Lithographic apparatus and device manufacturing method
AssigneeASML Netherlands B.V.
InventorsRobertus De Kruif, Richard Bruls
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Abstract
In known lithographic apparatus the projection beam is symmetrical, while the process window can be asymmetrical. The invention addresses this problem by providing a lithographic apparatus comprising an illumination system configured to condition a radiation beam; a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table constructed to hold a substrate; and a projection system configured to project the patterned radiation beam onto a target portion of the substrate, wherein there is further provided a system for providing an asymmetric projection beam bandwidth distribution.
Claims19
A lithographic apparatus comprising:
- an illumination system for providing a beam of radiation;
- a support structure for supporting a patterning device, the patterning device serving to impart the beam of radiation with a pattern in its cross-section;
- a substrate table for holding a substrate;
- a projection system for projecting the patterned beam of radiation onto a target portion of the substrate;
- and
- a controller configured and arranged to change an energy spectrum of the beam of radiation such that the energy spectrum is asymmetric.
A device manufacturing method comprising:
- patterning a beam of radiation with a pattern in its cross-section;
- projecting the patterned beam of radiation onto a target portion of a substrate;
- and
- controlling an energy spectrum of the beam of radiation to be asymmetric.
Dependencies are inferred from the claim text.