US5262660A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High power pseudomorphic gallium arsenide high electron mobility transistors
Assignee: Northrop Grumman Systems Corp
•
Filing: 1991-08-01
•
Granted: 1993-11-16
•
Expires: 2011-08-01
Abstract
Abstract A high power pseudomorphic (PM) AlGaAs/InGaAs high electron mobility transistor (HEMT) (26) with improved gain at 94 GHz. The transistor (26) includes an InGaAs quantum well (32) having a silicon planar doping layer (34) located at the bottom. A donor layer (36) comprises AlGaAs with a silicon planar doping layer (37). The resulting transistor (26) exhibits superior gain and noise characteristics that relatively high power levels when operating at 94 GHz. The transistor (26) is produced using an optimized growth process which involves growing the quantum well at a relatively low temperature and then raising the temperature to grow subsequent layers.
Inventors
- 👤 Dwight C. Streit
- 👤 Kin L. Tan
- 👤 Po-Hsin Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:28
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/40; H10D30/47; H10D30/471; H10D30/475; H10D30/4755
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
114 words
A gallium arsenide (GaAs) field effect transistor comprising: a GaAs substrate layer; a buffer layer deposited on top of said GaAs substrate; an InGaAs quantum well deposited on top of said buffer; a layer of silicon planar doping within said InGaAs quantum well, and deposited near the bottom of said InGaAs quantum well; a donor layer of AlGaAs deposited on top of said InGaAs quantum well; an n-type GaAs contact layer deposited on top of said AlGaAs donor layer; a gate structure deposited on said AlGaAs donor layer between gaps in said GaAs layer; and source and drain ohmic layers deposited on top of said GaAs layer on opposite sides of said gate structure.
Claim 2
Dependent Claim
114 words
A gallium arsenide (GaAs) field effect transistor comprising: a GaAs substrate layer; a buffer layer deposited on top of said GaAs substrate; an InGaAs quantum well deposited on top of said buffer; a layer of silicon planar doping within said InGaAs quantum well, and deposited near the bottom of said InGaAs quantum well; a donor layer of AlGaAs deposited on top of said InGaAs quantum well; an n-type GaAs contact layer deposited on top of said AlGaAs donor layer; a gate structure deposited on said AlGaAs donor layer between gaps in said GaAs layer; and source and drain ohmic layers deposited on top of said GaAs layer on opposite sides of said gate structure.
Claim 3
Dependent Claim
14 words
The transistor of claim 1 wherein said buffer layer is a superlattice type material.
Claim 4
Dependent Claim
28 words
The transistor of claim 1 wherein said InGaAs layer is approximately 150 angstroms thick and said silicon planer doping layer is located approximately 50 angstroms from the buffer.
Claim 5
Dependent Claim
16 words
The transistor of claim 3 wherein said InGaAs layer has an Indium mole fraction of 22%.
Claim 6
Dependent Claim
24 words
The transistor of claim 1 wherein said silicon planar doping layer in said InGaAs quantum well is composed of 1×10 12 cm -2 Si.
Claim 7
Dependent Claim
18 words
The transistor of claim 1 wherein said AlGaAs donor layer includes a silicon planer doping layer deposited within.
Claim 8
Dependent Claim
15 words
The transistor of claim 1 wherein said AlGaAs donor layer is approximately 300 angstroms thick.
Claim 9
Dependent Claim
17 words
The transistor of claim 7 wherein said AlGaAs layer has an aluminum mole fraction of approximately 25%.
Claim 10
Dependent Claim
17 words
The transistor of claim 1 wherein said n type GaAs contact layer is approximately 400 angstroms thick.
Claim 11
Dependent Claim
17 words
The transistor of claim 1 wherein said gate is a T-shaped gate of approximately 0.1-μm in length.
Claim 12
Dependent Claim
140 words
A high power pseudomorphic AlGaAs/InGaAs HEMT for use at microwave frequencies comprising: a GaAs substrate layer; a superlattice buffer layer deposited on top of said GaAs substrate; an InGaAs quantum well deposited on top of said buffer having an Indium mole fraction of approximately 22%, said quantum well being approximately 150 angstroms thick; a layer of silicon planar doping within said InGaAs quantum well deposited approximately 50 angstroms from the superlattice buffer; a donor layer of AlGaAs deposited on top of said InGaAs quantum well; an n-type GaAs contact layer deposited on top of said AlGaAs donor layer; a T-shaped gate structure of approximately 0.1 μm in length deposited on said AlGaAs donor layer between gaps in said GaAs layer; and source and drain ohmic layers deposited on top of said GaAs layer on opposite sides of said gate structure.
Claim 13
Dependent Claim
140 words
A high power pseudomorphic AlGaAs/InGaAs HEMT for use at microwave frequencies comprising: a GaAs substrate layer; a superlattice buffer layer deposited on top of said GaAs substrate; an InGaAs quantum well deposited on top of said buffer having an Indium mole fraction of approximately 22%, said quantum well being approximately 150 angstroms thick; a layer of silicon planar doping within said InGaAs quantum well deposited approximately 50 angstroms from the superlattice buffer; a donor layer of AlGaAs deposited on top of said InGaAs quantum well; an n-type GaAs contact layer deposited on top of said AlGaAs donor layer; a T-shaped gate structure of approximately 0.1 μm in length deposited on said AlGaAs donor layer between gaps in said GaAs layer; and source and drain ohmic layers deposited on top of said GaAs layer on opposite sides of said gate structure.
References Cited (Backward Citations)
US5023685A
Cited
US4935935A
Cited
US5021841A
Cited
US5012315A
Cited
US5079620A
Cited
US5099295A
Cited
US5012304A
Cited
US4978910A
Cited
US4975567A
Cited
US5023944A
Cited
US5091759A
Cited
US5038187A
Cited
US5004325A
Cited
US5132746A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-15 | 1997-05-17 | 1997-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-15 | 2001-05-17 | 2001-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-15 | 2005-05-17 | 2005-11-16 | $7700.00 | Window Closed / Lapsed |