US 2025/0109934 A1Published application

Multi-phase interferometer for 3d metrology

OwnerYuri Paskover, Hanina Golan +4inventors

InventorsYuri Paskover, Hanina Golan, Ilia Lutsker, Nir Turko, Oleg Yermak, Saki Hakim

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Abstract

In the system, an illumination source emits light, a first beam splitter directs a portion of the light toward a sample and directs another portion of the light toward a reference surface that reflects the light back to the first beam splitter to be recombined with light reflected by the sample, at least one second beam splitter that directs n portions of the light toward n detectors, each of the n portions of the light having a preset phase shift and n≥2, and a processor receives intensities of the n portions of the light. The processor calculates an interferogram envelope based on the intensities measured by the n detectors as the reference surface moves between a plurality of signal collection positions.

Claims23

Dependent claims

A system comprising:

an illumination source configured to emit light along an illumination path;
a first beam splitter disposed in the illumination path and configured to direct a portion of the light toward a sample and direct another portion of the light along a reference path, wherein the sample reflects the light along a collection path;
a reference surface disposed in the reference path and configured to reflect the light back to the first beam splitter to be recombined with the light reflected by the sample in the collection path;
n detectors disposed in the collection path, where n≥2;
at least one second beam splitter disposed in the collection path and configured to direct n portions of the light toward the n detectors, respectively, wherein each of the n portions of the light have a preset phase shift;
and
a processor in electronic communication with the n detectors that is configured to receive intensities of the n portions of the light measured by the n detectors, respectively;
wherein the reference surface is movable between a plurality of signal collection positions to vary the length of the reference path, and the processor is further configured to calculate an interferogram envelope based on the intensities of the n portions of the light measured by the n detectors at at least some two of the plurality of signal collection positions.

5 more elements

A method comprising:

emitting light with an illumination source along an illumination path;
directing a portion of the light toward a sample with a first beam splitter disposed in the illumination path, wherein the sample reflects the light along a collection path;
directing another portion of the light along a reference path with the first beam splitter, wherein a reference surface disposed in the reference path reflects the light back to the first beam splitter and is recombined with the light reflected by the sample in the collection path;
directing n portions of the light toward n detectors, respectively, with at least one second beam splitter disposed in the collection path, wherein each of the n portions of the light have a preset phase shift and n≥2;
measuring intensities of the n portions of the light received by the n detectors, respectively;
moving the reference surface between a plurality of signal collection positions to vary the length of the reference path;
and
calculating, using a processor, an interferogram envelope based on the intensities of the n portions of the light measured by the n detectors at at least two of the plurality of signal collection positions.

5 more elements

Dependencies are inferred from the claim text.