Patent US3842272A successfully refreshed from Google Patents.
US3842272A
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Scanning charged particle microprobe with external spurious electric field effect correction
Assignee: American Optical Corp
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Filing: 1973-07-24
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Granted: 1974-10-15
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Expires: 1993-07-24
Abstract
Abstract This invention relates to a scanning charged-particle microscope system, such as a scanning electron microscope system. More particularly, the invention relates to apparatus that is used in compensating for external interference with the charged particle beam.
Inventors
- 👤 V Coates
- 👤 L Welter
- 👤 J Gold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:15
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/09; H01J37/24; H01J37/26; H01J37/28
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
174 words
In a scanning charged particle microprobe system including a source of charged particles, means for collimating said particles into a beam, means for scanning said beam in a predetermined raster over a specimen in said microprobe system, detector means including means for generating a signal proportional to charged particles detected and recording means connected to said detector means to record detection of charged particles exiting the surface of said specimen, the improvement of a waveform function generator to correct the effects of external spurious electric fields which cause unwanted deflection of the beam, comprising; means to determine said spurious beam deflection at predetermined beam positions, means for generating beam scan correction signals complementary to said spurious beam deflection, means for applying said beam correction signals to said means for scanning said beam whereby said spurious beam scanning distortion deflection may be detected and a function correction to eliminate said distortion may be generated and applied to said scanning means to cause said beam to track over said specimen in substantially said predetermined raster pattern.
Claim 2
Dependent Claim
174 words
In a scanning charged particle microprobe system including a source of charged particles, means for collimating said particles into a beam, means for scanning said beam in a predetermined raster over a specimen in said microprobe system, detector means including means for generating a signal proportional to charged particles detected and recording means connected to said detector means to record detection of charged particles exiting the surface of said specimen, the improvement of a waveform function generator to correct the effects of external spurious electric fields which cause unwanted deflection of the beam, comprising; means to determine said spurious beam deflection at predetermined beam positions, means for generating beam scan correction signals complementary to said spurious beam deflection, means for applying said beam correction signals to said means for scanning said beam whereby said spurious beam scanning distortion deflection may be detected and a function correction to eliminate said distortion may be generated and applied to said scanning means to cause said beam to track over said specimen in substantially said predetermined raster pattern.
Claim 3
Dependent Claim
70 words
The improvement according to claim 1 wherein said means for scanning said beam includes means for deflecting said beam in substantially orthogonal directions and said means for generating a beam scan correction signal includes means for generating a deflection correction signal in at least one of said directions substantially equal and opposite said spurious beaM deflection and means for superimposing said correction signal upon said means for deflecting said beam.
Claim 4
Dependent Claim
38 words
The improvement according to claim 2 wherein said means for generating a beam correction signal includes a means for identifying segments of said beam scan and means for generating a beam correcting signal for each segment of scan.
Claim 5
Dependent Claim
26 words
The improvement according to claim 3 wherein said means for applying said correction signals includes means for storing said correction signals for each segment of scan.
Claim 6
Dependent Claim
28 words
The improvement according to claim 4 wherein said means to apply said correction signals includes means to selectively apply said stored correction signals according to a predetermined sequence.
Claim 7
Dependent Claim
25 words
The improvement according to claim 5 wherein said recording means is a scanned display device the scan of which is synchronized with said beam deflection.
Claim 8
Dependent Claim
16 words
The improvement according to claim 6 wherein said scanned display device is a cathode ray tube.
Claim 9
Dependent Claim
33 words
The improvement according to claim 7 wherein said beam scan and said cathode ray scan are in a raster pattern of a plurality of horizontally disposed sweep lines arranged in a vertical array.
Claim 10
Dependent Claim
63 words
The improvement according to claim 8 includes means for dividing said array into a plurality of scan groups and means for generating a beam correction signal for each of the orthogonal directions of said beam deflection for substantially all of said scan groups and means for selectively applying said corrections to said beam deflection means as said beam is scanned through said groups.
Claim 11
Dependent Claim
26 words
The improvement according to claim 9 wherein said means for applying said correction signals is synchronized with said beam scanning means and said display device scan.
References Cited (Backward Citations)
US3549883A
Cited
US3678333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |