The difference between the printed CD affected by vertical-type PD and that affected by diagonal-type PD is explained by a simple model, without the absorber pattern. Figure 12 represents a relationship between the inclination angle of bump-PDs and pit-PDs (4 nm in height or depth, and 50 nm in width), and position shift of minimum intensity of the PD images on mask scale under the illumination with a chief ray angle of 6 deg. The result obviously shows that the inclination angle causes a position shift of the minimum intensity of PD image (bump-defect: 0.7 to , pit-defect: 0.8 to ). Therefore, defect mitigation by shifting the absorber layer should be performed while taking into consideration this position shift of the PD images. To verify the effectiveness of the absorber pattern shifting method to mitigate the printable PDs while considering the inclination angle of PD, three models were designed, that involved an hp 88 nm L/S pattern and PDs with several inclination angles; defect printability was evaluated as shown in Fig. 13. Here, the designed PD is 4 nm in height, 50 nm in width, and 0 deg or 6 deg in its inclination angle. Model 1 represents a basic model where the position of PD is , and the inclination angle is 0 deg. The calculated wafer CD is 20.3 nm (7.7% of CD error). Model 2 shows diagonal-type PD with an inclination angle of 6 deg where a relationship between the absorber pattern position and the position of the top of PD is same as that of model 1. The calculated CD is 18.9 nm (14.1% of CD error). From the calculation results shown in Fig. 12, a bump PD with 6 deg inclination corresponds to a shift in the vertical-type PD’s position by about 5 nm. Therefore, in Model 3, the absorber pattern was shifted 5 nm along with the direction of PD’s position shift. The calculated CD was well matched with Model 1, as expected, where the CD was 20.2 nm (8.2% of CD error). These results show that identifying the value of the position shift of a PD while considering the inclination angle is important for defect mitigation by shifting the absorber pattern.