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US 2002/0172876 A1Published application
Method of calibration of a lithographic apparatus, mask for use in calibration of lithographic apparatus, lithographic apparatus, device manufacturing method, device manufactured thereby
AssigneeASML Netherlands B.V.
InventorJohannes Jacobus Matheus Baselmans
Life of this patent
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Abstract
An alignment marker for use in calibration of a lithographic projection apparatus has focus sensitive parts and dose sensitive parts, each of which includes an area having a plurality of dots against a contrasting background forming part of a periodic line structure.
Claims25
A method of calibrating a lithographic projection apparatus, the apparatus comprising:
- a radiation system constructed and arranged to provide a projection beam of radiation;
- a support structure constructed and arranged to support a patterning device, the pattern device constructed and arranged to pattern the projection beam according to a desired pattern;
- a substrate table to hold a substrate;
- a projection system constructed and arranged to image the patterned beam onto a target portion of the substrate, the method comprising:
- imaging at least one alignment marker provided in the patterning device onto a radiation-sensitive layer on a substrate held by the substrate table, wherein the at least one alignment marker comprises at least one grating and has a focus sensitive part and a dose sensitive part, the focus sensitive part and the dose sensitive part each having a plurality of dots on a contrasting background, the pluralities of dots being arranged such that variations in focus settings and dose settings in the imaging cause shifts in the apparent position of the at least one grating.
2 more elements
A patterning device constructed and arranged to pattern a projection beam in a lithographic projection apparatus according to a desired pattern, the patterning device comprising:
- at least one alignment marker comprising including at least one grating and having a focus sensitive part and a dose sensitive part, the focus sensitive part and the dose sensitive part each having a plurality of dots on a contrasting background, the pluralities of dots being arranged such that variations in focus settings and dose settings when projecting an image of the at least one marker cause shifts in the apparent position of the at least one grating.
A lithographic projection apparatus, comprising:
- a radiation system constructed and arranged to provide a projection beam of radiation;
- a patterning constructed and arranged to pattern the projection beam according to a desired pattern;
- a substrate table to hold a substrate;
- a projection system constructed and arranged to image the patterned beam onto a target portion of the substrate, wherein the patterning device comprises at least one alignment marker comprising at least one grating and has a focus sensitive part and a dose sensitive part, the focus sensitive part and the dose sensitive part each having a plurality of dots on a contrasting background, the pluralities of dots being arranged such that variations in focus settings and dose settings in imaging cause shifts in an apparent position of the at least one grating.
1 more element
Dependencies are inferred from the claim text.