US3780359A
Expired / Lapsed
US
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Bipolar transistor with a heterojunction emitter and a method fabricating the same
Assignee: International Business Machines Corp
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Filing: 1971-12-20
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Granted: 1973-12-18
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Expires: 1991-12-20
Abstract
Abstract An improved heterojunction transistor and a method of fabricating the same is provided. The device is comprised of liquid phase epitaxially grown binary compound layers of group IIIA-VB semiconductor materials which serve as collector and base regions and of a ternary compound layer of group IIIA-VB semiconductor material which serves as the heterojunction emitter.
Inventors
- 👤 W Dumke
- 👤 V Rideout
- 👤 J Woodall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:04
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/80; H10D10/821; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S148/072; Y10S148/107
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
41 words
A bipolar transistor with a heterojunction emitter according to claim 1, wherein said first and third epitaxial layers are doped with an element selected from the group consisting of Sn and Te, and said second epitaxial layer is doped with Ge.
Claim 2
Dependent Claim
27 words
A bipolar transistor with a heterojunction emitter according to claim 1 wherein said substrate is n+ type GaAs and said first epitaxial layer is n type GaAs.
Claim 3
Dependent Claim
63 words
A bipolar transistor with a heterojunction according to claim 3 with said first epitaxial layer having a donor concentration of from about 1016 cm 3 to about 1017 cm 3, said second epitaxial layer having an acceptor concentration of about 1018 cm 3 and said third epitaxial layer having a carrier concentration of from about 1017 cm 3 to about 1018 cm 3.
Claim 4
Dependent Claim
37 words
A bipolar transistor with a heterojunction emitter according to claim 4 wherein said second epitaxial layer has a sheet resistance on the order of 1000 ohms/sq. inch and a minority carrier mobility greater than 1000 cm2/volt sec.
Claim 5
Dependent Claim
55 words
A bipolar transistor with a heterojunction emitter according to claim 5 wherein said first epitaxial layer is from about 1 Mu to about 50 Mu thick, said second epitaxial layer is from about 0.1 Mu to about 1.0 Mu thick and said third epitaxial layer is from about 1 Mu to about 10 Mu thick.
Claim 6
Dependent Claim
34 words
A bipolar transistor with a heterojunction emitter according to claim 6 wherein said ohmic contact to said third layer is selected from the group consisting of an Au-Ge alloy, an Au-Sn alloy and Sn.
Claim 7
Dependent Claim
36 words
A bipolar transistor with a heterojunction emitter according to claim 7 wherein said ohmic contact disposed on a surface portion of thE second layer is selected from the group of alloys consisting of Au-Ge and Au-Zn.
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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |