Lithographic apparatus and inspection system for measuring wafer deformation
AssigneeASML Netherlands B.V.
InventorHenricus Petrus Maria PELLEMANS
Life of this patent
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Abstract
A system for measuring deformation of a substrate includes an illuminator, a camera, a modulator system, and a controller. The illuminator directs two beams of radiation at each target of a plurality of targets disposed on the substrate to produce two beams of scattered radiation from each target. The camera detects interference patterns of the two beams of scattered radiation from the plurality of targets and generates an interferogram based on the interference pattern. The modulator system adjusts the interference patterns by adjusting a relative phase of the two beams of radiation. The controller analyzes the measurement signal to determine the deformation of the substrate based on the interferogram and the adjusting of the relative phase.
Claims20
A system comprising:
- an illuminator configured to direct two beams of radiation at each target of a plurality of targets disposed on a substrate to produce two beams of scattered radiation from the each target;
- a camera configured to detect interference patterns of the two beams of scattered radiation from the plurality of targets and to generate a measurement signal comprising a signal representation of an interferogram based on the interference patterns;
- a modulator system configured to adjust the interference patterns by adjustment of a relative phase of the two beams of radiation;
- and
- a controller configured to analyze the measurement signal and to determine the deformation of the substrate based on the interferogram and the adjustment of the relative phase.
A lithographic apparatus comprising:
- an illumination system configured to illuminate a pattern of a patterning device;
- a projection system configured to project an image of the pattern onto a substrate;
- and
- an inspection system comprising:
- an illuminator configured to direct two beams of radiation at each target of a plurality of targets disposed on the substrate to produce two beams of scattered radiation from each target;
- a camera configured to detect interference patterns of the two beams of scattered radiation from the plurality of targets and to generate a measurement signal comprising a signal representation of an interferogram based on the interference patterns;
- a modulator system configured to adjust the interference patterns by adjustment of a relative phase of the two beams of radiation;
- and
- a controller configured to analyze the measurement signal and to determine deformation of the substrate based on the interferogram and the adjustment of the relative phase.
A method comprising:
- directing two beams of radiation at each target of a plurality of targets disposed on a substrate to produce two beams of scattered radiation from each target;
- detecting interference patterns of the two beams of scattered radiation from the plurality of targets using a camera;
- generating a measurement signal comprising a signal representation of an interferogram based on the interference patterns detected by the camera;
- adjusting the interference patterns by adjusting a relative phase of the two beams of radiation;
- analyzing the measurement signal using a controller;
- and
- determining a deformation of the substrate based on the interferogram and the adjusting of the relative phase.
Dependencies are inferred from the claim text.