US4743951A
Expired / Lapsed
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Field effect transistor
Assignee: International Business Machines Corp
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Filing: 1982-03-08
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Granted: 1988-05-10
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Expires: 2002-03-08
Abstract
Abstract The mobility of carriers in the channel region of a field effect transistor can be increased by providing a layered structure wherein electrons are separated from impurities. The channel is made up of external layers of wide bandgap material and internal layers with a narrower bandgap where the bottom of the conduction band of one layer is below the top of the valence band of the adjacent layer. A structure is shown with a layered channel having AlSb external layers and at least one or both of InAs and GaSb internal layers.
Inventors
- 👤 Chin-An Chang
- 👤 Leroy L. Chang
- 👤 Leo Esaki
- 👤 Emilio E. Mendez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:51
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
In a field effect transistor of the type wherein current in a channel is influenced by a signal applied to a gate eletrode positioned on each side of said channel, the improvement comprising a multilayer epitaxial channel region between said gate electrodes wherein the layer adjacent said gate electrodes is of the material AlSb and the central conductive portion of said channel being of a material taken from the group of InAs and GaSb and their alloys.
Claim 2
Dependent Claim
77 words
In a field effect transistor of the type wherein current in a channel is influenced by a signal applied to a gate eletrode positioned on each side of said channel, the improvement comprising a multilayer epitaxial channel region between said gate electrodes wherein the layer adjacent said gate electrodes is of the material AlSb and the central conductive portion of said channel being of a material taken from the group of InAs and GaSb and their alloys.
Claim 3
Dependent Claim
78 words
A field effect transistor having a source and a drain electrode separated by a monocrystalline channel region, said channel region having first and second external layers of AlSb material extending from said source to said drain, first and second gate electrodes each essentially covering the exposed surface of said first and second external layers respectively, said channel region having a conductive region of one material taken from the group of InAs and GaSb epitaxial with said external regions.
Claim 4
Dependent Claim
78 words
A field effect transistor having a source and a drain electrode separated by a monocrystalline channel region, said channel region having first and second external layers of AlSb material extending from said source to said drain, first and second gate electrodes each essentially covering the exposed surface of said first and second external layers respectively, said channel region having a conductive region of one material taken from the group of InAs and GaSb epitaxial with said external regions.
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) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |