US5448084A
Expired / Lapsed
US
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Field effect transistors on spinel substrates
Assignee: OL Security LLC
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Filing: 1991-05-24
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Granted: 1995-09-05
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Expires: 2011-05-24
Abstract
Abstract A field effect transistor including a substrate comprised of a material having a spinel crystal structure and a buffer layer lattice matched to the crystal structure of the substrate comprising gallium aluminum indium arsenide is described. Several types of field effect transistors are possible with the described substrate arrangement, including metal semiconductor field effect transistors, insulating gate field effect transistors, pseudomorphically strained and pseudomorphically strain compensated metal semiconductor field effect transistors, as well as, high electron mobility transistor structures.
Inventors
- 👤 William E. Hoke
- 👤 H. Jerrold Van Hook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:28
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/80; H10D30/87; H10D30/875; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732; H10D30/801
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
116 words
A semiconductor device comprising: a substrate comprised of a material having a spinel crystal structure, such substrate having a surface, such surface having a (100) crystallographic orientation in the plane of such surface; and a buffer layer disposed on said surface, such buffer layer being comprised of (Ga 1-X Al X ) 1-Y In Y As, said composition ratio Y being selected to provide a buffer layer having a lattice constant which is substantially matched to a lattice constant of the material of the substrate, and wherein said spinel material of the substrate has a crystal structure including a cubic sublattice crystal structure having a lattice constant to which the buffer layer is substantially matched thereto.
Claim 2
Dependent Claim
116 words
A semiconductor device comprising: a substrate comprised of a material having a spinel crystal structure, such substrate having a surface, such surface having a (100) crystallographic orientation in the plane of such surface; and a buffer layer disposed on said surface, such buffer layer being comprised of (Ga 1-X Al X ) 1-Y In Y As, said composition ratio Y being selected to provide a buffer layer having a lattice constant which is substantially matched to a lattice constant of the material of the substrate, and wherein said spinel material of the substrate has a crystal structure including a cubic sublattice crystal structure having a lattice constant to which the buffer layer is substantially matched thereto.
Claim 3
Dependent Claim
31 words
The device, as recited in claim 1, wherein said substrate is comprised of magnesium aluminate and said buffer layer is (Ga 1-X Al X ) 0 .85 In 0 .15 As.
Claim 4
Dependent Claim
132 words
A semiconductor device comprising: a substrate comprised of a material having a spinel crystal structure, such substrate having a surface disposed in the (100) crystallographic plane and a lattice constant A 0 ; a buffer layer disposed on said surface, such buffer layer being comprised of (Ga 1-x Al x ) 1-y In y As where y is selected to provide buffer layer with a lattice constant which is substantially matched to a sublattice constant, A 0 /√2, where A 0 is the lattice constant of the spinel material of the substrate; and a channel layer disposed over said buffer layer comprised of a layer of Ga 1-Z In Z As; means for providing a Schottky barrier contact over said channel layer; and means for providing ohmic collection from said channel layer.
Claim 5
Dependent Claim
132 words
A semiconductor device comprising: a substrate comprised of a material having a spinel crystal structure, such substrate having a surface disposed in the (100) crystallographic plane and a lattice constant A 0 ; a buffer layer disposed on said surface, such buffer layer being comprised of (Ga 1-x Al x ) 1-y In y As where y is selected to provide buffer layer with a lattice constant which is substantially matched to a sublattice constant, A 0 /√2, where A 0 is the lattice constant of the spinel material of the substrate; and a channel layer disposed over said buffer layer comprised of a layer of Ga 1-Z In Z As; means for providing a Schottky barrier contact over said channel layer; and means for providing ohmic collection from said channel layer.
Claim 6
Dependent Claim
35 words
The field effect transistor, as recited in claim 3, wherein said substrate is comprised of magnesium aluminate and said buffer layer is comprised of (Ga 1-x Al x ) 0 .85 In 0 .15 As.
Claim 7
Dependent Claim
29 words
The field effect transistor, as recited in claim 4, wherein said channel layer has a composition (Z) of Ga 1-Z In Z As where Z≦0.2 and is doped N-type.
Claim 8
Dependent Claim
46 words
The transistor, as recited in claim 5, wherein said channel layer has a composition of Ga 1-Z In Z As where Z≦0.15 and said Schottky barrier contact is disposed on said channel layer and said means for providing ohmic collection are disposed over said channel layer.
Claim 9
Dependent Claim
22 words
The transistor, as recited in claim 5, wherein said channel layer has a composition ratio (Z) of indium to arsenic of 0.15<Z≦0.2.
Claim 10
Dependent Claim
24 words
The transistor, as recited in claim 4, further comprising a charge donor layer disposed adjacent said channel layer, with said channel layer being undoped.
Claim 11
Dependent Claim
21 words
The transistor, as recited in claim 8, wherein said channel layer has a composition Z of indium to arsenic of Z=0.15.
Claim 12
Dependent Claim
21 words
The transistor, as recited in claim 8, wherein said channel layer has a composition Z of indium to arsenic of Z>0.15.
Claim 13
Dependent Claim
47 words
The transistor, as recited in claim 8, wherein the channel layer has a composition Z of indium to gallium of Z>0.2 and wherein the transistor further comprises: a strain compensation layer disposed adjacent said channel layer having strain characteristics opposite to strain characteristics of said channel layer.
Claim 14
Dependent Claim
29 words
The transistor, as recited in claim 3, further comprising: an insulating layer disposed between the channel layer and the means for providing Schottky barrier contact over said channel layer.
Claim 15
Dependent Claim
15 words
The transistor, as recited in claim 12, wherein said insulating layer is aluminum indium arsenide.
Claim 16
Dependent Claim
79 words
The transistor, as recited in claim 4, further comprising: a strain compensation layer disposed between said buffer layer and said channel layer having a strain characteristic opposite to the strain characteristic of said channel layer and comprised of (Ga 1-x Al x )As; with said channel layer having a composition ratio (Z) of indium to arsenic of Z>0.2; and having a charge donor layer disposed over said channel layer with said charge donor layer comprised of gallium aluminum arsenide.
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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) | 1998-09-04 | 1999-03-06 | 1999-09-05 | $2000.00 | Window Closed / Lapsed |
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