US5153444A
Expired / Lapsed
US
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Method and apparatus for detecting patterns
Assignee: Hitachi Ltd
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Filing: 1991-01-14
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Granted: 1992-10-06
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Expires: 2011-01-14
Abstract
Abstract A method and apparatus for detecting a defect in a circuit pattern by detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another, and detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern.
Inventors
- 👤 Shunji Maeda
- 👤 Takashi Hiroi
- 👤 Hitoshi Kubota
- 👤 Hiroshi Makihira
- 👤 Fumiaki Endo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:05
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/0002; G06T7/0004; G06T7/001; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95607; G01N21/8851; G01N2021/8896; G01N2021/95615; G06T2207/00; G06T2207/30; G06T2207/30108; G06T2207/30148
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
79 words
A method for detecting a defect in a circuit pattern comprising the steps: detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another; and detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern.
Claim 2
Independent Claim
79 words
A method for detecting a defect in a circuit pattern comprising the steps: detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another; and detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern.
Claim 3
Dependent Claim
35 words
A method according to claim 1, wherein the step of detecting a defect includes obtaining a difference of the comparing of the detected gray image signals and detecting a defect in accordance with the difference.
Claim 4
Dependent Claim
36 words
A method according to claim 2, wherein the step of detecting a defect includes obtaining a difference of gray image signals having a larger value at a normal portion than a value at a defect portion.
Claim 5
Dependent Claim
25 words
A method according to claim 1, wherein the step of detecting a defect includes comparing polarities of the gray image signals to detect a defect.
Claim 6
Dependent Claim
36 words
A method according to claim 4, wherein the step of detecting a defect includes subjecting the gray image signals to differentiation processing to provide differentiated signals and, comparing polarities of the differentiated signals with each other.
Claim 7
Dependent Claim
17 words
A method according to claim 5, wherein the differentiation processing is linear differentiation processing providing linear derivatives.
Claim 8
Dependent Claim
35 words
A method according to claim 6, wherein comparison of polarities of the linear derivatives as the differentiated signals is performed only for image signals having linear derivatives with absolute values larger than a preset value.
Claim 9
Dependent Claim
44 words
A method according to claim 5, wherein the differentiation processing includes linear differentiation processing providing linear derivatives and second differentiation processing providing second derivatives, and the comparing of polarities of the linear derivatives is performed in regions obtained in accordance with the second derivatives.
Claim 10
Dependent Claim
53 words
A method according to claim 5, wherein the step of detecting a defect includes comparing, in an edge region, polarities of the differentiated signals with each other and obtaining, in a non-edge region, difference image signals between the compared gray image signals, and binarizing the difference image signals with a predetermined threshold value.
Claim 11
Dependent Claim
47 words
A method according to claim 5, wherein the step of detecting a defect includes aligning the gray image signals with each other at a position where the number of pixels disagreeing in polarity is at a minimum, and comparing the aligned gray image signals with each other.
Claim 12
Dependent Claim
70 words
A method according to claim 5, wherein the step of detecting a defect includes aligning the gray image signals with each other at a plurality of positions where the number of pixels disagreeing in polarity is less than a preset value, detecting difference image signals between the gray image signals aligned with each other at the plurality of positions, and binarizing the difference image signals with a predetermined threshold value.
Claim 13
Dependent Claim
52 words
A method according to claim 5, wherein the step of detecting a defect includes aligning the gray image signals with each other at a plurality of positions where the number of pixels disagreeing in polarity is less than a preset value, and comparing the polarity signals aligned at the plurality of positions.
Claim 14
Dependent Claim
68 words
A method according to claim 5, wherein the step of detecting a defect includes aligning the gray image signals with each other at a plurality of positions where the number of pixels disagreeing in polarity is less than a preset value, and comparing the polarity signals aligned at the plurality of positions so as to detect a polarity disagreement common at a plurality of positions as the defect.
Claim 15
Independent Claim
81 words
An apparatus for detecting a defect in a circuit pattern comprising: means for detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another; and means for detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern.
Claim 16
Independent Claim
81 words
An apparatus for detecting a defect in a circuit pattern comprising: means for detecting a gray image signal from each of a plurality of circuit patterns as objects of inspection, which circuit patterns have been fabricated so as to be identical with one another; and means for detecting a defect as a difference of edge position between two circuit patterns by comparing the detected gray image signal of one circuit pattern with the detected gray image signal of another circuit pattern.
Claim 17
Dependent Claim
40 words
An apparatus according to claim 14, wherein the means for detecting a defect includes comparison means for comparing the gray image signals and obtaining a difference of the comparison, and means for detecting a defect in accordance with the difference.
Claim 18
Dependent Claim
37 words
An apparatus according to claim 15, wherein means for detecting a defect includes means for obtaining a difference of gray image signals having a larger value at a normal portion than a value at a defect portion.
Claim 19
Dependent Claim
28 words
An apparatus according to claim 14, wherein the means for detecting a defect includes comparison means for comparing polarities of the gray image signals to detect a defect.
Claim 20
Dependent Claim
41 words
An apparatus according to claim 17, wherein the means for detecting a defect includes differentiating means for subjecting the gray image signals to differentiation processing to provide differentiated signals and means for comparing polarities of the differentiated signals with each other.
Claim 21
Dependent Claim
18 words
An apparatus according to claim 18, wherein the differentiation means is a linear differentiation means providing linear derivatives.
Claim 22
Dependent Claim
35 words
An apparatus according to claim 19, wherein the comparison means effects comparison of the linear derivatives as the differentiated signals only for image signals having linear derivatives with absolute values larger than a preset value.
Claim 23
Dependent Claim
39 words
An apparatus according to claim 18, wherein the differentiation means includes linear differentiation means and second differentiation means and the comparison means effects comparing of polarities of the linear derivatives in regions obtained in accordance with the second derivatives.
Claim 24
Dependent Claim
57 words
An apparatus according to claim 18, wherein the means for detecting a defect includes the comparison means comparing, in an edge region, the polarities of the differentiated signals with each other and obtaining, in a non-edge region, difference image signals between gray image signals, and means for binarizing the difference image signals with a predetermined threshold value.
Claim 25
Dependent Claim
52 words
An apparatus according to claim 18, wherein the means for detecting a defect includes aligning means for aligning the gray image signals with each other at a position where the number of pixels disagreeing in polarity is at a minimum, and the comparison means comparing the aligned image signals with each other.
Claim 26
Dependent Claim
77 words
An apparatus according to claim 18, wherein the means for detecting a defect includes aligning means for aligning the gray image signals with each other at a plurality of positions where the number of pixels disagreeing in polarity is less than a preset value, means for detecting difference image signals between the gray image signals aligned with each other at the plurality of positions, and means for binarizing the difference image signals with a predetermined threshold value.
Claim 27
Dependent Claim
58 words
An apparatus according to claim 18, wherein the means for detecting a defect includes aligning means for aligning the gray image signals with each other at a plurality of positions where the number of pixels disagreeing in polarity is less than a preset value, and the comparison means comparing the polarity signals aligned at the plurality of positions.
Claim 28
Dependent Claim
74 words
An apparatus according to claim 18, wherein the means for detecting a defect includes aligning means for aligning the gray image signals with each other at a plurality of positions where the number of pixels disagreeing in polarity is less than a preset value, and the comparison means comparing the polarity signals aligned at the plurality of positions so as to detect a plurality disagreement common at a plurality of positions as the defect.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-06 | 1996-04-06 | 1996-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-06 | 2000-04-06 | 2000-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-06 | 2004-04-06 | 2004-10-06 | $7700.00 | Window Closed / Lapsed |