ELECTRON BEAM SOURCE, AND ELECTRON-BEAM APPLICATION DEVICE

摘要

An electron gun having a simple configuration and a small aberration. A magnetic-field superposed electron source comprising an electric field radiation type electron source (4) having a leading end portion of a diameter of not more than 100 nm and immersed in a magnetic field, and an outgoing electrode (2). A major source for generating the magnetic field is a permanent magnet (3) disposed in the same vacuum container as that of the electron source. The permanent magnet has such a shape as is generally axially symmetric with respect to a center axis in the electron emitting direction, as viewed from the leading end of the electron source, so that the magnetic polarization is axially symmetric in the center axis direction or in the radial direction. A magnetic flux is applied to the electron source by connecting it directly or through a magnetic pole (1) made of a soft magnetic material, with the electron source, so that the potentials of the permanent magnet and the magnetic pole are made identical to that of the electron source or the outgoing electrode.