Correlation between printability and visibility of defects in EUV mask blanks

In this paper, reflective mask for EUV lithography consists of multilayer-coated substrate called a mask blank, and a patterned absorber layer on top. The near field reflected off a Mo/Si multilayer with a gaussian shaped defect is calculated using a time-domain finite-element method. The reasonably good correlation indicates that critical defects can be differentiated from non-critical defects with high reliability. We will also present the correlation for other types of multilayer defects.