IP Library Granted Patent US 6,996,000
Granted Patent B2
US 6,996,000 · App. 10/961,429 · Granted Feb 7, 2006

Non-volatile ferroelectric SRAM

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Quick Facts
Patent No.
US 6,996,000
App. No.
10/961,429
Granted
Feb 7, 2006
Kind
B2
Abstract

A non-volatile SRAM memory comprising a plurality of memory cells, each memory cell including a SRAM memory cell portion and a ferroelectric memory cell portion including a ferroelectric element, the ferroelectric memory cell portion including a switch system for permitting the ferroelectric element to be isolated from the ferroelectric elements in all other memory cells.

Claims (22)

1. A non-volatile memory comprising a plurality of memory cells, each memory cell including: a SRAM memory cell portion and a ferroelectric memory cell portion including a ferroelectric element;

said memory including a data transfer circuit for transferring data from said SRAM cell portion to said ferroelectric memory cell portion when said memory is turned off and for transferring data from said ferroelectric memory cell portion to said SRAM memory cell when said memory is turned on; and

said ferroelectric memory cell portion including a switch system for isolating said ferroelectric element from the ferroelectric elements in all other said memory cells when said data is not being transferred.

2. A non-volatile memory as in claim 1 wherein said ferroelectric element is a capacitor.

3. A non-volatile memory as in claim 1 wherein said switch system comprises a transistor.

4. A non-volatile memory as in claim 1 wherein each of said ferroelectric memory cell portions include a first ferroelectric capacitor, a second ferroelectric capacitor, a first switch and a second switch, and wherein said first switch isolates said first ferroelectric capacitor and said second switch isolates said second ferroelectric capacitor.

5. A non-volatile memory as in claim 4 wherein said first ferroelectric capacitor and said first switch are connected in parallel, and said second ferroelectric capacitor and said second switch are connected in parallel.

6. A non-volatile memory cell as in claim 4 wherein said first ferroelectric capacitor and said first switch are connected in series, and said second ferroelectric capacitor and said second switch are connected in series.

7. A non-volatile memory as in claim 1 wherein said memory includes a plate line and said switch is connected between said ferroelectric element and said plate line.

8. A non-volatile memory comprising a plurality of memory cells, each memory cell including a SRAM memory cell portion and a ferroelectric memory cell portion including a ferroelectric element, said ferroelectric memory cell portion including a switch system for permitting said ferroelectric element to be isolated from the ferroelectric elements in all other of said memory cells.

9. A non-volatile memory as in claim 8 wherein said ferroelectric element is a capacitor.

10. A non-volatile memory as in claim 8 wherein said switch system comprises a transistor.

11. A non-volatile memory comprising a plurality of memory cells, each memory cell including: a SRAM memory cell portion and a ferroelectric memory cell portion including a ferroelectric element;

said memory including a data transfer circuit for transferring data from said SRAM cell portion to said ferroelectric memory cell portion when said memory is turned off and for transferring data from said ferroelectric memory cell portion to said SRAM memory cell when said memory is turned on; and

said ferroelectric memory cell portion including a switch system for creating a short circuit across said ferroelectric element when said SRAM portion is operating normally.

12. A non-volatile memory as in claim 11 wherein said ferroelectric element is a capacitor.

13. A non-volatile memory as in claim 12 wherein said switch system comprises a transistor.

14. A method of operating a non-volatile SRAM memory cell in a memory containing a plurality of said cells, said method comprising:

providing a SRAM memory cell portion and a ferroelectric memory cell portion including a ferroelectric element;

transferring data between said SRAM memory cell portion and said ferroelectric memory cell portion; and

isolating said ferroelectric element from all other ferroelectric elements in said memory when said data is not being transferred.

15. A method as in claim 14 wherein said ferroelectric element is a ferroelectric capacitor having two electrodes, said method further including shorting out the two electrodes of said ferroelectric element while said SRAM portion is operating normally.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 31, 2020
From: PANASONIC CORPORATION
To: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.
Reel/Frame 053362/0177 →
CHANGE OF NAME Recorded Mar 18, 2020
From: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
To: PANASONIC CORPORATION
Reel/Frame 052184/0943 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 13, 2004
From: SYMETRIX CORPORATION
To: SYMETRIX CORPORATION; MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Reel/Frame 016064/0476 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 13, 2004
From: CHEN, ZHANG; PAZ DE AGRAUJO, CARLOS A.; MCMILLAN, LARRY D.
To: SYMETRIX CORPORATION; MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Reel/Frame 016094/0866 →