Patent ID: 8716671
Filing Date: 2014-05-06
Classification: B82Y,H01J,Y10T

Abstract:
1. Projection lens assembly for 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, an annular body comprising a conductive circumferential wall, wherein the annular body and the support element are electrically connected and set substantially at ground potential.