Method and device for improved alignment of a high brightness charged particle gun

摘要

A charged particle gun alignment assembly for emitting a charged particle beam along an optical axis of a charged particle beam device (200; 300) is described. The charged particle gun alignment assembly is configured to compensate for misalignment of the charged particle beam and includes: a charged particle source (30; 230) having an emitter (31; 231) with a virtual source defining a virtual source plane substantially perpendicular to the optical axis; a condenser lens (220) for imaging the virtual source; a final beam limiting aperture (250) adapted for shaping the charged particle beam; and a double stage deflection assembly (240) positioned between the condenser lens and the final beam limiting aperture, wherein the working distance of the condenser lens is 15 mm or less.