Patent ID: 9601302
Date: 2017-03-21
CPC Classifications: G01N,H01J

Claim:
1. An inspection apparatus for inspecting a sample surface using an electron beam, comprising: an electron beam source; a primary electron optical system that comprises a primary system lens and guides the electron beam emitted from the electron beam source; a stage on which a sample to be irradiated with primary electrons guided by the primary electron optical system is arranged; a secondary electron optical system that comprises a secondary system lens and guides secondary charged particles emitted from the surface of the sample due to irradiation with the electron beam; a detector that detects the secondary charged particles guided by the secondary electron optical system; a gap control plate that is arranged above the stage so as to cover the surface of the sample arranged on the stage, and internally includes a through hole allowing the electron beam to pass therethrough; and a cover member that is attached to a condenser lens arranged in the through hole in the secondary system lens, and blocks a gap between the through hole and the condenser lens in view of a direction perpendicular to the gap control plate.