Influence of phase defect structures on Extreme Ultraviolet (EUV) microscope images were examined to predict the inclination angle dependency of the phase defect impact on wafers since the phase defect does not always propagate in a vertical direction from an EUV mask substrate surface through the multilayer. Two types of the programmed phase defect mask were prepared. One is an EUV blank with programmed bump phase defects to analyze the inclination angle of the phase defects. The other is a programmed phase defect EUV mask that consists of bump phase defects of 80-nmwide and 2.4-nm-high with half-pitch 88 nm lines-and-spaces pattern. The positions of the phase defects relative to the absorber lines were designed to be shifted accordingly. Transmission electron microscope observation revealed that the bump phase defects starting from the substrate surface propagated through the multilayer toward the center of the substrate as they reach the top surface of the multilayer. At the distances of 0 and 66 mm from the substrate center, the inclination angles varied from 0 to 4 degrees. The impacts of the inclination angles on EUV microscope images were significant even though the positions of the phase defect relative to the absorber line, as measured by a scanning prove microscope, were same.