Defect inspection device and defect inspection method

A defect inspection device for inspecting a sample having a structure repeatedly formed on a surface thereof, comprising:

• a sample stage configured to support the sample;
• an illumination optical system configured to illuminate the sample placed on the sample stage with illumination light;
• a scanning device configured to drive and rotate the sample stage to change a relative position between the sample and the illumination optical system;
• a plurality of detection optical systems configured to condense illumination scattered light from the surface of the sample;
• a plurality of sensors configured to convert illumination scattered light condensed by the corresponding detection optical systems into an electric signal and output a detection signal;
• and
• a signal processing device configured to process the detection signal input from the plurality of sensors, wherein
• the signal processing device
• extracts, for any inspection portion on the surface of the sample, a comparison portion whose θ coordinates are in a set correspondence relationship with those of the inspection portion in an rθ circular coordinate system of the sample in which a center of the sample is set as an origin,
• compares a detection signal from the inspection portion with a detection signal from the comparison portion, and detects a defect of the sample based on a difference between the detection signals,
• reads data of a linear or strip-shaped determination region passing through the center of the sample as the correspondence relationship, and
• extracts, as the comparison portion, a portion at least a part of which overlaps the determination region that at least overlaps a part of the inspection portion or a portion on another sample corresponding to the portion.