Patent ID: 8039813
Filing Date: 2011-10-18
Classification: H01J

Abstract:
1. A charged particle multi-beam system comprising: a charged particle source configured to generate at least one beam of charged particles; a stage configured to hold a flat substrate to be inspected; and a particle-optical component disposed in a beam path of the at least one beam of charged particles downstream of the charged particle source, the particle-optical component comprising: a first multi-aperture plate having a plurality of apertures and a second multi-aperture plate having a plurality of apertures, wherein the second multi-aperture plate is spaced apart from the first multi-aperture plate such that a gap is formed therebetween; wherein the plurality of apertures of the first multi-aperture plate is arranged such that each aperture of the plurality of apertures of the first multi-aperture plate is aligned with a corresponding aperture of the plurality of apertures of the second multi-aperture plate; and wherein a first width of the gap at a location of a first aperture of the plurality of apertures of the first multi-aperture plate is by at least 5% greater than a second width of the gap at a location of a second aperture of the plurality of apertures of the first multi-aperture plate; wherein the system further comprises: a voltage supply system configured to apply different electric potentials to the first and second multi-aperture plates of the particle-optical component; and at least one focusing particle-optical lens disposed in the beam path of the at least one charged particle beam downstream of the particle-optical component and configured to focus charged particle beamlets having traversed the particle-optical component onto the flat substrate.