Patent ID: 6603873
Filing Date: 2003-08-05
Classification: G01N,G06T

Abstract:
A method of inspecting a target feature formed on a surface, which method comprises:imaging the target feature to produce one or more target data elements representative of the target feature, each target data element having a gray level and associated with a respective location on the surface; isolating the target feature; calculating a value of a parameter of the isolated target feature; identifying the target feature as corresponding to a target reference feature; and comparing the target feature parameter value with a corresponding parameter value associated with the target reference feature to determine whether a defect exists in the target feature; wherein calculating the target feature parameter value comprises calculating an energy value for the target feature by summing the gray levels of the target data elements corresponding to the target feature, and calculating scatter values for the target feature in several directions, each scatter value based on a moment of inertia with respect to an equilibrium center of the target feature.