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US5416735A
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Non-volatile random access memory with ferroelectric capacitor
Assignee: Sharp Corp
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Filing: 1994-02-22
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Granted: 1995-05-16
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Expires: 2014-02-22
Abstract
Abstract Random access memory includes a pair of metal oxide semiconductor (MOS) transistors which are connected to each other by a common impurity diffusion region, and a capacitor which is formed of ferroelectric film acting as a capacitor layer and is connected to the impurity diffusion region, one of the pair of MOS transistors being connected to a bit line and a word line.
Inventors
- 👤 Shigeo Onishi
- 👤 Kenichi Tanaka
- 👤 Keizo Sakiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:00
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/22; H; H10; H10B; H10B53/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
170 words
A non-volatile random access memory including a plurality of memory cells, each memory cell comprising a pair of metal oxide semiconductor transistors, said transistors being connected to each other by a common impurity diffusion region, and a capacitor having a ferroelectric film acting as a capacitor dielectric layer, a first electrode of said capacitor being connected to said common impurity diffusion region and a second electrode; and in which one of said pair of metal oxide semiconductor transistors is connected to a bit line and a word line; and electric potentials of said second electrode of the capacitor and an impurity diffusion region provided at the opposite side to said common impurity diffusion region with respect to another of the pair of metal oxide semiconductor transistors are fixed at all times to an intermediate voltage between those available for representing data "1" and "0" and said another of the pair of metal oxide semiconductor transistors is non-conducting when writing or reading data to or from the non-volatile random access memory.
Claim 2
Dependent Claim
170 words
A non-volatile random access memory including a plurality of memory cells, each memory cell comprising a pair of metal oxide semiconductor transistors, said transistors being connected to each other by a common impurity diffusion region, and a capacitor having a ferroelectric film acting as a capacitor dielectric layer, a first electrode of said capacitor being connected to said common impurity diffusion region and a second electrode; and in which one of said pair of metal oxide semiconductor transistors is connected to a bit line and a word line; and electric potentials of said second electrode of the capacitor and an impurity diffusion region provided at the opposite side to said common impurity diffusion region with respect to another of the pair of metal oxide semiconductor transistors are fixed at all times to an intermediate voltage between those available for representing data "1" and "0" and said another of the pair of metal oxide semiconductor transistors is non-conducting when writing or reading data to or from the non-volatile random access memory.
Claim 3
Dependent Claim
15 words
A memory according to claim 1, said ferroelectric film is a lead zirconate titanate film.
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) | 1998-05-15 | 1998-11-14 | 1999-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-15 | 2002-11-14 | 2003-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-15 | 2006-11-14 | 2007-05-16 | $7700.00 | Window Closed / Lapsed |