Abstract: The invention relates to a multi-beam pattern definition device for use in a particle-beam processing or inspection apparatus, said device being adapted to be irradiated with a beam of electrically charged particles and allow passage of the beam through a plurality of apertures thus forming a corresponding number of beamlets, said device comprising an aperture array device in which at least two sets of apertures are realized, an opening array device located downstream of the aperture array device having a plurality of openings configured for the passage of beamlets, said opening array device comprises impact regions, wherein charged impinge upon said impact regions.

Abstract: A pattern writing method for charged-particle lithography apparatuses using an improved correction for thermal distortion of the substrate includes determining an exposure position where the beam impinges on the substrate and the power of the beam at the exposure position; calculating heating of the substrate at the exposure position, and calculating, for a plurality of locations over the substrate, and the thermal diffusion and radiative cooling; calculating, for the same or a reduced plurality of locations on the substrate, the positional change of the substrate due to thermal expansion; determining a displacement distance which compensates the positional change at the exposure position, updating the structure to be written by shifting the exposure position of the beam by said displacement distance, and writing the updated structures on the substrate with the beam. These steps are repeated as a function of time and/or varying exposure position of the beam substrate position.