Patent ID: 8502174

Claim:
A method of exposing a field on a target by means of a plurality of charged particle beamlets, the method comprising: providing a plurality of beamlets, the beamlets being generated by one or more aperture arrays having apertures arranged in a two-dimensional array to produce a plurality of groups of beamlets; providing a target to be exposed, the target comprising the field; creating relative movement in a first direction between the plurality of beamlets and the target; deflecting the plurality of beamlets in a second direction simultaneously with the relative movement in the first direction, such that each beamlet exposes a plurality of parallel scan lines on the target; wherein different groups of beamlets expose a different single stripe of the field in the first direction, each stripe having a length as long as the field in the first direction, and the beamlets of each croup of beamlets expose the full stripe width, and wherein the relative movement in the first direction and the deflection of the plurality of beamlets in the second direction are such that the distance between adjacent parallel scan lines exposed by the plurality of beamlets is smaller than a pitch between beamlets of the plurality of beamlets in the array.