Patent ID: 7714298

Claim:
A multi-beam pattern definition device for use in a particle-beam processing or inspection apparatus, said device being adapted to be irradiated with a beam of electrically charged particles and allow passage of the beam through a plurality of apertures thus forming a corresponding number of beamlets, said device comprising a deflection array having a plurality of blanking openings located such that each of the beamlets traverses one of the blanking openings along a nominal path, the deflection array comprising a plurality of electrostatic deflector electrodes, each of which is associated with a blanking opening and is individually provided with a connecting line for applying an electrostatic potential and is, in conjunction with an associated counter electrode, configured to deflect a beamlet traversing the respective blanking opening by an amount sufficient to deflect the beamlet off its nominal path when applied an activating voltage against the respective counter electrode, and a counter-electrode array providing electrical connection of counter electrodes to a counter potential independently of the deflection array.