Magnetoresistance effect element and magnetic memory

• US 9,202,545 B2
• Filed: 03/25/2013
• Issued: 12/01/2015
• Est. Priority Date: 04/09/2012
• Status: Active Grant

• Current Assignee: Tohoku University National Universities Corporation
• Original Assignee: Tohoku University National Universities Corporation
• Inventors: Yamanouchi, Michihiko, Ikeda, Shoji, Matsukura, Fumihiro, Ohno, Hideo, Sato, Hideo, Fukami, Shunsuke
• Primary Examiner(s): Ho, Hoai V
• Assistant Examiner(s): Mancera, Roberto
• Application Number:
  US14/390,324
• Publication Number:
  US 20150109853A1
• Time in Patent Office: 981 Days
• Field of Search: 365/158, 365/171, 365/173, 257/E27.005, 257/E21.665, 257/295, 257/E43.004
• US Class Current: 1/1
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• 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 11/1653 Address circuits or decoders
• CPC Class Codes: G11C 11/1655 Bit-line or column 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: H01F 10/3286 Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
• 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: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A magnetoresistance effect element including a recording layer of high thermal stability to perform perpendicular magnetic recording within a film surface, and a magnetic memory using the element. The element includes: a first ferromagnetic layer of an invariable magnetization direction; a second ferromagnetic layer of a variable magnetization direction; a first non-magnetic layer between the first and second ferromagnetic layers; current supply terminals connected to the first and second ferromagnetic layers; a non-magnetic coupling layer on a surface of the second ferromagnetic layer opposite the first non-magnetic layer; a third ferromagnetic layer of a variable magnetization direction on a surface of the non-magnetic coupling layer opposite the second ferromagnetic layer; and a second non-magnetic layer on a surface of the third ferromagnetic layer opposite the non-magnetic coupling layer. The second and third ferromagnetic layers have the same magnetization direction and are reversed in magnetization by spin injection with a current.

Claims

1. A magnetoresistance effect element, comprising:

a fixed layer including a first ferromagnetic layer of a magnetization direction invariable in a direction perpendicular to a film surface;

a second ferromagnetic layer of a magnetization direction variable in the direction perpendicular to the film surface;

a first non-magnetic layer adjacent to the second ferromagnetic layer;

a non-magnetic coupling layer adjacent to a surface of the second ferromagnetic layer on a side opposite the first non-magnetic layer;

a third ferromagnetic layer of a magnetization direction variable in the direction perpendicular to the film surface adjacent to a surface of the non-magnetic coupling layer on a side opposite the second ferromagnetic layer; and

a second non-magnetic layer adjacent to a surface of the third ferromagnetic layer on a side opposite the non-magnetic coupling layer,

wherein the second and third ferromagnetic layers each include at least one of Fe, Co and Ni and include at least one of B, C, N, O, F, Si, Al, P and S in order to place each of the second and third ferromagnetic layers in an amorphous condition immediately after thin film deposition thereof,

the second and third ferromagnetic layers have the same magnetization direction, and a total of the respective thicknesses of the second and third ferromagnetic layers is 2 nm or more, and

the non-magnetic coupling layer has a thickness of 0.3 nm or more and less than 1.0 nm.

2. The magnetoresistance effect element according to claim 1, wherein the non-magnetic coupling layer is made of metal including at least one of Ta, Hf, Zr, Nb, Mo and Ti.

3. The magnetoresistance effect element according to claim 1, wherein the first and second non-magnetic layers include at least one of N, O and C.

4. The magnetoresistance effect element according to claim 1, wherein the non-magnetic coupling layer is metal including Ta.

5. The magnetoresistance effect element according to claim 1, wherein the second and third ferromagnetic layers have a thickness from 0.8 to 60 nm.

6. The magnetoresistance effect element according to claim 1, wherein the second and third ferromagnetic layers include Co, Fe and B.

7. The magnetoresistance effect element according to claim 1, wherein the first and second non-magnetic layers are made of magnesium oxide.

8. The magnetoresistance effect element according to claim 1, comprising:

a first current terminal connected to the first ferromagnetic layer; and

a second current terminal connected to the second ferromagnetic layer, wherein

the first ferromagnetic layer is adjacent to a surface opposite the second ferromagnetic layer with respect to the first non-magnetic layer, and

the second and third ferromagnetic layers are reversed in magnetization by spin injection with a current.

9. The magnetoresistance effect element according to claim 1, comprising a first current terminal, a second current terminal, and a third current terminal, wherein

the second and third ferromagnetic layers include a first magnetization fixed area, a second magnetization fixed area, and a magnetization free area of a variable magnetization direction, the first and second magnetization fixed areas being magnetized in opposite directions,

the fixed layer is connected to the first current terminal,

the first magnetization fixed area is connected to the second current terminal, and

the second magnetization fixed area is connected to the third current terminal.

10. A magnetic memory comprising:

multiple source lines parallel to each other;

multiple word lines parallel to each other in a direction crossing the source lines;

multiple bit lines parallel to the source lines;

the magnetoresistance effect element as recited in claim 8 arranged in a place where the bit line and the word line cross each other; and

a circuit that applies a current in a direction perpendicular to a film surface of the magnetoresistance effect element, wherein

one of the first and second current terminals of the magnetoresistance effect element is electrically connected to a source electrode or a drain electrode of a selection transistor and the other of the first and second current terminals is electrically connected to the bit line,

the word line is electrically connected to a gate electrode of the selection transistor, and

the source line is electrically connected to the source electrode or the drain electrode of the selection transistor.

11. A magnetic memory comprising:

multiple first bit lines and multiple second bit lines parallel to each other;

multiple word lines parallel to each other in a direction crossing the first bit lines and the second bit lines;

the magnetoresistance effect element as recited in claim 9 arranged in a place where the first bit line and the second bit line cross the word line; and

a circuit that applies a current into a film surface of the magnetoresistance effect element and in a direction perpendicular to the film surface, wherein

the second current terminal is electrically connected to a source electrode or a drain electrode of a first selection transistor,

the third current terminal is electrically connected to a source electrode or a drain electrode of a second selection transistor,

the other of the source and drain electrodes of the first selection transistor is electrically connected to the first bit line,

the other of the source and drain electrodes of the second selection transistor is electrically connected to the second bit line, and

a gate electrode of the first selection transistor is connected to the word line and a gate electrode of the second selection transistor is connected to the word line.

12. A magnetoresistance effect element, comprising:

a fixed layer including a first ferromagnetic layer of a magnetization direction invariable in a direction perpendicular to a film surface;

a second ferromagnetic layer of a magnetization direction variable in the direction perpendicular to the film surface;

a first non-magnetic layer adjacent to the second ferromagnetic layer;

a non-magnetic coupling layer adjacent to a surface of the second ferromagnetic layer on a side opposite the first non-magnetic layer;

a third ferromagnetic layer of a magnetization direction variable in the direction perpendicular to the film surface adjacent to a surface of the non-magnetic coupling layer on a side opposite the second ferromagnetic layer; and

a second non-magnetic layer adjacent to a surface of the third ferromagnetic layer on a side opposite the non-magnetic coupling layer,

wherein the second and third ferromagnetic layers each include at least one of Fe, Co and Ni and include at least one of B, C, N, O, F, Si, Al, P and S,

the second and third ferromagnetic layers have the same magnetization direction, and a total of the respective thicknesses of the second and third ferromagnetic layers is 2 nm or more, and

the non-magnetic coupling layer has a thickness of 0.3 nm or more and less than 1.0 nm.