ELECTRON-BEAM IMAGE FORMATION SYSTEM

摘要

PURPOSE: To provide an electron beam image forming system using an integral type secondary electron detector for obtaining excellent image formation. CONSTITUTION: An electron source 10 with a sharp chip 18 is biased so as to generate an electron current, and a conductive target is arranged in the route of the electron flow. In the route of the electron flow a flat electrostatic focusing lens 12 is arranged between the electron source and the target. The lens comprises an aperture 25, first conductive sheet 20 biased in positive potential by the electron source, and one or more conductor rings 24 separated by a dielectric layer 22. A secondary electron detector 28 is formed on the face of the electrostatic focusing lens closest to the conductive target so that the lens can be arranged close to the target, but the collision of secondary electrons emitted therefrom with the secondary electron detector is allowed not to be blocked.