US4961958A
Expired / Lapsed
US
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Process for making diamond, and doped diamond films at low temperature
Assignee: CALIFORNIA 300 LAKESIDE DRIVE 22ND FLR OAKLAND CA 94612-3550, University of, Regents of
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Filing: 1989-06-30
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Granted: 1990-10-09
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Expires: 2009-06-30
Abstract
Abstract A process and apparatus that may be used for the production of diamond and doped diamond films at high rates by activated reactive vapor deposition. Carbon is evaporated in a vacuum chamber in the presence of atomic hydrogen containing plasma to form diamond precursors which then deposit on a substrate located within the vacuum chamber. The substrate temperature is maintained at between about 20°-600° C.
Inventors
- 👤 Chandra V. Desphandey
- 👤 Rointan F. Bunshah
- 👤 Hans J. Doerr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:38
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/0605; C23C14/0611; C23C14/0021; Y; Y10; Y10S; Y10S427/00; Y10S427/103; Y10S427/106
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
124 words
A process for depositing a film consisting essentially of diamond on a substrate, said process comprising the steps of: supporting a substrate in a vacuum; evaporating a source of carbon to produce carbon atoms in a zone between the source of carbon and the substrate; introducing a hydrogen containing gas into said zone; accelerating electrons from an electron source into said zone to form a plasma of carbon atoms and hydrogen containing gas, which react to form carbon-hydrogen molecular precursors in said zone; depositing said precursors from said zone onto said carbon-hydrogen molecular substrate; and maintaining said substrate at a temperature of between about 20° to 600° C. to dissociate said deposited carbon-hydrogen molecular precursor molecules to form said film consisting essentially of diamond.
Claim 2
Dependent Claim
124 words
A process for depositing a film consisting essentially of diamond on a substrate, said process comprising the steps of: supporting a substrate in a vacuum; evaporating a source of carbon to produce carbon atoms in a zone between the source of carbon and the substrate; introducing a hydrogen containing gas into said zone; accelerating electrons from an electron source into said zone to form a plasma of carbon atoms and hydrogen containing gas, which react to form carbon-hydrogen molecular precursors in said zone; depositing said precursors from said zone onto said carbon-hydrogen molecular substrate; and maintaining said substrate at a temperature of between about 20° to 600° C. to dissociate said deposited carbon-hydrogen molecular precursor molecules to form said film consisting essentially of diamond.
Claim 3
Dependent Claim
15 words
A diamond deposition process according to claim 1 wherein said source of carbon is graphite.
Claim 4
Dependent Claim
17 words
A diamond deposition process according to claim 2 wherein said graphite is evaporated by an electron beam.
Claim 5
Dependent Claim
27 words
A diamond deposition process according to claim 1 wherein said hydrogen containing gas is selected from the group consisting of hydrogen, methane, ethane and other hydrocarbon gases.
Claim 6
Dependent Claim
37 words
A diamond deposition process according to claim 4 wherein said hydrogen containing gas is a mixture of hydrogen and hydrocarbon gases or a mixture of hydrogen and argon or a mixture of hydrogen, argon and hydrocarbon gases.
Claim 7
Dependent Claim
28 words
A diamond deposition process according to claim 1 wherein said substrate is selected from the group consisting of stainless steel, molybdenum, glass, quartz, silicon, sodium chloride and aluminum.
Claim 8
Dependent Claim
27 words
A diamond deposition process according to claim 1 wherein the partial pressure of said hydrogen containing gas is between about 2×10 -4 torr and 20×10 -3 torr.
Claim 9
Dependent Claim
15 words
A diamond deposition process according to claim 7 wherein said hydrogen containing gas is hydrogen.
Claim 10
Dependent Claim
27 words
A diamond deposition process according to claim 1 wherein the electrons which are deflected into said zone are produced by said electron source comprising a heated filament.
Claim 11
Dependent Claim
17 words
A diamond deposition process according to claim 9 wherein said filament is tungsten, tantalum, molybdenum or carbon.
Claim 12
Dependent Claim
23 words
A diamond deposition process according to claim 1 wherein said electrons are deflected into said zone by accelerating said electrons toward an anode.
Claim 13
Dependent Claim
23 words
A diamond deposition process according to claim 9 wherein the electrons generated by said filament are accelerated through said zone toward an anode.
Claim 14
Dependent Claim
18 words
A diamond deposition process according to claim 12 wherein the potential at said anode is about 80 volts.
Claim 15
Dependent Claim
25 words
A diamond deposition process according to claim 1 wherein said film is doped with p and n type dopants such as aluminum, lithium or boron.
Claim 16
Dependent Claim
18 words
A deposition process according to claim wherein a film consisting essentially of diamond cubic boron nitride is deposited.
Claim 17
Dependent Claim
28 words
A diamond deposition process according to claim 14 wherein a boron containing gas is introduced into said zone to provide a film consisting essentially of boron doped diamond.
Claim 18
Dependent Claim
33 words
A diamond deposition process according to claim 14 wherein vapor of metal organic compounds such as trimethyl aluminum are introduced into said zone to provide a film consisting essentially of aluminum doped diamond.
Claim 19
Dependent Claim
42 words
A diamond deposition process according to claim 1 wherein said hydrogen containing gas contains CH 4 , nitrogen and hydrogen and boric acid/boric oxide is co-evaporated with said carbon to thereby form a film consisting essentially of cubic boron nitride doped diamond.
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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) | 1993-10-08 | 1994-04-09 | 1994-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-08 | 1998-04-09 | 1998-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-08 | 2002-04-09 | 2002-10-09 | $7700.00 | Window Closed / Lapsed |