Wafer level response to mask deficiencies in 0.55-numerical aperture extreme ultraviolet photolithography

BackgroundThis study investigates the impact of 0.55-numerical aperture (NA) imaging on wafer defectivity when multilayer ripple is present in extreme ultraviolet (EUV) mask.AimWe investigate 0.55-NA anamorphic one-dimensional (1D) and two-dimensional (2D) horizontal vertical mask feature deficiencies defectivity. The information intended to guide experimentation aid setting standards for EUV blanks lithography.ApproachThis stochastically simulated 1D 2D features using an with varied random configurations. photoresist critical dimension (CD) was measured from used generate statistical analysis simulation.ResultsHorizontal show ?2.5 × improvement failure ratio versus features. Vertical appear have a lower compared features, but difference not as clear found case. light scattered leaf shaped illuminator into pupil background region due appears smaller than Potentially deficient structures may benefit orientating CD vertically system reduce level defectivity.ConclusionsThere be saturation at which variation become constant. Horizontal preferable all CDs. roughness threshold computational shortcut deficiency characterization sufficient this does change previous standard suggestions.