Method of detecting defect location using multi-surface specular reflection
First Claim
1. A method for detecting defects, comprising:
- (a) directing a scanning beam to a first location on a first surface of a transparent sample, wherein a portion of the scanning beam irradiates a second surface of the transparent sample;
(b) at the first location, measuring top surface specular reflection intensity, wherein the top surface specular reflection intensity results from irradiation by the scanning beam at the first location on the first surface of the transparent sample;
(c) storing coordinate values of the first location and the measured top surface specular reflection intensity in a memory;
(d) comparing the top surface specular reflection intensity measured with an expected top surface specular reflection intensity value; and
(e) determining that a defect is present on the top surface of the transparent sample when the measured top surface specular reflection intensity is less than the expected top surface specular reflection intensity value.
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Abstract
A method for detecting defects includes directing a scanning beam to a location on a surface of a transparent sample, measuring top and bottom surface specular reflection intensity, and storing coordinate values of the first location and the top and bottom surface specular reflection intensity in a memory. The method may further include comparing the top surface specular reflection intensity measured at each location with a first threshold value, comparing the bottom surface specular reflection intensity measured at each location with a second threshold value, and determining if a defect is present at each location and on which surface the defect is present. The method may further include comparing the top surface specular reflection intensity measured at each location with a first intensity range, comparing the bottom surface specular reflection intensity measured at each location with a second intensity range, and determining on which surface the defect is present.
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Citations
16 Claims
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1. A method for detecting defects, comprising:
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(a) directing a scanning beam to a first location on a first surface of a transparent sample, wherein a portion of the scanning beam irradiates a second surface of the transparent sample; (b) at the first location, measuring top surface specular reflection intensity, wherein the top surface specular reflection intensity results from irradiation by the scanning beam at the first location on the first surface of the transparent sample; (c) storing coordinate values of the first location and the measured top surface specular reflection intensity in a memory; (d) comparing the top surface specular reflection intensity measured with an expected top surface specular reflection intensity value; and (e) determining that a defect is present on the top surface of the transparent sample when the measured top surface specular reflection intensity is less than the expected top surface specular reflection intensity value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for detecting defects, comprising:
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(a) directing a scanning beam to a first location on a first surface of a transparent sample, wherein a portion of the scanning beam irradiates a second surface of the transparent sample; (b) at the first location, measuring top surface specular reflection intensity, wherein the top surface specular reflection intensity result from irradiation by the scanning beam at the first location on the first surface of the transparent sample; (c) storing coordinate values of the first location and the measured top surface specular reflection intensity in a memory; (d) determining if the measured top surface specular reflection intensity is within a first intensity range, wherein the first intensity range includes an expected top surface specular reflection intensity value; and (e) determining that a defect is present on the top surface of the transparent sample when the measured top surface specular reflection intensity is not within the first intensity range. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification