MAGNETIC STORAGE DEVICE

• US 20180075890A1
• Filed: 03/15/2017
• Published: 03/15/2018
• Est. Priority Date: 09/13/2016
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Toshiba Memory Corporation (Kioxia Corporation)
• Inventors: INABA, Tsuneo
• Granted Patent: US 10,325,638 B2
• Time in Patent Office: Days
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1655 Bit-line or column circuits
• 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 11/1697 Power supply circuits
• CPC Class Codes: G11C 7/04 with means for avoiding disturbances due to temperature effects
• CPC Class Codes: G11C 7/1096 Write circuits, e.g. I/O line write drivers

Abstract

According to an embodiment, a magnetic storage device includes a memory cell including a magnetoresistive effect element including a storage layer and a reference layer; first and second line electrically coupled to the magnetoresistive effect element; and a write driver. The write driver supplies a first voltage to the first line in a first write operation in which a first resistance value of the magnetoresistive effect element is changed to a second resistance value smaller than the first resistance value, and supplies a second voltage different from the first voltage to the second line in a second write operation in which the second resistance value of the magnetoresistive effect element is changed to the first resistance value.

Claims

1. A magnetic storage device comprising:

a memory cell including a magnetoresistive effect element, the magnetoresistive effect element including a storage layer and a reference layer;

a first line electrically coupled to a first terminal of the magnetoresistive effect element;

a second line electrically coupled to a second terminal of the magnetoresistive effect element; and

a write driver,

wherein the write driver supplies a first voltage to the first line in a first write operation in which a first resistance value of the magnetoresistive effect element is changed to a second resistance value smaller than the first resistance value, and supplies a second voltage different from the first voltage to the second line in a second write operation in which the second resistance value of the magnetoresistive effect element is changed to the first resistance value.

2. The device of claim 1, wherein the first voltage is lower than the second voltage.

3. The device of claim 2, wherein the second voltage is lower than a power supply voltage

4. The device of claim 1, wherein a current flowing through the magnetoresistive effect element with the second resistance value in the first write operation is smaller than a current flowing through the magnetoresistive effect element with the second resistance value in the second write operation.

5. The device of claim 1, wherein a current flowing through the magnetoresistive effect element with the first resistance value in the first write operation is smaller than a current flowing through the magnetoresistive effect element with the first resistance value in the second write operation.

6. The device of claim 1, wherein the write driver includes:

a first transistor having a first terminal electrically coupled to the first line and a second terminal electrically coupled to the first voltage, the first .transistor being set to an on state in the first write operation to supply the first voltage to the first line and being set to an off state in the second write operation, and

a second transistor having a first terminal electrically coupled to the second line and a second terminal electrically coupled to the second voltage, the first transistor being set to the on state in the second write operation to supply the second voltage to the second line and being set to the off state in the first write operation.

7. The device of claim 6, wherein the first transistor has a smaller gate size than the second transistor.

8. A magnetic storage device comprising:

a memory cell including a magnetoresistive effect element, the magnetoresistive effect element including a storage layer and a reference layer;

a first line electrically coupled to a first terminal of the magnetoresistive effect element;

a second line electrically coupled to a second terminal of the magnetoresistive effect element;

a temperature detection element configured to detect a temperature;

a write driver; and

a voltage generator,

wherein the voltage generator generates a first voltage, and varies the generated first voltage according to the temperature,

wherein the write driver supplies the varied first voltage to the first line in a first write operation in which a first resistance value of the magnetoresistive effect element is changed to a second resistance value smaller than the first resistance value.

9. The device of claim 8, wherein the first voltage has a negative correlation with the temperature.

10. The device of claim 9,

wherein the voltage generator generates a second voltage, and the second voltage is uncorrelated with the temperature, and

wherein the write driver supplies the second voltage different from the first voltage to the second line in a second write operation in which the second resistance value of the magnetoresistive effect element is changed to the first resistance value.

11. The device of claim 8,

wherein the voltage generator generates a second voltage, and varies the generated second voltage according to the temperature,

wherein the write driver supplies the varied second voltage different from the first voltage to the second line in a second write operation in which the second resistance value of the magnetoresistive effect element is changed to the first resistance value.

12. The device of claim 11, wherein the second voltage has a positive correlation with the temperature.

13. The device of claim 12, wherein the first voltage has a negative correlation with the temperature.

14. The device of claim 13, wherein an amount of variation in the first voltage with respect to the temperature has a larger absolute value than an amount of variation in the second voltage with respect to the temperature.

15. The device of claim 11, wherein an amount of variation in the second voltage with respect to the temperature is larger than an amount of variation in the first voltage with respect to the temperature.

16. The device of claim 11;

wherein the first voltage is lower than the second voltage.

17. The device of claim 16, wherein the second voltage is lower than a power supply voltage.

18. The device of claim 11, wherein the write driver includes:

a first transistor having a first terminal electrically coupled to the first line and a second terminal electrically coupled to the first voltage, the first transistor being set to an on state in the first write operation to supply the first voltage to the first line and being set to an off state in the second write operation, and

a second transistor having a first terminal electrically coupled to the second line and a second terminal electrically coupled to the second voltage, the first transistor being set to the on state in the second write operation to supply the second voltage to the second line and being set to the off state in the first write operation.

19. The device of claim 18, wherein the first transistor has a smaller gate size than the second transistor.

20. The device of claim 19, wherein the first voltage is equal to or lower than the second voltage.