Electron beam apparatus for measuring a voltage of a sample

An electron beam apparatus having, inside of an objective lens for focussing a primary electron beam and irradiating it on a sample surface, a secondary electron energy analyzer for analyzing the energy of a secondary electron emitted from a point on said sample surface at which said primary electron beam is irradiated, said objective lens being a magnetic field type refracting an electron by a magnetic field distribution, said secondary electron energy analyzer comprising:

• a planar retarding mesh electrode means having a planar surface for creating an electrical field for decelerating said secondary electron;
• a collimation means having at least three cylindrical electrodes positioned between said sample surface and said planar retarding mesh electrode means and numbered first, second and third from the one closest to the sample surface;
• and
• a power supply means, provided outside of said collimation means, for applying an appropriate voltage to each of said cylindrical electrodes neighboring cylinrical electrodes to form an electrostatic lens produced by a non-uniform electric field.

An electron beam apparatus having, inside of an objective lens for focussing a primary electron beam and irradiating it on a sample surface, a secondary electron energy analyzer for analyzing the energy of a secondary electron emitted from a point on said sample surface at which said primary electron beam is irradiated, said objective lens being an electrical field type refracting an electron by an electric field distribution, said secondary electron energy analyzer comprising:

• a planar retarding mesh electrode means having a planar surface for creating an electrical field for decelerating said secondary electron;
• a collimation means having at least three cylindrical electrodes positioned between said sample surface and said planar retarding mesh electrode means and numbered first, second and third from the one closest to the sample surface;
• and
• a power supply means, provided outside of said collimation means, for applying an appropriate voltage to each of said cylindrical electrodes neighboring cylindrical electrodes to form an electrostatic lens produced by a non-uniform electric field.

A method for energy analysis and detection of an electron emitted radially from a point, comprising the steps of:

• (a) accelerating the electron in a specified direction parallel to an axis and reducing the speed of the electron vertical to and outward from said axis, said axis extending from said point in said specified direction;
• (b) reducing the speed of the electron vertical to and outward from said axis by the electron passing through a first electrostatic lens formed by a first nonuniform electric field, said axis extending from said point in said specified direction;
• (c) reducing a speed of the electron parallel to said axis and reducing the speed of the electron vertical to and outward from said axis by the electron passing through a second electrostatic lens formed by a second non-uniform electrical field;
• (d) reducing the speed of the electron parallel to said axis by applying a uniform electrical field;
• and
• (e) analyzing by detecting the electron which has enough energy to pass through the uniform electrical field.