Electron beam application apparatus and inspection method

An electron beam application apparatus comprising:

• an optical system configured to irradiate a sample with excitation light;
• an electron optical system configured to project, onto a camera, a photoelectron image formed by photoelectrons emitted from the sample irradiated with the excitation light;
• and
• a control unit, wherein
• the optical system includes a light source configured to generate the excitation light and a pattern forming unit, the excitation light forms an optical pattern on a surface of the sample when the pattern forming unit is turned on, and the excitation light is emitted to the sample without forming the optical pattern on the surface of the sample when the pattern forming unit is turned off,
• the control unit adjusts the electron optical system based on a sharpness and a magnification of a bright and dark pattern formed by the optical pattern in the photoelectron image obtained by turning on the pattern forming unit, and
• the optical pattern is an interference fringe, and the interference fringe is generated by branching the excitation light from the light source into a plurality of pieces of excitation light having an optical path difference formed by the pattern forming unit and causing the plurality of pieces of excitation light to interfere with each other.