US5285089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diamond and silicon carbide heterojunction bipolar transistor
Assignee: Kobe Steel USA Inc
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Filing: 1992-12-02
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Granted: 1994-02-08
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Expires: 2012-12-02
Abstract
Abstract A double heterojunction bipolar transistor includes diamond as the semiconductor material for the collector and emitter, while silicon carbide provides the base. Accordingly, the diamond is readily and reproducibly p-doped, and the silicon carbide may be fabricated by a solid state reaction to form an n-type intrinsic semiconductor. The base is preferably not so thick as to greatly increase transit time, yet sufficiently thick to prevent tunneling. In one embodiment single crystal diamond and single crystal silicon carbide are used in direct contact with each other. In another embodiment of the transistor, polycrystalline diamond is used, and a layer of insulating diamond is positioned between each face of the silicon carbide layer and the diamond layers. A method for fabricating the transistor includes depositing silicon on the diamond and annealing same so as to produce silicon carbide by a solid state reaction. The silicon carbide so produced is intrinsically n-type. Alternately, the silicon carbide may be directly deposited.
Inventors
- 👤 Kalyankumar Das
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:56
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/83; H10D62/8303; H10D10/00; H10D10/80; H10D10/821; H10D62/82
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
44 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of p-type semiconducting diamond; a base on said collector, said base comprising a layer of n-type semiconducting silicon carbide; and an emitter on said base, said emitter comprising a layer of p-type semiconducting diamond.
Claim 2
Dependent Claim
44 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of p-type semiconducting diamond; a base on said collector, said base comprising a layer of n-type semiconducting silicon carbide; and an emitter on said base, said emitter comprising a layer of p-type semiconducting diamond.
Claim 3
Dependent Claim
33 words
A heterojunction bipolar transistor according to claim 1 wherein said silicon carbide layer has a thickness not greater than a predetermined value to provide a sufficiently short transit time for bipolar transistor operation.
Claim 4
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 2 wherein said silicon carbide layer has a thickness not greater than about 500Å.
Claim 5
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 1 wherein said thickness of said base is not less than a tunneling thickness.
Claim 6
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 4 wherein said silicon carbide layer has a thickness not less than about 50Å.
Claim 7
Dependent Claim
50 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of single crystal p-type semiconducting diamond; a base comprising a layer of n-type semiconducting silicon carbide on said single crystal diamond layer of said collector; and an emitter comprising a layer of p-type single crystal semiconducting diamond on said base.
Claim 8
Dependent Claim
50 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of single crystal p-type semiconducting diamond; a base comprising a layer of n-type semiconducting silicon carbide on said single crystal diamond layer of said collector; and an emitter comprising a layer of p-type single crystal semiconducting diamond on said base.
Claim 9
Dependent Claim
33 words
A heterojunction bipolar transistor according to claim 6 wherein said silicon carbide layer has a thickness not greater than a predetermined value to provide a sufficiently short transit time for bipolar transistor operation.
Claim 10
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 7 wherein said silicon carbide layer has a thickness not greater than about 500Å.
Claim 11
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 1 wherein said thickness of said base is not less than a tunneling thickness.
Claim 12
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 9 wherein said silicon carbide layer has a thickness not less than about 50Å.
Claim 13
Dependent Claim
46 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of p-type polycrystalline semiconducting diamond; a base on said collector, said base comprising a layer of n-type semiconducting silicon carbide; and an emitter on said base, said emitter comprising a layer of p-type polycrystalline semiconducting diamond.
Claim 14
Dependent Claim
46 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of p-type polycrystalline semiconducting diamond; a base on said collector, said base comprising a layer of n-type semiconducting silicon carbide; and an emitter on said base, said emitter comprising a layer of p-type polycrystalline semiconducting diamond.
Claim 15
Dependent Claim
30 words
A heterojunction bipolar transistor according to claim 11 wherein said base further comprises an insulating layer on each face of said silicon carbide layer between respective layers of polycrystalline diamond.
Claim 16
Dependent Claim
15 words
A heterojunction bipolar transistor according to claim 12 wherein said insulating layer comprises insulating diamond.
Claim 17
Dependent Claim
33 words
A heterojunction bipolar transistor according to claim 11 wherein said silicon carbide layer has a thickness not greater than a predetermined value to provide a sufficiently short transit time for bipolar transistor operation.
Claim 18
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 14 wherein said silicon carbide layer has a thickness not greater than about 500Å.
Claim 19
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 11 wherein said thickness of said base is not less than a tunneling thickness.
Claim 20
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 16 wherein said silicon carbide layer has a thickness not less than about 50Å.
Claim 21
Dependent Claim
87 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of semiconducting diamond having a first conductivity type; a base on said collector, said base comprising a layer of semiconducting silicon carbide having a second conductivity type, said base having a thickness not greater than a predetermined value to provide a sufficiently short transit time for bipolar transistor operation and the thickness not less than a tunneling thickness; and an emitter on said base, said emitter comprising a layer of semiconducting diamond having the first conductivity type.
Claim 22
Dependent Claim
87 words
A heterojunction bipolar transistor comprising: a collector comprising a layer of semiconducting diamond having a first conductivity type; a base on said collector, said base comprising a layer of semiconducting silicon carbide having a second conductivity type, said base having a thickness not greater than a predetermined value to provide a sufficiently short transit time for bipolar transistor operation and the thickness not less than a tunneling thickness; and an emitter on said base, said emitter comprising a layer of semiconducting diamond having the first conductivity type.
Claim 23
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 18 wherein said silicon carbide layer has a thickness not greater than about 500Å.
Claim 24
Dependent Claim
21 words
A heterojunction bipolar transistor according to claim 18 wherein said silicon carbide layer has a thickness not less than about 50Å.
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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 |