Patent ID: 6710868
Filing Date: 2004-03-23
Classification: G01N

Abstract:
Apparatus for inspection of a sample, comprising:an optical assembly, which comprises first and second optical heads comprising respective first and second radiation detection devices, which are configured to capture radiation scattered from a succession of spots on a surface of the sample with respective first and second levels of spatial resolution, and to generate respective first and second signals responsive to the captured radiation, such that the second level of spatial resolution is substantially higher than the first level; a positioning device, which is adapted to impart motion to at least one of the optical assembly and the sample, so as to cause the optical assembly to scan over the surface of the sample, whereby the first and second optical heads are positioned over the spots in the succession; and an inspection controller, coupled to receive and process the first and second signals and, responsive to the first signal, configured to identify a subset of the spots that should be inspected at the second level of spatial resolution, to control the second optical head so as to capture the scattered radiation from the spots in the subset, and to analyze the second signal to determine characteristics of the spots in the subset.