MAGNETIC OSCILLATION ELEMENT AND SPIN WAVE DEVICE

• US 20120242438A1
• Filed: 09/21/2011
• Published: 09/27/2012
• Est. Priority Date: 03/25/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Morise, Hirofumi, Nakamura, Shiho, Kondo, Tsuyoshi, Kurosaki, Yoshinari
• Granted Patent: US 8,569,852 B2
• Time in Patent Office: Days
• US Class Current: 335/302
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G01R 33/1284 Spin resolved measurements; Influencing spins during measurements, e.g. in spintronics devices G01R33/093 takes precedence; semiconductor devices using spin polarized carriers H01L29/66984
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H01F 10/329 Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect
• CPC Class Codes: H01F 10/3295 Spin-exchange coupled multilayers wherein the magnetic pinned or free layers are laminated without anti-parallel coupling within the pinned and free layers
• CPC Class Codes: H03B 15/006 using spin transfer effects or giant magnetoresistance
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

According to one embodiment, a magnetic oscillation element includes a first electrode/a second magnetic layer/a nonmagnetic spacer layer/a first magnetic layer/ a second electrode, stacked in this order. The first magnetic layer has variable magnetization direction. The second magnetic layer has fixed magnetization direction. A thickness of the first magnetic layer in a direction connecting the first and second electrodes is greater than 2 times a spin penetration depth of the first magnetic layer. The thickness of the first magnetic layer is less than a maximum width of the second electrode. The first magnetic layer has edge portion provided outside the first surface when viewed along the direction. A width of the edge portion in a direction perpendicular to a tangent of an edge of the second electrode is not less than an exchange length of the first magnetic layer.

Claims

1. A magnetic oscillation element, comprising:

a first electrode;

a second electrode;

a first magnetic layer provided between the first electrode and the second electrode, the first magnetic layer having a variable magnetization direction;

a second magnetic layer provided between the first electrode and the first magnetic layer, the second magnetic layer having a fixed magnetization direction; and

a first spacer layer being nonmagnetic and provided between the first magnetic layer and the second magnetic layer,

a thickness of the first magnetic layer in a first direction connecting the first electrode and the second electrode being greater than 2 times a spin penetration depth of the first magnetic layer,

the thickness of the first magnetic layer being less than a maximum width of a first surface of the second electrode on the first magnetic layer side,

the first magnetic layer having a first edge portion provided outside the first surface when viewed along the first direction, a width of the first edge portion in a direction perpendicular to a tangent of an edge of the first surface being not less than an exchange length of the first magnetic layer.

2. The element according to claim 1, further comprising an antiferromagnetic layer provided between the second magnetic layer and the first electrode.

3. The element according to claim 1, further comprising:

a third magnetic layer provided between the first magnetic layer and the second electrode, the third magnetic layer having a fixed magnetization direction in a direction parallel to the magnetization direction of the second magnetic layer; and

a second spacer layer being nonmagnetic and provided between the first magnetic layer and the third magnetic layer.

4. The element according to claim 1, wherein:

a magnetization of the first magnetic layer oscillates when a current is caused to flow between the first electrode and the second electrode;

the first magnetic layer has a first portion on the first electrode side and a second portion on the second electrode side; and

a phase of the oscillation of the magnetization of the first portion is different from a phase of the oscillation of the magnetization of the second portion.

5. The element according to claim 1, wherein a current is conducted from the first magnetic layer toward the second magnetic layer via the first electrode and the second electrode.

6. The element according to claim 1, wherein at least one selected from the first magnetic layer and the second magnetic layer includes an alloy including at least one element selected from the group consisting of Fe, Co, Ni, Mn, and Cr and at least one element selected from the group consisting of Pt, Pd, Ir, Ru, and Rh.

7. A magnetic oscillation element, comprising:

a first electrode;

a second electrode;

a first magnetic layer provided between the first electrode and the second electrode, the first magnetic layer having a variable magnetization direction;

a second magnetic layer provided between the second electrode and the first magnetic layer, the second magnetic layer having a fixed magnetization direction; and

a first spacer layer being nonmagnetic and provided between the first magnetic layer and the second magnetic layer,

a thickness of the first magnetic layer in a first direction connecting the first electrode and the second electrode being greater than 2 times a spin penetration depth of the first magnetic layer,

the thickness of the first magnetic layer being less than a maximum width of a first surface of the second electrode on the second, magnetic layer side,

the first magnetic layer having a first edge portion provided outside the first surface when viewed along the first direction, a width of the first edge portion in a direction perpendicular to a tangent of an edge of the first surface being not less than an exchange length of the first magnetic layer.

8. The element according to claim 7, wherein a width of the second magnetic layer in a second direction perpendicular to the first direction is smaller than a width of the first magnetic layer in the second direction.

9. The element according to claim 7, further comprising:

a third electrode juxtaposed with the second electrode in a direction intersecting the first direction;

a third magnetic layer provided between the third electrode and the first magnetic layer, the third magnetic layer having a fixed magnetization direction; and

a second spacer layer provided between the first magnetic layer and the third magnetic layer,

a thickness of the first magnetic layer being less than a maximum width of a second surface of the third electrode on the third magnetic layer side,

the first magnetic layer having a second edge portion provided outside the second surface when viewed along the first direction, a width of the second edge portion in a direction perpendicular to a tangent of an edge of the second surface being not less than an exchange length of the first magnetic layer.

10. The element according to claim 7, wherein:

a magnetization of the first magnetic layer oscillates when a current is caused to flow between the first electrode and the second electrode;

the first magnetic layer has a first portion on the first electrode side and a second portion on the second electrode side; and

a phase of the oscillation of the magnetization of the first portion is different from a phase of the oscillation of the magnetization of the second portion.

11. The element according to claim 7, wherein a current is conducted from the first magnetic layer toward the second magnetic layer via the first electrode and the second electrode.

12. The element according to claim 7, wherein at least one selected from the first magnetic layer and the second magnetic layer includes an alloy including at least one element selected from the group consisting of Fe, Co, Ni, Mn, and Cr and at least one element selected from the group consisting of Pt, Pd, Ir, Ru, and Rh.

13. A magnetic oscillation element, comprising:

a first electrode;

a second electrode;

a first magnetic layer provided between the first electrode and the second electrode, the first magnetic layer having a variable magnetization direction;

a second magnetic layer provided between the first electrode and the first magnetic layer, the second magnetic layer having a fixed magnetization direction;

a first spacer layer being nonmagnetic provided between the first magnetic layer and the second magnetic layer; and

a cap layer being nonmagnetic and provided between the first magnetic layer and the second electrode, the cap layer having a thickness of not more than 5 nanometers,

a thickness of the first magnetic layer in a first direction connecting the first electrode and the second electrode being greater than 2 times a spin penetration depth of the first magnetic layer,

the thickness of the first magnetic layer being less than a maximum width of a first surface of the second electrode on the first magnetic layer side,

the first magnetic layer having a first edge portion provided outside the first surface when viewed along the first direction, a width of the first edge portion in a direction perpendicular to a tangent of an edge of the first surface being not less than an exchange length of the first magnetic layer.

14. The element according to claim 13, wherein a current is conducted from the first magnetic layer toward the second magnetic layer via the first electrode and the second electrode.

15. A magnetic oscillation element, comprising:

a first electrode;

a second electrode;

a first magnetic layer provided between the first electrode and the second electrode, the first magnetic layer having a variable magnetization direction;

a second magnetic layer provided between the first electrode and the first magnetic layer, the second magnetic layer having a fixed magnetization direction; and

a first spacer layer being nonmagnetic and provided between the first magnetic layer and the second magnetic layer,

the first magnetic layer including;

a ferromagnetic fourth magnetic layer; and

a ferromagnetic fifth magnetic layer contacting the first spacer layer between the fourth magnetic layer and the first spacer layer,

a thickness of the first magnetic layer in a first direction connecting the first electrode and the second electrode being greater than 2 times a thickness of the fifth magnetic layer in the first direction,

the thickness of the first magnetic layer being less than a maximum width of a first surface of the second electrode on the first magnetic layer side,

the first magnetic layer having a first edge portion provided outside the first surface when viewed along the first direction, a width of the first edge portion in a direction perpendicular to a tangent of an edge of the first surface being not less than an exchange length of the fifth magnetic layer.

16. The element according to claim 15, wherein the maximum width of the first surface is not more than 100 nanometers.

17. The element according to claim 15, wherein the fifth magnetic layer includes an alloy including at least one selected from the group consisting of Fe, Co, and Ni or an alloy including at least one selected from the group consisting of Fe, Co, Ni, Mn, and Cr.

18. A magnetic oscillation element, comprising:

a first electrode;

a second electrode;

a first magnetic layer provided between the first electrode and the second electrode, the first magnetic layer having a variable magnetization direction;

a second magnetic layer provided between the first electrode and the first magnetic layer, the second magnetic layer having a fixed magnetization direction;

a first spacer layer being nonmagnetic and provided between the first magnetic layer and the second magnetic layer; and

a cap layer being nonmagnetic and provided between the first magnetic layer and the second electrode, the cap layer having a thickness of not more than 5 nanometers,

the first magnetic layer including;

a ferromagnetic fourth magnetic layer; and

a ferromagnetic fifth magnetic layer contacting the first spacer layer between the fourth magnetic layer and the first spacer layer,

a thickness of the first magnetic layer in a first direction connecting the first electrode and the second electrode being greater than 2 times a thickness of the fifth magnetic layer in the first direction,

a thickness of the first magnetic layer being less than a maximum width of a first surface of the second electrode on the first magnetic layer side,

the first magnetic layer having a first edge portion provided outside the first surface when viewed along the first direction, a width of the first edge portion in a direction perpendicular to a tangent of an edge of the first surface being not less than an exchange length of the fifth magnetic layer.

19. The element according to claim 18, wherein the maximum width of the first surface is not more than 100 nanometers.

20. A spin wave device, comprising:

a first electrode;

a second electrode;

a third electrode juxtaposed with the second electrode in a direction intersecting a first direction connecting the first electrode and the second electrode;

a first magnetic layer provided between the first electrode and the second electrode and between the first electrode and the third electrode, the first magnetic layer having a variable magnetization direction;

a second magnetic layer provided between the first magnetic layer and the second electrode, the second magnetic layer having a fixed magnetization direction;

a first spacer layer being nonmagnetic and provided between the first magnetic layer and the second magnetic layer;

a third magnetic layer provided between the first magnetic layer and the third electrode, the third magnetic layer having a fixed magnetization direction; and

a second spacer layer being nonmagnetic and provided between the first magnetic layer and the third magnetic layer,

a thickness of the first magnetic layer in the first direction being greater than 2 times a spin penetration depth of the first magnetic layer,

the thickness of the first magnetic layer being less than a maximum width of a first surface of the second electrode on the second magnetic layer side,

the first magnetic layer having a first edge portion provided outside the first surface when viewed along the first direction, a width of the first edge portion in a direction perpendicular to a tangent of an edge of the first surface being not less than an exchange length of the first magnetic layer.