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US4589009A
Expired / Lapsed
US
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Non-volatile piezoelectric memory transistor
Assignee: United States Department of the Army
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Filing: 1984-10-09
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Granted: 1986-05-13
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Expires: 2004-10-09
Abstract
Abstract A piezoelectric double diffusion MOS structure in which three gates are inserted in the CVD oxide element. These gates are overlapped layers of CVD polysilicon on top of the ZnO and are capacitively coupled to the silicon substrate. The charge is placed on the middle floating gate and is retained because of the oxide layers which separate the gates. A program erase, gate is provided for discharging the floating gate and to set the modes.
Inventors
- 👤 Manouchehr E. Motamedi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:25
CPC Classifications
H; H10; H10D; H10D48/00; H10D48/50; H10D30/00; H10D30/60; H10D30/68; H10D30/681; H10D30/683
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
146 words
In a piezoelectric double diffusion MOS structure having a silicon base with ZnO film thereon and a CVD oxide element between ZnO film and a gate connection; the improvement comprising adding overlapping layers of CVD polysilicon on top of the ZnO film; said overlapping layers being separated by thin oxide layers; said structure being formed on a silicon substrate; one of said overlapping layers is a floating gate which is coupled capacitively to the silicon substrate to form a transistor whereby the presence or absence of a charge on the floating gate determines whether the transistor is on or off; once a charge is on the floating gate the charge will remain trapped as the oxide forms a barrier to the flow of current; and another of the overlapping layers form the function of an erase gate for dissipating a trapped charge in the floating gate.
Claim 2
Dependent Claim
146 words
In a piezoelectric double diffusion MOS structure having a silicon base with ZnO film thereon and a CVD oxide element between ZnO film and a gate connection; the improvement comprising adding overlapping layers of CVD polysilicon on top of the ZnO film; said overlapping layers being separated by thin oxide layers; said structure being formed on a silicon substrate; one of said overlapping layers is a floating gate which is coupled capacitively to the silicon substrate to form a transistor whereby the presence or absence of a charge on the floating gate determines whether the transistor is on or off; once a charge is on the floating gate the charge will remain trapped as the oxide forms a barrier to the flow of current; and another of the overlapping layers form the function of an erase gate for dissipating a trapped charge in the floating gate.
Claim 3
Dependent Claim
28 words
A structure as set forth in claim 2 wherein the overlapping layers are three in number, and the remaining layer is designed to be an electrical reference potential.
Claim 4
Dependent Claim
31 words
A structure as set forth in claim 2 wherein piezoelectric oxide and the floating gate combination provide an ability to store stressed induced charges in a large time-bandwidth convolution and correlation.
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) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |