US4775882A
Expired / Lapsed
US
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Lateral bipolar transistor
Assignee: Conexant Systems LLC
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Filing: 1986-11-19
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Granted: 1988-10-04
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Expires: 2006-11-19
Abstract
Abstract Silicon doping of GaAs provides n conductivity in {100} planes and p conductivity in {111} A planes. A split level of Si-doped GaAs utilizes this phenomena to provide a bipolar transistor. In one embodiment, the emitter is one level of the layer in the {100} planes, and the collector is another level of the layer in the {100} planes. These n conductivity levels are joined by {111} A planes to form a p conductivity base. The junctions in the layer between the {100} planes and the {111} A planes form an npn transistor.
Inventors
- 👤 David L. Miller
- 👤 Peter M. Asbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:29
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/40; H10D62/405; H10D10/00; H10D10/60; H10D62/80; H10D62/85; H10D62/854
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
116 words
A lateral bipolar transistor comprising: a III-V semiconductor substrate; an epitaxial active layer supported by the substrate, the active layer comprising a semiconductor having a dopant that provides a first conductivity in {100} planes and an opposite conductivity in {111} A planes, the active layer having lower and upper portions in {φ} planes which are joined by a base portion in {111} A planes thereby forming a bipolar junction in the active layer; a contact on the lower portion; a contact on the upper portion; and a base contact on the base portion, whereby the base portion has a first conductivity and the lower and upper portions have an opposite conductivity thus forming a bipolar transistor.
Claim 2
Dependent Claim
116 words
A lateral bipolar transistor comprising: a III-V semiconductor substrate; an epitaxial active layer supported by the substrate, the active layer comprising a semiconductor having a dopant that provides a first conductivity in {100} planes and an opposite conductivity in {111} A planes, the active layer having lower and upper portions in {φ} planes which are joined by a base portion in {111} A planes thereby forming a bipolar junction in the active layer; a contact on the lower portion; a contact on the upper portion; and a base contact on the base portion, whereby the base portion has a first conductivity and the lower and upper portions have an opposite conductivity thus forming a bipolar transistor.
Claim 3
Dependent Claim
19 words
The bipolar transistor as claimed in claim 1 including an epitaxial buffer layer between the substrate and active layer.
Claim 4
Dependent Claim
47 words
The bipolar transistor as claimed in claim 1 wherein the base contact comprises: an epitaxial spacer layer on the base portion of the active layer and extending over the bipolar junction; an epitaxial contact layer on the spacer layer; and a metal contact on the contact layer.
Claim 5
Dependent Claim
37 words
The bipolar transistor as claimed in claim 1 wherein the substrate comprises semi-insulating GaAs, the active layer comprises GaAs doped with Si, whereby the first conductivity is n conductivity and the bipolar junction is an npn junction.
Claim 6
Dependent Claim
50 words
The bipolar transistor as claimed in claim 4 wherein the base contact comprises: an epitaxial AlGaAs spacer layer on the base portion of the active layer and extending over the npn junction; an epitaxial p-conductivity GaAs contact layer on the spacer layer; and a metal contact on the contact layer.
Claim 7
Dependent Claim
21 words
The bipolar transistor as claimed in claim 4 including an epitaxial AlGaAs buffer layer between the substrate and the active layer.
Claim 8
Dependent Claim
61 words
A bipolar transistor comprising: a semi-insulating GaAs substrate; an epitaxial GaAs active layer above the substrate doped with Si to provide n conductivity in {100} planes, the active layer having lower and upper portions in {100} planes which are joined by a base portion in {111} A planes; a contact on the lower portion; a contact on the upper portion; and
Claim 9
Dependent Claim
61 words
A bipolar transistor comprising: a semi-insulating GaAs substrate; an epitaxial GaAs active layer above the substrate doped with Si to provide n conductivity in {100} planes, the active layer having lower and upper portions in {100} planes which are joined by a base portion in {111} A planes; a contact on the lower portion; a contact on the upper portion; and
Claim 10
Dependent Claim
33 words
a base contact on the base portion, whereby the base portion is p conductivity GaAs joined to the lower and upper portions of n conductivity GaAs to form an npn junction bipolar transistor.
Claim 11
Dependent Claim
33 words
a base contact on the base portion, whereby the base portion is p conductivity GaAs joined to the lower and upper portions of n conductivity GaAs to form an npn junction bipolar transistor.
Claim 12
Dependent Claim
21 words
The bipolar transistor as claimed in claim 7 including an epitaxial AlGaAs buffer layer between the substrate and the active layer.
Claim 13
Dependent Claim
50 words
The bipolar transistor as claimed in claim 7 wherein the base contact comprises: an epitaxial GaAs spacer layer on the base portion of the active layer and extending over the npn junction; an epitaxial p-conductivity GaAs contact layer on the spacer layer; and a metal contact on the contact layer.
Claim 14
Dependent Claim
121 words
A lateral bipolar transistor comprising: a III-V semiconductor substrate; an epitaxial active layer above the substrate, the active layer comprising a semiconductor having a dopant that provides a first conductivity in planes having a first orientation and an opposite conductivity in planes having a second orientation, the active layer having lower and upper portions which are parallel to the first orientation planes and which are joined by a base portion which is parallel to the second orientation planes; a contact on the lower portion; a contact on the upper portion; and a base contact on the base portion, whereby the base portion has a conductivity which is opposite the conductivity of the lower and upper portions thus forming a bipolar transistor.
Claim 15
Dependent Claim
121 words
A lateral bipolar transistor comprising: a III-V semiconductor substrate; an epitaxial active layer above the substrate, the active layer comprising a semiconductor having a dopant that provides a first conductivity in planes having a first orientation and an opposite conductivity in planes having a second orientation, the active layer having lower and upper portions which are parallel to the first orientation planes and which are joined by a base portion which is parallel to the second orientation planes; a contact on the lower portion; a contact on the upper portion; and a base contact on the base portion, whereby the base portion has a conductivity which is opposite the conductivity of the lower and upper portions thus forming a bipolar transistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |