US5034611A
Expired / Lapsed
US
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Method for non-destructive identification for electronic inhomogeneities in semiconductor layers
Assignee: Siemens AG
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Filing: 1990-07-10
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Granted: 1991-07-23
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Expires: 2010-07-10
Abstract
Abstract A semiconductor layer is irradiated with an intensity-modulated laser emission to induce a modulated optical reflectivity which is a valid measure for the density of the electronic inhomogeneities in the semiconductor layer. The use of a test laser beam having a wavelength in a range of 200-345 nm makes exact measurements possible in the entire range of application and is particularly enabling for identification of low and high implantation doses and the identification of residual damage in crystalline semiconductor layers.
Inventors
- 👤 Peter Alpern
- 👤 Dominique Savignac
- 👤 Stefan Wurm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:54
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/9501; G01N21/17; G01N21/1717; G01N21/55; G01N21/9505
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
95 words
A method for non-destructive identification of electronic inhomogeneities of a semiconductor layer, comprising the steps of: irradiating a semiconductor layer with an intensity-modulated laser emission; directing a second laser emission onto the semiconductor layer for reflection, said second laser emission having a wavelength differing from a wavelength of said intensity-modulated laser emission, said second laser emission having a wavelength of approximately 200 through 345 nm; and measuring a modulated optical reflectivity of the semiconductor layer which is induced in said second laser emission as a measure of density of electronic inhomogeneities in the semiconductor layer.
Claim 2
Independent Claim
95 words
A method for non-destructive identification of electronic inhomogeneities of a semiconductor layer, comprising the steps of: irradiating a semiconductor layer with an intensity-modulated laser emission; directing a second laser emission onto the semiconductor layer for reflection, said second laser emission having a wavelength differing from a wavelength of said intensity-modulated laser emission, said second laser emission having a wavelength of approximately 200 through 345 nm; and measuring a modulated optical reflectivity of the semiconductor layer which is induced in said second laser emission as a measure of density of electronic inhomogeneities in the semiconductor layer.
Claim 3
Dependent Claim
40 words
A method as claimed in claim 1, further comprising the steps of: focusing said second laser emission so that a test spot having a diameter of 0.5 through 5 micrometers arises on the semiconductor layer for implementing topically resolved measurements.
Claim 4
Dependent Claim
23 words
A method as claimed in claim 1, wherein said modulated optical reflectivity is used to identify an implantation dose in the semiconductor layer.
Claim 5
Dependent Claim
15 words
A method as claimed in claim 3, wherein said semiconductor layer is a silicon layer.
Claim 6
Dependent Claim
23 words
A method as claimed in claim 1, wherein said modulated optical reflectivity is used to identify residual damage in a crystalline semiconductor layer.
Claim 7
Dependent Claim
17 words
A method as claimed in claim 5, wherein said crystalline semiconductor layer is a crystalline silicon layer.
Claim 8
Independent Claim
91 words
A method for non-destructive identification of electronic inhomogeneities in a semiconductor layer, comprising the steps of: directing a modulated laser emission of a first wavelength onto a surface of a semiconductor layer; directing a laser emission of a second wavelength in the range of approximately 200-345 nm onto the surface of the semiconductor layer at the same location as impinged by the modulated laser emission; and measuring the modulated optical reflectivity of the laser emission of the second wavelength to determine the density of the electronic inhomogeneities in the semiconductor layer.
Claim 9
Independent Claim
91 words
A method for non-destructive identification of electronic inhomogeneities in a semiconductor layer, comprising the steps of: directing a modulated laser emission of a first wavelength onto a surface of a semiconductor layer; directing a laser emission of a second wavelength in the range of approximately 200-345 nm onto the surface of the semiconductor layer at the same location as impinged by the modulated laser emission; and measuring the modulated optical reflectivity of the laser emission of the second wavelength to determine the density of the electronic inhomogeneities in the semiconductor layer.
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) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |