Patent ID: 7791721
Filing Date: 2010-09-07
Classification: G01N

Abstract:
1. A surface inspection apparatus for detecting a foreign particle or a defect present on an inspection object surface or inside the proximity of the surface, comprising: an inspection object movement stage having a rotational movement unit and a translational movement unit configured so as to be able to scan said inspection object at an approximately constant rotational angular speed; a laser beam source; an illumination unit irradiating a laser beam emitted from said laser beam source on an illumination spot of a predetermined size on the inspection object surface; a light detection unit, which detects a light generated from said illumination spot and converts the light to an electric signal; an A/D converter for conversion of said electric signal into digital data; a particle diameter calculation device for calculating a size of the foreign particle or the defect from the digital data obtained by said A/D conversion; wherein: said A/D converter executes sampling of said electric signal at approximately constant sampling time intervals, said particle diameter calculation device executes detection of the foreign particle/defect by using a result of a removal treatment of an undesired low frequency fluctuation component on the digital data obtained by said A/D converter, and said particle diameter calculation device determines a parameter of the removal treatment of the undesired low frequency fluctuation component based on any plural combination of (1) type or thickness of film formed on the inspection object surface, (2) surface roughness on the inspection object surface, (3) crystal orientation on the inspection object surface, and (4) warpage amount on the inspection object surface.