Patent ID: 6025593
Filing Date: 2000-02-15
Classification: H01J

Abstract:
A scanning electron microscope comprising:an electron gun for generating an electron beam;a beam irradiation system for condensing and irradiating said electron beam on a specimen;a secondary electron detector for detecting secondary electrons emitted from said specimen which is irradiated by said electron beam;a deflection electrode for forming a deflecting field in order to deflect said secondary electrons emitted from said specimen toward said secondary electron detector;a magnetic field generation unit for forming a magnetic field in a direction orthogonal to the deflecting field formed by said deflecting electrode;a field generation unit which is connected to said deflecting electrode and has a power supply for applying a variable voltage to a voltage which forms said deflecting field by superimposing thereon;an electrode which is disposed between said field generation unit and said specimen and has an opening for allowing said electron beam to pass through; anda control power supply for supplying a negative voltage which is variable to said electrode having the opening.