US4645929A
Expired / Lapsed
US
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Method and apparatus for the compensation of charges in secondary ion mass spectrometry (SIMS) of specimens exhibiting poor electrical conductivity
Assignee: Siemens AG
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Filing: 1985-01-31
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Granted: 1987-02-24
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Expires: 2005-01-31
Abstract
Abstract A method and an apparatus are provided for the compensation of charges in the secondary ion mass spectrometry of specimens exhibiting poor electrical conductivity. A scanning ion gun and an electron gun allow secondary ion mass spectra specimens exhibiting poor electrical conductivity to be registered under better-defined conditions than heretofore possible. The electron beam of the electron gun is focused to approximately the same diameter as the ion beam and impinges approximately the same point on the surface of the specimen as the ion beam.
Inventors
- 👤 Rolf V. Criegern
- 👤 Ingo Weitzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:34
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/252; H01J37/256; H01J37/02; H01J37/026
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
62 words
A method of compensating charges in secondary ion mass spectrometry, comprising the steps of: focusing an ion beam and an electron beam to approximately the same diameter; directing the ion beam and the electron beam to approximately the same point on a surface of a specimen; and scanning the ion beam and the electron beam synchronously over an area of the specimen.
Claim 2
Independent Claim
62 words
A method of compensating charges in secondary ion mass spectrometry, comprising the steps of: focusing an ion beam and an electron beam to approximately the same diameter; directing the ion beam and the electron beam to approximately the same point on a surface of a specimen; and scanning the ion beam and the electron beam synchronously over an area of the specimen.
Claim 3
Dependent Claim
29 words
The method of claim 1, wherein the step of scanning is further defined as: controlling the ion beam and the electron beam with a scan generator in common thereto.
Claim 4
Dependent Claim
31 words
The method of claim 3, wherein the step of controlling is further defined as: controlling congruent scanning by generating and applying to respective deflection systems for the beams respective deflection voltages.
Claim 5
Dependent Claim
55 words
The method of claim 3, wherein the step of controlling is further defined as: generating ion beam deflection voltages and applying the same to a deflection system for the ion beam; and generating and superposing d.c. voltages on the ion beam deflection voltages and applying the same to a deflection system for the electron beam.
Claim 6
Dependent Claim
50 words
The method of claim 3, wherein the step of controlling is further defined as: generating ion beam deflection voltages and applying the same to a deflection system for the ion beam; and amplifying the ion beam deflection voltages and applying the same to a deflection system for the electron beam.
Claim 7
Dependent Claim
50 words
The method of claim 4, wherein the step of controlling is further defined as: generating ion beam deflection voltages and applying the same to a deflection system for the ion beam; and attenuating the ion beam deflection voltages and applying the same to a deflection system for the electron beam.
Claim 8
Dependent Claim
78 words
Apparatus for compensating charges in secondary ion mass spectrometry, comprising: an ion gun generating an ion beam focused to a predetermined diameter; an electron gun generating an electron beam focused to approximately the predetermined diameter; an ion beam deflection system; an electron beam deflection system; and scan means connected to said ion beam deflection system and to said electron beam deflection system and operable to cause synchronous common scanning of said beams over a surface of a specimen.
Claim 9
Dependent Claim
78 words
Apparatus for compensating charges in secondary ion mass spectrometry, comprising: an ion gun generating an ion beam focused to a predetermined diameter; an electron gun generating an electron beam focused to approximately the predetermined diameter; an ion beam deflection system; an electron beam deflection system; and scan means connected to said ion beam deflection system and to said electron beam deflection system and operable to cause synchronous common scanning of said beams over a surface of a specimen.
Claim 10
Dependent Claim
39 words
The apparatus of claim 7, wherein said scan means comprises: a scan generator operable to produce deflection voltages for one of said deflection systems; and modifying means for modifying the deflection voltages for the other of said deflection systems.
Claim 11
Dependent Claim
20 words
The apparatus of claim 8, wherein said modifying means comprises: superposition means for superimposing d.c. voltages on said deflection voltages.
Claim 12
Dependent Claim
16 words
The apparatus of claim 8, wherein said modifying means comprises: means for amplifying said deflection voltages.
Claim 13
Dependent Claim
16 words
The apparatus of claim 9, wherein said modifying means comprises: means for attenuating said deflection voltages.
Claim 14
Dependent Claim
73 words
The apparatus of claim 8, wherein each of said deflection systems comprises an x-y deflection system and wherein said modifying means comprises: means for amplifying the deflection voltages with an amplification factor such that the deflection voltage for one deflection direction is modified in response to the actual generated deflection voltage for the other deflection direction to compensate for the different viewing directions of both guns relative to the surface of the specimen.
Claim 15
Dependent Claim
73 words
The apparatus of claim 8, wherein each of said deflection system comprises an x-y deflection system and wherein said modifying means comprises: means for attenuating the deflection voltages with an attenuation factor such that the deflection voltage for one deflection direction is modified in response to the actual generated deflection voltage for the other deflection direction to compensate for the different viewing directions of both guns relative to the surface of the specimen.
Claim 16
Dependent Claim
46 words
The apparatus of claim 7, and further comprising: electronic means responsive to the sample current flowing to ground for rapid regulation of the electron beam on each subarea of the sputter crater during the scan of both coinciding beams for reducing the sample current to zero.
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) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |