US5285084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diamond schottky diodes and gas sensors fabricated therefrom
Assignee: Kobe Steel USA Inc
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Filing: 1992-09-02
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Granted: 1994-02-08
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Expires: 2012-09-02
Abstract
Abstract Schottky diodes and gas sensors include a diamond layer having a Schottky contact thereon and an ohmic contact thereon, wherein the diamond layer includes a highly doped region adjacent the ohmic contact to provide a low resistance ohmic contact. Dramatically reduced frequency dependence of the capacitance/voltage characteristic of Schottky diodes and gas sensors formed thereby, compared to Schottky diodes and gas sensors which do not include the highly doped region adjacent the ohmic contact, is provided. The highly doped region is preferably boron doped at a concentration of at least 10 20 atoms per cubic centimeter to form an ohmic contact with a contact resistance of less than 10 -3 Ω-cm 2 . The ohmic contact is preferably a back contact on the face of the diamond layer opposite the Schottky contact.
Inventors
- 👤 Jesko von Windheim
- 👤 Vasudev Venkatesan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:41
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/60; G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/129; H10D62/00; H10D62/80; H10D62/83; H10D62/8303; H10D64/00; H10D64/60; H10D64/62
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
114 words
A gas sensor comprising: a diamond layer having first and second opposing faces; a first contact on said first face, wherein said first contact forms a Schottky barrier of predetermined Schottky barrier height between said first contact and said first face, and wherein said first contact allows gas to interact with said first face and alter said predetermined Schottky barrier height; and a second contact on said second face, wherein said diamond layer includes a highly doped region adjacent said second contact, said highly doped region being doped at a concentration of at least 10 20 atoms per cubic centimeter, and wherein said second contact forms an ohmic contact with said highly doped region.
Claim 2
Dependent Claim
114 words
A gas sensor comprising: a diamond layer having first and second opposing faces; a first contact on said first face, wherein said first contact forms a Schottky barrier of predetermined Schottky barrier height between said first contact and said first face, and wherein said first contact allows gas to interact with said first face and alter said predetermined Schottky barrier height; and a second contact on said second face, wherein said diamond layer includes a highly doped region adjacent said second contact, said highly doped region being doped at a concentration of at least 10 20 atoms per cubic centimeter, and wherein said second contact forms an ohmic contact with said highly doped region.
Claim 3
Dependent Claim
31 words
The gas sensor of claim 1 wherein said highly doped region comprises a region which is doped with boron at a concentration of at least 10 20 atoms per cubic centimeter.
Claim 4
Dependent Claim
21 words
The gas sensor of claim 1 wherein said second contact has contact resistance of less than 10 -3 Ω-cm 2 .
Claim 5
Dependent Claim
15 words
The gas sensor of claim 1 wherein said diamond layer is a monocrystalline diamond layer.
Claim 6
Dependent Claim
45 words
The gas sensor of claim 1 wherein said diamond layer is a polycrystalline diamond layer, said gas sensor further comprising at least one of a layer of undoped diamond and a thin layer of silicon dioxide, between said second contact and said polycrystalline diamond layer.
Claim 7
Dependent Claim
27 words
The gas sensor of claim 1 wherein said first contact comprises a catalytic metal layer which is sufficiently thin to allow gas interaction with said first face.
Claim 8
Dependent Claim
26 words
The gas sensor of claim 6 wherein said first contact comprises at least one of a platinum and palladium layer less than about 1000 Ångstroms thick.
Claim 9
Dependent Claim
23 words
The gas sensor of claim 1 further comprising at least one of a diamond substrate and a nondiamond substrate on said second face.
Claim 10
Dependent Claim
132 words
A gas sensor comprising: a diamond layer having first and second opposing faces; a first contact on said first face, wherein said first contact forms a Schottky barrier of predetermined Schottky barrier height between said first contact and said first face, and wherein said first contact allows gas to interact with said first face and alter said predetermined Schottky barrier height; and a second contact on said second face, wherein said diamond layer includes a doped region adjacent said second contact, and wherein said second contact forms an ohmic contact with said doped region; and at least one of a diamond substrate and a nondiamond substrate on said second face, wherein said substrate includes an aperture therein, and wherein said second contact layer is formed on said second face, within said aperture.
Claim 11
Dependent Claim
132 words
A gas sensor comprising: a diamond layer having first and second opposing faces; a first contact on said first face, wherein said first contact forms a Schottky barrier of predetermined Schottky barrier height between said first contact and said first face, and wherein said first contact allows gas to interact with said first face and alter said predetermined Schottky barrier height; and a second contact on said second face, wherein said diamond layer includes a doped region adjacent said second contact, and wherein said second contact forms an ohmic contact with said doped region; and at least one of a diamond substrate and a nondiamond substrate on said second face, wherein said substrate includes an aperture therein, and wherein said second contact layer is formed on said second face, within said aperture.
Claim 12
Dependent Claim
86 words
A gas sensor comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a highly doped region adjacent said ohmic contact, said highly doped region being doped at a concentration of at least 10 20 atoms per cubic centimeter, said gas sensor being configured such that gas external to said gas sensor is absorbed within said diamond layer, said diamond layer being responsive to gas absorbed therein to alter the barrier height of said Schottky contact and thereby provide a gas sensor.
Claim 13
Dependent Claim
86 words
A gas sensor comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a highly doped region adjacent said ohmic contact, said highly doped region being doped at a concentration of at least 10 20 atoms per cubic centimeter, said gas sensor being configured such that gas external to said gas sensor is absorbed within said diamond layer, said diamond layer being responsive to gas absorbed therein to alter the barrier height of said Schottky contact and thereby provide a gas sensor.
Claim 14
Dependent Claim
31 words
The gas sensor of claim 10 wherein said highly doped region comprises a region which is doped with boron at a concentration of at least 10 20 atoms per cubic centimeter.
Claim 15
Dependent Claim
21 words
The gas sensor of claim 10 wherein said ohmic contact has contact resistance of less than 10 -3 Ω-cm 2 .
Claim 16
Dependent Claim
24 words
The gas sensor of claim 10 wherein said diamond layer is at least one of a monocrystalline diamond layer and a polycrystalline diamond layer.
Claim 17
Dependent Claim
45 words
The gas sensor of claim 10 wherein said diamond layer is a polycrystalline diamond layer, said gas sensor further comprising at least one of a layer of undoped diamond and a thin layer of silicon dioxide, between said ohmic contact and said polycrystalline diamond layer.
Claim 18
Dependent Claim
27 words
The gas sensor of claim 10 wherein said Schottky contact comprises a catalytic metal layer which is sufficiently thin to allow gas interaction with said diamond layer.
Claim 19
Dependent Claim
26 words
The gas sensor of claim 15 wherein said Schottky contact comprises at least one of a platinum and palladium layer less than about 1000 Ångstroms thick.
Claim 20
Dependent Claim
23 words
The gas sensor of claim 10 further comprising at least one of a diamond substrate and a nondiamond substrate on said diamond layer.
Claim 21
Dependent Claim
79 words
A gas sensor comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a doped region adjacent said ohmic contact, said diamond layer being responsive to gas absorbed therein to alter the barrier height of said Schottky contact; at least one of a diamond substrate and a nondiamond substrate on said diamond layer, wherein said substrate includes an aperture therein, and wherein said ohmic contact layer is formed on said diamond layer, within said aperture.
Claim 22
Dependent Claim
79 words
A gas sensor comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a doped region adjacent said ohmic contact, said diamond layer being responsive to gas absorbed therein to alter the barrier height of said Schottky contact; at least one of a diamond substrate and a nondiamond substrate on said diamond layer, wherein said substrate includes an aperture therein, and wherein said ohmic contact layer is formed on said diamond layer, within said aperture.
Claim 23
Dependent Claim
49 words
A diode comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a highly doped region adjacent said ohmic contact said highly doped region being doped at a concentration which is greater than 10 20 atoms per cubic centimeter, to thereby provide a Schottky diode.
Claim 24
Dependent Claim
49 words
A diode comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a highly doped region adjacent said ohmic contact said highly doped region being doped at a concentration which is greater than 10 20 atoms per cubic centimeter, to thereby provide a Schottky diode.
Claim 25
Dependent Claim
30 words
The diode of claim 19 wherein said highly doped region comprises a region which is doped with boron at a concentration of at least 10 20 atoms per cubic centimeter.
Claim 26
Dependent Claim
21 words
The diode of claim 19 wherein said ohmic contact has a contact resistance of less than 10 -3 Ω-cm 2 .
Claim 27
Dependent Claim
14 words
The diode of claim 19 wherein said diamond layer is a monocrystalline diamond layer.
Claim 28
Dependent Claim
43 words
The diode of claim 19 wherein said diamond layer is a polycrystalline diamond layer, said diode further comprising at least one of a layer of undoped diamond and a thin layer of silicon dioxide, between said ohmic contact and said polycrystalline diamond layer.
Claim 29
Dependent Claim
19 words
The diode of claim 19 wherein said Schottky contact comprises a metal layer more than about 2000 Ångstroms thick.
Claim 30
Dependent Claim
22 words
The diode of claim 19 further comprising at least one of a diamond substrate and a nondiamond substrate on said diamond layer.
Claim 31
Dependent Claim
68 words
A diode comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a highly doped region adjacent said ohmic contact, to thereby provide a Schottky diode; and at least one of a diamond substrate and a nondiamond substrate on said diamond layer wherein said substrate includes an aperture therein, and wherein said ohmic contact layer is formed on said diamond layer, within said aperture.
Claim 32
Dependent Claim
68 words
A diode comprising: a diamond layer having a Schottky contact and an ohmic contact thereon, and a highly doped region adjacent said ohmic contact, to thereby provide a Schottky diode; and at least one of a diamond substrate and a nondiamond substrate on said diamond layer wherein said substrate includes an aperture therein, and wherein said ohmic contact layer is formed on said diamond layer, within said aperture.
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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) | 1997-02-07 | 1997-08-09 | 1998-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-07 | 2001-08-09 | 2002-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-07 | 2005-08-09 | 2006-02-08 | $7700.00 | Window Closed / Lapsed |