Patent US1814841A successfully refreshed from Google Patents.
Patent US5506748A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5506748A Expired / Lapsed US ⏱️ 0.0 years remaining

Capacitor for semiconductor integrated circuit

Assignee: Rohm Co Ltd
•
Filing: 1994-10-03
•
Granted: 1996-04-09
•
Expires: 2014-10-03
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

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 06:26
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.

References Cited (Backward Citations)

US3599185A Cited
US4437139A Cited
US4827323A Cited
US5046043A Cited
US5029128A Cited
US5043049A Cited
JPH02304796A Cited
US5155573A Cited
US5122477A Cited
US5293510A Cited
US5164808A Cited

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

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag