Device and method for controlling focussed electron beams

摘要

The device includes a field emitter beam source (4-2) with an emitter (4-3) and an extraction electrode (4-4) to generate an electron beam. An anode accelerates the electrons of the beam towards a specimen. Focussing components (4-5) focus the beam onto the specimen. A control circuit (4-30) senses deviation of an actual current value of the electron beam from a desired value. The control circuit controls a voltage V1 between the emitter and the extraction electrode to adjust the actual current value of the electron beam. The control circuit controls a second voltage V2 to adjust the actual focus position of the beam. Independent claims are also included for the following: (a) a method for controlling an electron beam; (b) a method for controlling electron beams; (c) a method for controlling an array of electron beams.