| CPC G01N 21/9501 (2013.01) [G01B 11/0608 (2013.01); G01N 21/47 (2013.01); G06T 7/0006 (2013.01); G06T 7/70 (2017.01); G01N 2201/06113 (2013.01); G01N 2201/0636 (2013.01); G06T 2207/30148 (2013.01)] | 15 Claims |
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1. A defect detection device that detects a defect on a sample using light, the defect detection device comprising:
an illumination unit configured to irradiate a sample with light emitted from a light source;
a detection unit configured to detect scattered light generated from the sample when the sample is irradiated with the light;
a photoelectric conversion unit configured to convert the scattered light detected by the detection unit into an electrical signal; and
a signal processing unit configured to detect the defect by processing the electrical signal, wherein
the detection unit includes: as a detection optical system,
a condenser lens configured to condense the scattered light, and
a second lens configured to guide the scattered light condensed by the condenser lens to the photoelectric conversion unit,
the second lens divides a light beam for each pupil region and makes the light beam to be incident on the photoelectric conversion unit,
the condenser lens and the second lens are configured such that:
first scattered light whose elevation angle from the sample is a first elevation angle is incident on the condenser lens at a first incident angle, and is incident on the second lens, and
second scattered light whose elevation angle from the sample is a second elevation angle larger than the first elevation angle is incident on the condenser lens at a second incident angle different from the first incident angle, is incident on the second lens, and is incident on the photoelectric conversion unit at a region different from that of the first scattered light,
the defect detection device further comprises:
a correction unit configured to correct at least one of a first position of a first image of the first scattered light and a second position of a second image of the second scattered light, and
a first correction amount when the correction unit corrects the first position is larger than a second correction amount when the correction unit corrects the second position.
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