Multi-axis interferometers and methods and systems using multi-axis interferometers
AssigneeZygo Corporation
InventorHenry A. Hill
Life of this patent
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Abstract
In general, in one aspect, the invention features an apparatus including a multi-axis interferometer configured to produce at least three output beams each including interferometric information about a distance between the interferometer and a measurement object along a corresponding measurement axis, wherein at least three of the measurement axes are in a common plane, wherein the output beams each include a component that makes a pass to the measurement object along a common beam path.
Claims29
A lithography system for use in fabricating integrated circuits on a substrate, the system comprising:
- a stage for supporting the substrate;
- an illumination system including a radiation source, a mask, a positioning system, a lens assembly;
- a positioning system configured to adjust the position of the stage relative to the lens assembly;
- and
- an interferometer configured to produce at least three output beams each including interferometric information about a distance between the interferometer and a measurement object along a corresponding measurement axis,
- wherein at least one of the interferometer and the measurement object are attached to the stage, and the output beams each include a component that makes a pass to the measurement object along a common beam path.
A lithography system for use in fabricating integrated circuits on a substrate, the system comprising:
- a stage for supporting the substrate;
- an illumination system including a radiation source, a mask, a positioning system, a lens assembly;
- a positioning system configured to adjust the position of the stage relative to the lens assembly;
- and
- an interferometer configured to produce at least three output beams each including interferometric information about a distance between the interferometer and a measurement object along a corresponding measurement axis, wherein at least one of the interferometer and the measurement object are attached to the stage;
- and
- an electronic processing system coupled to the interferometer, wherein the electronic processing system is configured to calculate a value for a second difference parameter (SDP) for the measurement object based on the distances between the interferometer and the measurement object along the at least three measurement axes.
A lithography system for use in fabricating integrated circuits on a substrate, the system comprising:
- a stage for supporting the substrate;
- an illumination system including a radiation source, a mask, a positioning system, a lens assembly;
- a positioning system configured to adjust the position of the stage relative to the lens assembly;
- and
- an interferometer configured to produce at least three output beams each including interferometric information about a distance between the interferometer and a measurement object along a corresponding measurement axis, wherein at least one of the interferometer and the measurement object are attached to the stage and the output beams each include a component that makes one pass to the measurement object along a common measurement beam path;
- and
- an electronic processor configured to derive information about the surface figure profile of the measurement object from the output beams as the measurement object is scanned relative to the interferometry system along a distance non-parallel to the measurement axes.
A lithography method for use in fabricating integrated circuits on a substrate, the method comprising:
- supporting the substrate on a moveable stage;
- imaging spatially patterned radiation onto the substrate;
- adjusting the position of the stage;
- producing at least three output beams each including interferometric information about a distance between an interferometer and a measurement object along a corresponding measurement axis, wherein at least one of the interferometer and the measurement object are attached to the stage and the output beams each include a component that makes a pass to the measurement object along a common beam path;
- and
- monitoring the position of the stage based on the interferometric information from at least one of the output beams.
A lithography method for fabricating integrated circuits on a substrate comprising:
- positioning a first component of a lithography system relative to a second component of a lithography system to expose the substrate to spatially patterned radiation;
- producing at least three output beams each including interferometric information about a distance between an interferometer and a measurement object along a corresponding measurement axis, wherein at least one of the interferometer and the measurement object are attached to the first component and the output beams each include a beam component that makes a pass to the measurement object along a common beam path;
- and
- monitoring the position of the stage based on the interferometric information from at least one of the output beams.
Dependencies are inferred from the claim text.