Apparatus for generating a plurality of beamlets

The charged particle beam lithography system of the preceding claim, wherein said controller is adapted for applying voltages to each deflector of said deflector array for deflecting a beamlet, with the controller adapted for setting the voltages to have each deflector assert a deflecting effect sufficient for compensating aberrations of further converging devices of the converging means.

The charged particle beam lithography system according to the preceding claim, wherein said lens comprises an end plate providing a first electrode in said electrostatic lens.

The charged particle beam lithography system according to the preceding claim, further provided with a second controller for applying a voltage to the electrodes of said electrostatic lens for operating said electrostatic lens substantially free of spherical aberration.

The charged particle beam lithography system according to the preceding claim, relating each lens to an individual beamlet.

The charged particle beam lithography system according to the three but preceding claim, wherein said splitting means comprises a spatial filter comprising an aperture array, for splitting said charged particle beam in a plurality of charged particle beamlets.

The charged particle beam lithography system of the preceding claim, wherein said spatial filter is located between said charged particle source and said lens array to split up said diverging charged particle beam into a plurality of charged particle beamlets.

The charged particle beam lithography system of the one but preceding claim, wherein said spatial filter is concave with respect to said source.

The charged particle beam lithography system of the preceding claim, wherein the curvature of said spatial filter has its focal point substantially in the origin of the charged particle beam.

The charged particle beam lithography system of the preceding claim, wherein the curvature of said lens array has its focal point substantially in the origin of the charged particle beam.

The charged particle beam lithography system of the preceding claim, wherein the equipotential surface is defined substantially parallel to said aperture plate.

The charged particle beam lithography system of the preceding claim, wherein the aperture plate has an electrically conducting surface and means for defining the electrostatic potential of said surface.

The charged particle beam lithography system of the preceding claim, wherein said means for defining an equipotential surface comprises a plate having a through hole at the location of the beam of beamlets, in particular a circular hole having its center at the optical axis of the charged particle beam.

The charged particle beam lithography system of the preceding claim, wherein said means for defining an equipotential surface are located between said source and said lens array.

The charged particle beam lithography system of the one but preceding claim, wherein said means for defining an equipotential surface are located between said array of converging elements and said converging means.