Patent ID: 6515742
Filing Date: 2003-02-04
Classification: G01N

Abstract:
A method of inspecting a workpiece surface, said method comprising:providing a workpiece having a surface to be inspected; illuminating the workpiece surface with an energy beam, said energy beam illuminating the workpiece surface at an angle of incidence and reflecting off of the workpiece surface; collecting in a first collector a first portion of the energy beam reflected off of the workpiece surface at a first collection angle; collecting in a second collector a second portion of the energy beam reflected off of the workpiece surface at a second collection angle; determining a first size characterization of a defect associated with the workpiece surface; determining a second size characterization of the defect associated with the workpiece surface; and determining a defect type characterization by comparing the first and the second size characterizations to a plurality of logarithmic functions, said logarithmic functions being selected to identify at least three defect types.