System and method for analyzing topological features on a surface
First Claim
1. A method for analyzing the condition of a surface of an electronic device, the surface having a defined pattern, the method comprising:
- (a) illuminating a first region of the surface such that light is scattered and diffracted off of features of the surface;
(b) detecting light scattered and diffracted from the first region surface;
(c) comparing the diffracted light detected to a baseline diffraction pattern of light diffracted from a baseline region having a condition corresponding to an expected condition of the first region; and
(d) determining whether the detected light diffracted from the first region significantly deviates from the baseline diffraction pattern.
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Accused Products
Abstract
Disclosed is a method and apparatus for using far field scattered and diffracted light to determine whether a collection of topological features on a surface (e.g., a semiconductor wafer) conforms to an expected condition or quality. This determination is made by comparing the far field diffraction pattern of a surface under consideration with a corresponding diffraction pattern (a "baseline"). If the baseline diffraction pattern and far field diffraction pattern varies by more than a prescribed amount or in characteristic ways, it is inferred that the surface features are defective. The method may be implemented as a die-to-die comparison of far field diffraction patterns of two dies on a semiconductor wafer. The portion of the far field scattered and diffracted light sensitive to a relevant condition or quality can also be reimaged to obtain an improved signal-to-noise ratio.
152 Citations
29 Claims
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1. A method for analyzing the condition of a surface of an electronic device, the surface having a defined pattern, the method comprising:
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(a) illuminating a first region of the surface such that light is scattered and diffracted off of features of the surface; (b) detecting light scattered and diffracted from the first region surface; (c) comparing the diffracted light detected to a baseline diffraction pattern of light diffracted from a baseline region having a condition corresponding to an expected condition of the first region; and (d) determining whether the detected light diffracted from the first region significantly deviates from the baseline diffraction pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 24, 25, 26)
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10. A method for inspecting a plurality of openings in a film on a substrate, comprising:
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illuminating a first portion of said openings; detecting far field diffracted light produced by said illumination of said first portion; illuminating a second portion of said openings, said second portion of said openings having a pattern which is substantially identical to said first portion; detecting far field diffracted light produced by said illumination of said second portion; and comparing signals detected from illumination of said first portion with signals detected from illumination of said second portion, thereby determining whether variations exist in said openings. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An apparatus for evaluating the condition of topological features on a substrate surface, the apparatus comprising:
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a light source arranged to direct light onto the substrate surface such that the light is diffracted by the substrate surface; a sensor configured to capture and transmit a diffraction pattern of the light diffracted by the substrate surface; and a computer configured to compare the diffraction pattern from the substrate surface with a baseline diffraction pattern of light diffracted from a baseline surface having a condition corresponding to an expected condition of the substrate surface. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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27. A method for analyzing the condition of a surface of an electronic device, the surface having a defined pattern, the method comprising:
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(a) illuminating a first region of the surface such that light is diffracted off of features the surface; (b) filtering diffracted light to block one or more portions of a diffraction pattern from the substrate surface which portions contain little or no information pertaining to a surface feature of interest, while passing diffracted light containing information relevant to the surface feature of interest; (c) detecting the filtered diffracted light; and (d) comparing the filtered diffracted light to a baseline diffraction pattern of light diffracted from a baseline region having a condition corresponding to an expected condition of the surface feature of interest. - View Dependent Claims (28, 29)
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Specification