Patent ID: 6661008
Filing Date: 2003-12-09
Classification: G01N,H01J

Abstract:
An electron-optical system, comprising:irradiation means which irradiates a surface of a sample with an irradiating electron beam; observation means which focuses an observational electron beam emitted from the surface of the sample as an image on electron beam detection means, the observation means including a cathode lens; and an accelerating electric field is formed by the surface of the sample and the cathode lens, the surface of the sample is biased to a negative potential (âˆ’V1, V1>0), the cathode lens has a plurality of electrodes, at least one of said plurality of electrodes is biased to a positive potential (V2, V2>V1), so that the observational electron beam that has just been emitted from the surface of the sample is accelerated monotonically, without a decrease in velocity, to the energy of approximately (V1+V2).