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US4733482A
Expired / Lapsed
US
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EEPROM with metal doped insulator
Assignee: Hughes Microelectronics Ltd
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Filing: 1987-04-07
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Granted: 1988-03-29
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Expires: 2007-04-07
Abstract
Abstract Insulating layers responsible for the trapping of electric charge in non-volatile semiconductor memories, such as FAMOS or MNOS, are fabricated as thicker layers when doped with metals having partially filled d or f electron shells. Typically the insulating layer is silicon oxide doped with up to 10 atomic % of a first transition series metal.
Inventors
- 👤 James L. West
- 👤 Alan E. Owen
- 👤 Komanduri V. Krishna
- 👤 Jaoquim J. Delima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:55
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/68; H10D30/681; H10D30/683
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A semiconductor memory device wherein non-volatile information is retained by storage of electrical charge trapped in or at a layer of the device surrounded by a dielectric layer, at least a portion of said dielectric layer comprising an amorphous inorganic oxide and/or nitride insulating material doped with a metal whose atomic number is 21 to 28, 39 to 45, or 57 to 78.
Claim 2
Dependent Claim
63 words
A semiconductor memory device wherein non-volatile information is retained by storage of electrical charge trapped in or at a layer of the device surrounded by a dielectric layer, at least a portion of said dielectric layer comprising an amorphous inorganic oxide and/or nitride insulating material doped with a metal whose atomic number is 21 to 28, 39 to 45, or 57 to 78.
Claim 3
Dependent Claim
13 words
A device according to claim 1 wherein the metal is a transition metal.
Claim 4
Dependent Claim
16 words
A device according to claim 2 wherein the metal is from the first transition metal series.
Claim 5
Dependent Claim
13 words
A device according to claim 3 wherein the metal is vanadium or cobalt.
Claim 6
Dependent Claim
22 words
A device according to claim 1 wherein the amorphous inorganic insulating material is silicon oxide, aluminum oxide, silicon oxynitride or silicon nitride.
Claim 7
Dependent Claim
17 words
A device according to claim 1 wherein the metal dopant concentration is up to 10 atomic percent.
Claim 8
Dependent Claim
23 words
A device according to claim 1 which has a floating gate disposed above a thin layer of the metal-doped amorphous inorganic insulating material.
Claim 9
Dependent Claim
26 words
A device according to claim 7 wherein the thickness of the thinnest part of said metal-doped amorphous inorganic insulating material layer is 200 to 1000 Angstroms.
Claim 10
Dependent Claim
35 words
A device according to claim 1 wherein the metal-doped amorphous inorganic insulating material layer has two predictable, stable conductance states, and said device operates with said layer in the lower of said two conductance states.
References Cited (Backward Citations)
US4494996A
Cited
EP0128061A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |