Patent ID: 6900892
Filing Date: 2005-05-31
Classification: G01J,G01N,H01L

Abstract:
1. A method for finding a profile of a structure on and/or below one or more layers of material, said structure having a dimension in the micron or sub-micron range and fabricated by a process, wherein a measurement is carried out by directing a polychromatic beam of electromagnetic radiation at said structure and detecting at a number of wavelengths corresponding radiation data from said beam after it has been modified by the structure and the one or more layers, comprising: providing a gallery of profile types, each profile type and the one or more layers associated with a set of one or more parameters and a set of radiation data at the number of wavelengths; selecting a profile type from the gallery based on information on the process; carrying out a measurement of the structure to obtain measured radiation data from said beam after it has been modified by the structure and the one or more layers; and comparing the measured radiation data to the set of radiation data associated with the selected profile type to arrive at a set of value(s) of the one or more parameters.