Defect inspection method and device for same

摘要

In defect scanning carried out in a process of manufacturing a semiconductor or the like, a light detection optical system comprising a plurality of photosensors is used for detecting scattered light reflected from a sample. The photosensors used for detecting the quantity of weak background scattered light include a photon counting type photosensor having few pixels whereas the photosensors used for detecting the quantity of strong background scattered light include a photon counting type photosensor having many pixels or an analog photosensor. In addition, nonlinearity caused by the use of the photon counting type photosensor as nonlinearity of detection strength of defect scattered light is corrected in order to correct a detection signal of the defect scattered light.

主权项

1. 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 so that a photon detection efficiency of the front detector is higher than a photon detection efficiency of the backward detector.