Patent ID: 6444981
Filing Date: 2002-09-03
Classification: H01J

Abstract:
A scanning electron microscope including an electron source, an object lens for converging a primary electron beam emitted from the electron source, and at least one detector for detecting electrons generated from a sample irradiated with said primary electron beam converged by said object lens, said scanning electron microscope comprising:a sample holder for holding said sample on said sample holder; a shield electrode located between said object lens and said sample, in which an aperture for passing said primary electron beam is formed; negative-voltage applying means for substantially applying the same negative voltage to said sample holder and said shield electrode; an acceleration tube located in an electron-beam passing hole in said object lens, provided to pass said primary electron beam, for further accelerating said primary electron beam; and a control electrode located between said acceleration tube and said sample, in which an aperture whose size is smaller than said aperture formed in said shield electrode is provided to pass said primary electron beam, a positive voltage in the positive direction to said negative voltage being applied to said control electrode, superimposed on said negative voltage.