Thin film magnetic memory device having a highly integrated memory array

• US 6,608,776 B2
• Filed: 04/11/2001
• Issued: 08/19/2003
• Est. Priority Date: 11/14/2000
• Status: Expired due to Term

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hidaka, Hideto
• Primary Examiner(s): NGUYEN, VAN THU T
• Application Number:
  US09/832,025
• Publication Number:
  US 20020057593A1
• Time in Patent Office: 860 Days
• Field of Search: 365/171, 365/173, 365/158, 365/51, 365/63
• US Class Current: 365/171
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11C 11/15 using multiple magnetic layers G11C11/155 takes precedence
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/1653 Address circuits or decoders
• CPC Class Codes: G11C 11/1657 Word-line or row circuits
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 11/1693 Timing circuits or methods
• CPC Class Codes: G11C 5/025 Geometric lay-out considerations of storage- and peripheral-blocks in a semiconductor storage device geometrical lay-out of the components in integrated circuits, H01L27/0207
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type

Abstract

Read word lines and write word lines are provided corresponding to the respective MTJ (Magnetic Tunnel Junction) memory cell rows, and bit lines and reference voltage lines are provided corresponding to the respective MTJ memory cell columns. Adjacent MTJ memory cells share at least one of these signal lines. As a result, the pitches of signal lines provided in the entire memory array can be widened. Thus, the MTJ memory cells can be efficiently arranged, achieving improved integration of the memory array.

Claims

1. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a plurality of reference voltage lines provided corresponding to either the respective rows or the respective columns, for supplying a reference voltage to be used in said data read operation, wherein

adjacent magnetic memory cells share a corresponding one of at least one of said plurality of write word lines, said plurality of read word lines, said plurality of data lines and said plurality of reference voltage lines,

every two of said plurality of data lines form a data line pair in said data read operation and said data write operation,

the magnetic memory cells selected by a same read word line are respectively connected to one of the two data lines of each of said data line pairs, and a plurality of magnetic memory cells selected by a same write word line are respectively connected to the other data line of each of said data line pairs,

said data read current is supplied to each of the two data lines of the data line pair corresponding to a column selection result, and

said first data write current is supplied to each of said two data lines as currents of opposite directions.

2. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a word line current control circuit for coupling said plurality of write word lines to a reference voltage that is used in said data read operation, wherein

said magnetic storage portion and said memory cell selection gate are connected in series between ones of said plurality of write word lines and plurality of data lines in each of said plurality of magnetic memory cells, and

adjacent magnetic memory cells share a corresponding one of at least one of said plurality of write word lines, said plurality of read word lines and said plurality of data lines.

10. The thin film magnetic memory device according to claim 2, wherein that pair of two magnetic memory cells of said plurality of magnetic memory cells, which are adjacent along said columns share a corresponding one of at least one of said plurality of write word lines and said plurality of read word lines.

11. The thin film magnetic memory device according to claim 2, wherein that pair of two magnetic memory cells of said plurality of magnetic memory cells, which are adjacent along said rows share a corresponding one of said plurality of data lines.

3. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing, a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a word line current control circuit for coupling said plurality of write word lines to a reference voltage that is used in said data read operation, wherein

adjacent magnetic memory cells share a corresponding one of at least one of said plurality of write word lines, said plurality of read word lines and said plurality of data lines,

said adjacent magnetic memory cells share one of the corresponding write word line and the corresponding data line, which is located farther from the respective magnetic storage portions, and

said one of the write word line and the data line has a larger cross-sectional area than that of the other of the write word line and the data line.

4. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing, a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a word line current control circuit for coupling said plurality of write word lines to a reference voltage that is used in said data read operation, wherein

adjacent magnetic memory cells share a corresponding one of at least one of said plurality of write word lines, said plurality of read word lines and said plurality of data lines,

one of each write word line and each data line, which is located farther from the corresponding magnetic storage portions, is formed from a material having higher electromigration resistance than that of the other of each write word line and each data line.

5. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing, a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a word line current control circuit for coupling said plurality of write word lines to a reference voltage that is used in said data read operation, wherein

adjacent magnetic memory cells share a corresponding one of at least one of said plurality of write word lines, said plurality of read word lines and said plurality of data lines,

adjacent magnetic memory cells in the column direction share a corresponding one of said plurality of write word lines,

every two of said plurality of data lines form a data line pair in said data read operation,

the magnetic memory cells selected by a same read word line are respectively connected to one of the two data lines of each of said data line pairs, and

said data read current is supplied to each of the two data lines of the data line pair corresponding to a column selection result.

6. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing, a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a word line current control circuit for coupling said plurality of write word lines to a reference voltage that is used in said data read operation, wherein

adjacent magnetic memory cells share a corresponding one of at least one of said plurality of write word lines, said plurality of read word lines and said plurality of data lines,

adjacent magnetic memory cells in the column direction share a corresponding one of said plurality of read word lines,

every two of said plurality of data lines form a data line pair in said data write operation,

a plurality of magnetic memory cells selected by a same write word line are respectively connected to one of the two data lines of each of said data line pairs, and

said first data write current is supplied to each of the two data lines of the data line pair corresponding to a column selection result as currents of opposite directions.

7. The thin film magnetic memory device according to claim 6, further comprising:

a switching circuit for electrically coupling the two data lines of said data line pair to each other in said data write operation, and

a data write circuit for supplying first and second voltages respectively to the two data lines of said data line pair corresponding to the column selection result in said data write operation.

8. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided, corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a plurality of reference voltage lines provided corresponding to either the respective rows or the respective columns, for supplying a reference voltage to be used in said data read operation, wherein

that pair of two magnetic memory cells of said plurality of magnetic memory cells which are adjacent along said columns share a corresponding one of at least one of said plurality of write word lines and said plurality of read word lines.

9. A thin film magnetic memory device, comprising:

a memory array having a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including

a magnetic storage portion having a resistance value that varies according to a level of storage data to be written by first and second data write currents, and

a memory cell selection gate for passing a data read current therethrough into said magnetic storage portion in a data read operation;

a plurality of read word lines provided corresponding to the respective rows of the magnetic memory cells, for actuating the corresponding memory cell selection gate according to a row selection result in said data read operation;

a plurality of data lines provided corresponding to the respective columns of the magnetic memory cells, for causing said first data write current and said data read current to flow therethrough in a data write operation and said data read operation, respectively;

a plurality of write word lines provided corresponding to the respective rows, and selectively activated according to a row selection result in said data write operation so as to cause said second data write current to flow therethrough; and

a plurality of reference voltage lines provided corresponding to either the respective rows or the respective columns, for supplying a reference voltage to be used in said data read operation, wherein

that pair of two magnetic memory cells of said plurality of magnetic memory cells which are adjacent along said rows share a corresponding one of said plurality of data lines.