Imaging system

A charged particle multi-beamlet system for exposing a target using a plurality of beamlets, the system comprising:

• a charged particle source for generating a charged particle beam;
• a first aperture array for defining groups of beamlets from the generated beam;
• a second aperture array;
• a beamlet blanker array comprising an array of blankers for controllably blanking the beamlets;
• a beam stop array for blanking beamlets deflected by the blankers, the beam stop array comprising an array of apertures, each beam stop aperture corresponding to a plurality of the blankers;
• and
• an array of projection lens systems for projecting beamlets on to the surface of the target,
• wherein the system images the source onto a plane at the beamlet blanker array, and the system images the beamlet blanker array onto the target.

A charged particle multi-beamlet system for exposing a target using a plurality of beamlets, the system comprising:

• at least one charged particle source for generating a charged particle beam;
• a first aperture array for creating sub-beams from the generated beam;
• a condenser lens array for focusing the sub-beams;
• a second aperture array for creating a group of beamlets from each focused sub-beam;
• a beamlet blanker for controllably blanking beamlets in the groups of beamlets;
• and
• an array of projection lens systems for projecting beamlets on to the surface of the target,
• wherein the condenser lens array is adapted for focusing each sub-beam at a point corresponding to one of the projection lens systems.