Systems and methods for a wafer inspection system using multiple angles and multiple wavelength illumination
First Claim
1. A method for detecting an anomaly on a top surface of a substrate, or within the substrate, comprising:
- directing a first radiation beam having a first ultraviolet or deep ultraviolet wavelength to illuminate a first spot on the top surface of the substrate at a first non-zero angle measured from a normal direction to the top surface;
directing a second radiation beam having a second wavelength to illuminate a second spot on the top surface of the substrate at a second angle measured from a normal direction to the top surface, wherein the second wavelength is greater than the first wavelength, so that radiation from the second beam penetrates the surface of the substrate by a distance greater than that by radiation from the first beam;
causing relative motion between the first and second radiation beams and the top surface of the substrate so that the spots scan paths on the top surface;
detecting radiation from the first radiation beam scattered by the top surface in the first spot to provide a single output corresponding to a position of the first spot on the top surface;
detecting radiation from the second radiation beam scattered by the top surface in the second spot to provide a single output corresponding to a position of the second spot on the top surface; and
generating from the outputs first data set(s) containing only data on anomalies at or substantially at the surface of the substrate and second data set(s) containing data on anomalies away from the surface of the substrate, so that anomalies at or substantially at the surface of the substrate are detectable independently from anomalies away from the surface of the substrate from the data sets.
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Abstract
A method for detecting an anomaly on a top surface of a substrate comprises directing a first radiation beam having a first wavelength at the top surface of the substrate at a first angle measured from normal, and directing a second radiation beam having a second wavelength at the top surface of the substrate at a second angle measured from normal, wherein the second wavelength is not equal to the first wavelength. The method then comprises detecting scattered radiation from the first radiation beam and the second radiation beam to detect the presence of particles or COPs, and to differentiate between the two. Differences in the scattered radiation detected from the first radiation beam and from the second radiation beam provide the data needed to differentiate between particles and COPs.
53 Citations
75 Claims
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1. A method for detecting an anomaly on a top surface of a substrate, or within the substrate, comprising:
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directing a first radiation beam having a first ultraviolet or deep ultraviolet wavelength to illuminate a first spot on the top surface of the substrate at a first non-zero angle measured from a normal direction to the top surface;
directing a second radiation beam having a second wavelength to illuminate a second spot on the top surface of the substrate at a second angle measured from a normal direction to the top surface, wherein the second wavelength is greater than the first wavelength, so that radiation from the second beam penetrates the surface of the substrate by a distance greater than that by radiation from the first beam;
causing relative motion between the first and second radiation beams and the top surface of the substrate so that the spots scan paths on the top surface;
detecting radiation from the first radiation beam scattered by the top surface in the first spot to provide a single output corresponding to a position of the first spot on the top surface;
detecting radiation from the second radiation beam scattered by the top surface in the second spot to provide a single output corresponding to a position of the second spot on the top surface; and
generating from the outputs first data set(s) containing only data on anomalies at or substantially at the surface of the substrate and second data set(s) containing data on anomalies away from the surface of the substrate, so that anomalies at or substantially at the surface of the substrate are detectable independently from anomalies away from the surface of the substrate from the data sets. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method for detecting an anomaly on a top surface of a substrate, or within the substrate, comprising:
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directing a first radiation beam having a first wavelength to illuminate a first spot on the top surface of the substrate at a first non-zero angle measured from normal, wherein the first wavelength is in the ultraviolet or deep ultraviolet spectrum of radiation;
directing a second radiation beam having a second wavelength to illuminate a second spot on the top surface of the substrate at a second angle measured from normal, wherein the second wavelength is in the visible spectrum of radiation;
detecting radiation from the first and second radiation beams;
causing relative motion between the first and second radiation beams and the top surface of the substrate, so that the spots scan paths on the top surface, wherein said detecting detects radiation scattered by the top surface to provide one or more outputs;
generating from the outputs first data set(s) containing only data on anomalies at or substantially at the surface of the substrate and second data set(s) containing data on anomalies away from the surface of the substrate, so that anomalies at or substantially at the surface of the substrate are detectable independently from anomalies away from the surface of the substrate from the data sets; and
documenting the presence of an anomaly if the data sets shows an increase in the amount of scattered radiation produced by the first radiation beam or the second radiation beam. - View Dependent Claims (26)
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27. A system for detecting an anomaly on a top surface of a substrate, or within the substrate, comprising:
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a device providing a first wavelength radiation and a second wavelength radiation to illuminate the top surface, said first wavelength being ultraviolet or deep ultraviolet;
optics focusing the first wavelength radiation into a first radiation beam at an oblique first angle to the top surface to illuminate a first spot on the top surface and focusing the second wavelength radiation into a second radiation beam at a second angle to a normal direction to top surface to illuminate a second spot on the top surface, wherein the second wavelength is greater than the first wavelength, so that radiation of the second wavelength penetrates the surface of the substrate by a distance greater than that by radiation of the first wavelength;
means for causing relative motion between the first and second radiation beams and the top surface of the substrate, so that the spots scan paths on the top surface; and
a detector mounted to detect radiation scattered by the top surface in the first or second spot to provide a first single output in response to the scattered radiation in the first beam corresponding to a position of the first spot on the top surface in one of the scan paths, and a second single output in response to the scattered radiation in the second beam corresponding to a position of the second spot on the top surface in one of the scan paths; and
means for generating from the outputs first data set(s) containing only data on anomalies at or substantially at the surface of the substrate and second data set(s) containing data on anomalies away from the surface of the substrate, so that anomalies at or substantially at the surface of the substrate are detectable independently from anomalies away from the surface of the substrate from the data sets. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
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43. A method for detecting an anomaly on a surface of a substrate, or within the substrate, comprising:
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directing a first radiation beam to illuminate a first spot on the surface of the substrate at an oblique angle to the surface, said first beam having a ultraviolet or deep ultraviolet first wavelength;
directing a second radiation beam having a second wavelength to illuminate a second spot on the surface of the substrate at a second angle measured from the normal direction to the surface, wherein the second wavelength is greater than the first wavelength, so that radiation from the second beam penetrates the surface of the substrate by a distance greater than that by radiation from the first beam;
causing relative motion between the first and second radiation beams and the surface of the substrate so that the beams scans paths on the surface;
detecting radiation from the first and second radiation beams scattered by the surface in the spots to provide one or more outputs in response to the scattered radiation in the beams; and
generating from the outputs first data set(s) containing only data on anomalies at or substantially at the surface of the substrate and second data set(s) containing data on anomalies away from the surface of the substrate, so that anomalies at or substantially at the surface of the substrate are detectable independently from anomalies away from the surface or the substrate from the data sets. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62)
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63. An apparatus for detecting an anomaly on a surface of a substrate, or within the substrate, comprising:
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optics directing a first radiation beam to illuminate a first spot on the top surface of the substrate at an oblique angle to the surface, said first beam having a ultraviolet or deep first ultraviolet wavelength;
optics directing a second radiation beam having a second wavelength to illuminate a second spot on the surface of the substrate at a second angle measured from the normal direction to the surface, wherein the second wavelength is grater than the first wavelength, so that radiation from the second beam penetrates the surface of the substrate by a distance greater than that by radiation from the first beam;
means for causing relative motion between the first and second radiation beams and the surface of the substrate so that the beams scans paths on the surface; and
a detector detecting radiation from the first and second radiation beams scattered by the surface in the spots to provide one or more outputs in response to the scattered radiation in the beams; and
means for generating from the outputs first data set(s) containing only data on anomalies at or substantially at the surface of the substrate and second data set(s) containing data on anomalies away from the surface of the substrate, so that anomalies at or substantially at the surface of the substrate are detectable independently from anomalies away from the surface of the substrate from the data sets. - View Dependent Claims (64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75)
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Specification