US5289260A
Expired / Lapsed
US
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Pattern defect detection device and a spatial frequency filter used therein
Assignee: Mitsubishi Electric Corp
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Filing: 1991-11-06
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Granted: 1994-02-22
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Expires: 2011-11-06
Abstract
Abstract A spatial frequency filter used in a pattern defect detection device, including a pattern which includes a black spot having a diameter expanded by a controlled amount in comparison with the diameter of a black spot on a photosensitive plate obtained by exposure by diffracted light from a pattern on a model specimen
Inventors
- 👤 Yoko Miyazaki
- 👤 Toshimasa Tomoda
- 👤 Hitoshi Tanaka
- 👤 Nobuyuki Kosaka
- 👤 Toyomi Ohshige
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:10
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/24; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95623; G06; G06V; G06V10/00; G06V10/88
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
134 words
A pattern defect detection device comprising: a stage for supporting a specimen having a repetitive pattern on the surface thereof; a light source for emitting coherent light, mirror means for directing said light to the pattern on said specimen, said mirror means including mirror angle changing means for changing the angle of reflection of said light, a lens for focusing light diffracted by the pattern on said specimen, plate holding means for holding at the back focal plane of said lens either of at least one photosensitive plate to form a spatial frequency filter, and a created spatial frequency filter including at least one plate having a pattern, and detection signal detect means for detecting light transmitting said spatial frequency filter as a detection signal corresponding to defection in the pattern of said specimen.
Claim 2
Dependent Claim
134 words
A pattern defect detection device comprising: a stage for supporting a specimen having a repetitive pattern on the surface thereof; a light source for emitting coherent light, mirror means for directing said light to the pattern on said specimen, said mirror means including mirror angle changing means for changing the angle of reflection of said light, a lens for focusing light diffracted by the pattern on said specimen, plate holding means for holding at the back focal plane of said lens either of at least one photosensitive plate to form a spatial frequency filter, and a created spatial frequency filter including at least one plate having a pattern, and detection signal detect means for detecting light transmitting said spatial frequency filter as a detection signal corresponding to defection in the pattern of said specimen.
Claim 3
Dependent Claim
21 words
A pattern defect detection device in accordance with claim 1, the angle of said mirror can be changed within one degree.
Claim 4
Dependent Claim
26 words
A pattern defect detection device in accordance with claim 1, said mirror angle changing means has two tilting axes which are not parallel to each other.
Claim 5
Dependent Claim
36 words
A pattern defect detection device in accordance with claim 1, wherein said plate holding means holds either of a plurality of said photosensitive plates and said created spatial frequency filter including a plurality of said plate.
Claim 6
Dependent Claim
36 words
A pattern defect detection device in accordance with claim 2, where said plate holding means holds either of a plurality of said photosensitive plates and said created spatial frequency filter including a plurality of said plate.
Claim 7
Dependent Claim
15 words
A spatial frequency filter in accordance with claim 3, comprising a plurality of said plate.
Claim 8
Dependent Claim
149 words
A pattern defect detection device comprising: a stage for supporting a specimen having a repetitive pattern on the surface thereof, a light source for emitting coherent light, mirror means for directing said light to the pattern on said specimen, a lens for focusing light diffracted by the pattern on said specimen, plate holding means for holding at the back focal plane of said lens either of at least one photosensitive plate to form a spatial frequency filter, and a created spatial frequency filter including at least one plate having a pattern, said plate holding means including moving means for moving either of at least one said photosensitive plate and said created spatial frequency filter in two dimensional directions traversing said diffracted light, and detection signal detect means for detecting light transmitted through said spatial frequency filter as a detection signal corresponding to detection in the pattern of said specimen.
Claim 9
Dependent Claim
149 words
A pattern defect detection device comprising: a stage for supporting a specimen having a repetitive pattern on the surface thereof, a light source for emitting coherent light, mirror means for directing said light to the pattern on said specimen, a lens for focusing light diffracted by the pattern on said specimen, plate holding means for holding at the back focal plane of said lens either of at least one photosensitive plate to form a spatial frequency filter, and a created spatial frequency filter including at least one plate having a pattern, said plate holding means including moving means for moving either of at least one said photosensitive plate and said created spatial frequency filter in two dimensional directions traversing said diffracted light, and detection signal detect means for detecting light transmitted through said spatial frequency filter as a detection signal corresponding to detection in the pattern of said specimen.
Claim 10
Dependent Claim
53 words
A spatial frequency filter used in a pattern defect detection device, comprising a pattern which comprises black spots, each having a diameter expanded by a controlled amount in comparison with a corresponding black spot diameter on a photosensitive plate obtained by exposure by diffracted light from a model spectrum which contains no defects.
Claim 11
Dependent Claim
53 words
A spatial frequency filter used in a pattern defect detection device, comprising a pattern which comprises black spots, each having a diameter expanded by a controlled amount in comparison with a corresponding black spot diameter on a photosensitive plate obtained by exposure by diffracted light from a model spectrum which contains no defects.
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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) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |