US5078492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test wafer for an optical scanner
Assignee: VLSI Standards Inc
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Filing: 1991-06-17
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Granted: 1992-01-07
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Expires: 2011-06-17
Abstract
Abstract A patterned wafer for testing an optical scanner. The wafer has standard size light scattering features, such as pits, distributed in aligned groups arranged in annular bands about a concentric center. Empty annular bands separate the feature containing annular bands. The empty bands simulate wafer edges for various size wafers. In this manner, wafer edges may be excluded in a particle count for a predetermined size wafer. Apparent size variations in multiple scans indicate misalignments relative to the scan center.
Inventors
- 👤 Bradley W. Scheer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:58
CPC Classifications
H; H10; H10P; H10P74/00; H10P74/27; H10P74/277; G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/93
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
46 words
A reference for an optical surface scanner comprising, a wafer having groups of light scattering features disposed in annular bands about the center of the wafer, adjacent bands containing features being spaced apart from each other by empty annular bands, whereby wafer edges may be simulated.
Claim 2
Dependent Claim
46 words
A reference for an optical surface scanner comprising, a wafer having groups of light scattering features disposed in annular bands about the center of the wafer, adjacent bands containing features being spaced apart from each other by empty annular bands, whereby wafer edges may be simulated.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein individual light scattering features in said groups are arranged in a geometric pattern of rows and columns.
Claim 4
Dependent Claim
16 words
The apparatus of claim 1 wherein said groups which are in different bands are linearly aligned.
Claim 5
Dependent Claim
61 words
A reference for an optical surface scanner comprising, a wafer having groups of light scattering features distributed radially about a common center, each group having rows and columns of said features of a spacing such that a beam simultaneously illuminates fewer features than in the entire group, said spacing including concentric, empty annular bands simulating wafer edges for various size wafers.
Claim 6
Dependent Claim
61 words
A reference for an optical surface scanner comprising, a wafer having groups of light scattering features distributed radially about a common center, each group having rows and columns of said features of a spacing such that a beam simultaneously illuminates fewer features than in the entire group, said spacing including concentric, empty annular bands simulating wafer edges for various size wafers.
Claim 7
Dependent Claim
22 words
The apparatus of claim 4 wherein said light scattering features have a spacing in the range of between 1 and 3 millimeters.
Claim 8
Dependent Claim
17 words
The apparatus of claim 4 wherein said light scattering features are pits etched in said wafer surface.
Claim 9
Dependent Claim
26 words
The apparatus of claim 4 wherein said light scattering features are disposed in annular bands including a first annular band containing four groups of said features.
Claim 10
Dependent Claim
16 words
The apparatus of claim 7 wherein a second annular band contains eight groups of said features.
Claim 11
Dependent Claim
16 words
The apparatus of claim 8 wherein a third annular band contains twelve group of said features.
Claim 12
Dependent Claim
23 words
The apparatus of claim 4 wherein individual light scattering features in said groups are arranged in a geometric pattern of rows and columns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |