Patent ID: 9653263
Date: 2017-05-16
CPC Classifications: H01J

Claim:
1. A method for irradiating a target with a beam of energetic radiation formed by electrically charged particles for writing a desired pattern on said target, comprising providing a pattern definition device having a plurality of apertures transparent to said radiation, illuminating said pattern definition device using an illuminating wide beam, which traverses the pattern definition device through said apertures thus forming a patterned beam consisting of a corresponding plurality of beamlets, forming said patterned beam into a pattern image on the location of the target, said pattern image comprising the images of at least part of the plurality of apertures covering a number of pattern pixels on the target, and generating a relative movement between said target and the pattern definition device producing a stepwise movement of said pattern image on the target along a path over a region where a beam exposure is to be performed, exposing a plurality of pattern pixels in said region, wherein the pattern comprises a primary pattern region and a secondary pattern region, the primary pattern region including structure features being written with a predetermined primary feature size whereas the secondary pattern region is composed of structure features capable of being written with a secondary feature size which is larger than the primary feature size by a factor of at least 2, wherein writing structure features of the primary pattern region comprises exposing a plurality of exposure spots which are located on the target at respective grid positions of a first exposure grid in a regular arrangement, and writing structure features in the secondary pattern region comprises exposing a plurality of exposure spots which are located on the target at respective grid positions of a second exposure grid according to a second arrangement which is coarser that the regular arrangement of the first exposure grid.