In this paper, phase defect impact variation, which is caused by the characteristics of defect shapes, is verified by a
simulation. Actinic blank inspection (ABI) signal intensity, and defect image intensity on wafer, affected by characteristics changes in the shape of the phase defect, was calculated. ABI signal intensity and defect image intensity on wafer did not remain constant even when the phase defect volume was fixed. According to this simulated result, defect side wall angle and defect volume (with tilted top surface) affected both intensities. When the impacts, caused by phase defect, on ABI signal intensity, and on defect image intensity on wafer, are monitored then shape of the phase defect should be taken into consideration for accurate estimation. Also, through this simulation, a relationship between ABI signal intensity and defect image intensity on wafer was confirmed. The impact variation (which is caused by defect shape change) for both intensities showed similar tendencies. Therefore, it is believed that ABI system is an effective way to capture harmful phase defects affecting the wafer intensity, even when there were defects with various shapes.