Patent JPS5022459A successfully refreshed from Google Patents.
Patent USH763H successfully refreshed from Google Patents.
USH763H
Expired / Lapsed
US
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Submicron bipolar transistor with edge contacts
Assignee: AT&T Inc
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Filing: 1989-03-21
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Granted: 1990-04-03
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Expires: 2009-03-21
Abstract
Abstract A new sub-micron bipolar transistor structure is proposed which utilizes narrow horizontal conducting layers between the edges of the active areas and the associated metal contacts. This structure allows the formation of a completely vertical transistor structure and eliminates the need for the extended buried collector and collector reach-through diffusion regions.
Inventors
- 👤 Anatoly Feygenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:52
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/051; H10D10/054; H10D10/40; H10D10/441; H10D64/00; H10D64/20; H10D64/23; H10D64/231; H10W; H10W20/00; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
335 words
A bipolar transistor comprising a semiconductor substrate of a first conductivity type having predefined top and bottom major surfaces; a buried collecting region of a second conductivity type formed in a selected region of said semiconductor substrate, extending downward a predetermined depth from the semiconductor substrate top major surface; a collector region of the second conductivity type, including top and bottom major surfaces with vertical sidewalls extending therebetween, disposed over said buried collector region and extending upward from said semiconductor substrate top major surface such that the bottom major surface of said collector region is in contact with the top major surface of said substrate; a base region of the first conductivity type and including top and bottom major surfaces with vertical sidewalls extending therebetween, said base region bottom major surface formed to contact the top major surface of said collector region; an emitter region of the second conductivity type formed in a centrally located portion of said base region, extending downward into said base region from the base region top major surface; a horizontal collector conducting layer of the second conductivity type extending from a sidewall of the collector region at a predetermined height above said semiconductor substrate top major surface; a collector isolation region formed between the base region top major surface and said semiconductor substrate top major surface so as to surround the horizontal collector conducting layer; a horizontal base conducting layer of the first conductivity type extending from a sidewall of said base region at a predetermined height above said semiconductor substrate top major surface; a base isolation region formed between the base region top major surface and said semiconductor substrate top major surface so as to surround the horizontal base conducting layer; collector ohmic contact means extending downward through the collector isolation region to contact the horizontal collector conducting layer; base ohmic contact means extending downward through the base isolation region to contact the horizontal base conducting layer; and emitter ohmic contact means disposed to contact the emitter diffusion region.
Claim 2
Dependent Claim
335 words
A bipolar transistor comprising a semiconductor substrate of a first conductivity type having predefined top and bottom major surfaces; a buried collecting region of a second conductivity type formed in a selected region of said semiconductor substrate, extending downward a predetermined depth from the semiconductor substrate top major surface; a collector region of the second conductivity type, including top and bottom major surfaces with vertical sidewalls extending therebetween, disposed over said buried collector region and extending upward from said semiconductor substrate top major surface such that the bottom major surface of said collector region is in contact with the top major surface of said substrate; a base region of the first conductivity type and including top and bottom major surfaces with vertical sidewalls extending therebetween, said base region bottom major surface formed to contact the top major surface of said collector region; an emitter region of the second conductivity type formed in a centrally located portion of said base region, extending downward into said base region from the base region top major surface; a horizontal collector conducting layer of the second conductivity type extending from a sidewall of the collector region at a predetermined height above said semiconductor substrate top major surface; a collector isolation region formed between the base region top major surface and said semiconductor substrate top major surface so as to surround the horizontal collector conducting layer; a horizontal base conducting layer of the first conductivity type extending from a sidewall of said base region at a predetermined height above said semiconductor substrate top major surface; a base isolation region formed between the base region top major surface and said semiconductor substrate top major surface so as to surround the horizontal base conducting layer; collector ohmic contact means extending downward through the collector isolation region to contact the horizontal collector conducting layer; base ohmic contact means extending downward through the base isolation region to contact the horizontal base conducting layer; and emitter ohmic contact means disposed to contact the emitter diffusion region.
Claim 3
Dependent Claim
44 words
A bipolar transistor as defined in claim 1 wherein the horizontal collector conducting layer comprises a layer of polysilicon doped to comprise the second conductivity type; and the horizontal base conducting layer comprises a layer of polysilicon doped to comprise the first conductivity type.
Claim 4
Dependent Claim
46 words
A bipolar transistor as defined in claim 2 wherein the horizontal collector conducting layer further comprises a layer of silicide disposed to cover the doped polysilicon layer; and the horizontal base conducting layer further comprises a layer of silicide disposed to cover the doped polysilicon layer.
Claim 5
Dependent Claim
60 words
A bipolar transistor as defined in claim 1 wherein the transistor further comprises a vertical connection region of the second conductivity type formed adjacent to the sidewall of the collector region between the semiconductor top major surface and the horizontal collector conducting layer, said vertical connection region for electrically connecting the buried collector region to the horizontal collector conducting layer.
Claim 6
Dependent Claim
28 words
A bipolar transistor as defined in claim 1 wherein the first conductivity type is defined as p-type conductivity and the second conductivity type is defined as n-type conductivity.
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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) | 1993-04-02 | 1993-10-02 | 1994-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-02 | 1997-10-02 | 1998-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-02 | 2001-10-02 | 2002-04-03 | $7700.00 | Window Closed / Lapsed |