Defect inspection method and defect inspection device

A defect inspection device comprising:

• a light source that emits laser;
• a vertical illumination unit that applies the laser emitted from the light source to a sample having a line pattern formed thereon from a vertical direction via an objective lens;
• an oblique illumination unit that applies the laser emitted from the light source to the sample having the line pattern formed thereon from an oblique direction;
• a detection optical system unit which condenses and detects light that is reflected/scattered from the sample illuminated with the laser applied by the vertical illumination unit or the oblique illumination unit but that enters the objective lens;
• and
• a signal processing unit that processes a signal generated by the detection optical system unit to thereby detect a defect on the sample having the line pattern formed thereon,
• wherein, the vertical illumination unit includes a polarization conversion unit that converts the laser emitted from the light source into linearly polarized light and the vertical illumination unit applies the laser passed through the polarization conversion unit to the line pattern formed on the sample, with the laser being set in a state polarized in a direction orthogonal to a longitudinal direction of the line pattern;
• and
• wherein, the detection optical, system unit includes an optical filter that selectively transmits a scattered light component from the defect on the sample having the line pattern by converting the polarization state of the reflected/scattered light entered and condensed by the objective lens into linear polarization.