Patent ID: 7227649

Claim:
A surface inspection apparatus, comprising: a light source for emitting a light beam with known polarization conditions; an optical illumination system for projecting the light beam emitted from the light source on a predetermined area of an inspected surface formed by a predetermined film; an optical detection system having lenses and an aperture stop, wherein the lenses spatially split reflection lights from multiple mutually different small areas of the predetermined area and transilluminate the reflection lights, the aperture stop has the same number of apertures corresponding to that of the small areas; polarization elements which are disposed on light paths of the respective reflection lights passed through the respective apertures in the aperture stop and transilluminate mutually different polarized light components; a light intensity detection device for individually detecting the light intensities of the respective reflection lights passed through the respective polarization elements; a scanning device for making the light beam scan the inspected surface in a way to assure that the reflection lights from the respective small areas would pass all the respective apertures in the aperture stop sequentially; and an arithmetic processing device for detecting the polarization conditions of the respective reflection lights from the predetermined area based on the detection result of the light intensities of the multiple mutually different polarized light components of the respective reflection lights, and on the basis of the determined polarization conditions a film thickness of the film and at least one of the physical properties of the film can be obtained.