US5563418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broad beam ion implanter
Assignee: University of California
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Filing: 1995-02-17
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Granted: 1996-10-08
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Expires: 2015-02-17
Abstract
Abstract An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.
Inventors
- 👤 Ka-Ngo Leung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:23
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/3002; H01J37/3007; H01J2237/00; H01J2237/06; H01J2237/083; H01J2237/30; H01J2237/317; H01J2237/31701
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
93 words
An apparatus for ion implantation comprising, a) an ion source having an exit aperture; b) an anode located at the ion source exit aperture; c) a plasma boundary shaping element which forms a plasma boundary which is convex in two orthogonal directions located in the exit aperture; d) an extraction electrode, located downstream from the anode; e) an ion beam divergence-limiting electrode located downstream from the extraction electrode; f) an ion acceleration electrode located downstream from the divergence-limiting electrode; g) means to connect one or more voltage sources to the anode and electrodes.
Claim 2
Independent Claim
93 words
An apparatus for ion implantation comprising, a) an ion source having an exit aperture; b) an anode located at the ion source exit aperture; c) a plasma boundary shaping element which forms a plasma boundary which is convex in two orthogonal directions located in the exit aperture; d) an extraction electrode, located downstream from the anode; e) an ion beam divergence-limiting electrode located downstream from the extraction electrode; f) an ion acceleration electrode located downstream from the divergence-limiting electrode; g) means to connect one or more voltage sources to the anode and electrodes.
Claim 3
Dependent Claim
62 words
The apparatus of claim 1 wherein a) the anode potential is between about 30 kV and about 50 kV relative to the acceleration electrode; b) the extraction electrode potential is between about 20 kV and about 32 kV relative to the acceleration electrode; c) the divergence-limiting electrode potential is between about 16 kV and about 30 kV relative to the acceleration electrode.
Claim 4
Dependent Claim
47 words
The apparatus of claim 2 wherein a) the anode potential is about 40 kV relative to the acceleration electrode; b) the extraction electrode potential is about 26 kV relative to the acceleration electrode; c) the divergence-limiting electrode potential is about 23 kV relative to the acceleration electrode.
Claim 5
Dependent Claim
22 words
The apparatus of claim 1 wherein the plasma shaping element is an electric field from the voltage applied to the extraction electrode.
Claim 6
Dependent Claim
23 words
The apparatus of claim 4 wherein the extraction electrode has a voltage sufficient to create a convex plasma boundary at the exit aperture.
Claim 7
Dependent Claim
15 words
The apparatus of claim 1 wherein the plasma boundary shaping element is a conducting screen.
Claim 8
Dependent Claim
18 words
The apparatus of claim 6 wherein the conducting screen comprises molybdenum, tantalum, stainless steel, graphite, or alloys thereof.
Claim 9
Dependent Claim
16 words
The apparatus of claim 6 wherein the screen transparency is between about 50% and about 95%.
Claim 10
Dependent Claim
16 words
The apparatus of claim 8 wherein the screen transparency is between about 65% and about 85%.
Claim 11
Dependent Claim
12 words
The apparatus of claim 9 wherein the screen transparency is about 75%.
Claim 12
Dependent Claim
18 words
The apparatus of claim 1 further comprising a diffuse gas located at the surface of an implant target.
Claim 13
Dependent Claim
27 words
The apparatus of claim 11 wherein the diffuse gas has a density of between 2×10 13 particles per cubic centimeter and 6×10 13 particles per cubic centimeter.
Claim 14
Dependent Claim
19 words
The apparatus of claim 11 wherein the diffuse gas is the same gas ionized in the ion source volume.
Claim 15
Dependent Claim
20 words
The apparatus of claim 1 wherein a mass spectrometer filter is located between the extraction electrode and the divergence-limiting electrode.
Claim 16
Dependent Claim
21 words
The apparatus according to claim 1 additionally comprising a second ion acceleration electrode located down stream from the first acceleration electrode.
Claim 17
Independent Claim
97 words
A method for producing a large diameter ion beam comprising the steps of, a) applying an electric potential to an anode located at or near an ion source exit aperture; b) applying an electric potential to an extraction electrode; c) shaping the plasma boundary at the exit aperture to be convex with respect to the extraction electrode; d) applying an electric potential to a divergence-limiting electrode sufficient to convert a diverging ion beam to an essentially parallel ion beam; e) applying an electric potential to an acceleration electrode to adjust the desired energy of the ion beam.
Claim 18
Independent Claim
97 words
A method for producing a large diameter ion beam comprising the steps of, a) applying an electric potential to an anode located at or near an ion source exit aperture; b) applying an electric potential to an extraction electrode; c) shaping the plasma boundary at the exit aperture to be convex with respect to the extraction electrode; d) applying an electric potential to a divergence-limiting electrode sufficient to convert a diverging ion beam to an essentially parallel ion beam; e) applying an electric potential to an acceleration electrode to adjust the desired energy of the ion beam.
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) | 1999-10-08 | 2000-04-08 | 2000-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-08 | 2004-04-08 | 2004-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-08 | 2008-04-08 | 2008-10-08 | $7700.00 | Window Closed / Lapsed |