Lithographic method and apparatus
AssigneeASML Netherlands B.V.
InventorsJohannes Jacobus Matheus Baselmans, Johannes Christiaan Maria Jasper
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Abstract
A method of patterning substrates using a lithographic apparatus. The method comprising providing a beam of radiation using an illumination system, using a patterning device to impart the radiation beam with a pattern in its cross-section, and using a projection system to project the patterned radiation beam onto target portions of a lot of substrates, wherein the method further comprises performing a radiation beam aberration measurement after projecting the patterned radiation beam onto a subset of the lot of substrates, performing an adjustment of the projection system using the results of the radiation beam aberration measurement, then projecting the patterned radiation beam onto a further subset of the lot of substrates.
Claims20
A method of patterning substrates, comprising:
- determining whether an adjustment to a projection system is needed based on a lens heating model;
- if adjustment is needed based on the determining, adjusting the projection system and
- projecting a patterned radiation beam onto target portions of a subset of a substrate lot using the adjusted projection system;
- if adjustment is not needed based on the determining, projecting a patterned radiation beam onto target portions of the subset of the substrate lot using the unadjusted projection system;
- and
- determining whether a radiation beam aberration measurement of the projection system is needed for a next lot of substrates.
A lithographic apparatus comprising:
- an illumination system configured to provide a radiation beam;
- a support structure configured to support a patterning device, the patterning device imparting the radiation beam with a pattern;
- a substrate table configured to hold a substrate;
- a projection system configured to project the patterned radiation beam onto a target portion of the substrate;
- and
- a controller configured to:
- determine whether an adjustment to the projection system is needed based on a lens heating model;
- adjust the projection system and project a patterned radiation beam onto target portions of a subset of a substrate lot using the adjusted projection system if adjustment is needed based on the determining;
- project a patterned radiation beam onto target portions of the subset of the substrate lot using the unadjusted projection system if adjustment is not needed based on the determining;
- and
- determine whether a radiation beam aberration measurement of the projection system is needed for a next lot of substrates.
Dependencies are inferred from the claim text.