Patent ID: 8987679
Filing Date: 2015-03-24
Classification: H01J

Abstract:
1. Projection lens assembly for a directing a multitude of charged particle beamlets onto an image plane, said projection lens assembly comprising a beam stop array comprising an array of apertures, for blocking charged particle beamlets provided with a blanking deflection by a beam blanker and letting through charged particle beamlets not provided with a blanking deflection by said beam blanker, at least one support element comprising a through-opening for allowing the multitude of charged particle beamlets to pass through, a first electrode and a second electrode, said first electrode and second electrode supported by said at least one support element, wherein the first and second electrode are arranged in or near a plane defined by a downstream distal edge of the projection lens assembly, said first and second electrodes each comprising a lens hole-array aligned with the through-opening for allowing one or more charged particle beamlets of the multitude of charged particle beamlets to pass through, said projection lens assembly further comprising a deflector unit arranged upstream from said first and second electrode and downstream from said beam blanker, wherein said beam stop array is arranged between said deflector unit and said first and/or second electrode.