MULTI-BEAM WRITING OF PATTERN AREAS OF RELAXED CRITICAL DIMENSION

摘要

To irradiate a target with a beam of energetic electrically charged particles, the beam is formed and imaged onto a target, where it generates a pattern image composed of pixels. For a pattern which comprises a primary pattern region (102) to be written with a predetermined primary feature size and a secondary pattern region (103) which is composed of structure features capable of being written with a secondary feature size, larger than the primary feature size. The structure features of the primary pattern region (102) are written by exposing a plurality of exposure spots on grid positions of a first exposure grid; the structure features in the secondary pattern region (103) are written by exposing a plurality of exposure spots on grid positions of a second exposure grid (164) according to a second arrangement which is coarser than the regular arrangement of the first exposure grid.