US5506748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitor for semiconductor integrated circuit
Assignee: Rohm Co Ltd
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Filing: 1994-10-03
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Granted: 1996-04-09
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Expires: 2014-10-03
Abstract
Abstract A first electrode, first ferroelectric thin-film, second electrode, second ferroelectric thin-film and third electrode are laid in this order on a source region of a field-effect transistor. The first and third electrodes are connected by a metal lead. The second electrode is connected to a ground line or a drive line.
Inventors
- 👤 Kazuhiro Hoshiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:23
CPC Classifications
H; H10; H10B; H10B53/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
182 words
A semiconductor integrated circuit nonvolatile memory unit, comprising: a semiconductor substrate; a switching transistor formed on the semiconductor substrate including spaced source and drain regions and a gate electrode spaced therefrom by an insulating layer; a capacitor comprising a first electrode, a first ferroelectric film, a second electrode, a second ferroelectric film and a third electrode which are laid in this order on one of the source and drain regions of the semiconductor substrate; the switching transistor and the capacitor electrodes and ferroelectric films being confined between spaced field oxide regions; an insulating layer extending over the switching transistor and the capacitor; a first conductive lead extending through the insulating layer to connect the first and third electrodes and providing one terminal of the capacitor, the first electrode being connected to said one of the source and drain regions on which the capacitor is formed; a second conductive lead connected to the second electrode and providing another terminal of the capacitor; and a third conductive lead extending through the insulating layer and connected to the other of the source and drain regions.
Claim 2
Dependent Claim
182 words
A semiconductor integrated circuit nonvolatile memory unit, comprising: a semiconductor substrate; a switching transistor formed on the semiconductor substrate including spaced source and drain regions and a gate electrode spaced therefrom by an insulating layer; a capacitor comprising a first electrode, a first ferroelectric film, a second electrode, a second ferroelectric film and a third electrode which are laid in this order on one of the source and drain regions of the semiconductor substrate; the switching transistor and the capacitor electrodes and ferroelectric films being confined between spaced field oxide regions; an insulating layer extending over the switching transistor and the capacitor; a first conductive lead extending through the insulating layer to connect the first and third electrodes and providing one terminal of the capacitor, the first electrode being connected to said one of the source and drain regions on which the capacitor is formed; a second conductive lead connected to the second electrode and providing another terminal of the capacitor; and a third conductive lead extending through the insulating layer and connected to the other of the source and drain regions.
Claim 3
Dependent Claim
20 words
The nonvolatile memory unit of claim 1, wherein the first and second ferroelectric films are made of lead zirconate titanate.
Claim 4
Dependent Claim
18 words
The nonvolatile memory unit of claim 1, wherein the first and second ferroelectric films are made of PLZT.
Claim 5
Dependent Claim
29 words
The nonvolatile memory unit of claim 1, wherein the switching transistor is a field-effect transistor, and the first electrode is formed on the source region of the field-effect transistor.
Claim 6
Dependent Claim
21 words
The nonvolatile memory unit of claim 4, wherein the second electrode is connected to a ground line or a drive line.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-09 | 1999-10-09 | 2000-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-09 | 2003-10-09 | 2004-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-09 | 2007-10-09 | 2008-04-09 | $7700.00 | Window Closed / Lapsed |