US5134303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser apparatus and method for measuring stress in a thin film using multiple wavelengths
Assignee: Tencor Instruments Inc
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Filing: 1990-08-14
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Granted: 1992-07-28
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Expires: 2010-08-14
Abstract
Abstract In accordance with the present invention, an apparatus and a method for measuring the radius of curvature of a surface using laser beams of multiple wavelengths are provided. The present invention avoids poor measurement due to destructive interference of the beams reflected at a thin film's upper and lower surfaces. The present invention is applicable to laser reflection stress measurement apparatuses of both scanning and beam-splitting types.
Inventors
- 👤 Ilan A. Blech
- 👤 Dov E. Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:09
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/16; G01L; G01L1/00; G01L1/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
64 words
An apparatus for measuring a local radius of curvature of a surface, comprising: means for producing a laser beam of multiple wavelengths; means for directing said laser beam on said surface so as to provide a reflected beam of said laser beam; and means for detecting the angle of said reflected beam so as to provide a measurement of said local radius of curvature.
Claim 2
Independent Claim
64 words
An apparatus for measuring a local radius of curvature of a surface, comprising: means for producing a laser beam of multiple wavelengths; means for directing said laser beam on said surface so as to provide a reflected beam of said laser beam; and means for detecting the angle of said reflected beam so as to provide a measurement of said local radius of curvature.
Claim 3
Dependent Claim
60 words
An apparatus as in claim 1, wherein said means for producing a laser beam of multiple wavelengths comprises: a first laser producing a first laser beam of a first wavelength; a second laser producing a second laser beam of a second wavelength; and means for combining said first and second laser beams to provide said laser beam of multiple wavelength.
Claim 4
Dependent Claim
32 words
An apparatus as in claim 1 wherein said means for producing a laser beam of multiple wavelengths comprises a single laser producing a laser beam with radiations of at least two wavelengths.
Claim 5
Dependent Claim
23 words
An apparatus as in claim 1, wherein said surface is the surface of a semiconductor wafer on which is formed a thin film.
Claim 6
Independent Claim
70 words
A method for measuring a local radius of curvature of a surface, comprising the steps of: providing means for producing a laser beam of multiple wavelengths; providing means for directing said laser beam on said surface so as to provide a reflected beam of said laser beam; and providing means for detecting the angle of said reflected beam so as to provide a measurement of said local radius of curvature.
Claim 7
Independent Claim
70 words
A method for measuring a local radius of curvature of a surface, comprising the steps of: providing means for producing a laser beam of multiple wavelengths; providing means for directing said laser beam on said surface so as to provide a reflected beam of said laser beam; and providing means for detecting the angle of said reflected beam so as to provide a measurement of said local radius of curvature.
Claim 8
Dependent Claim
69 words
A method as in claim 5, wherein said step of providing means for producing a laser beam of multiple wavelengths comprises the steps of: providing a first laser producing a first laser beam of a first wavelength; providing a second laser producing a second laser beam of a second wavelength; and providing means for combining said first and second laser beam to provide sad laser beam of multiple wavelengths.
Claim 9
Dependent Claim
39 words
A method as in claim 5, wherein said step of providing means for producing a laser beam of multiple wavelengths comprises the step of providing a single laser producing a laser beam with radiations of at least two wavelengths.
Claim 10
Dependent Claim
23 words
A method as in claim 5, wherein said surface is the surface of a semiconductor wafer on which is formed a thin film.
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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) | 1995-07-28 | 1996-01-27 | 1996-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-28 | 2000-01-27 | 2000-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-28 | 2004-01-27 | 2004-07-28 | $7700.00 | Window Closed / Lapsed |