Patent US4664769A successfully refreshed from Google Patents.
US4664769A
Expired / Lapsed
US
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Photoelectric enhanced plasma glow discharge system and method including radiation means
Assignee: International Business Machines Corp
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Filing: 1985-10-28
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Granted: 1987-05-12
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Expires: 2005-10-28
Abstract
Abstract Plasma enhancement is achieved in a plasma glow system by increasing the number of photoelectric electrons in the plasma glow by producing photoelectrons from the surface of a target in the system by the use of a radiation source. This is more particularly accomplished by flooding the surface of the target with a UV laser beam during the plasma process where emitted photoelectrons are injected into the plasma to increase the plasma density. The plasma enhancement is used in a sputter etching/deposition system which includes a chamber containing a cathode, a target, a substrate platform containing substrate and a pump. An ultraviolet light source such as a UV laser and focussing optics for focussing the UV radiation onto the target through a UV transmission window are also provided. A plasma region in the chamber is enhanced by photons from the laser striking the target and producing photoelectrons which are injected into the plasma to increase its density.
Inventors
- 👤 Jerome J. Cuomo
- 👤 Charles R. Guarnieri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:13
CPC Classifications
G; G21; G21B; G21B1/00; G21B1/11; G21B1/23; H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32321; Y; Y02; Y02E; Y02E30/00; Y02E30/10
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
57 words
In a plasma system of the type including a chamber containing plasma glow discharge, a means for adding electrons to said plasma to increase the intensity of said plasma glow discharge including a target, a source of photons directed onto said target for producing photoinduced photoelectrons which are emitted from said target and injected into said plasma.
Claim 2
Dependent Claim
57 words
In a plasma system of the type including a chamber containing plasma glow discharge, a means for adding electrons to said plasma to increase the intensity of said plasma glow discharge including a target, a source of photons directed onto said target for producing photoinduced photoelectrons which are emitted from said target and injected into said plasma.
Claim 3
Dependent Claim
36 words
A plasma system according to claim 1 wherein said system further includes a chamber containing said target, a substrate holder and substrates thereon subject to etching or deposition processing, and a sputtering gas in said chamber.
Claim 4
Dependent Claim
22 words
A plasma system according to claim 1 wherein said source of photons is a beam of electromagnetic radiation directed onto said target.
Claim 5
Dependent Claim
22 words
A plasma system according to claim 2 wherein said beam of electromagnetic radiation is an ultraviolet light source located within said chamber.
Claim 6
Dependent Claim
23 words
A plasma system according to claim 2 wherein said beam of electromagnetic radiation is an ultraviolet light source located external to said chamber.
Claim 7
Dependent Claim
17 words
A plasma system according to claim 3 wherein said ultraviolet light source is a continuous light source.
Claim 8
Dependent Claim
17 words
A plasma system according to claim 4 wherein said ultraviolet light source is a continuous light source.
Claim 9
Dependent Claim
17 words
A plasma system according to claim 3 wherein said ultraviolet light source is a pulsed light source.
Claim 10
Dependent Claim
17 words
A plasma system according to claim 4 wherein said ultraviolet light source is a pulsed light source.
Claim 11
Dependent Claim
15 words
A plasma system according to claim 6 wherein said ultraviolet light source is a laser.
Claim 12
Dependent Claim
37 words
A plasma system according to claim 2 wherein said beam of electromagnetic radiation is directed onto said target in a given image pattern, and wherein said photoelectrons are emitted from said target in a corresponding image pattern.
Claim 13
Independent Claim
73 words
A method for enhancing the intensity of a plasma glow in a chamber by adding electrons to said plasma glow comprising: the step of forming a plasm glow region in said chamber using a glow discharge diode structure including a cathode and a target, and the step of directing ultraviolet radiation onto said target to generate photoelectrons which are injected into said plasma glow region to enhance the plasma density of said glow.
Claim 14
Independent Claim
73 words
A method for enhancing the intensity of a plasma glow in a chamber by adding electrons to said plasma glow comprising: the step of forming a plasm glow region in said chamber using a glow discharge diode structure including a cathode and a target, and the step of directing ultraviolet radiation onto said target to generate photoelectrons which are injected into said plasma glow region to enhance the plasma density of said glow.
Claim 15
Dependent Claim
32 words
A method according to claim 12 wherein the step of directing ultraviolet radiation onto said target is carried out by directing a UV laser beam from a UV laser onto said target.
Claim 16
Dependent Claim
41 words
A method according to claim 12 wherein said chamber includes a specimen and said method includes the step of providing a sputtering gas in said chamber and said plasma glow functions to effect an etching or deposition process on said specimen.
Claim 17
Dependent Claim
22 words
A method according to claim 13 further including the step of forming said laser beam into a given pattern on said target.
Claim 18
Dependent Claim
30 words
A method according to claim 12 wherein the energy of said ultraviolet radiation is selected to be less than the work function of said target to provide non-linear multiphoton effects.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |