Pattern definition device having distinct counter-electrode array plate

摘要

A multi-beam pattern definition device (300) for use in a particle-beam processing or inspection apparatus, which is set up to be irradiated with a beam of electrically charged particles and allow passage of the beam through a plurality of apertures thus forming beamlets, which are imaged onto a target. A deflection array means (302) has a plurality of electrostatic deflector electrodes (321) for each beamlet. Each deflector electrode can be applied an electrostatic potential individually. Counter electrodes (311) are electrically connected to a counter potential independently of the deflection array means through a counter-electrode array means (301). The counter potentials may be a common ground potential or individual potentials in order to improve system reliability. In conjunction with an associated counter electrode (311), each deflector electrode deflects its beamlet sufficiently to deflect the beamlet off its nominal path when applied an activating voltage against the respective counter electrode.