Patent ID: 8097847
Filing Date: 2012-01-17
Classification: B82Y,H01J

Abstract:
1. A particle-optical arrangement, comprising: at least one charged-particle source for generating at least one beam of charged particles; at least one multi-aperture plate having a plurality of apertures formed in the plate, wherein the plurality of apertures are arranged in a first pattern, wherein a plurality of charged-particle beamlets is formed from the at least one beam of charged particles downstream of the aperture plate; a first voltage supply for supplying predetermined first voltages to the plurality of apertures; a first single-aperture plate arranged at a distance upstream or downstream of the multi-aperture plate, the first single-aperture plate having a single aperture for allowing the beam of charged particles or the plurality of charged-particle beamlets to pass therethrough; and a second voltage supply for supplying a predetermined second voltage to the first single-aperture plate; wherein at least one of the following conditions is fulfilled: (1) the distance between the multi-aperture plate and the first single-aperture plate is less than five times a diameter of the single aperture of the first single-aperture plate; (2) the distance between the multi-aperture plate and the first single-aperture plate is less than 75 mm; (3) the distance between the multi-aperture plate and the first single-aperture plate is selected such that it is less than one half of an average focal length of the apertures of the multi aperture plate; and (4) the distance between the multi-aperture plate and the first single-aperture plate is selected such that an average electrical field on a surface of the multi aperture plate at a center thereof is higher than at least one of 100 V/mm, 200 V/mm, 300 V/mm, 500 V/mm, and 1 kV/mm.