Patent ID: 6771364
Filing Date: 2004-08-03
Classification: G01N

Abstract:
A surface inspection apparatus, comprising:a light source section that emits a first luminous flux and a second luminous flux; an irradiation optical system that irradiates the first luminous flux and the second luminous flux on a surface of a film-coated inspection subject; a displacement section that relatively displaces the film-coated inspection subject and an irradiation luminous flux from the irradiation optical system; a light-receiving optical system that receives scattered light generated from the inspection subject on the film-coated inspection subject after irradiation of the first luminous flux from the irradiation optical system and scattered light generated from the inspection subject on the film-coated inspection subject after irradiation of the second luminous flux from the irradiation optical system; a first light-receiving section that transforms the scattered light of the first luminous flux received by the light-receiving optical system into a first light reception signal; a second light-receiving section that transforms the scattered light of the second luminous flux received by the light-receiving optical system into a second light reception signal; and a sensitivity stabilizing section that synthesizes the first light reception signal and the second light reception signal to form a signal for sampling, the sensitivity stabilizing section being configured to select a signal having a wavelength for large reflectivity by considering a film thickness of the film-coated inspection subject so that sensitivity is prevented from becoming unstable due to changes of the film thickness.