US5798540A
Expired / Lapsed
US
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Electronic devices with InAlAsSb/AlSb barrier
Assignee: United States Department of the Navy
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Filing: 1997-04-29
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Granted: 1998-08-25
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Expires: 2017-04-29
Abstract
Abstract An electronic device characterized by a GaAs substrate and a base disposedn the substrate, the base comprising InAs channel layer, AlSb layer above the channel layer, In x Al 1-x As y Sb 1-y layer containing at least In, Al, and As disposed above the AlSb channel layer, InAs cap layer disposed above and in contact with the In x Al 1-x As y Sb 1-y layer disposed below the InAs channel layer and in contact with the substrate, p + GaSb layer disposed within the AlSb layer, Schottky gate with a pad disposed on and in contact with the In x Al 1-x As y Sb 1-y layer, at least one ohmic contact disposed on the InAs cap layer, and a trench extending through the base to the substrate isolating the gate bonding pad from the device and providing a gate air bridge which prevents contact between the gate and the InAs layer. The gate air bridge fabrication is accomplished by a liquid etchant containing more than half, on volume basis, of concentrated lactic acid or acetic acid with remainder hydrogen peroxide and concentrated hydrofluoric acid. The etchant attacks InAs, In x Al 1-x As y Sb 1-y , AlSb, and GaSb but does not attack GaAs and Au-based alloys.
Inventors
- 👤 John Bradley Boos
- 👤 Walter Kruppa
- 👤 Doewon Park
- 👤 Brian R. Bennett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:33
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/40; H10D30/47; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10D30/471; H10D30/473; H10D30/4732; H10D62/85; H10D62/852
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
69 words
An electronic device comprising a first layer of a semiconducting material, a second layer of a semiconducting material, a third layer of a semiconducting material, and Schottky gate in contact with said third layer; said third layer is of a wider band gap than said first layer, said second layer is an AlSb-based material and is disposed between and is in contact with said first and said third layers.
Claim 2
Dependent Claim
69 words
An electronic device comprising a first layer of a semiconducting material, a second layer of a semiconducting material, a third layer of a semiconducting material, and Schottky gate in contact with said third layer; said third layer is of a wider band gap than said first layer, said second layer is an AlSb-based material and is disposed between and is in contact with said first and said third layers.
Claim 3
Dependent Claim
36 words
The device of claim 1 wherein said first layer is InAs and said third layer is In x Al 1-x As y Sb 1-y wherein said third layer contains at least some In, Al and As.
Claim 4
Dependent Claim
29 words
The device of claim 2 wherein thickness of the layers is as follows: said first layer, 50-300 Å; said second layer, 50-300 Å; and said third layer, 20-200 Å.
Claim 5
Dependent Claim
27 words
The device of claim 3 including a fourth layer in contact with said third layer and at least one ohmic contact in contact with said fourth layer.
Claim 6
Dependent Claim
20 words
The device of claim 4 wherein said fourth layer is 10-50 Å thick InAs and said ohmic contact is Pd/barrier/Au.
Claim 7
Dependent Claim
54 words
The device of claim 5 wherein in said ohmic contact thickness is as follows: palladium layer, 50-500 Å; barrier layer, 100-500 Å; and gold layer, 200-2000 Å; and said barrier in said ohmic contact is selected from the group consisting of platinum, titanium, titanium tungsten, platinum silicide, titanium carbide, titanium silicide, and mixtures thereof.
Claim 8
Dependent Claim
27 words
The device of claim 5 including a buffer layer below said first layer, a doped layer within said buffer layer, and a substrate below said buffer layer.
Claim 9
Dependent Claim
23 words
The device of claim 7 wherein said buffer layer is AlSb, said doped layer is p + GaSb, and said substrate is GaAs.
Claim 10
Dependent Claim
27 words
The device of claim 8 wherein said buffer layer is 1-5 microns thick and said doped layer is 100-500 Å thick and is doped with silicon atoms.
Claim 11
Dependent Claim
134 words
An electronic device comprising the following layers disposed on a GaAs substrate: a first AlSb layer disposed on said substrate; p + GaSb layer disposed on said first AlSb layer; a second AlSb layer disposed on said p + GaSb layer; an InAs channel layer disposed on the said second AlSb layer; a third AlSb layer disposed on said InAs channel layer; an In x Al 1-x As y Sb 1-y layer containing at least In, Al and As disposed on said third AlSb layer; an InAs cap layer disposed on said In x Al 1-x As y Sb 1-y layer; two ohmic contacts disposed on said InAs cap layer; and a Schottky gate disposed between the ohmic contacts and being in contact with said In x Al 1-x As y Sb 1-y layer.
Claim 12
Dependent Claim
134 words
An electronic device comprising the following layers disposed on a GaAs substrate: a first AlSb layer disposed on said substrate; p + GaSb layer disposed on said first AlSb layer; a second AlSb layer disposed on said p + GaSb layer; an InAs channel layer disposed on the said second AlSb layer; a third AlSb layer disposed on said InAs channel layer; an In x Al 1-x As y Sb 1-y layer containing at least In, Al and As disposed on said third AlSb layer; an InAs cap layer disposed on said In x Al 1-x As y Sb 1-y layer; two ohmic contacts disposed on said InAs cap layer; and a Schottky gate disposed between the ohmic contacts and being in contact with said In x Al 1-x As y Sb 1-y layer.
Claim 13
Dependent Claim
62 words
The device of claim 10 wherein the various thicknesses are as follows: said first AlSb layer, 2.4 microns: said p + GaSb layer, 200 Å; said second AlSb layer, 500 Å; said InAs channel layer, 100 Å; said third AlSb layer, 125 Å; said In x Al 1-x As y Sb 1-y layer, 40 Å; and said InAs cap layer, 15 Å.
Claim 14
Dependent Claim
31 words
The device of claim 11 wherein each of said two ohmic contacts is Pd/Pt/Au having respective thickness of 100 Å, 200 Å, and 600 Å; and said Schottky gate is Cr/Au.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-08-24 | 2002-02-23 | 2002-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-24 | 2006-02-23 | 2006-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-24 | 2010-02-23 | 2010-08-25 | $7700.00 | Window Closed / Lapsed |