US3832700A
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Ferroelectric memory device
Assignee: Westinghouse Electric Corp
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Filing: 1973-04-24
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Granted: 1974-08-27
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Expires: 1993-04-24
Abstract
Abstract A ferroelectric memory device utilizing the remanent polarization of a thin, ferroelectric film to control the surface conductivity of a bulk semiconductor and perform the memory function. The structure of the device is similar to a conventional MIS field effect transistor with the exception that the gate insulating layer is replaced by a thin film of active ferroelectric material comprising a reversably polarizable dielectric exhibiting hysteresis.
Inventors
- 👤 S Wu
- 👤 M Francombe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:10
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/22; G11C16/00; G11C16/02; G11C16/04; G11C16/0466; H; H10; H10B; H10B53/00; H10D; H10D30/00; H10D30/60; H10D30/701; G11C11/223
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
14 words
The memory device of claim 1 wherein said film is formed by sputtering techniques.
Claim 2
Dependent Claim
72 words
The memory device of claim 1, with no injection and extraction of carriers at the ferroelectric-semiconductor interface, wherein said substrate is formed from P-type semiconductive material, said spaced regions are N+-type, and wherein an inversion layer defining an N-type channel connecting said N+-type regions is formed when a potential is applied and then removed between said ferroelectric film and said substrate such that the film is positive with respect to the substrate.
Claim 3
Dependent Claim
73 words
The memory device of claim 1, with no injection and extraction of carriers at the ferroelectric-semiconductor interface, wherein said substrate is formed from N-type semiconductive material and said spaced regions are P+-type, and wherein an inversion layer forming a P-type channel between said P+-type regions is formed when a potential is applied and then removed between said ferroelectric film and said substrate such that the film is negative with respect to the substrate.
Claim 4
Dependent Claim
70 words
The memory device of claim 1, with injection and extraction of carriers at the ferroelectric-semiconductor interface, wherein said substrate is formed from P-type semiconductive material, said spaced regions and N+-type, and wherein an inversion layer defining an N-channel connecting said N+-type regions is formed when a potential is applied and then removed between said ferroelectric film and said substrate such that the film is negative with respect to the substrate.
Claim 5
Dependent Claim
72 words
The memory device of claim 1, with injection and extraction of carriers at the ferroelectric-semiconductor interface, wherein said substrate is formed from N-type semiconductive material and said spaced regions are P+-type, and wherein an inversion layer forming a P-type channel between said P+-type regions is formed when a potential is applied and then removed between said ferroelectric film and said substrate such that the film is positive with respect to the substrate.
Claim 6
Dependent Claim
61 words
The memory device of claim 1 including metallizations in contact with said spaced regions and a metallization overlying said film of ferroelectric material spanning the space between said regions, the metallization over said ferroelectric film acting as a gate electrode and the metallization in contact with said spaced regions forming the source and drain electrodes of a field effect transistor structure.
Claim 7
Dependent Claim
13 words
The memory device of claim 1 wherein said ferroelectric material comprises bismuth titanate.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |