MAGNETIC MEMORY WITH SPIN DEVICE ELEMENT EXHIBITING MAGNETORESISTIVE EFFECT

• US 20160260771A1
• Filed: 06/02/2015
• Published: 09/08/2016
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Bluespin, Inc.
• Original Assignee: Bluespin, Inc.
• Inventors: FUKUZAWA, Hideaki
• Granted Patent: US 9,847,374 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 30/204 using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

A magnetic memory includes a deformable base plate, a spin device element coupled with the deformable base plate and storing a data as a magnetization direction, and a bending mechanism to bend the deformable base plate. At least one of upper and lower surfaces of the deformable base plate faces a space which is not filled with solid substance.

Claims

1. A magnetic memory, comprising:

a deformable base plate;

at least one spin device element coupled with the deformable base plate and storing a data as a magnetization direction; and

a bending mechanism to bend the deformable base plate,

wherein at least one of upper and lower surfaces of the deformable base plate faces a space which is not filled with solid substance.

2. The magnetic memory according to claim 1, wherein the bending mechanism is configured to bend the deformable base plate with a piezoelectric effect.

3. The magnetic memory according to claim 1, wherein the spin device element is positioned opposed to the space which is not filled with solid substance, across the deformable base plate.

4. The magnetic memory according to claim 3, wherein the spin device element is coupled with the upper surface of the deformable base plate, and

wherein the lower surface of the deformable base plate faces the space which is not filled with solid substance.

5. The magnetic memory according to claim 1, wherein the bending mechanism includes a piezoelectric layer coupled with the deformable base plate.

6. The magnetic memory according to claim 1, wherein the deformable base plate includes:

a core layer;

a piezoelectric layer coupled with the core layer;

an electrode layer coupled with the piezoelectric layer; and

a dielectric layer covering the electrode layer and the core layer,

wherein the piezoelectric layer operates as the bending mechanism to bend the deformable base plate.

7. The magnetic memory according to claim 1,

wherein the bending mechanism includes a capacitor electrode,

wherein the deformable base plate includes an electrode layer,

wherein the capacitor electrode is opposed to the electrode layer, and

wherein the bending mechanism is configured to bend the deformable base plate by using a force exerted between the capacitor electrode and the electrode layer when a voltage is applied between the capacitor electrode and the electrode layer.

8. The magnetic memory according to claim 1, wherein the deformable base plate includes a deformable portion facing the space which is not filled with solid substance, and

wherein the deformable portion of the deformable base plate has a pair of fixed ends and a pair of free ends so that a first direction between the fixed ends is perpendicular to a second direction between the free ends.

9. The magnetic memory according to claim 8, wherein the spin device element includes a recording layer storing the data as the magnetization direction, and

wherein the recording layer has a first end facing the first direction and a second end facing a third direction opposite to the first direction,

wherein the spin device element is arranged so that a distance between a center plane of the deformable portion and the first end of the recording layer is different from a distance between the center plane of the deformable portion and the second end of the recording layer, the center plane being defined as a plane which is perpendicular to the first direction and equally distant from the fixed ends of the deformable portion.

10. The magnetic memory according to claim 8, wherein the spin device element includes a recording layer storing the data as the magnetization direction, and

wherein the spin device element is arranged so that the whole of the recording layer is located between a center plane of the deformable portion and one of the fixed ends of the deformable portion.

11. The magnetic memory according to claim 1, wherein the number of the at least one spin device element is plural, and

wherein the plurality of spin device elements are coupled with the deformable base plate.

12. A data writing method into a magnetic memory including:

a deformable base plate;

at least one spin device element coupled with the deformable base plate and storing a data as a magnetization direction; and

a bending mechanism, at least one of upper and lower surfaces of the deformable base plate facing a space which is not filled with solid substance, and the data writing method comprising;

writing a data into the spin device element by feeding a write signal to the spin device element in a state in which the deformable base plate is bent by the bending mechanism.

13. The data writing method according to claim 12, wherein the deformable base plate is bent by using a piezoelectric effect in the step of writing the data into the spin device element.

14. The data writing method according to claim 12, wherein the bending mechanism includes a piezoelectric layer coupled with the deformable base plate, and

wherein the deformable base plate is bent by applying an electric field to the piezoelectric layer in the step of writing the data into the spin device element.

15. The data writing method according to claim 12, wherein the bending mechanism includes a capacitor electrode,

wherein the deformable base plate includes an electrode layer,

wherein the capacitor electrode is opposed to the electrode layer, and

wherein the deformable base plate is bent by applying a voltage between the capacitor electrode and the electrode layer in the step of writing the data into the spin device element.

16. The data writing method according to claim 12, wherein the spin device element includes:

a reference layer having a fixed magnetization;

a recording layer having a reversible magnetization; and

a non-magnetic spacer layer across which the reference layer and the recording layer are opposed to each other,

wherein a write current is generated to flow between the reference layer and the recording layer in the step of writing the data, and

wherein a direction of the write current is determined based on the data to be written into the spin device element.

17. The data writing method according to claim 12, wherein the magnetic memory further includes a write current line disposed in a vicinity of the spin device element,

wherein, in the step of writing the data, a current-induced magnetic field is applied to the spin device element by generating a write current which flows through the write current line, and

wherein a direction of the write current is dependent on the data to be written into the spin device element.

18. The data writing method according to claim 12, wherein the bending mechanism includes a piezoelectric layer coupled with the deformable base plate, and

wherein the spin device element includes:

a reference layer having a fixed magnetization;

a recording layer having a reversible magnetization; and

a non-magnetic spacer layer across which the reference layer and the recording layer are opposed to each other,

wherein, in the step of writing the data, a write current is generated to flow between the reference layer and the recording layer with the deformable base plate bent by applying an electric field to the piezoelectric layer, and

wherein a direction of the write current is determined based on the data to be written into the spin device element.

19. The data writing method according to claim 12, wherein the bending mechanism includes a piezoelectric layer coupled with the deformable base plate, and

wherein the magnetic memory further includes a write current line disposed in a vicinity of the spin device element,

wherein, in the step of writing the data, a current-induced magnetic field is applied to the spin device element by generating a write current which flows through the write current line with the deformable base plate bent by applying an electric field to the piezoelectric layer, and

wherein a direction of the write current is determined based on the data to be written into the spin device element.

20. A semiconductor device, comprising:

a magnetic memory; and

a package incorporating the magnetic memory in an enclosing space formed in the package,

wherein the magnetic memory includes;

a deformable base plate;

at least one spin device element coupled with the deformable base plate and storing a data as a magnetization direction; and

a bending mechanism to bend the deformable base plate,

wherein the enclosed space includes such a cavity that at least one of upper and lower surfaces of the deformable base plate faces a space which is not filled with solid substance.