US4494069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical scanning method of testing material defects
Assignee: Individual
•
Filing: 1981-09-14
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Granted: 1985-01-15
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Expires: 2001-09-14
Abstract
Abstract A method of testing material defects utilizing photovoltaic effect. A detachable, transparent probe coated with either transparent metal or semiconductor is placed in contact with the material under test. The contact forms either a Schottky barrier or a p-n junction. A light spot scanning the material produces photo currents which is sensed. Defects cause a reduction in photo current.
Inventors
- 👤 Hung C. Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:36
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/265; G01R31/2656
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
58 words
A method of detecting defects in a material comprising the steps of placing an at least partially transparent probe on said material, said probe forming a potential barrier with said material, scanning a light spot over said probe, producing a photovoltaic effect where said light spot is incident, sensing said photovoltaic effect corresponding to said light spot position.
Claim 2
Independent Claim
58 words
A method of detecting defects in a material comprising the steps of placing an at least partially transparent probe on said material, said probe forming a potential barrier with said material, scanning a light spot over said probe, producing a photovoltaic effect where said light spot is incident, sensing said photovoltaic effect corresponding to said light spot position.
Claim 3
Dependent Claim
18 words
A method of detecting defects in a material as defined in claim 1, wherein said material in semiconductor.
Claim 4
Dependent Claim
27 words
A method of detecting defects in a material as defined in claim 1, wherein said probe is made of a transparent support coated with a thin film.
Claim 5
Dependent Claim
23 words
A method of detecting defects in a material as defined in claim 3, wherein said material is semiconductor, and said film is metal.
Claim 6
Dependent Claim
28 words
A method of detecting defects in material as defined in claim 4, wherein said semiconductor is p-type and said metal is of lower work function than said semiconductor.
Claim 7
Dependent Claim
28 words
A method of detecting defects in material as defined in claim 4, wherein said semiconductor is n-type and said metal is of higher work function than said semiconductor.
Claim 8
Dependent Claim
21 words
A method of detecting defects in material as defined in claim 2, wherein said probe is coated with a semiconductor film.
Claim 9
Dependent Claim
24 words
A method of detecting defects in material as defined in claim 7, wherein said film is of opposite conductivity type as said semiconductor material.
Claim 10
Dependent Claim
22 words
A method of detecting defects in material as defined in claim 3, wherein said material is metal and said film is semiconductor.
Claim 11
Dependent Claim
25 words
A method of detecting defects in material as defined in claim 3, wherein said probe is flexible and conforms with the surface of said material.
Claim 12
Dependent Claim
23 words
A method of detecting defects in material as defined in claim 3, wherein said material is semiconductor and said film is tin oxide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-15 | 1988-07-16 | 1989-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-15 | 1992-07-16 | 1993-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-15 | 1996-07-16 | 1997-01-15 | $7700.00 | Window Closed / Lapsed |