Patent ID: 7952803

Claim:
A lithographic apparatus comprising: a first beam splitter configured to create a first plurality of spatially coherent radiation beams; a second beam splitter configured to receive at least a portion of the first plurality of spatially coherent radiation beams and to create, based on the first plurality of spatially coherent radiation beams, a second plurality of spatially coherent radiation beams; with the first and second beam splitters are diffraction gratings, a phase plate, an attenuator, or both a phase plate and an attenuator, configured to modify the phase, amplitude, or both the phase and amplitude, of one beam of the second plurality of spatially coherent beams relative to another of the secondary plurality of spatially coherent beams; and a beam combiner adapted to redirect and combine at least a portion of the second plurality of spatially coherent radiation beams onto a surface of a substrate to form an interference pattern, wherein the phase plate, the attenuator, or both the phase plate and the attenuator are arranged between the second beam splitter and the beam combiner.