| 摘要 |
A lithographic projection apparatus including a radiation system for providing a projection beam of radiation; a support structure for supporting a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate holder having a plurality of protrusions, the extremities thereof defining a substantially flat plane of support for supporting a substantially flat substrate, the substrate holder provided with the ability to provide a pressing force for pressing the substrate against the extremities of the protrusions, the protrusions in an edge zone of the substrate holder arranged to provide a substantially flat overhanging of the substrate in relation to the pressing force of the pressing means; and a projection system for projecting the patterned beam onto a target portion of the substrate. The lithographic projection apparatus is characterized in that the protrusions in an off-edge zone of the substrate holder are distributed so as to provide a substantial equal supporting area for each protrusion of the plurality of protrusions, the supporting areas being defined by a Voronoi diagram distribution associated to the protrusions. The lithographic apparatus offers a substrate holder with a reduced overlay and focus error.
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