Patent ID: 8355044

Claim:
A reticle defect inspection method in which an image sensor is moved relative to a reticle, and an optical image obtained by amplifying an output of each pixel of the image sensor by a sensor amplifier is compared with a reference image defined as a standard image relative to the optical image to perform a defect inspection of the reticle, the sensor amplifier being capable of calibrating a gain and an offset of a signal amplitude every pixel, the reticle defect inspection method comprising, before the defect inspection: imaging some of patterns of the reticle by the image sensor, and storing bottom and peak values of an amount-of-light signal of each pixel amplified by the sensor amplifier, wherein when the bottom and peak values of each of the pixels are stored, a relative moving speed of the reticle is set slower than a pixel moving speed determined according to a pixel size and an imaging period of the image sensor; setting a plurality of offsets in the sensor amplifier by setting each offset of a signal amplitude for each pixel of the sensor amplifier, based on the stored bottom value of each pixel; and setting a plurality of gains in the sensor amplifier by setting each gain of a signal amplitude for each pixel of the sensor amplifier, based on the offset of the signal amplitude of each pixel and on the stored peak value of each pixel.