US4937204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a superlattice heterojunction bipolar device
Assignee: Sony Corp
•
Filing: 1989-01-04
•
Granted: 1990-06-26
•
Expires: 2009-01-04
Abstract
Abstract A semiconductor apparatus is disclosed, in which the entire or part of an electron active region is formed by a superlattice structure semiconductor layer in which a plurality of different semiconductor layers, less than 8 monolayers, and containing a fraction or a binary compound semiconductor layers are alternately and epitaxially grown and a main current direction is selected to be in the direction perpendicular to the laminae of said superlattice layers.
Inventors
- 👤 Akira Ishibashi
- 👤 Yoshifumi Mori
- 👤 Masao Itabashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:34
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/81; H10D62/815; H10D62/8161; H10D62/8162; H10D62/8164; H10D10/00; H10D10/80; H10D10/821; H10D10/881; Y; Y10; Y10S; Y10S148/00; Y10S148/011; Y10S148/056; Y10S148/072; Y10S148/097; Y10S148/119; Y10S148/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
168 words
A method of forming a superlattice device comprising the successive steps of: (a) epitaxially growing on a semiinsulating substrate an N type GaAs collector layer of low resistivity; (b) epitaxially growing an N type, AlGaAs collector layer having a large band-gap; (c) epitaxially growing a P doped superlattice structure, constituting a base layer and forming a pn junction with the AlGaAs collector layer by forming n monolayers of a first compound semiconductor followed by m monolayers of a second compound semiconductor followed by n monolayers of the first compound semiconductor, and so on, ending with m monolayers of the second semiconductor, where n and m are less than eight; (d) epitaxially growing an N type AlGaAs emitter layer having a large band-gap and which forms an emitter junction of the heterojunction type with the superlattice base layer; (e) epitaxially growing an N type GaAs emitter layer; (f) epitaxially growing an N type GaAs emitter layer of low resistivity; and (g) causing electrons to flow perpendicularly through the monolayers.
Claim 2
Independent Claim
168 words
A method of forming a superlattice device comprising the successive steps of: (a) epitaxially growing on a semiinsulating substrate an N type GaAs collector layer of low resistivity; (b) epitaxially growing an N type, AlGaAs collector layer having a large band-gap; (c) epitaxially growing a P doped superlattice structure, constituting a base layer and forming a pn junction with the AlGaAs collector layer by forming n monolayers of a first compound semiconductor followed by m monolayers of a second compound semiconductor followed by n monolayers of the first compound semiconductor, and so on, ending with m monolayers of the second semiconductor, where n and m are less than eight; (d) epitaxially growing an N type AlGaAs emitter layer having a large band-gap and which forms an emitter junction of the heterojunction type with the superlattice base layer; (e) epitaxially growing an N type GaAs emitter layer; (f) epitaxially growing an N type GaAs emitter layer of low resistivity; and (g) causing electrons to flow perpendicularly through the monolayers.
Claim 3
Dependent Claim
59 words
A method of forming a superlattice device as recited in claim 1 wherein the step of forming the superlattice structure comprises the successive steps of forming n monolayers of GaAs followed by m monolayers of AIAs followed by n monolayers of GaAs, and so on, ending with m monolayers of AIAs, where n and m are less than eight.
Claim 4
Dependent Claim
36 words
A method of forming a superlattice device as recited in claim 1 wherein the step of epitaxially growing the collector layer on the substrate comprises the step of growing it on a Cr doped GaAs substrate.
Claim 5
Dependent Claim
39 words
A method of forming a superlattice device as recited in claim 1 wherein the steps of forming the superlattice structure comprise repeating the forming steps until the thickness of the superlattice structure is between 1300 to 2500 Å thick.
Claim 6
Dependent Claim
22 words
A method of forming a superlattice device as recited in claim 1 wherein in the steps of forming the superlattice layer, m=n.
References Cited (Backward Citations)
US3626257A
Cited
US4058430A
Cited
US4261771A
Cited
US4639275A
Cited
US4675709A
Cited
US4616241A
Cited
US4688068A
Cited
US4675708A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |