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US 6,989,905 B2Granted
Phase gap analysis for scanning interferometry
AssigneeZygo Corporation
InventorPeter J. De Groot
Life of this patent
Estimating the term…
Abstract
A method including: providing a coherence profile and a phase profile derived from interferometry data for a test surface; calculating a phase gap map, wherein the phase gap map is related to a difference between the coherence profile and the phase profile; fitting an expression including a term based on the coherence profile to the phase gap map; and determining a height profile for the test surface using information derived from the fit.
Claims48
A method comprising:
- providing a coherence profile and a phase profile derived from interferometry data for a test surface;
- calculating a phase gap map, wherein the phase gap map is related to a difference between the coherence profile and the phase profile;
- fitting an expression including a term based on the coherence profile to the phase gap map;
- and
- determining a height profile for the test surface using information derived from the fit.
2 more elements
An interferometry system comprising:
- a height-scanning interferometer which during operation measures height-scanning interferometry data for a test surface;
- and
- an electronic processor coupled to the height-scanning interferometer, wherein during operation the electronic processor:
- determines a coherence profile and a phase profile from the height-scanning interferometry data;
- calculates a phase gap map, wherein the phase gap map is related to a difference between the coherence profile and the phase profile;
- fits an expression including a term based on the coherence profile to the phase gap map;
- and determines a height profile for the test surface using information derived from the fit.
4 more elements
Dependencies are inferred from the claim text.