Patent ID: 7763851
Filing Date: 2010-07-27
Classification: B82Y,H01J

Abstract:
1. A particle-beam apparatus for irradiating a target, comprising a particle source adapted to generate a beam of energetic electrically charged particles the majority of which conform to a nominal species of a nominal mass having a nominal kinetic energy, an illumination optics system for forming said beam into an illuminating beam which is substantially tele/homocentric along an optical path, a pattern definition means located after the illumination optics system as seen along the direction of the beam, said pattern definition means comprising a plurality of apertures, said apertures being adapted to form the illuminating beam into a plurality of beamlets, a projection system configured to form the beamlets emerging from the pattern definition means into a final image of the apertures, and a target stage means adapted to position a target at the position of said final image, wherein the illuminating optics system comprises a velocity-dependent deflector means adapted to form a deflecting field comprising at least one of an dipole electrical field transversal to the optical path and a dipole magnetic field transversal to the optical path, the deflecting field being adapted to act upon the particles, causing a deviation of the path of particles in the beamlets with regard to respective nominal paths, said deviation being dependent on the velocity of the particles, wherein a delimiting means is provided as a component of one of the pattern definition means and projection system, said delimiting means being adapted to remove particles whose paths are deviating from the nominal paths of the beamlets at the location of the delimiting means, and wherein the velocity-dependent deflector means comprises a set of electrostatic electrodes and/or a set of magnetostatic electrodes, each of said electrodes having a planar surface oriented toward the beam, wherein its geometric extension meets a virtual source point of the particle source.