Patent ID: 8599379

Claim:
A method for inspecting defects in an object to be inspected by polarizing, with a polarizer, light of a wavelength that can penetrate into the object to be inspected and irradiating the polarized light onto a surface of the object to be inspected, thereby detecting scattered light therefrom in a state where stress is not applied to the object to be inspected and in a state where stress is applied thereto, the method comprising: irradiating polarized light obliquely onto the surface of the object to be inspected, at a position thereof, in a state where stress is not applied to the object to be inspected and separating scattered light generated as a result of the irradiation into P-polarized component light and S-polarized component light, then obtaining intensities of each component light and a polarization direction as a ratio thereof; irradiating polarized light obliquely onto the surface of the object to be inspected, in a state where stress is applied to the object to be inspected, at the same position of the surface as where the light was irradiated in a state where no stress is applied to the object to be inspected and separating scattered light generated as a result of the irradiation into P-polarized component light and S-polarized component light, then obtaining intensities of each component light and a polarization direction as a ratio thereof; and detecting defects and/or classifying the defects by comparing the intensity and polarization direction of each component light obtained in a state where no stress is applied to the object to be inspected and the intensity and polarization direction of each component light obtained in a state where stress is applied to the object to be inspected respectively with a predetermined threshold value.