Patent US3622741A successfully refreshed from Google Patents.
US3622741A
Expired / Lapsed
US
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Electron-beam-processing machine having means for deflecting impurities from the path of the electron beam
Assignee: Messer Griesheim GmbH
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Filing: 1970-08-05
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Granted: 1971-11-23
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Expires: 1990-08-05
Abstract
Abstract Apparatus in electron-beam-processing machines for keeping the path of the working beam free of impurities, the apparatus having a screening device associated with the working beam for catching impurities, comprising an ionization device acting in the region of the working beam path, and a deflecting device effective in the region of the said beam path to produce a deflecting field for electrically charged particles, the ionization device being so formed that it acts with an ionization probability greater than that of the working beam on atom-sized or larger particles, the deflecting device exerting a sufficient deflecting action on such electrically charged particles, which move at substantially thermal speeds as to remove these particles from the path of the working beam.
Inventors
- 👤 Karl-Heinz Steigerwald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:52
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J29/00; H01J29/84
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
84 words
In electron-beam-processing machines apparatus for keeping the path of the working beam free of impurities, comprising a screening device associated with said working beam for catching impurities, an ionization device acting in the region of the said beam path to produce an ionization probability greater than that of said working beam on particles of impurity therein, and a deflecting device producing a deflecting field for said ionized particles, effective in the region of said working beam to remove said particles from said beam path.
Claim 2
Dependent Claim
84 words
In electron-beam-processing machines apparatus for keeping the path of the working beam free of impurities, comprising a screening device associated with said working beam for catching impurities, an ionization device acting in the region of the said beam path to produce an ionization probability greater than that of said working beam on particles of impurity therein, and a deflecting device producing a deflecting field for said ionized particles, effective in the region of said working beam to remove said particles from said beam path.
Claim 3
Dependent Claim
27 words
Apparatus as recited in claim 1, wherein said deflecting device produces a deflecting field transverse of said beam path along at least a proportion of said path.
Claim 4
Dependent Claim
27 words
Apparatus as recited in claim 1 wherein said ionization device is arranged in an end region of said deflecting device remote from the source of said beam.
Claim 5
Dependent Claim
24 words
Apparatus as recited in claim 2 comprising a plurality of deflecting devices acting over a part of said beam path on said ionized particles.
Claim 6
Dependent Claim
21 words
Apparatus as recited in claim 4, comprising at least two deflecting devices acting on said ionized particles with opposite deflecting actions.
Claim 7
Dependent Claim
18 words
Apparatus as recited in claim 4, comprising a plurality of ionization devices spread out along said beam path.
Claim 8
Dependent Claim
17 words
Apparatus as recited in claim 6, with at least one ionization device associated with each deflecting device.
Claim 9
Dependent Claim
14 words
Apparatus as recited in claim 4, comprising a screen between individual adjacent deflecting devices.
Claim 10
Dependent Claim
28 words
Apparatus as recited in claim 1, wherein said deflecting device comprises electrostatically acting deflecting electrodes arranged along said beam path, said electrodes having means ensuring easy replacement thereof.
Claim 11
Dependent Claim
28 words
Apparatus as recited in claim 1, wherein said ionization device comprises an auxiliary electron source, which produces electrons of lower energy than the electrons in said working beam.
Claim 12
Dependent Claim
16 words
Apparatus as recited in claim 10, comprising an acceleration system for each said auxiliary electron source.
Claim 13
Dependent Claim
27 words
Apparatus as recited in claim 10, comprising a focusing device for each auxiliary electron source, said focusing device producing linear focusing of electrons from said auxiliary source.
Claim 14
Dependent Claim
22 words
Apparatus as recited in claim 1, comprising a glow discharge space in said ionization device for ionization of said particles of impurities.
Claim 15
Dependent Claim
23 words
Apparatus as recited in claim 1, comprising a high-current arc discharge space in said ionization device for ionization of said particles of impurities.
Claim 16
Dependent Claim
35 words
Apparatus as recited in claim 14, comprising an auxiliary electrode provided with a small aperture, said high-current discharge space extending between the impact region of the working beam on the workpiece and said auxiliary electrode.
Claim 17
Dependent Claim
23 words
Apparatus as recited in claim 10, wherein said auxiliary electron source is provided with an auxiliary cathode extending parallel to said working beam.
Claim 18
Dependent Claim
24 words
Apparatus as recited in claim 16, comprising a grid surrounding said auxiliary cathode and an envelope electrode surrounding said working beam and said grid.
Claim 19
Dependent Claim
114 words
Apparatus as recited in claim 17 comprising a grid surrounding said electron source which is at a positive potential relative thereto and an envelope electrode surrounding said grid And at a negative potential relative to said electron source, said potentials and the spacings of said grid causing electrons emitted by said electron source to be concentrated in the space between said grid and said envelope electrode and to execute oscillatory movement therein to produce relatively heavy negative and positive particles by ionization of impurities, said negative particles concentrating at said grid and said positive particles concentrating at said envelope electrode, said particles being at least in part, deposited on said grid and said electrode.
Claim 20
Dependent Claim
78 words
Apparatus as recited in claim 9, wherein said ionization device comprises an auxiliary electron source which produces electrons of lower energy than the electrons in said working beam, the apparatus further comprising at least two deflecting electrodes provided on opposite sides of said working beam said electrodes being charged to different electric potentials, said auxiliary electron source being so positioned that auxiliary electrons generated thereby to produce ionization are accelerated in the electric field between said deflecting electrodes.
Claim 21
Dependent Claim
33 words
Apparatus as recited in claim 9, wherein said ionization device comprises an auxiliary electron source and a negative deflecting electrode associated therewith, said electrode defining an aperture near which said source is located.
Claim 22
Dependent Claim
50 words
Apparatus as recited in claim 19, comprising a plurality of auxiliary electron sources and deflecting electrodes arranged around part of the circumference of said working beam, said electrodes connected to substantially the same potential, and at least one relatively positive deflecting electrode occupying at least part of the remaining circumference.
Claim 23
Dependent Claim
31 words
Apparatus as recited in claim 10, wherein said auxiliary electron source is so formed that the low-energy electrons therefrom move in the region of said working beam and substantially parallel thereto.
Claim 24
Dependent Claim
60 words
Apparatus as recited in claim 22, wherein said auxiliary electron source is provided with an auxiliary cathode at least partly surrounding the path of said working beam and an annular auxiliary anode offset with respect thereto along the direction of said working beam, said auxiliary anode accelerating the electrons emitted by said auxiliary cathode substantially parallel to said working beam.
Claim 25
Dependent Claim
35 words
Apparatus as recited in claim 23, comprising at least one deflecting device in an axial region of said working beam on the side of said auxiliary electron source remote from said workpiece to be processed.
Claim 26
Dependent Claim
39 words
Apparatus as recited in claim 23, comprising a focusing device for said auxiliary electron source, wherein said focusing device is so formed that it concentrates said electrons into a substantially cylindrical space extending substantially coaxial to said working beam.
Claim 27
Dependent Claim
33 words
Apparatus as recited in claim 10, comprising a magnetic device which in the ionization region of said apparatus extends the tracks of said electrons supplied by said auxiliary electron device by curvature thereof.
Claim 28
Dependent Claim
39 words
Apparatus as recited in claim 26, comprising a working beam magnetic focusing device, wherein said auxiliary electron source is so arranged that said magnetic focusing device also acts to curve the tracks of electrons emitted by said ionization device.
Claim 29
Dependent Claim
27 words
Apparatus as recited in claim 1, wherein the acceleration path of the electrons in said working beam lies outside of the working region of said deflecting device.
Claim 30
Dependent Claim
18 words
Apparatus as recited in claim 1, wherein said screening device is provided with at least one replaceable screen.
References Cited (Backward Citations)
US3005859A
Cited
US3156811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |