US5365090A
Expired / Lapsed
US
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Hetero bipolar transistor and method of manufacturing the same
Assignee: Toshiba Corp
•
Filing: 1993-04-14
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Granted: 1994-11-15
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Expires: 2013-04-14
Abstract
Abstract The specification discloses a hetero bipolar transistor which comprises a semiconductor substrate, a first silicon layer serving as a collector, a first silicon-germanium layer serving as a base, a second silicon layer serving as a collector, and a second silicon-germanium layer. A side wall of the second silicon-germanium layer is in contact with side walls of the first silicon layer, the first silicon-germanium layer and the second silicon layer. The second silicon-germanium layer is disposed to surround the first silicon layer, the first silicon-germanium layer, and the second silicon layer, and has an energy band gap substantially the same as that of the first silicon-germanium layer.
Inventors
- 👤 Shin-ichi Taka
- 👤 Kouji Kimura
- 👤 Hiroshi Naruse
- 👤 Kuniaki Kumamaru
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:52
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/021; H10D10/051; H10D10/40; H10D10/80; H10D10/821; H10D10/891
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
211 words
A hetero bipolar transistor, comprising: a semiconductor substrate; an insulating film formed on said semiconductor substrate, said film having a hole for exposing a surface of said substrate; a first semiconductor layer of a first conductivity type formed on said surface of said substrate; a second semiconductor layer of a second conductivity type formed on said first semiconductor layer; a third semiconductor layer of the first conductivity type formed on said second semiconductor layer, said third semiconductor layer having an energy band gap larger than an energy band gap of said second semiconductor layer; and a fourth semiconductor layer of the second conductivity type surrounding said first, second and third semiconductor layers, wherein a side wall of said fourth semiconductor layer contacts an upper portion of a side wall of said first semiconductor layer, all of a side wall of said second semiconductor layer and a lower portion of a side wall of said third semiconductor layer, a lowest portion of said side wall of said fourth semiconductor layer contacts with said insulating film, and an energy band gap of said fourth semiconductor layer is substantially the same as the energy band gap of said second semiconductor layer; wherein said first, second and third semiconductor layers have the same surface area.
Claim 2
Dependent Claim
211 words
A hetero bipolar transistor, comprising: a semiconductor substrate; an insulating film formed on said semiconductor substrate, said film having a hole for exposing a surface of said substrate; a first semiconductor layer of a first conductivity type formed on said surface of said substrate; a second semiconductor layer of a second conductivity type formed on said first semiconductor layer; a third semiconductor layer of the first conductivity type formed on said second semiconductor layer, said third semiconductor layer having an energy band gap larger than an energy band gap of said second semiconductor layer; and a fourth semiconductor layer of the second conductivity type surrounding said first, second and third semiconductor layers, wherein a side wall of said fourth semiconductor layer contacts an upper portion of a side wall of said first semiconductor layer, all of a side wall of said second semiconductor layer and a lower portion of a side wall of said third semiconductor layer, a lowest portion of said side wall of said fourth semiconductor layer contacts with said insulating film, and an energy band gap of said fourth semiconductor layer is substantially the same as the energy band gap of said second semiconductor layer; wherein said first, second and third semiconductor layers have the same surface area.
Claim 3
Dependent Claim
26 words
The hetero bipolar transistor according to claim 1, wherein said first, second, third and fourth semiconductor layers are formed by means of an epitaxial growth technique.
Claim 4
Dependent Claim
40 words
The hetero bipolar transistor according to claim 1, wherein each of said first and third semiconductor layers is formed of a single crystal silicon layer, and each of said second and fourth semiconductor layers is formed of a silicon-germanium layer.
Claim 5
Dependent Claim
45 words
The hetero bipolar transistor according to claim 1, wherein said first semiconductor layer is a collector, said second semiconductor layer is a base, said third semiconductor layer is an emitter, and said fourth semiconductor layer is a part of an outer base draw out region.
Claim 6
Dependent Claim
16 words
The hetero bipolar transistor according to claim 1, wherein said semiconductor substrate has an SOI structure.
Claim 7
Dependent Claim
232 words
A hetero bipolar transistor, comprising: a semiconductor substrate; an insulating film formed on said semiconductor substrate, said film having a hole for exposing a surface of said substrate; a first semiconductor layer of a first conductivity type formed on said surface of said substrate; a second semiconductor layer of a second conductivity type formed on said first semiconductor layer; a third semiconductor layer of the first conductivity type formed on said second semiconductor layer, said third semiconductor layer having an energy band gap larger than an energy band gap of said second semiconductor layer; a fourth semiconductor layer of the second conductivity type surrounding said first, second and third semiconductor layers, wherein a side wall of said fourth semiconductor layer contacts an upper portion of a side wall of said first semiconductor layer, all of a side wall of said second semiconductor layer and a lower portion of a side wall of said third semiconductor layer, a lowest portion of said side wall of said fourth semiconductor layer contacts said insulating film, and an energy band gap of said fourth semiconductor layer is substantially the same as the energy band gap of said second semiconductor layer; and a fifth semiconductor layer of the second conductivity type formed under said fourth semiconductor layer and surrounded by said fourth semiconductor layer; wherein said first, second and third semiconductor layers have the same surface area.
Claim 8
Dependent Claim
232 words
A hetero bipolar transistor, comprising: a semiconductor substrate; an insulating film formed on said semiconductor substrate, said film having a hole for exposing a surface of said substrate; a first semiconductor layer of a first conductivity type formed on said surface of said substrate; a second semiconductor layer of a second conductivity type formed on said first semiconductor layer; a third semiconductor layer of the first conductivity type formed on said second semiconductor layer, said third semiconductor layer having an energy band gap larger than an energy band gap of said second semiconductor layer; a fourth semiconductor layer of the second conductivity type surrounding said first, second and third semiconductor layers, wherein a side wall of said fourth semiconductor layer contacts an upper portion of a side wall of said first semiconductor layer, all of a side wall of said second semiconductor layer and a lower portion of a side wall of said third semiconductor layer, a lowest portion of said side wall of said fourth semiconductor layer contacts said insulating film, and an energy band gap of said fourth semiconductor layer is substantially the same as the energy band gap of said second semiconductor layer; and a fifth semiconductor layer of the second conductivity type formed under said fourth semiconductor layer and surrounded by said fourth semiconductor layer; wherein said first, second and third semiconductor layers have the same surface area.
Claim 9
Dependent Claim
27 words
The hetero bipolar transistor according to claim 6, wherein said first, second, third and fourth semiconductor layers are formed by means of an epitaxial vapor growth technique.
Claim 10
Dependent Claim
40 words
The hetero bipolar transistor according to claim 6, wherein each of said first and third semiconductor layers is formed of a single crystal silicon layer, and each of said second and fourth semiconductor layers is formed of a silicon-germanium layer.
Claim 11
Dependent Claim
45 words
The hetero bipolar transistor according to claim 6, wherein said first semiconductor layer is a collector, said second semiconductor layer is a base, said third semiconductor layer is an emitter, and said fourth semiconductor layer is a part of an outer base draw out region.
Claim 12
Dependent Claim
16 words
The hetero bipolar transistor according to claim 6, wherein said semiconductor substrate has an SOI structure.
Claim 13
Dependent Claim
18 words
The hetero bipolar transistor according to claim 6, wherein said fifth semiconductor layer is a polycrystalline silicon layer.
Claim 14
Dependent Claim
23 words
The hetero bipolar transistor according to claim 6, wherein said fourth and fifth semiconductor layers collectively constitute an outer base draw out region.
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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) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |