Patent US3927320A successfully refreshed from Google Patents.
US3927320A
Expired / Lapsed
US
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Method and apparatus for deriving from a scanning electron microscope signals that can be displayed stereoscopically
Assignee: Ortech Corp
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Filing: 1974-08-02
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Granted: 1975-12-16
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Expires: 1994-08-02
Abstract
Abstract A scanning electron microscope having line deflection coils ahead of its final aperture is modified by the addition of an ALD (after lens deflection) coil. Rectangular waveforms are supplied to these coils with the polarities of the waveforms being reversed in a predetermined fashion dependent upon the scanning sequence, thus enabling a given area on the object being scanned to be ''''seen'''' from two different angles. The derived signals may be supplied to a colour television receiver or monitor along with appropriate switching signals to enable the image of the object to be shown stereoscopically.
Inventors
- 👤 Eric John Chatfield
- 👤 Verner Henrick Nielsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:05
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/26; H01J37/28; H01J37/02; H01J37/04; H01J37/147; H01J37/1478; H01J37/15
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
591 words
In a scanning electron microscope of the type having an electron gun for producing an electron beam, a final aperture through which at least a part of said electron beam passes prior to impingement on an object being scanned by said electron beam, a longitudinal axis extending from said electron gun through said final aperture and through the object being scanned by said electron beam, and an electron beam deflecting system for scanning said electron beam across the object being scanned in adjacent parallel lines, said electron beam deflecting system including a plurality of electron beam line deflection devices and means for supplying a scanning waveform to at least one of said electron beam line deflection devices to scan said electron beam in a line across the object being scanned by said electron beam, said plurality of electron beam line deflection devices including at least two electron beam line deflection devices located between said electron gun and said final aperture and a third electron beam line deflection device located between said final aperture and the object being scanned by said electron beam; the improvement comprising apparatus for enabling said scanning electron microscope to generate signals that enable an image of the object being scanned by said electron beam to be viewed in three dimensions, said apparatus comprising means for supplying to at least two of said electron beam line deflection devices located between said electron gun and said final aperture a waveform which (a) during the scanning of a firsT set of said lines, and in addition to any deflection of said electron beam caused by said scanning waveform, creates a field which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a first path firstly away from said longitudinal axis and to one side of said longitudinal axis and lastly towards said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on the opposite side thereof and (b) during the scanning of a second set of said lines, and in addition to any deflection of said electron beam caused by said scanning waveform, creates a field which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a second path firstly away from said longitudinal axis and to said opposite side thereof and lastly towards said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on said one side thereof, and means for supplying to said third electron beam line deflection device an electron beam deflecting waveform, said electron beam deflecting waveform being applied to said third electron beam deflection device during the scanning of said respective sets of lines and deflecting said electron beam in addition to any deflection thereof caused by said scanning waveform, the nature of said electron beam deflecting waveform being such that said electron beam deflecting waveform creates a field which, when acting on an electron beam travelling in the portions of said first and second paths that are beyond said final aperture, deflects an electron beam travelling in the portions of said first and second paths respectively that are beyond said final aperture back towards said longitudinal axis to intersect said longitudinal axis at the object being scanned by said electron beam from both said one and said opposite sides thereof.
Claim 2
Dependent Claim
591 words
In a scanning electron microscope of the type having an electron gun for producing an electron beam, a final aperture through which at least a part of said electron beam passes prior to impingement on an object being scanned by said electron beam, a longitudinal axis extending from said electron gun through said final aperture and through the object being scanned by said electron beam, and an electron beam deflecting system for scanning said electron beam across the object being scanned in adjacent parallel lines, said electron beam deflecting system including a plurality of electron beam line deflection devices and means for supplying a scanning waveform to at least one of said electron beam line deflection devices to scan said electron beam in a line across the object being scanned by said electron beam, said plurality of electron beam line deflection devices including at least two electron beam line deflection devices located between said electron gun and said final aperture and a third electron beam line deflection device located between said final aperture and the object being scanned by said electron beam; the improvement comprising apparatus for enabling said scanning electron microscope to generate signals that enable an image of the object being scanned by said electron beam to be viewed in three dimensions, said apparatus comprising means for supplying to at least two of said electron beam line deflection devices located between said electron gun and said final aperture a waveform which (a) during the scanning of a firsT set of said lines, and in addition to any deflection of said electron beam caused by said scanning waveform, creates a field which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a first path firstly away from said longitudinal axis and to one side of said longitudinal axis and lastly towards said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on the opposite side thereof and (b) during the scanning of a second set of said lines, and in addition to any deflection of said electron beam caused by said scanning waveform, creates a field which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a second path firstly away from said longitudinal axis and to said opposite side thereof and lastly towards said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on said one side thereof, and means for supplying to said third electron beam line deflection device an electron beam deflecting waveform, said electron beam deflecting waveform being applied to said third electron beam deflection device during the scanning of said respective sets of lines and deflecting said electron beam in addition to any deflection thereof caused by said scanning waveform, the nature of said electron beam deflecting waveform being such that said electron beam deflecting waveform creates a field which, when acting on an electron beam travelling in the portions of said first and second paths that are beyond said final aperture, deflects an electron beam travelling in the portions of said first and second paths respectively that are beyond said final aperture back towards said longitudinal axis to intersect said longitudinal axis at the object being scanned by said electron beam from both said one and said opposite sides thereof.
Claim 3
Dependent Claim
24 words
The invention according to claim 1 wherein said scanning electron microscope employs interlaced scanning and said first and second sets of lines are interlaced.
Claim 4
Dependent Claim
35 words
The invention according to claim 1 wherein said electron beam is scanned across the object following each adjacent line in sequence and said first and second sets of lines are the same sets of lines.
Claim 5
Dependent Claim
80 words
The invention according to claim 1 wherein said scanning electron microscope includes a final electromagnetic lens, said third electron beam line deflection device also being located between said final electromagnetic lens and the object being scanned by said electron beam, and means for rotating the electron beam deflecting field of said third electron beam line deflection device relative to the electron beam deflecting fields of said electron beam line deflection devices located between said electron gun and said final aperture.
Claim 6
Dependent Claim
48 words
The invention according to claim 1 wherein said scanning waveform is a sawtooth waveform, said means for supplying said scanning waveform to at least one of said electron beam line deflection devices comprising means for supplying said scanning waveform to at least two electron beam line deflection devices.
Claim 7
Dependent Claim
49 words
The invention according to claim 1 wherein said scanning waveform is a sawtooth waveform, said means for supplying said scanning waveform to at least one of said electron beam line deflection devices comprising means for supplying said scanning waveform to at least said third electron beam line deflection device.
Claim 8
Dependent Claim
50 words
The invention according to claim 1 wherein said scanning waveform is a sawtooth waveform, said means for supplying said scanning waveform to at least one of said electron beam line deflection devices comprising means for supplying said scanning waveform to said two and said third electron beam line deflection devices.
Claim 9
Dependent Claim
21 words
The invention according to claim 1 wherein said electron beaM line deflection devices comprise electromagnetic devices for deflecting said electron beam.
Claim 10
Dependent Claim
38 words
The invention according to claim 1 wherein said supplying means comprise a rectangular waveform generator and means connecting said rectangular waveform generator to supply a rectangular waveform to said two and said third electron beam line deflection devices.
Claim 11
Dependent Claim
24 words
The invention according to claim 9 wherein said scanning electron microscope employs interlaced scanning and said first and second sets of lines are interlaced.
Claim 12
Dependent Claim
49 words
The invention according to claim 10 wherein said scanning waveform is a sawtooth waveform, said means for supplying said scanning waveform to at least one of said electron beam line deflection devices comprising means for supplying said scanning waveform to at least said two electron beam line deflection devices.
Claim 13
Dependent Claim
72 words
The invention according to claim 11 wherein said scanning electron microscope includes a final electromagnetic lens, said third electron beam line deflection device also being located between said final electromagnetic lens and the object being scanned by said electron beam, and means for rotating the electron beam deflecting field of said third electron beam line deflection device relative to the electron beam deflecting fields of said two electron beam line deflection devices.
Claim 14
Dependent Claim
21 words
The invention according to claim 12 wherein said electron beam line deflection devices comprise electromagnetic devices for deflecting said electron beam.
Claim 15
Dependent Claim
35 words
The invention according to claim 12 wherein said third electron beam line deflection device is the only electron beam line deflection device between said final aperture and the object being scanned by said electron beam.
Claim 16
Dependent Claim
35 words
The invention according to claim 1 wherein said third electron beam line deflection device is the only electron beam line deflection device between said final aperture and the object being scanned by said electron beam.
Claim 17
Independent Claim
416 words
A method for operating a scanning electron microscope of the type having an electron gun, a final aperture through which at least a part of said beam passes prior to impingement on an object being scanned by said electron beam and a longitudinal axis extending from said electron gun through said final aperture and through the object being scanned by said electron beam to enable said scanning electron microscope to generate signals that enable an image of the object being scanned by said electron beam to be viewed in three dimensions, said method comprising: (a) scanning said electron beam across the object being scanned in adjacent parallel lines, (b) between said electron gun and said final aperture and in addition to any deflection of said electron beam by said scanning (i) providing a field during the scanning of a first set of said lines which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a first path firstly away from said longitudinal axis and to one side of said longitudinal axis and lastly towards said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on the opposite side thereof and (ii) providing a field during the scanning of a second set of said lines which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a second path firstly away from said longitudinal axis and to said opposite side thereof and lastly toward said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on said one side thereof, and (c) between said final aperture and the object being scanned by said electron beam, and in addition to any deflection of said electron beam by said scanning, during said scanning of said respective sets of lines providing fields which are of such a nature that, when acting upon electron beams travelling in the portions of said first and second paths that are beyond said final aperture, deflect electron beams travelling in the portions of said first and second paths respectively that are beyond said final aperture back towards said longitudinal axis to intersect said longitudinal axis at the object being scanned by said electron beam from both said one and said opposite sides thereof.
Claim 18
Independent Claim
416 words
A method for operating a scanning electron microscope of the type having an electron gun, a final aperture through which at least a part of said beam passes prior to impingement on an object being scanned by said electron beam and a longitudinal axis extending from said electron gun through said final aperture and through the object being scanned by said electron beam to enable said scanning electron microscope to generate signals that enable an image of the object being scanned by said electron beam to be viewed in three dimensions, said method comprising: (a) scanning said electron beam across the object being scanned in adjacent parallel lines, (b) between said electron gun and said final aperture and in addition to any deflection of said electron beam by said scanning (i) providing a field during the scanning of a first set of said lines which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a first path firstly away from said longitudinal axis and to one side of said longitudinal axis and lastly towards said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on the opposite side thereof and (ii) providing a field during the scanning of a second set of said lines which deflects an electron beam that is travelling from said electron gun through said final aperture on said longitudinal axis in a second path firstly away from said longitudinal axis and to said opposite side thereof and lastly toward said longitudinal axis to intersect said longitudinal axis in the immediate vicinity of said final aperture and then to proceed away from said longitudinal axis but on said one side thereof, and (c) between said final aperture and the object being scanned by said electron beam, and in addition to any deflection of said electron beam by said scanning, during said scanning of said respective sets of lines providing fields which are of such a nature that, when acting upon electron beams travelling in the portions of said first and second paths that are beyond said final aperture, deflect electron beams travelling in the portions of said first and second paths respectively that are beyond said final aperture back towards said longitudinal axis to intersect said longitudinal axis at the object being scanned by said electron beam from both said one and said opposite sides thereof.
Claim 19
Dependent Claim
21 words
A method according to claim 16 wherein said scanning is interlaced and said first and second sets of lines are interlaced.
Claim 20
Dependent Claim
31 words
A method according to claim 16 wherein said scanning electron microscope includes at least one electron beam line deflection device and said scanning is accomplished by applying a sawtooth waveform thereto.
Claim 21
Dependent Claim
80 words
A method according to claim 16 wherein said scanning electron microscope includes a plurality of electron beam line deflection devices, at least a first and a second of said devices being located between said electron gun and said final aperture and a third of said devices being located between said final aperture and the object being scanned by said electron beam, said fields being provided by applying rectangular waveforms to said first, second and third electron beam line deflection devices.
Claim 22
Dependent Claim
28 words
A method according to claim 19 wherein said scanning is accomplished by applying a sawtooth waveform to at least said first and second electron beam line deflection devices.
Claim 23
Dependent Claim
43 words
A method according to claim 19 wherein said scanning is accomplished by applying a sawtooth waveform to at least said first and second electron beam line deflection devices by applying a sawtooth waveform to at least said third electron beam line deflection device.
Claim 24
Dependent Claim
44 words
A method according to claim 19 wherein said scanning is accomplished by applying a sawtooth waveform to at least said first and second electron beam line deflection devices by applying a sawtooth waveform to said first, second and third electron beam line deflection devices.
References Cited (Backward Citations)
US3657593A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |