MASK INSPECTION APPARATUS, AND MASK INSPECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a mask inspection apparatus capable of suppressing variation of a gradation value of a sensor image when performing calibration using a mask other than a mask to be inspected and a mask inspection method.SOLUTION: A gain-resetting circuit 16 resets a gain set on a sensor amplifier 15 on the basis of a difference between a normalized gain of an irradiation light volume sensor 30 using a stored mask 1b for calibration and a gain detected by the irradiation light volume sensor 30 when performing defect inspection of a mask 1a to be inspected. Pseudo defect induction is reduced when performing defect inspection of the mask 1a to be inspected by resetting the gain on the sensor amplifier 15 according to variation of a light volume of a light source 6.