US4453172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Field effect transistor with gate insulation of cubic fluoride material
Assignee: UK Secretary of State for Defence
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Filing: 1981-12-01
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Granted: 1984-06-05
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Expires: 2001-12-01
Abstract
Abstract An FET device comprises a substrate with source and drain regions separated by a gate structure. Between the gate and substrate is an insulator formed of a cubic fluorite structure material that is lattice matched within 1% to the substrate. The insulator may be a group II fluoride such as CayCd1-yF2 (0</=y</=1), SrzBa1-zF2 (0</=z</=1), or BaxCa1-xF2 (0</=x</=1), or an oxide such as CeO2, PbO2. The substrate may be a bulk semiconductor or an epitaxial layer such as Si, InP, GaAs, GaxAl1-xAs, GaSb, InAs, or AlAs.
Inventors
- 👤 Robin F. C. Farrow
- 👤 Gordon R. Jones
- 👤 Philip W. Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:07
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01342; H10D64/01358; H10D64/60; H10D64/66; H10D64/68; H10D64/691; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6332; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69396; H10P14/69397
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
106 words
A field effect transistor device comprising a semiconductor substrate, source and drain regions spaced apart on the substrate, and a gate arranged between the source and drain regions and separated from the substrate by a layer of electrically insulating material, the insulating layer being a cubic fluorite structure material selected from the group containing Ca y Cd 1-y F 2 where 0<y<1, Sr z Ba 1-z F 2 where 0<z<1, Ba x Ca 1-x F 2 where 0<x<1, having a lattice parameter that is different from the lattice parameter of the substrate by less than 1% over a temperature range of 25° C. to 200° C.
Claim 2
Dependent Claim
106 words
A field effect transistor device comprising a semiconductor substrate, source and drain regions spaced apart on the substrate, and a gate arranged between the source and drain regions and separated from the substrate by a layer of electrically insulating material, the insulating layer being a cubic fluorite structure material selected from the group containing Ca y Cd 1-y F 2 where 0<y<1, Sr z Ba 1-z F 2 where 0<z<1, Ba x Ca 1-x F 2 where 0<x<1, having a lattice parameter that is different from the lattice parameter of the substrate by less than 1% over a temperature range of 25° C. to 200° C.
Claim 3
Dependent Claim
27 words
A device according to claim 1 wherein the substrate is selected from the group containing Si, InP, GaAs, Ga x Al 1-x As, GaSb, InAs or AlAs.
Claim 4
Dependent Claim
20 words
A device according to claim 2 wherein the substrate is an epitaxial layer formed on a supporting semiconductor material base.
Claim 5
Dependent Claim
25 words
A device according to claim 1 wherein the substrate is Si and the insulating material is Ca 0 .58 Cd 0 .42 F 2 .
Claim 6
Dependent Claim
34 words
A device according to claim 1 wherein the substrate is InP and the insulating material is Sr 0 .8 Ba 0 .2 F 2 or Ca 0 .45 Ba 0 .55 F 2 .
Claim 7
Dependent Claim
25 words
A device according to claim 1 wherein the substrate is GaAs and the insulating material is Ca 0 .26 Ba 0 .74 F 2 .
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) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |