Non-volatile semiconductor integrated memory device

• US 6,198,652 B1
• Filed: 04/13/1999
• Issued: 03/06/2001
• Est. Priority Date: 04/13/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Abe, Kazuhide, Takashima, Daisaburo, Kawakubo, Takashi
• Primary Examiner(s): Hoang, Huan
• Application Number:
  US09/289,940
• Time in Patent Office: 693 Days
• Field of Search: 365/145, 365/149, 365/65, 365/117, 257/295, 257/300
• US Class Current: 365/145
• CPC Class Codes: G11C 11/22 using ferroelectric elements
• CPC Class Codes: G11C 11/223 using MOS with ferroelectric gate insulating film
• CPC Class Codes: H10B 53/00 Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors

Abstract

A semiconductor integrated memory device comprises a plurality of memory cell blocks, which are formed in the form of a matrix and each of which comprises: a memory cell chain including a plurality of units, each comprising a ferroelectric memory capacitor and a control transistor connected in parallel thereto; a reference capacitor of a unit comprising a reference capacitor and a control transistor connected in parallel thereto; a read transistor having a gate electrode connected to a connection point between the memory cell chain and the reference cell; and a control transistor for adjusting potentials of storage node which is a connection point of the first electrode of the memory capacitor, the third electrode of the reference capacitor and the read transistor. With this construction, the semiconductor integrated memory device is able to be easily produced, to stably retain a ferroelectric polarization and to scale down.

Claims

1. A semiconductor integrated memory device comprising a plurality of memory cells, which are arranged in the form of a matrix and each of which comprises:

a memory capacitor having at least a first electrode, a second electrode facing said first electrode, and a ferroelectric thin-film sandwiched between said first and second electrodes;

a reference capacitor having at least a third electrode connected to said first electrode, a fourth electrode facing said third electrode, and a dielectric thin-film sandwiched between said third and fourth electrodes;

a read transistor having a gate electrode connected to said first and third electrodes; and

a control transistor for adjusting potentials of storage node which is a connection point of said first electrode of said memory capacitor, said third electrode of said reference capacitor and said gate electrode of said read transistor.

2. A semiconductor integrated memory device as set forth in claim 1, wherein said control transistor is connected to between said first and second electrodes of said memory capacitor.

3. A semiconductor integrated memory device as set forth in claim 2, wherein said control transistor is connected to between said third and fourth electrodes of said reference capacitor.

4. A semiconductor integrated memory device as set forth in claim 1, wherein said control transistor is connected to between said third and fourth electrodes of said reference capacitor.

5. A semiconductor integrated memory device as set forth in claim 1, the amount of charges, which include a polarization inverting component obtained when a voltage corresponding to a read voltage is applied to said reference capacitor, is greater than or equal to one-fourth and less than or equal to four times as large as the amount of charges, which include a polarization inverting component obtained when a voltage corresponding to the read voltage is applied to said memory capacitor.

6. A semiconductor integrated memory device comprising a plurality of memory cell blocks, which are arranged in the form of a matrix and each of which comprises:

a memory cell column having a plurality of memory cells connected in series, each memory cell comprising a memory capacitor, which has at least a first electrode, a second electrode facing said first electrode, and a ferroelectric thin-film sandwiched between said first and second electrodes, and a control transistor connected to between said first and second electrodes;

a reference capacitor having at least a third electrode, which electrically connected to said first electrode of said memory capacitor arranged at one end of said memory cell column, a fourth electrode facing said third electrode, and a dielectric thin-film sandwiched between said third and fourth electrodes; and

a read transistor having a gate electrode electrically connected to said first and third electrodes.

7. A semiconductor integrated memory device as set forth in claim 6, wherein said control transistor connected to between said first and second electrodes of said memory cell serves as a first control transistor, and which further comprises a second control transistor provided between said third and fourth electrodes of said reference capacitor.

8. A semiconductor integrated memory device as set forth in claim 6, the amount of charges, which include a polarization inverting component obtained when a voltage corresponding to a read voltage is applied to said reference capacitor, is greater than or equal to one-fourth and less than or equal to four times as large as the amount of charges, which include a polarization inverting component obtained when a voltage corresponding to the read voltage is applied to said memory capacitor.

9. A semiconductor integrated memory device as set forth in claim 6, wherein said dielectric thin-film of said reference capacitor is a paraelectric thin-film.

10. A semiconductor integrated memory device as set forth in claim 6, wherein said dielectric thin-film of said reference capacitor is a ferroelectric thin-film.

11. A semiconductor integrated memory device comprising a plurality of memory cell blocks, which are arranged in the form of a matrix and each of which comprises:

a NAND type memory cell column comprising a plurality of selecting MOS transistors connected in series, and a plurality of memory capacitors of dielectric films, each of which is sandwiched between a storage electrode connected to a common main electrode of each of said selecting MOS transistors, and a plate electrode facing said storage electrode;

a reference capacitor electrically connected to a main electrode of said selecting transistor arranged at one end of said memory cell column; and

a read transistor having a gate electrode electrically connected to a connection part between a main electrode of said selecting MOS transistor and a main electrode of said reference capacitor.

12. A semiconductor integrated memory device as set forth in claim 11, further comprising a control transistor for adjusting potentials of storage nodes, which are all of connection points between said first electrode of said memory capacitor, said third electrode of said reference capacitor and said read transistor.

13. A semiconductor integrated memory device as set forth in claim 11, the amount of charges, which include a polarization inverting component obtained when a voltage corresponding to a read voltage is applied to said reference capacitor, is greater than or equal to one-fourth and less than or equal to four times as large as the amount of charges, which include a polarization inverting component obtained when a voltage corresponding to the read voltage is applied to said memory capacitor.

14. A semiconductor integrated memory device as set forth in claim 11, wherein said dielectric film of said memory capacitor is a ferroelectric film.

15. A semiconductor integrated memory device as set forth in claim 11, wherein said dielectric film of said memory capacitor is a paraelectric film, which is a non-linear capacitor that the maximum capacity value of said memory capacitor within an operating voltage range is greater than or equal to twice as large as the minimum capacity value thereof.

16. A semiconductor integrated memory device as set forth in claim 11, wherein said dielectric film of said reference capacitor is a ferroelectric film.

17. A semiconductor integrated memory device as set forth in claim 11, wherein said dielectric film of said reference capacitor is a paraelectric film.