Patent ID: 7352457
Filing Date: 2008-04-01
Classification: G01N

Abstract:
1. An optical inspection system for inspecting a surface of a mask, reticle or semiconductor wafer for defects, comprising: a light source for emitting an incident light beam along an optical axis; an optical system disposed along the optical axis and including one or more optical components for separating the incident light beam into a plurality of individual light beams, all of the individual light beams being dedicated to defect inspection, all of the individual light beams working together to increase the speed of defect inspection, all of the individual light beams forming scanning spots at different locations on the surface of the mask, reticle or semiconductor wafer, the scanning spots being configured to scan the surface of the mask, reticle or semiconductor wafer in order to find defects associated with the surface of the mask, reticle or semiconductor wafer when the mask, reticle or semiconductor wafer and the plurality of individual light beams are linearly moved relative to one another in a first direction, wherein the one or more optical components are further arranged to deflect the individual light beams along individual scan paths in a second direction that differs from the first direction, the individual scan paths being offset from each other in the first direction.