Patent ID: 6399945
Filing Date: 2002-06-04
Classification: H01J

Abstract:
A detection system for detecting electrons backscattered from a locus on a sample surface irradiated with an electron beam, the system comprising:(a) a first backscattered-electron detector, having a first prescribed energy-sensitivity band, configured and situated so as to receive a first group of backscattered electrons propagating from the locus due to irradiation of the locus with the electron beam, and to produce, from the received backscattered electrons, a first electrical signal; (b) a second backscattered-electron detector, having a second prescribed energy-sensitivity band different from the first energy-sensitivity band, configured and situated so as to receive a second group of backscattered electrons propagating from the locus due to irradiation of the locus with the electron beam, and to produce, from the received backscattered electrons, a second electrical signal; (c) a signal combiner connected to the first and second backscattered-electron detectors, the signal combiner being configured to combine the first and second signals, yielding a composite output signal waveform having an amplitude that differs depending upon a characteristic of the locus.