IP Library › Granted Patent US 7,646,623
Granted Patent B2
US 7,646,623 · App. 11/608,391 · Granted Jan 12, 2010

Ferroelectric memory device and electronic apparatus

Assignee: Seiko Epson Corporation
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Quick Facts
Patent No.
US 7,646,623
App. No.
11/608,391
Granted
Jan 12, 2010
Kind
B2
Abstract

A ferroelectric memory device includes: a memory cell having a transistor and a ferroelectric capacitor connected in series between a bit line and a plate line, and a connecting section below the ferroelectric capacitor; a dummy cell having a transistor, a ferroelectric capacitor and a connecting section, wherein the dummy cell has an electrically disconnected section among the bit line, the transistor, the ferroelectric capacitor, the connecting section and the plate line.

Claims (18)

1. A ferroelectric memory device comprising:

a memory cell having a transistor and a ferroelectric capacitor connected in series between a bit line and a plate line, and a connecting section below the ferroelectric capacitor;

a dummy cell having a transistor, a ferroelectric capacitor and a connecting section, the dummy cell having an electrically disconnected section among the bit line, the transistor, the ferroelectric capacitor, the connecting section and the plate line, and the transistor of the dummy cell having a gate electrode, an isolation dielectric film formed below the gate electrode, and a source/drain region formed on each side of the gate electrode, a width of the isolation dielectric film being greater than a width of the gate electrode such that an end section of the gate electrode is separated from an end section of the source/drain region by a distance corresponding to a difference between the width of the isolation dielectric film and the width of the gate electrode.

2. A ferroelectric memory device comprising:

a first cell; and

a second cell, each of the first cell and the second cell having:

a gate electrode formed on a substrate;

first and second diffusion layers formed in the substrate on both sides of the gate electrode;

a connecting section formed on the first diffusion layer; and

a ferroelectric capacitor formed on the connecting section,

the second cell having an isolation dielectric film formed below the gate electrode of the second cell, a width of the isolation dielectric film being greater than a width of the gate electrode of the second cell;

wherein the gate electrode of the second cell is separated from an end section of the first diffusion layer of the second cell located adjacent to the gate electrode of the second cell by a distance corresponding to a difference between the width of the isolation dielectric film and the width of the gate electrode of the second cell.

3. A ferroelectric memory device according to claim 2 , wherein the gate electrode is separated from an end section of the second diffusion layer located adjacent to the gate electrode.

4. A ferroelectric memory device according to claim 2 , comprising another connecting section provided above the ferroelectric capacitor.

5. A ferroelectric memory device according to claim 2 , wherein the first cell and the second cell are formed in a memory region, wherein the second cell is located more outside than the first cell.

6. A ferroelectric memory device according to claim 2 , wherein a plurality of the first cells are disposed in an array, and the second cell is disposed in an outer circumference of the plurality of the first cells arranged in an array, or among the plurality of the first cells.

7. An electric apparatus comprising:

a ferroelectric memory device, wherein the ferroelectric memory device includes: a memory cell having a transistor and a ferroelectric capacitor connected in series between a bit line and a plate line, and a connecting section below the ferroelectric capacitor; a dummy cell having a transistor, a ferroelectric capacitor and a connecting section, wherein the dummy cell has an electrically disconnected section among the bit line, the transistor, the ferroelectric capacitor, the connecting section and the plate line, and the transistor of the dummy cell having a gate electrode, an isolation dielectric film formed below the gate electrode, and a source/drain region formed on each side of the gate electrode, a width of the isolation dielectric film being greater than a width of the gate electrode such that an end section of the gate electrode is separated from an end section of the source/drain region by a distance corresponding to a difference between the width of the isolation dielectric film and the width of the gate electrode.

Assignments (3)
CHANGE OF ADDRESS Recorded Dec 23, 2016
From: FUJITSU SEMICONDUCTOR LIMITED
To: FUJITSU SEMICONDUCTOR LIMITED
Reel/Frame 041188/0401 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 15, 2016
From: SEIKO EPSON CORPORATION
To: FUJITSU SEMICONDUCTOR LIMITED
Reel/Frame 037987/0149 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 8, 2006
From: KOIDE, YASUNORI
To: SEIKO EPSON CORPORATION
Reel/Frame 018603/0303 →
Priority Claims (1)
JP 2005-356944 · Dec 9, 2005 · national
Continuity (1)
Related Publication 20070133328A1 · Jun 14, 2007