US4873434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scanning optical microscope using single laser beam
Assignee: BTG International Ltd
•
Filing: 1987-07-20
•
Granted: 1989-10-10
•
Expires: 2007-07-20
Abstract
Abstract A scanning optical microscope which comprises a source of optical radiation and means for focussing radiation from the source into an interrogating spot on a surface under examination. The spot is deflected about a point on the surface, and the surface topography is measured by measuring the amplitude and/or phase of the radiation reflected from the surface at the spot position.
Inventors
- 👤 Chung W. See
- 👤 Mehdi Vaez-Iravani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:38
CPC Classifications
G; G02; G02B; G02B21/00; G02B21/0004; G02B21/002; G01; G01B; G01B11/00; G01B11/30; G01B11/303
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
95 words
A scanning optical microscope comprising: a source of optical radiation; means for focussing a single beam of radiation from said source into an interrogating spot on a surface under examination; means for scanning said interrogating spot across said surface; deflecting means for providing an oscillatory deflection of said interrogating spot so as to move said interrogating spot sinusoidally across said surface as said interrogating spot is scanned across said surface; and means for measuring the amplitude variation of the radiation reflected from said surface upon impingement of radiation at said oscillatory deflected scanning interrogating spot.
Claim 2
Dependent Claim
95 words
A scanning optical microscope comprising: a source of optical radiation; means for focussing a single beam of radiation from said source into an interrogating spot on a surface under examination; means for scanning said interrogating spot across said surface; deflecting means for providing an oscillatory deflection of said interrogating spot so as to move said interrogating spot sinusoidally across said surface as said interrogating spot is scanned across said surface; and means for measuring the amplitude variation of the radiation reflected from said surface upon impingement of radiation at said oscillatory deflected scanning interrogating spot.
Claim 3
Dependent Claim
31 words
A scanning optical microscope as claimed in claim 1 wherein said deflecting means is adapted to oscillate the spot about a distance which is a fraction of one focal spot diameter.
Claim 4
Dependent Claim
19 words
A scanning optical microscope as claimed in claim 1 wherein the deflecting means is a standing-wave acousto-optic beam deflector.
Claim 5
Dependent Claim
17 words
A scanning optical microscope as claimed in claim 1 wherein the deflecting means is a Bragg cell.
Claim 6
Dependent Claim
32 words
A scanning optical microscope as claimed in claim 1 wherein said means for focussing radiation is adapted to produce a spot substantially larger than a period of the structure to be investigated.
Claim 7
Dependent Claim
21 words
A scanning optical microscope as claimed in claim 5 wherein the spot size is between 2 and 8 micrometers in diameter.
Claim 8
Dependent Claim
95 words
An optical scanning device, comprising: a source of optical radiation; means for focussing a single beam of radiation from said source into an interrogating spot on a surface under examination; means for scanning said interrogating spot across said surface; deflecting means for providing an oscillatory deflection of said interrogating spot so as to move said interrogating spot sinusoidally across said surface as said interrogating spot is scanned across said surface; and means for measuring the amplitude variation of the radiation reflected from said surface upon impingement of radiation at said oscillatory deflecting scanning interrogating spot.
Claim 9
Dependent Claim
95 words
An optical scanning device, comprising: a source of optical radiation; means for focussing a single beam of radiation from said source into an interrogating spot on a surface under examination; means for scanning said interrogating spot across said surface; deflecting means for providing an oscillatory deflection of said interrogating spot so as to move said interrogating spot sinusoidally across said surface as said interrogating spot is scanned across said surface; and means for measuring the amplitude variation of the radiation reflected from said surface upon impingement of radiation at said oscillatory deflecting scanning interrogating spot.
Claim 10
Dependent Claim
49 words
An optical scanning device as in claim 7 wherein radiation reflected from said surface causes an AC signal to be produced at a deflection frequency of said oscillatory deflection, the measuring means measuring variations in said AC signal so as to measure the amplitude variation of the reflected radiation.
Claim 11
Independent Claim
74 words
A method of investigating the topography of a surface, comprising the steps of: focussing a single beam of radiation into an interrogating spot on the surface; scanning said interrogating spot across said surface; deflecting said interrogating spot during said scanning step so that the interrogating spot moves sinusoidally over the surface during scanning; and measuring the amplitude variation of the radiation reflected from said surface upon impingement of said sinusoidally deflected scanning interrogating spot.
Claim 12
Independent Claim
74 words
A method of investigating the topography of a surface, comprising the steps of: focussing a single beam of radiation into an interrogating spot on the surface; scanning said interrogating spot across said surface; deflecting said interrogating spot during said scanning step so that the interrogating spot moves sinusoidally over the surface during scanning; and measuring the amplitude variation of the radiation reflected from said surface upon impingement of said sinusoidally deflected scanning interrogating spot.
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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |