Patent ID: 6396059
Filing Date: 2002-05-28
Classification: H01J

Abstract:
A method for determining the resolution of a measurement system employing an electron beam and a detector for detecting secondary emissions and generating a signal corresponding to the secondary emissions, the method comprising the steps of:providing a wafer with at least one re-entrant feature and an open region adjacent the at least one re-entrant feature; performing a scan of the at least one re-entrant feature with the electron beam to provide a signal corresponding to an image of the re-entrant feature, the signal having a first state corresponding to secondary electron emissions when the electron beam exclusively scans the open region, an intermediary state corresponding to secondary electron emissions when the electron beam partially scans the open region and partially scans the at least one re-entrant feature and a second state corresponding to secondary electron emissions when the electron beam exclusively scans the at least one re-entrant feature; evaluating the intermediary state of the signal; and determining a first width of the electron beam based on the evaluation.