Patent ID: 7978323
Filing Date: 2011-07-12
Classification: G01N

Abstract:
1. A surface inspection method for detecting anomalies on a surface, comprising the following steps: causing relative motion between a beam of radiation and the surface; collecting radiation scattered from the surface and directing the collected radiation to one or more channels; converting the collected radiation carried by at least one of the channels into respective signals; determining presence of potential anomalies in or on the surface from said signals; storing information in the signals converted from radiation scattered from locations of the surface determined by the determining step to have potential anomalies and information in the signals converted from radiation scattered from portions of the surface adjacent to such locations and determined by the determining step not to have potential anomalies, so that the information stored can be retrieved without re-scan of the surface; wherein the causing causes relative rotational and translational motion between the beam of radiation and the surface so that the beam scans substantially the entire surface along a spiral scan path.