Patent ID: 6124140
Filing Date: 2000-09-26
Classification: H01J

Abstract:
A method for determining a dimension of a semiconductor device feature, comprising:positioning a portion of the feature at a first axial distance from a focal point of an electron beam;detecting a first flow of electrons corresponding to the electron beam and received from the feature when the electron beam impinges on the feature and the portion of the feature is spaced apart from the focal point by the first distance;effectively moving at least one of the feature and the focal point of the electron beam to position the portion of the feature at a second axial distance from the focal point of the electron beam;detecting a second flow of electrons corresponding to the electron beam and received from the feature when the electron beam impinges on the feature and the portion of the feature is spaced apart from the focal point by the second distance; andanalyzing the first and second flows to determine a dimension of the feature.