Patent ID: 8237120
Filing Date: 2012-08-07
Classification: G01N

Abstract:
1. An instrument for characterizing a defect on a sample comprising: a primary electron source, configured to direct primary radiation to a measurement location on the sample; a position sensitive detector; an electrostatic electron energy analyzer configured to collect secondary electrons emitted from the measurement location and focus the secondary electrons in a focusing direction at the position sensitive detector at locations that depend on energies of the secondary electrons; and a transverse electrostatic focusing device proximate an entrance aperture of the electron energy analyzer, wherein the transverse focusing device is configured to focus electrons emitted from the measurement location in a transverse direction that is perpendicular to the focusing direction, wherein the transverse electrostatic focusing device includes an electrostatic component positioned inside the electron energy analyzer and configured to produce a transverse electrostatic field inside the electrostatic electron energy analyzer.