Charged-particle exposure apparatus

A particle-beam projection processing apparatus for irradiating a target by means of a patterned beam of energetic electrically charged particles, comprising

• an illumination system for generating and forming said energetic particles into an illuminating beam which is substantially tele/homocentric and whose diameter is greater by at least one order of magnitude than the length of the tele/homocentricity region of the illuminating beam,
• a pattern definition assembly located after the illumination system as seen along the direction of the beam, said pattern definition assembly being adapted to position an aperture pattern composed of apertures transparent to the energetic particles in the path of the illuminating beam, thus forming a patterned beam emerging from the aperture pattern,
• a projection system positioned after the pattern definition assembly and comprising a number of optical elements for shaping an electrical or electromagnetic field into at least one particle-optical lens, each of said optical elements having a central opening surrounding the path of the patterned beam, the projection system being adapted to form a final image of the aperture pattern, said final image being located within a field-free space after the projection system, and
• a target stage located after the projection system and adapted to position a target at the position of a final image formed by the projection system, the target being the first object to obstruct the path of the patterned beam after the last optical element of the projection system,
• further comprising a first diaphragm located between the projection system and the target stage and having a central aperture surrounding the path of the patterned beam, wherein at least the portions of the first diaphragm defining the central aperture are located within said field-free space.