ANGLE LIMITATION DEVICE IN A CHARGED-PARTICLES BEAM SYSTEM

摘要

The device according to the invention comprises a source and an electronic optical system permitting the projection of the beam onto a target plane. According to the invention, a diaphragm for the angular limitation of the beam is positioned between the source and the electronic optical system, the useful current of the beam at the target plane being more than one thousandth of the current emitted by the source.