Fast and highly accurate simulation of the printing behavior of EUV multilayer defects based on different models
This paper employs rigorous electromagnetic field (EMF)solvers to investigate the printing behavior of EUV multilayer defects. A compression model is applied to compute the defect induced deformation of the multilayer. A fully rigorous Waveguide method is used to simulate the light diffraction from the defective EUV mask. This fully rigorous method is compared with two other methods: A decomposition method combined with the Waveguide algorithm and a hybrid method which computes the multilayer with an analytical method based on the Fresnel-formulas and the mask absorber with a finite-difference time-domain (FDTD) algorithm. Cross sections and the critical dimensions (CD) of the printed wafer features are evaltuated by the application of a threshold model to the computed aerial images. The p rintability of the multilayer defects and their impact on the CD of printed absorber features are investigated versus the defect position, size and other parameters of the defect modell. Finally, the influence of the mask absorber properties on the defect-induced CD variation is investigated. It is shown that the printability of the defect depends on the absorber properties.