Pattern inspection method and pattern inspection apparatus

A pattern inspection apparatus comprising:

• an illumination unit configured to generate a light, and apply the light to a substrate under a plurality of optical conditions which are different from each other, the substrate comprising an inspection target pattern in which a stacked film is formed;
• a detection unit configured to detect a reflected light from the substrate to output a signal;
• a gray value difference output unit configured to process the signal from the detection unit to acquire a pattern image for each of the different optical conditions, and output a gray value difference between the pattern image and a reference image for each of the different optical conditions;
• and
• a defect position specifying unit configured to specify the position of the defect in the stacking direction of the stacked film from a magnitude relation of the gray value difference between the different optical conditions,
• wherein the optical conditions comprise at least one of a wavelength, a focus position, and a polarized light.

A pattern inspection apparatus comprising:

• an illumination unit configured to generate a light, and apply the light to a substrate under a plurality of optical conditions which are different from each other, the substrate comprising an inspection target pattern in which a stacked film is formed;
• a detection unit configured to detect a reflected light from the substrate to output a signal;
• a gray value difference output unit configured to process the signal from the detection unit to acquire a pattern image for each of the different optical conditions, and output a gray value difference between the pattern image and a reference image for each of the different optical conditions;
• and
• a defect position specifying unit configured to specify the position of the defect in a stacking direction of the stacked film by comparing a ratio of the gray value difference of the pattern image and the reference image between the optical conditions with a data table regarding the position of the defect in the stacking direction and the ratio of the gray value difference between the different optical conditions,
• wherein the optical conditions comprise at least one of a wavelength, a focus position, and a polarized light.