actinic printing with advanced simulation for EUV masks

We describe the printability of native phase defects categorized by type and dimension using NXE3100 EUV scanner and DPS (Defect Printability Simulator) software developed by Luminescent Technologies. The critical dimension (CD) error on wafers simulated by the DPS is strongly affected by the geometry of the multilayer (ML) used as an input parameter for simulation. This finding is supported by cross section images of the ML acquired from transmission electron microscopy (TEM) showing that the diameter of the defect and geometry of the ML are closely related. Accordingly, the selection of the type of ML geometry seems to be important in the accuracy of defect printability simulation. The CD error simulated from the DPS using reconstructed ML geometry shows better correspondence with that measured on a wafer than conformal or smoothed ML geometry. The DPS software shows good simulation performance in predicting defect printability at 27nm HP node. This is verified by wafer printing and RCWA simulation.