Patent ID: 7781748

Claim:
A charged-particle exposure apparatus for exposure of a target with a beam of electrically charged particles, said apparatus comprising: an illumination system; a pattern definition means; and a projection optics system, the illumination system being adapted to produce the beam illuminating the pattern definition means, the pattern definition means being adapted to form the shape of the illuminating beam into a desired pattern, and the projection optics system being adapted to project an image of the beam shape defined in the pattern definition means onto the target, the pattern definition means comprising: a plurality of apertures adapted to shape the cross-section of the illuminating beam into a multitude of beamlets, by allowing the passage of the illuminating beam only through said plurality of apertures defining the shape of beamlets permeating said apertures, and a blanking means having a plurality of individual beamlet deflectors adapted to selectively divert the respective beamlets from respective nominal imaging paths, the illumination system comprising: a deflector means adapted to vary a direction of incidence of the illuminating beam upon the pattern definition means from a primary incidence axis, and the projection optics system comprising: a blocking aperture means ( 204 ) having an opening and being adapted to block passage of beams traversing outside said opening; the apparatus further comprising; control means adapted to generate a common blanking control signal for said deflector means which, as a function of time, switches between a first state wherein the illuminating beam propagates to the pattern definition means along the primary incidence axis (common blank-in) and a second state wherein the deflector means is activated to deflect the illuminating beam by a minimum angle sufficient to direct the path of the beam off the opening of the blocking aperture means blocking the entire beam.