Patent ID: 9429525
Filing Date: 2016-08-30
CPC Classification: G01N

Claim Text:
1. An optical module for surface inspection, comprising: a first light source unit including a first light source that produces a first light and a first beam splitter that changes the direction along which the first light propagates from the first light source, the first light source unit oriented to illuminate an imaging plane, corresponding to a surface of a substrate to be inspected using the module, with the first light whose direction of propagation has been changed by the beam splitter; a second light source unit that produces a second light polarized in a first direction, the second light source oriented to illuminate said imaging plane with the second light; a direction of polarization changing unit oriented to receive the second light reflected from said imaging plane when the field is occupied by the surface of the substrate to be inspected, wherein the direction of polarization changing unit comprises optics which convert the second light received into third light polarized in a second direction, perpendicular to the first direction, and propagating in a direction back to said imaging plane; and a detection unit operative to detect captured light and positioned in the module to capture fourth light that is a product of the first light reflecting from said imaging plane when the imaging plane is occupied by the surface of the substrate to be inspected, fifth light that is a product of the second light scattered from said imaging plane when the imaging plane is occupied by the surface of the substrate to be inspected, and sixth light that is a product of the third light scattered from said imaging plane when the imaging plane is occupied by the surface of the substrate to be inspected.