US4670767A
Expired / Lapsed
US
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Hetero-junction bipolar transistor having a high switching speed
Assignee: NEC Corp
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Filing: 1985-01-30
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Granted: 1987-06-02
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Expires: 2005-01-30
Abstract
Abstract The bipolar transistor comprises an emitter of a first semiconductor, a base of a second semiconductor and a collector of a third semiconductor, the first semiconductor having edges of conduction and valence bands positioned outside the energy band gap of the second semiconductor, and the third semiconductor having an edge of conduction band for majority carriers positioned inside the energy band gap of the second semiconductor and an edge of valence band for majority carriers positioned outside the energy band gap of the second semiconductor.
Inventors
- 👤 Kuniichi Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:32
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10D10/00; H10D10/80; H10D10/821
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
127 words
A bipolar transistor comprising an emitter region of one conductivity type made of a first semiconductor material, a base region of the other conductivity type formed of a second semiconductor material in contact with said emitter region and a collector region of said one conductivity type formed of a third semiconductor material in contact with said base region, said first semiconductor material having a conduction band and a valence band positioned outside a band gap of said second semiconductor material under a non-bias condition, the edge of a conduction band of said third semiconductor material positioned inside said band gap of said second semiconductor material, and the edge of a valence band of said third semiconductor material positioned outside said band gap of said second semiconductor material.
Claim 2
Dependent Claim
127 words
A bipolar transistor comprising an emitter region of one conductivity type made of a first semiconductor material, a base region of the other conductivity type formed of a second semiconductor material in contact with said emitter region and a collector region of said one conductivity type formed of a third semiconductor material in contact with said base region, said first semiconductor material having a conduction band and a valence band positioned outside a band gap of said second semiconductor material under a non-bias condition, the edge of a conduction band of said third semiconductor material positioned inside said band gap of said second semiconductor material, and the edge of a valence band of said third semiconductor material positioned outside said band gap of said second semiconductor material.
Claim 3
Dependent Claim
24 words
A bipolar transistor as claimed in claim 1, wherein said one conductivity type is an N-type and said other conductivity type is a P-type.
Claim 4
Dependent Claim
22 words
A bipolar transistor as claimed in claim 1, wherein said second and third semiconductor materials are compound semiconductors and forms a hetero-junction.
Claim 5
Dependent Claim
98 words
A bipolar transistor as claimed in claim 3, wherein the difference between an edges of a conduction band of said second semiconductor material and the edge of said conduction band of said third semiconductor materials is within a range from 0.1 to 0.9 times of said band gap of said second semiconductor material and the difference between an edge of a valence band of said second semiconductor material and the edge of said valence band of said third semiconductor material is within a range from 0.1 to 0.9 times of a band gap of said third semiconductor material.
Claim 6
Dependent Claim
40 words
A bipolar transistor as claimed in claim 1, wherein said first semiconductor material is a mixed semiconductor of AlAs and GaSb, said second semiconductor material is a mixed semiconductor of GaAs and GaSb and said third semiconductor material is InP.
Claim 7
Dependent Claim
68 words
A bipolar transistor as claimed in claim 1, wherein said bipolar transistor comprises a additional region inserted between said base region and said collector region, said additional region being made of a fourth semiconductor material of said one conductivity type having edges of conduction and valence bands which are graded in energy level to establish continuous changes of conduction and valence bands between said base and collector regions.
Claim 8
Dependent Claim
22 words
A bipolar transistor as claimed in claim 6, wherein said fourth semiconductor material is a mixed semiconductor of GaAs, GaSb and InP.
Claim 9
Dependent Claim
34 words
A bipolar transistor comprising an emitter region of a first mixed semiconductor of AlAs and GaSb, a base region of a second mixed semiconductor of GaAs and GaSb and a collector region of InP.
Claim 10
Dependent Claim
34 words
A bipolar transistor comprising an emitter region of a first mixed semiconductor of AlAs and GaSb, a base region of a second mixed semiconductor of GaAs and GaSb and a collector region of InP.
Claim 11
Dependent Claim
40 words
A bipolar transistor as claimed in claim 8, wherein said bipolar transistor further comprises an additional region of a third mixed semiconductor of InP, GaAs and GaSb, said additional region being inserted between said base region and said collector region.
Claim 12
Dependent Claim
62 words
A bipolar transistor as claimed in claim 9, wherein said third mixed semiconductor is a mixture of InP and said second mixed semiconductor, the mixing ratio of said InP and said second mixed semiconductor being changed so as to change from said mixed semiconductor only at the junction with said base region to said InP at the junction with said collector region.
Claim 13
Dependent Claim
57 words
A bipolar transistor comprising an emitter region, a base region and a collection region, said base and collector regions being formed of such semiconductor materials that discontinuities of energy levels at a junction between said base and collector regions prevent injection of minority carriers into both said base and collector regions when said junction is forward biased.
Claim 14
Dependent Claim
57 words
A bipolar transistor comprising an emitter region, a base region and a collection region, said base and collector regions being formed of such semiconductor materials that discontinuities of energy levels at a junction between said base and collector regions prevent injection of minority carriers into both said base and collector regions when said junction is forward biased.
Claim 15
Dependent Claim
14 words
A bipolar transistor as claimed in claim 11, wherein said junction is a hetero-junction.
Claim 16
Dependent Claim
66 words
A bipolar transistor as claimed in claim 12, wherein said bipolar transistor is an NPN type, and said collector region is made of a semiconductor material having an edge of conduction band positioned inside an energy band gap of a semiconductor material of said base region and an edge of valence band positioned outside said energy band gap of said semiconductor material of said base region.
Claim 17
Dependent Claim
66 words
A bipolar transistor as claimed in claim 12, wherein said bipolar transistor is a PNP type, and said collector region is made of a semiconductor material having an edge of conduction band positioned outside an energy band gap of a semiconductor material of said base region and an edge of valence band positioned inside said energy band gap of said semiconductor material of said base region.
Claim 18
Dependent Claim
127 words
A bipolar transistor comprising an emitter region of one conductivity type made of a first semiconductor material, a base region of the other conductivity type formed of a second semiconductor material in contact with said emitter region and a collector region of said one conductivity type formed of a third semiconductor material in contact with said base region, said first semiconductor material having a conduction band and a valence band positioned outside a band gap of said second semiconductor material under a non-bias condition, the edge of a valence band of said third semiconductor material positioned inside said band gap of said second semiconductor material, and the edge of a conduction band of said third semiconductor material positioned outside said band gap of said second semiconductor material.
Claim 19
Dependent Claim
127 words
A bipolar transistor comprising an emitter region of one conductivity type made of a first semiconductor material, a base region of the other conductivity type formed of a second semiconductor material in contact with said emitter region and a collector region of said one conductivity type formed of a third semiconductor material in contact with said base region, said first semiconductor material having a conduction band and a valence band positioned outside a band gap of said second semiconductor material under a non-bias condition, the edge of a valence band of said third semiconductor material positioned inside said band gap of said second semiconductor material, and the edge of a conduction band of said third semiconductor material positioned outside said band gap of said second semiconductor material.
Claim 20
Dependent Claim
24 words
A bipolar transistor as claimed in claim 15, wherein said one conductivity type is a P-type and said other conductivity type is an N-type.
Claim 21
Dependent Claim
22 words
A bipolar transistor as claimed in claim 15, wherein said second and third semiconductor materials are compound semiconductors and form a hetero-junction.
Claim 22
Dependent Claim
96 words
A bipolar transistor as claimed in claim 17, wherein the difference between an edge of a valence band of said second semiconductor material and the edge of said valence band of said third semiconductor materials is within a range from 0.1 to 0.9 times said band gap of said second semiconductor material and the difference between an edge of a conduction band of said second semiconductor material and the edge of said conduction band of said third semiconductor material is within a range from 0.1 to 0.9 times a band gap of said third semiconductor material.
Claim 23
Dependent Claim
40 words
A bipolar transistor as claimed in claim 15, wherein said first semiconductor material is a mixed semiconductor of AlAs and GaSb, said second semiconductor material is a mixed semiconductor of GaAs and GaSb and said third semiconductor material is InP.
Claim 24
Dependent Claim
68 words
A bipolar transistor as claimed in claim 15, wherein said bipolar transistor comprises an additional region inserted between said base region and said collector region, said additional region being made of a fourth semiconductor material of said one conductivity type having edges of conduction and valence bands which are graded in energy level to establish continuous changes of conduction and valence bands between said base and collector regions.
Claim 25
Dependent Claim
22 words
A bipolar transistor as claimed in claim 20, wherein said fourth semiconductor material is a mixed semiconductor of GaAs, GaSb and InP.
Claim 26
Dependent Claim
34 words
A bipolar transistor comprising an emitter region of a first mixed semiconductor of AlAs and GaSb, a base region of a second mixed semiconductor of GaAs and GaSb and a collector region of InP.
Claim 27
Dependent Claim
34 words
A bipolar transistor comprising an emitter region of a first mixed semiconductor of AlAs and GaSb, a base region of a second mixed semiconductor of GaAs and GaSb and a collector region of InP.
Claim 28
Dependent Claim
40 words
A bipolar transistor as claimed in claim 22, wherein said bipolar transistor further comprises an additional region of a third mixed semiconductor of InP, GaAs and GaSb, said additional region being inserted between said base region and said collector region.
Claim 29
Dependent Claim
62 words
A bipolar transistor as claimed in claim 23, wherein said third mixed semiconductor is a mixture of InP and said second mixed semiconductor, the mixing ratio of said InP and said second mixed semiconductor being changed so as to change from said mixed semiconductor only at the junction with said base region to said InP at the junction with said collector region.
References Cited (Backward Citations)
US4173763A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |