Defect inspection method and device for same

A defect inspection device, comprising:

• an illumination optical unit which illuminates a sample with a laser beam from a oblique direction;
• a detection optical unit which detects light diffracted from the sample illuminated with the laser beam by the illumination optical unit;
• and
• a signal processing unit which detects a defect on the sample by processing an electrical signal generated by detecting the light diffracted from the sample with the detection optical unit,
• wherein, the detection optical unit installs plural detectors including a photon counting type detector having plural pixels, the plural detectors including a front detector which detects forward-scattered light which scattered in forward direction to a illumination direction of the laser beam to the sample by the :illumination optical unit and a backward detector which detects back-scattered light which scattered in backward direction to a illumination direction of the laser beam to the sample by the illumination optical unit, and a pixel number of the front detector is larger than that of the backward detector.

A method of inspecting a defect, including the steps of:

• radiating a laser beam onto a sample from an oblique direction through an illumination optical unit;
• detecting a scattered light from the sample on which the laser beam is radiated, with a detection optical unit;
• and
• detecting a defect on the sample by processing an electrical signal output from the detection optical unit by the detection of the scattered light, with a signal processing unit,
• wherein, in the step of detecting the scattered light from the sample, the scattered light is detected by plural detectors including photon counting type detector, and among the plural detectors a forward-scattered light which scattered in forward direction to a illumination direction of the laser beam to the sample by the illumination optical unit is detected by a front detector and back-scattered light which scattered in backward direction to a illumination direction of the laser beam to the sample by the illumination optical unit is detected by a backward detector, and the front detector detects the forward-scattered light with sensors a pixel number of which is larger than that of the backward detector.