CN110034230B - Magnetoresistance effect device - Google Patents

Abstract

The present invention provides a magnetoresistance effect device including a magnetoresistance effect element and a magnetic field applying mechanism for applying a magnetic field to the magnetoresistance effect element, the magnetic field applying mechanism including: a first ferromagnetic body having a convex portion protruding toward the magnetoresistance effect element in a lamination direction of the magnetoresistance effect element, a second ferromagnetic body sandwiching the magnetoresistance effect element together with the first ferromagnetic body, and a coil wound around the first ferromagnetic body, wherein the first magnetization free layer of the magnetoresistance effect element has a portion that does not overlap with at least one of a second surface of the convex portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic body on the magnetoresistance effect element side when viewed from the lamination direction in a plan view, and a center of gravity of the first magnetization free layer is located in a region connecting the second surface and the third surface. This makes it possible to apply a magnetic field in an oblique direction to the magnetization free layer of the magnetoresistance effect element.

Description

Magnetoresistance effect device

Technical Field

The present invention relates to a magnetoresistance effect device.

Priority is claimed in the present application based on Japanese patent application No. 2017-235229, 2017, 12/7 and Japanese patent application No. 2018-150429, 2018, 8/9, and the contents of which are incorporated herein by reference.

Background

An element using spins possessed by a magnetic material is used for various purposes. For example, a Giant Magnetoresistance (GMR) element including a multilayer film of a ferromagnetic layer and a nonmagnetic layer, a Tunnel Magnetoresistance (TMR) element including a nonmagnetic layer using an insulating layer (tunnel barrier layer, barrier layer), and the like are known as a magnetoresistance effect element. The magnetoresistive effect element is used for a magnetic sensor, a high-frequency component, a magnetic head, a nonvolatile random access memory (MRAM), and the like.

For example, patent document 1 describes a high-frequency device using a ferromagnetic resonance phenomenon of a magnetoresistive element. A high-frequency signal is applied to a ferromagnetic layer included in the magnetoresistive element, and magnetization of the ferromagnetic layer is ferromagnetically resonated. When the ferromagnetic resonance is generated, the resistance value of the magnetoresistance effect element periodically fluctuates at the ferromagnetic resonance frequency. The high-frequency device described in patent document 1 functions as a high-frequency filter by utilizing the change in the resistance value.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-063397

Disclosure of Invention

Technical problem to be solved by the invention

The magnetoresistance effect element is obtained by stacking very thin layers of the order of several nm. The performance of the magnetoresistance effect element is affected by the lamination surface on which the magnetoresistance effect element is laminated. Therefore, it is difficult to stack the magnetoresistance effect element on the inclined stacking surface. That is, it is difficult to provide a process in which the lamination direction is an oblique direction in the process of manufacturing a magnetoresistance effect device, and it is difficult to easily realize a magnetoresistance effect device capable of applying a magnetic field in an oblique direction to a magnetoresistance effect element.

The present invention has been made in view of the above problems, and provides a magnetoresistance effect device capable of applying a magnetic field in an oblique direction to a magnetization free layer of a magnetoresistance effect element.

Means for solving the problems

The inventors of the present application found that: a magnetoresistive effect device in which a magnetic field in an oblique direction is applied to a magnetization free layer of a magnetoresistive effect element by controlling the positional relationship between two ferromagnetic bodies sandwiching the magnetoresistive effect element and the magnetoresistive effect element. Further, it has been found that, in a high-frequency device utilizing the ferromagnetic resonance phenomenon, when a magnetic field is applied obliquely to the magnetization free layer of the magnetoresistive element, the frequency band can be extended to the high-frequency side.

That is, the present invention provides the following means to solve the above-mentioned problems.

(1) A first mode provides a magnetoresistance effect device, comprising: a magnetoresistance effect element having a first magnetization free layer, a magnetization fixed layer, or a second magnetization free layer, and a spacer layer interposed between the first magnetization free layer and the magnetization fixed layer or the second magnetization free layer; and a magnetic field applying mechanism that applies a magnetic field to at least the first magnetization free layer of the magnetoresistive element, the magnetic field applying mechanism including: a first ferromagnetic body; a second ferromagnetic body that sandwiches the magnetoresistive element together with the first ferromagnetic body; and a coil wound around the first ferromagnetic body, wherein the first ferromagnetic body has a convex portion protruding from a first surface toward the magnetoresistance effect element in a lamination direction of the magnetoresistance effect element, the first magnetization free layer of the magnetoresistance effect element has a portion that does not overlap with at least one of a second surface and a third surface when viewed from above in the lamination direction, the second surface is a surface on the magnetoresistance effect element side in the lamination direction of the convex portion, the third surface is a surface on the magnetoresistance effect element side in the lamination direction of the second ferromagnetic body, and a center of gravity of the first magnetization free layer of the magnetoresistance effect element is located in a region connecting the second surface and the third surface.

(2) In the magnetoresistive device according to the above aspect, the first magnetization free layer of the magnetoresistive element may have a portion that does not overlap the second surface when viewed from above in the stacking direction.

(3) In the magnetoresistive device according to the above aspect, the first magnetization free layer of the magnetoresistive element may have a portion that does not overlap the third surface when viewed from above in the stacking direction.

(4) In the magnetoresistance effect device according to the above aspect, when the magnetoresistance effect element is viewed in plan from the stacking direction, a first perpendicular line passing through the center of gravity of the first magnetization free layer and extending in the stacking direction may not overlap at least one of the second surface and the third surface.

(5) In the magnetoresistive device according to the above aspect, the first perpendicular line may not overlap the second surface when the magnetoresistive element is viewed in a plan view from the stacking direction.

(6) In the magnetoresistance effect device according to the above aspect, in a cross section taken along the lamination direction through the center of gravity of the convex portion and the center of gravity of the first magnetization free layer, when a distance in the lamination direction between the second surface and the third surface is d1, and a distance in a direction orthogonal to the lamination direction between the end portions of the second surface and the third surface on the magnetoresistance effect element side is d2, d2/d1 may be satisfied to be not more than 2.5.

(7) In the magnetoresistive effect device according to the above aspect, the second ferromagnetic member may include: an opening having an opening when viewed from above in the stacking direction; or a recess recessed from the third surface toward the opposite side of the magnetoresistance effect element.

(8) In the magnetoresistive device according to the above aspect, when viewed from above in the stacking direction, the center of gravity of the opening or the recess may be located on the opposite side of the magnetoresistive element with respect to the center of gravity of the protrusion, and the end of the opening or the recess on the magnetoresistive element side may be located on the magnetoresistive element side with respect to the center of gravity of the protrusion.

(9) In the magnetoresistive device according to the above aspect, the convex portion may be included in the opening portion or the concave portion when viewed from the stacking direction.

(10) In the magnetoresistive device according to the above aspect, the first side surface that sandwiches the opening or the recess of the magnetoresistive element may be parallel to the second side surface of the protrusion when viewed in plan from the stacking direction.

(11) In the magnetoresistive device according to the above aspect, the first side surface and the second side surface may be straight lines when viewed from the stacking direction.

(12) In the magnetoresistive device according to the above aspect, the magnetoresistive element may include a magnetoresistive element row in which a plurality of the magnetoresistive elements are arranged along the first side surface and the second side surface when viewed from the stacking direction.

(13) In the magnetoresistive device according to the above aspect, the first ferromagnetic body may have a second recess portion that is located outside the projection portion when viewed in plan from the stacking direction and is recessed from the second opening portion or the first surface toward an opposite side of the magnetoresistive element.

Effects of the invention

According to the magnetoresistive device of the above aspect, a magnetic field can be applied to the magnetization free layer of the magnetoresistive element in an oblique direction.

Drawings

Fig. 1 is a schematic cross-sectional view of a magnetoresistive effect device of a first embodiment.

Fig. 2 is a diagram of the magnetoresistance effect device shown in the top view 1.

Fig. 3A is a schematic cross-sectional view of a main part of another example of the magnetoresistive effect device according to the first embodiment in an enlarged manner.

Fig. 3B is a schematic cross-sectional view of a main part of another example of the magnetoresistive effect device according to the first embodiment in an enlarged manner.

Fig. 4A is a schematic cross-sectional view of a main part of another example of the magnetoresistive effect device according to the first embodiment in an enlarged manner.

Fig. 4B is a schematic cross-sectional view of a main part of another example of the magnetoresistive effect device according to the first embodiment in an enlarged manner.

Fig. 5A is a schematic cross-sectional view of a main part of another example of the magnetoresistive effect device according to the first embodiment in an enlarged manner.

Fig. 5B is a schematic cross-sectional view of a main part of another example of the magnetoresistive effect device according to the first embodiment in an enlarged manner.

Fig. 6A is a plan view of an example of the magnetoresistive device according to the first embodiment, in which positional relationships among the center of gravity position of the convex portion, the center of gravity position of the opening portion, and the first end portion are changed.

Fig. 6B is a plan view of an example of the magnetoresistive device according to the first embodiment, in which positional relationships among the center of gravity position of the convex portion, the center of gravity position of the opening portion, and the first end portion are changed.

Fig. 7A is a schematic cross-sectional view of an example of the magnetoresistive device according to the first embodiment, in which the positional relationship among the center of gravity position of the convex portion, the center of gravity position of the opening portion, and the first end portion is changed.

Fig. 7B is a schematic cross-sectional view of an example of the magnetoresistive device according to the first embodiment, in which the positional relationship among the center of gravity position of the convex portion, the center of gravity position of the opening portion, and the first end portion is changed.

Fig. 8A is a schematic view of another example of the magnetoresistance effect device of the first embodiment in a plan view.

Fig. 8B is a schematic view of another example of the magnetoresistance effect device of the first embodiment in a plan view.

Fig. 9 is a schematic cross-sectional view of a magnetoresistance effect device in which a second ferromagnetic body has a recess.

Fig. 10 is a schematic cross-sectional view of another example of the magnetoresistance effect device in which the second ferromagnetic body does not have the opening portion nor the recess portion.

Fig. 11 is a schematic sectional view of a magnetoresistance effect device in which a first ferromagnetic body has a second opening portion.

Fig. 12 is a schematic cross-sectional view of a magnetoresistance effect device in which a first ferromagnetic body has a second recess.

Fig. 13A is a schematic cross-sectional view of an example of the magnetoresistive effect device according to the first embodiment, in which a main portion of an example of a protruding structure having a multi-step shape is enlarged.

Fig. 13B is a schematic cross-sectional view of an example of the magnetoresistance effect device according to the first embodiment, in which a main portion of an example of a protruding structure having a multi-step shape is enlarged.

Fig. 14 is a schematic view of another example of the magnetoresistance effect device of the first embodiment in a plan view.

Fig. 15 is a schematic view of another example of the magnetoresistance effect device of the first embodiment in a plan view.

Fig. 16 is a schematic diagram showing a circuit configuration of a high-frequency device using the magnetoresistive effect device of the second embodiment.

Fig. 17 is a schematic diagram showing a circuit configuration of another example of a high-frequency device using the magnetoresistive effect device according to the second embodiment.

Fig. 18 is a schematic diagram showing a circuit configuration of another example of a high-frequency device using the magnetoresistive effect device according to the second embodiment.

Fig. 19A is a diagram schematically showing a magnetoresistance effect device of the embodiment.

Fig. 19B is a diagram schematically showing a magnetoresistance effect device of the embodiment.

Fig. 20 is a diagram showing the magnetic field strength and the angle of the magnetic field generated by the magnetic field applying mechanism shown in example 1.

Fig. 21A is a diagram showing the magnetic field intensity and the angle of the magnetic field generated by the magnetic field applying mechanism shown in example 3.

Fig. 21B is a diagram showing the magnetic field strength and the angle of the magnetic field generated by the magnetic field applying mechanism shown in example 3.

Fig. 22A is a diagram showing the magnetic field strength and the angle of the magnetic field generated by the magnetic field applying mechanism shown in example 4.

Fig. 22B is a diagram showing the magnetic field strength and the angle of the magnetic field generated by the magnetic field applying mechanism shown in example 4.

Description of the symbols

1. First port

2. Second port

10. Magnetoresistive effect element

11. Magnetization pinned layer

12. Magnetization free layer

13. Spacer layer

20. Magnetic field applying mechanism

21. A first ferromagnetic body

21a first side

21A convex part

21Aa second face

21Ae first end

21B plane part

21C support part

22. Second ferromagnetic body

22a third surface

22e first end

23. Coil

25. Opening part

26. Concave part

27. A second opening part

28. Second concave part

30. First signal line

32. 52 reference potential terminal

40. DC applying terminal

41. Power supply

42. Inductor

50. Output signal line (second signal line)

51. Line

60. Input signal line

70. Output signal line

100. 101, 102, 103, 104, 105, 106, 107, 110, 111, 112, 113 magnetoresistance effect device

200. 300 high frequency device

Region A

C1 A first vertical line

C2, C3 center of gravity.

Detailed Description

Hereinafter, the magnetoresistance effect device is described in detail with reference to the drawings as appropriate. In the drawings used in the following description, for the sake of easy understanding of the features, the portions to be the features may be enlarged for convenience, and the dimensional ratios of the respective components may be different from those in reality. The materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited to these examples, and can be appropriately modified and implemented within a range in which the effects of the present invention are achieved.

(first embodiment)

Fig. 1 is a schematic sectional view of a magnetoresistive effect device of the first embodiment, also illustrating an enlarged view of a main portion. The magnetoresistance effect device 100 shown in fig. 1 has a magnetoresistance effect element 10 and a magnetic field applying mechanism 20.

In the following description of the drawings, the stacking direction of the magnetoresistive elements 10 is defined as the z direction, any direction in the in-plane direction of a plane perpendicular to the z direction is defined as the x direction, and a direction perpendicular to both the x direction and the z direction is defined as the y direction.

Magnetoresistive effect element

The magnetoresistive element 10 includes a first layer (magnetization fixed layer) 11, a second layer (magnetization free layer) 12, and a spacer layer 13. The spacer layer 13 is located between the magnetization fixed layer 11 and the magnetization free layer 12. The magnetization of the magnetization pinned layer 11 is less movable than the magnetization of the magnetization free layer 12, and is pinned in one direction in a predetermined magnetic field environment. The magnetization direction of the magnetization free layer 12 changes relative to the magnetization direction of the magnetization fixed layer 11, and thereby functions as the magnetoresistance effect element 10.

In the following description, a case where the first layer is a magnetization fixed layer and the second layer is a magnetization free layer is described as an example. On the other hand, it is not always necessary that either of the first layer and the second layer be a magnetization fixed layer, and both the first layer and the second layer may be a magnetization free layer. In this case, one of the first layer and the second layer serves as a first magnetization free layer, and the other layer serves as a second magnetization free layer. The magnetization directions of the first layer and the second layer may vary correspondingly to each other. As an example, a magnetoresistive effect element in which two magnetization free layers are magnetically coupled to each other via a spacer layer can be given. More specifically, there is an example in which the two magnetization free layers are magnetically coupled to each other via the spacer layer so that the magnetization directions of the two magnetization free layers are antiparallel to each other in a state where no external magnetic field is applied.

The magnetization pinned layer 11 is made of a ferromagnetic material. The magnetization pinned layer 11 is preferably made of a high spin polarizability material such as Fe, co, ni, an alloy of Ni and Fe, an alloy of Fe and Co, or an alloy of Fe, co, and B. By using these materials, the magnetoresistance change rate of the magnetoresistance effect element 10 becomes large. The magnetization pinned layer 11 may be made of a heusler alloy. The thickness of the magnetization pinned layer 11 is preferably 1 to 10nm.

The magnetization fixing method of the magnetization fixing layer 11 is not particularly limited. For example, in order to fix the magnetization of the magnetization pinned layer 11, an antiferromagnetic layer may be formed so as to be in contact with the magnetization pinned layer 11. In addition, the magnetization of the magnetization pinned layer 11 may be pinned by utilizing magnetic anisotropy due to a crystal structure, a shape, or the like.

FeO, coO, niO, cuFeS can be used as the antiferromagnetic layer ₂ IrMn, feMn, ptMn, cr or Mn, etc.

The magnetization free layer 12 is composed of a ferromagnetic material that can change its magnetization direction according to an external magnetic field or a spin-bias current.

As the magnetization free layer 12, as a material having an axis of easy magnetization in an in-plane direction perpendicular to the lamination direction in which the magnetization free layer 12 is laminated, it is possible to use: coFe, coFeB, coFeSi, coMnGe, coMnSi, coMnAl, or CoMnAl, as materials having an easy axis of magnetization in the lamination direction of the magnetization free layer 12, it is possible to use: co, coCr-based alloys, co multilayer films, coCrPt-based alloys, fePt-based alloys, smCo-based alloys containing rare earth, tbFeCo alloys, and the like. The magnetization free layer 12 may be made of a heusler alloy.

The thickness of the magnetization free layer 12 is preferably set to about 1 to 10nm. In addition, a high spin-polarizability material may be interposed between the magnetization free layer 12 and the spacer layer 13.

By inserting a high spin polarizability material, a higher rate of change of magnetoresistance may be obtained.

Examples of the high spin polarizability material include CoFe alloys and CoFeB alloys.

The film thickness of either CoFe alloy or CoFeB alloy is preferably set to be about 0.2 to 1.0 nm.

The spacer layer 13 is a layer disposed between the magnetization pinned layer 11 and the magnetization free layer 12. The spacer layer 13 is formed of a layer made of a conductor, an insulator, or a semiconductor, or a layer including a conductive point made of a conductor in an insulator. The spacer layer 13 is preferably a nonmagnetic layer.

For example, when the spacer layer 13 is made of an insulator, the Magnetoresistance effect element 10 is a Tunneling Magnetoresistance (TMR) effect element, and when the spacer layer 13 is made of a metal, it is a Giant Magnetoresistance (GMR) effect element.

In case of applying an insulating material as the spacer layer 13Can use Al ₂ O ₃ Or an insulating material such as MgO. By adjusting the film thickness of the spacer layer 13 so as to exhibit a coherent tunneling effect between the magnetization pinned layer 11 and the magnetization free layer 12, a high magnetoresistance change rate can be obtained. In order to effectively utilize the TMR effect, the film thickness of the spacer layer 13 is preferably in the range of 0.5 to 3.0 nm.

When the spacer layer 13 is made of a conductive material, a conductive material such as Cu, ag, au, or Ru can be used. In order to effectively utilize the GMR effect, the film thickness of the spacer layer 13 is preferably in the range of 0.5 to 3.0 nm.

In the case where the spacer layer 13 is formed of a semiconductor material, it is possible to use: znO and In ₂ O ₃ 、SnO ₂ 、ITO、GaO _x Or Ga ₂ O _x And the like. In this case, the thickness of the spacer layer 13 is preferably about 1.0 to 4.0 nm.

In the case of applying a layer containing a current-carrying point composed of a conductor in an insulator as the spacer layer 13, the spacer layer is composed of Al ₂ O ₃ Or an insulator made of MgO, it is preferable that the insulator has a structure including a current-carrying point made of a conductor such as CoFe, coFeB, coFeSi, commnge, coMnSi, coMnAl, fe, co, au, cu, al, or Mg. In this case, the thickness of the spacer layer 13 is preferably about 0.5 to 2.0 nm.

In terms of the size of the magnetoresistive element 10, when the magnetoresistive element 10 has a rectangular (including square) shape in plan view, the long side is preferably 300nm or less. When the plan view shape of the magnetoresistive element 10 is not a rectangle, the long side of the rectangle circumscribing the minimum area in the plan view shape of the magnetoresistive element 10 is defined as the long side of the magnetoresistive element 10.

When the long side is about 300nm and is small, the volume of the magnetization free layer 12 becomes small, and a ferromagnetic resonance phenomenon with high efficiency can be realized. Here, the "planar shape" is a shape viewed from the stacking direction of the layers constituting the magnetoresistive element 10.

Magnetic field applying mechanism

The magnetic field applying mechanism 20 shown in fig. 1 comprises a first ferromagnetic body 21, a second ferromagnetic body 22, a coil 23. The coil 23 is wound around the projection 21A. The coil 23 induces magnetic flux, and the induced magnetic flux is concentrated on the convex portion 21A to form a magnetic field toward the second ferromagnetic body 22 facing thereto. In fig. 1, the coil 23 is a spiral coil wound in a spiral shape around the projection 21A. In fig. 1, the coil 23 is provided as one layer in the z direction, but two or more layers may be stacked.

The first ferromagnetic body 21 and the second ferromagnetic body 22 are made of magnetic bodies. The first ferromagnetic body 21 and the second ferromagnetic body 22 can be used, for example: fe. Co, ni, an alloy of Ni and Fe, an alloy of Fe and Co, or an alloy of Fe, co and B, and the like. The coil 23 is formed of a wiring pattern having high conductivity, and for example, copper, aluminum, or the like can be used.

The first ferromagnetic body 21 has a convex portion 21A protruding from the first surface 21A. The first ferromagnetic member 21 shown in fig. 1 is composed of a convex portion 21A, a main portion 21B, and a support portion 21C. The main portion 21B is a main portion of the first ferromagnetic body 21, and is a portion extending in the xy in-plane direction in fig. 1.

The support portion 21C is a portion for connecting the first ferromagnetic body 21 and the second ferromagnetic body 22 and stabilizing the flow of the magnetic field. The convex portion 21A is a portion from whose surface magnetic flux lines flow out or into whose surface magnetic flux lines flow out. The magnetic flux lines flowing out of the protruding portion 21A or the magnetic flux lines flowing in share the main lines of the magnetic flux lines applied to the magnetization free layer from the first ferromagnetic body and the second ferromagnetic body. Here, "main line is assumed" means that the main line is assumed from the viewpoint of the strength (magnetic flux density) of the magnetic field.

The number of the convex portions 21A is not limited to one, and may be plural. In the example shown in fig. 1, the first surface 21a is a surface of the main portion 21B on the second ferromagnetic body 22 side. The shape of the first face 21a is not limited.

The second ferromagnetic body 22 is disposed at a position where the magnetoresistance effect element 10 is sandwiched between the first ferromagnetic body 21 and the second ferromagnetic body 22. The second ferromagnetic body 22 shown in fig. 1 has an opening 25. Fig. 2 is a diagram of the magnetoresistance effect device 100 shown in the top view 1. The opening 25 is formed inside the coil 23.

Positional relationship between magnetoresistive element 10 and magnetic field applying mechanism 20

The magnetoresistive element 10 and the magnetic field applying mechanism 20 are manufactured by a lamination process in the z direction. By controlling the positional relationship between the respective structures of the magnetic field applying mechanism 20 and the magnetoresistive effect element 10 through such a lamination process, a magnetic field in an oblique direction with respect to the in-plane direction (xy-plane) of the magnetoresistive effect element 10 can be easily applied to the magnetization free layer 12.

The magnetization free layer 12 of the magnetoresistive element 10 shown in fig. 1 has a portion that does not overlap with the second surface 21Aa of the protruding portion 21A and the third surface 22a of the second ferromagnetic body 22 when viewed from the z direction. Here, the second surface 21Aa is a surface of the convex portion 21A on the magnetoresistive element 10 side in the z direction (the stacking direction of the magnetoresistive elements 10) (see fig. 1). The third surface 22a is a surface of the second ferromagnetic body 22 on the magnetoresistive element 10 side in the z direction (the stacking direction of the magnetoresistive elements 10) (see fig. 1). The shapes of the second surface 21Aa and the third surface 22a are not limited.

The center of gravity of the magnetization free layer 12 is located in a region a connecting the second surface 21Aa and the third surface 22a.

When the magnetization free layer 12 is disposed at a position satisfying the above-described relationship with respect to the second surface 21Aa and the third surface 22a, the magnetic field directed toward the first end 22e of the third surface 22a is mainly applied to the magnetization free layer 12 from the first end 21Ae of the second surface 21 Aa. In the magnetic-field applying mechanism 20 shown in fig. 1, the magnetic field from the first end 21Ae toward the first end 22e is inclined at a predetermined angle with respect to the xy plane. Therefore, the magnetic field applied to the magnetization free layer 12 is in an oblique direction with respect to the in-plane direction (xy plane) of the magnetization free layer 12.

In fig. 1, the first end 21Ae and the first end 22e are corners of the convex portion 21A and the second ferromagnetic body 22 on the magnetoresistive element 10 side in a cross section taken on a plane including a line segment passing through the center of gravity of the convex portion 21A and the magnetization free layer 12. In fig. 1, the first end 21Ae and the first end 22e are illustrated as corners of two line segments perpendicular to each other. However, in an actual element, the second surface 21Aa and the side surface of the projection 21A may be connected by a gentle curved surface. In this case, a portion of the line connecting the curved surfaces, which has an inclination angle of 10 degrees with respect to the in-plane direction (xy-plane), is defined as a boundary between the second surface 21Aa and the side surface. The same applies to the third surface 22a.

The magnetoresistance effect device 100 shown in fig. 1 is an embodiment for applying a magnetic field from an oblique direction with respect to the in-plane direction of the magnetization free layer 12, and this structure is not necessarily required to be satisfied.

For example, although the magnetoresistance effect device 100 shown in fig. 1 has a structure having a portion where the magnetization free layer 12 does not overlap with any of the second surface 21Aa and the third surface 22a when viewed from the z direction, the magnetoresistance effect device may have a structure having a portion where the magnetization free layer 12 does not overlap with any of the surfaces.

Fig. 3A to 3B are schematic cross-sectional views, in which a main part of another example of the magnetoresistive effect device according to the present embodiment is enlarged. The magnetization free layer 12 of the magnetoresistive device 101 shown in fig. 3A has a portion that does not overlap the second surface 21Aa when viewed from the z direction, but overlaps the third surface 22a over the entire surface. In contrast, the magnetization free layer 12 of the magnetoresistance effect device 102 shown in fig. 3B entirely overlaps the second surface 21Aa but does not overlap the third surface 22a when viewed in a z-direction. In fig. 3A and 3B, the center of gravity of the magnetization free layer 12 is located in the region a connecting the second surface 21Aa and the third surface 22a.

In the magnetoresistive effect device 101 shown in fig. 3A, the magnetic flux lines flowing out from the first end portion 21Ae of the second surface 21Aa flow into the third surface 22a of the second ferromagnetic body 22. The area of the second surface 21Aa is smaller than the area of the third surface 22a. Therefore, the magnetic flux lines are formed in a direction expanding from the first end 21Ae toward the third surface 22a. The magnetic field extending from the first end 21Ae to the third surface 22a has a component inclined with respect to the xy plane. Therefore, in the magnetoresistive effect device 101 shown in fig. 3A, a magnetic field can also be applied to the magnetization free layer 12 in an oblique direction.

In the magnetoresistance effect device 102 shown in fig. 3B, the leakage magnetic field between the second surface 21Aa and the third surface 22a is strongly generated in the region a connecting the second surface 21Aa and the third surface 22a. For example, in fig. 3B, the magnetic flux lines flowing out from the second end 21Af opposite to the first end 21Ae flow into the third surface 22a of the second ferromagnetic member 22. Under the condition that the center of gravity of the magnetization free layer 12 is present in the region a, when the magnetization free layer 12 is disposed so as not to overlap the third surface 22a when viewed from the z direction, magnetic flux lines generated in the region a connecting the second surface 21Aa and the third surface 22a are applied to the magnetization free layer 12. Therefore, in the magnetoresistive effect device 101 shown in fig. 3B, a magnetic field can also be applied to the magnetization free layer 12 in an oblique direction.

In order to control the angle (applied angle) formed by the in-plane direction (xy plane) of the magnetization free layer 12 and the direction in which the magnetic field is applied, it is preferable to control the positional relationship between the first perpendicular line C1 passing through the center of gravity of the magnetization free layer 12 and extending in the z direction, the projection 21A, and the opening 25.

Fig. 4A to 4B and fig. 5A to 5B are schematic cross-sectional views in which a main portion of another example of the magnetoresistive effect device according to the present embodiment is enlarged. When the magnetoresistance effect device 103 shown in fig. 4A is viewed from the z direction, the first perpendicular line C1 overlaps the second surface 21Aa and the third surface 22a. When the magnetoresistance effect device 104 shown in fig. 4B is viewed from the z direction, the first perpendicular line C1 does not overlap the second surface 21Aa but overlaps the third surface 22a. When the magnetoresistance effect device 105 shown in fig. 5A is viewed from the z direction, the first perpendicular line C1 overlaps with the second surface 21Aa, and does not overlap with the third surface 22a. When the magnetoresistance effect device 106 shown in fig. 5B is viewed from the z direction, the first perpendicular line C1 does not overlap with the second surface 21Aa and the third surface 22a.

When the first perpendicular line C1 overlaps the second surface 21Aa and the third surface 22a when viewed from the z direction in a plan view (fig. 4A), the magnetoresistive element 10 is disposed at a position of the shortest distance between the second surface 21Aa and the third surface 22a (a position of a perpendicular line that hangs down from the second surface 21Aa to the third surface 22 a), and therefore, the angle of application of the magnetic field is an angle close to 90 °. Since a part of the magnetization free layer 12 has a portion that does not overlap the second surface 21Aa when viewed from the z direction, the application angle is not completely 90 °.

When the first perpendicular line C1 does not overlap the second surface 21Aa when viewed from the z direction (fig. 4B), the magnetization free layer 12 is disposed at a position deviated from the position of the shortest distance between the second surface 21Aa and the third surface 22a (the position of the perpendicular line hanging from the second surface 21Aa to the third surface 22 a). Therefore, the application angle can be reduced as compared with the case of fig. 4A, and a magnetic field in an oblique direction can be further applied to the magnetization free layer 12.

When the first perpendicular line C1 does not overlap the third surface 22a when viewed from the z direction (fig. 5A), the shortest distance between the second surface 21Aa and the third surface 22a is inclined with respect to the xy plane. That is, the component in the oblique direction of the leakage magnetic field generated between the second surface 21Aa and the third surface 22a increases. Therefore, the application angle can be reduced as compared with the case of fig. 4A, and a magnetic field in an oblique direction can be further applied to the magnetization free layer 12.

Finally, when viewed from the z direction, the first perpendicular line C1 does not overlap the second surface 21Aa and the third surface 22a (fig. 5B), and both the configurations of fig. 4B and 5A are satisfied, and therefore the application angle becomes smaller. As a result, the magnetic field can be inclined to about 45 ° with respect to the application angle of the magnetization free layer 12.

In addition to the positional relationship between the first perpendicular line C1 and the projection 21A and the opening 25, the angle of application of the magnetic field to the magnetization free layer 12 may be controlled based on the distance (d 1) in the z direction between the second surface 21Aa and the third surface 22a and the distance (d 2) in the orthogonal direction (for example, the x direction) orthogonal to the z direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a. By adjusting the relationship between these distances, an angle (application angle) formed by the in-plane direction (xy-plane) of the magnetoresistive element 10 and the direction in which the magnetic field is applied to the magnetization free layer 12 can be freely set. To set the application angle within the range of 45 to 80 degrees, it is preferable that d2/d1 | 2.5 be satisfied.

In addition to these relationships, the application angle may be controlled by controlling the positional relationship between the center of gravity C2 of the convex portion 21A and the center of gravity C3 of the opening 25 and the positional relationship between these and the first end 22 e.

The center of gravity of the opening 25 is a center of gravity position when the opening 25 is filled with a uniform medium. Fig. 6A to 6B and fig. 7A to 7B are examples of the magnetoresistive effect device of the present embodiment, and examples of changing the positional relationship between the center of gravity C2 of the convex portion 21A and the center of gravity C3 of the opening 25 and the positional relationship between them and the first end 22 e. Fig. 6A to 6B are views seen from the z direction, and fig. 7A to 7B are schematic views taken in a plane passing through the center of gravity C2 of the convex portion 21A and the center of gravity of the magnetization free layer 12.

The centers of gravity C3 of the openings 25 of the magnetoresistance effect devices 100 and 107 shown in fig. 6A to 6B and fig. 7A to 7B are located on the opposite side of the magnetoresistance effect element 10 with respect to the center of gravity C2 of the projection 21A. Here, "on the opposite side" means that when the line segment connecting the center of gravity C3 of the opening 25 and the magnetoresistance effect element 10 is orthogonal and divided by a straight line passing through the center of gravity C2 of the projection 21A, the center of gravity C3 of the opening 25 and the magnetoresistance effect element 10 are present in different regions. On the other hand, the end 25e of the opening 25 (the first end 22e of the third surface 22 a) of the magnetoresistance effect device 100 shown in fig. 6A and 7A is located closer to the magnetoresistance effect element 10 than the center of gravity C2 of the protrusion 21A, whereas the end 25e of the opening 25 of the magnetoresistance effect device 107 shown in fig. 6B and 7B is located opposite to the magnetoresistance effect element 10 than the center of gravity C2 of the protrusion 21A.

The end 25e of the opening 25 of the magnetoresistance effect device 100 shown in fig. 6A and 7A is close to the magnetoresistance effect element 10. Therefore, the magnetoresistance effect element 10 and the third surface 22a do not overlap when viewed from the z direction. That is, the component in the oblique direction of the magnetic field applied to the magnetoresistance effect element 10 can be increased. Further, when the convex portion 21A is disposed so as to be enclosed in the opening 25 as viewed in the z direction, the component in the oblique direction of the magnetic field applied to the magnetoresistance effect element 10 can be further increased.

As described above, the magnetic field applying mechanism 20 of the magnetoresistive effect devices 100 to 107 exemplified in the present embodiment has the convex portion 21A and the opening portion 25, and controls the positional relationship between them and the magnetoresistive effect element 10. Therefore, even when the magnetoresistive element 10 and the magnetic field applying mechanism 20 are manufactured by a lamination process in the z direction, the magnetic field can be applied in a direction inclined with respect to the in-plane direction (xy plane) of the magnetization free layer 12.

The present embodiment will be described in detail with reference to the drawings, but the configurations of the present embodiment, combinations thereof, and the like are examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present invention.

For example, the shape of the projection 21A and the opening 25 when viewed from the z direction is not limited to the rectangular shape shown in fig. 2. Fig. 8A to 8B are schematic diagrams of another example of the magnetoresistive effect device viewed from the z direction. The shape of the projection 21A and the opening 25 in plan view may be circular as shown in fig. 8A, or may be half-moon shaped as shown in fig. 8B. In addition, the planar shape may be an elliptical shape, a polygonal shape, or the like. As shown in fig. 8B, the shape of the convex portion 21A and the shape of the opening 25 may not be similar.

In the planar shape of the convex portion 21A and the opening 25, the first side surface 25b of the opening 25 is preferably parallel to the second side surface 21Ab of the convex portion 21A. Here, the first side surface 25b and the second side surface 21Ab are side surfaces on the side where the magnetoresistive effect element 10 is sandwiched when viewed from the z direction. As shown in fig. 8A, when the projection 21A and the opening 25 have circular shapes in plan view, the semicircles on the magnetoresistance effect element 10 side correspond to the first side surface 25b and the second side surface 21 Ab. That is, the parallelism may be either a parallel straight line or a parallel curved line.

When the first side surface 25b and the second side surface 21Ab are parallel to each other, the magnetic field distribution formed between the first side surface 25b and the second side surface 21Ab becomes uniform. A magnetic field is formed between the convex portion 21A and the second ferromagnetic body 22. If the first side surface 25b and the second side surface 21Ab are parallel, the distance between the first side surface 25b and the second side surface 21Ab becomes constant. Therefore, the magnetic field strength therebetween becomes constant. That is, even if the magnetoresistive effect element 10 is provided at any position therebetween, the magnetic field intensity applied to the magnetoresistive effect element 10 is constant, and the positional accuracy of the magnetoresistive effect element 10 can be relaxed.

As shown in fig. 2 and 8B, the first side surface 25B and the second side surface 21Ab are preferably straight lines. When these side surfaces are straight lines in plan view, the magnetic field strength between the first side surface 25b and the second side surface 21Ab can be made more constant.

Further, although the second ferromagnetic member 22 of the magnetoresistive effect device of the above-described embodiment has the opening 25, a recess 26 may be provided instead of the opening 25, as in the magnetoresistive effect device 110 shown in fig. 9, so as to be recessed from the third surface 22a toward the opposite side of the magnetoresistive effect element 10.

The center of gravity of the concave portion 26 is set to the center of gravity position when filled with a uniform medium, like the opening 25.

The magnetic flux lines between the first ferromagnetic body 21 and the second ferromagnetic body 22 are concentrated between the second surface 21Aa and the third surface 22a. Therefore, even if the opening 25 replaces the recess 26, the flow of the magnetic flux lines does not change greatly. That is, the magnetoresistance effect device 110 shown in fig. 9 can apply a magnetic field in an oblique direction to the magnetization free layer 12. In addition, a similar configuration can be selected by replacing the "opening 25" with the "recess 26" as a preferable configuration for controlling an angle (applied angle) formed by the in-plane direction (xy plane) of the magnetization free layer 12 and the direction in which the magnetic field is applied.

The second ferromagnetic member 22 may not have the opening 25 or the recess 26. Fig. 10 is a cross-sectional view schematically showing an example of the magnetoresistive device 111 having no recess and no opening. In this case, the magnetoresistance effect element 10 and the third surface 22a of the second ferromagnetic body 22 inevitably overlap when viewed from the z direction. Therefore, the magnetization free layer 12 of the magnetoresistive element 10 needs to have a portion that does not overlap with the second surface 21Aa of the protruding portion 21A when viewed from the z direction.

The area of the second surface 21Aa is smaller than the area of the third surface 22a. Therefore, the magnetic flux lines spread from the second surface 21Aa to the third surface 22a. That is, a leakage magnetic field between the second surface 21Aa and the third surface 22a is generated in the region a connecting the second surface 21Aa and the third surface 22a.

The magnetic field applied to the portion that does not overlap with the second surface 21Aa of the magnetoresistive element 10 is a magnetic field generated so as to spread from the second surface 21Aa to the third surface 22a when viewed from the z direction. The magnetic field has a component that is inclined with respect to the xy-plane. Therefore, in the magnetoresistive effect device 111 shown in fig. 10, a magnetic field can also be applied to the magnetization free layer 12 in an oblique direction.

Fig. 11 and 12 are diagrams schematically showing another example of the magnetoresistive effect device according to the present embodiment. The magnetoresistance effect device shown in fig. 11 is different from the magnetoresistance effect device 100 shown in fig. 1 in that the first ferromagnetic body 21 has the second opening portion 27 outside the convex portion 21A. The magnetoresistive device shown in fig. 12 differs from the magnetoresistive device 100 shown in fig. 1 in that the first ferromagnetic body 21 has a second recess 28 that is recessed from the first surface 21a toward the opposite side of the magnetoresistive element 10. The second opening 27 and the second recess 28 are both provided inside the coil 23 when viewed from the z direction.

When the first ferromagnetic body 21 has the second opening 27 or the second recess 28, the magnetic field distribution in the vicinity of the magnetoresistive effect element 10 becomes uniform, and the magnetic field can be applied to the magnetoresistive effect element 10 at a desired application angle. It is considered that the flux lines flow constantly by reducing the amount of the magnetic substance disposed in the vicinity of the magnetoresistive element 10.

Fig. 13A to 13B are diagrams schematically showing another example of the magnetoresistive effect device according to the present embodiment. The magnetoresistance effect devices shown in fig. 13A to 13B have a protruding structure having a two-step difference in the central portion. In the case of fig. 13A, the density of the magnetic flux lines applied to the magnetization free layer 12 from the step portion of the first step (the side away from the magnetoresistive element 10) is small, and the main flow direction of the magnetic flux lines applied to the magnetization free layer 12 does not greatly vary depending on the presence or absence of the first step. Therefore, in the case of fig. 13A, the portion of the second step is the convex portion 21A, and the portion of the first step belongs to the main portion 21B. In contrast, in the case of fig. 13B, the density of the magnetic flux lines applied to the magnetization free layer 12 from the step portion of the first step is large, and the main flow direction of the magnetic flux lines applied to the magnetization free layer 12 greatly varies depending on the presence or absence of the first step. Therefore, in the case of fig. 13B, the first step and the second step become the convex portion 21A.

As shown in fig. 13B, when the projection 21A has a multi-step structure, the magnetization free layer 12 preferably has a portion that does not overlap with a predetermined portion of the second surface 21Aa when viewed from the z direction, and the center of gravity of the magnetization free layer 12 is preferably located in a region a connecting the predetermined portion of the second surface 21Aa and the third surface 22a.

For example, when the shortest distance between the end of the surface of the nth step (n is an integer of 2 or more) from the main portion 21B side and the end of the third surface 22a (the surface on the magnetoresistance effect element 10 side in the z direction) is shorter than or equal to the shortest distance between the surface of the nth-1 step and the third surface 22a, it is preferable that the surface of the second surface 21Aa from the surface of the nth step from the main portion 21B side to the surface on the nearest side to the magnetoresistance effect element 10 in the z direction is a predetermined portion and satisfies the above-described relationship. For example, in the case where the projection 21A has a two-step structure, when the shortest distance between the end of the surface of the second step from the main portion 21B side and the end of the third surface 22a is shorter than or equal to the shortest distance between the surface of the first step from the main portion 21B side and the third surface 22a, the surface of the second step from the main portion 21B side and the surface closest to the magnetoresistance effect element 10 in the z direction are the same surface, and therefore, it is preferable that the surface of the second step from the main portion 21B side (the surface closest to the magnetoresistance effect element 10 in the z direction) is set to the predetermined portion and satisfies the above-described relationship.

On the other hand, when the relationship between the shortest distances is not satisfied, for example, as in the example of fig. 13B, when the shortest distance between the end (corner E1) of the surface S2 of the second step and the end (corner E2) of the third surface 22a is longer than the shortest distance between the surface S1 of the first step and the third surface 22a, it is preferable that a predetermined relationship is satisfied with the entire second surface 21Aa including the first step.

Fig. 14 and 15 are diagrams schematically showing another example of the magnetoresistive device according to the present embodiment. The magnetoresistive effect device shown in fig. 14 and 15 is different from the magnetoresistive effect device 100 shown in fig. 2 in that it has a plurality of magnetoresistive effect elements 10.

The magnetoresistance effect device 112 shown in fig. 14 has a magnetoresistance effect element row in which three magnetoresistance effect elements 10 are arranged in a column. The magnetoresistance effect device 112 shown in fig. 15 has a magnetoresistance effect element row in which three rows of three magnetoresistance effect elements 10 are arranged in a row. The three magnetoresistance effect elements 10 in the magnetoresistance effect element array are arranged along the first side surface 25b of the opening 25 and the second side surface 21Ab of the projection 21A. The first side 25b is parallel to the second side 21 Ab.

The magnetoresistance effect device 112 shown in fig. 14 is capable of applying a magnetic field in a tilt direction to the magnetization free layer 12 of each magnetoresistance effect element 10. Further, the magnitude and direction of the magnetic field applied to the three magnetoresistance effect elements 10 can be made substantially the same.

The magnetoresistance effect device 113 shown in fig. 15 is capable of applying a magnetic field in a tilt direction to the magnetization free layer 12 of each magnetoresistance effect element 10. Further, a magnetic field having at least one of a different magnitude and a different direction can be applied to each magnetoresistive element row.

Fig. 14 and 15 show an example in which three magnetoresistance effect elements 10 are used to form one magnetoresistance effect element row, but any number of magnetoresistance effect elements 10 in one magnetoresistance effect element row may be used. In addition, the number of rows of the magnetoresistive element is also arbitrary.

As described above, according to the magnetoresistance effect device of the present embodiment, a magnetic field can be applied in an oblique direction to the in-plane direction (xy-plane) of the magnetization free layer 12.

(second embodiment)

Fig. 16 is a schematic diagram showing a circuit configuration of a high-frequency device 200 using the magnetoresistive effect device according to the second embodiment. The high-frequency device 200 shown in fig. 16 includes a magnetoresistive element 10, a magnetic field applying mechanism 20, a first signal line 30, and a dc applying terminal 40. The high-frequency device 200 inputs a signal from the first port 1 and outputs a signal from the second port 2.

Magnetoresistive element, magnetic field applying mechanism

The magnetoresistance effect element 10 and the magnetic field applying mechanism 20 use components satisfying the structure of the magnetoresistance effect device of the first embodiment described above. The magnetic field applying mechanism 20 shown in fig. 16 illustrates only a main part. The magnetoresistive element 10 is provided with a lower electrode 14 and an upper electrode 15 for enhancing the high electric conductivity.

The magnetic field applying mechanism 20 can set the frequency of the output signal. The frequency of the output signal varies according to the ferromagnetic resonance frequency of the magnetization free layer 12. The ferromagnetic resonance frequency of the magnetization free layer 12 changes according to the effective magnetic field of the magnetization free layer 12. The effective magnetic field of the magnetization free layer 12 is influenced by an external magnetic field. Therefore, by changing the magnitude of the external magnetic field (static magnetic field) applied from the magnetic field applying mechanism 20 to the magnetization free layer 12, the ferromagnetic resonance frequency of the magnetization free layer 12 can be changed.

On the other hand, in order to obtain the high-frequency device 200 operating in a high-frequency band (preferably 5GHz or more, more preferably 10GHz or more), it is necessary to shift the ferromagnetic resonance frequency of the magnetization free layer 12 to a higher frequency side. This finding enables the ferromagnetic resonance frequency of the magnetization free layer 12 to shift to a higher frequency side when an external magnetic field is applied to the magnetization free layer 12 from an oblique direction. A preferred configuration of the magnetic field applying mechanism 20 capable of applying an external magnetic field to the magnetization free layer 12 from an oblique direction is the configuration described in the first embodiment.

First and second ports

The first port 1 is an input terminal of the high-frequency device 200. The first port 1 corresponds to one end of the first signal line 30. An ac signal source (not shown) is connected to the first port 1, whereby an ac signal (high-frequency signal) can be applied to the high-frequency device 200. The high-frequency signal applied to the high-frequency device 200 is a signal having a frequency of, for example, 100MHz or higher.

The second port 2 is an output terminal of the high-frequency device 200. The second port 2 corresponds to one end of an output signal line (second signal line) 50 that transmits a signal output from the magnetoresistive effect element 10.

First signal line

One end of the first signal line 30 in fig. 16 is connected to the first port 1. The other end of the first signal line 30 of the high-frequency device 200 is connected to a reference potential via a reference potential terminal 32. In fig. 16, ground G is connected as a reference potential. The ground G can be a portion outside the high-frequency device 200. A high-frequency current flows into the first signal line 30 in accordance with a potential difference between the high-frequency signal input to the first port 1 and the ground G. When a high-frequency current flows into the first signal line 30, a high-frequency magnetic field is generated from the first signal line 30. The high-frequency magnetic field is applied to the magnetization free layer 12 of the magnetoresistance effect element 10.

The first signal line 30 is not limited to one signal line, and may be a plurality of signal lines. In this case, it is preferable that a plurality of signal lines be provided at positions where the high-frequency magnetic field generated from each signal line is intensified at the position of the magnetoresistive element 10.

Output signal line, line

The output signal line 50 propagates the signal output from the magnetoresistance effect element 10.

The signal output from the magnetoresistive element 10 is a signal of a frequency selected by ferromagnetic resonance of the magnetization free layer 12. The output signal line 50 in fig. 16 has one end connected to the magnetoresistance effect element 10 and the other end connected to the second port 2.

That is, the output signal line 50 of fig. 1 connects the magnetoresistance effect element 10 and the second port 2.

A capacitor may be provided in the output signal line 50 between the second port 2 and a portion of the closed circuit including the power supply 41, the output signal line 50, the magnetoresistive element 10, the line 51, and the ground G (for example, the output signal line 50 between the second port 2 and a portion of the inductor 42 connected to the output signal line 50). By providing a capacitor in this portion, it is possible to avoid applying a constant component of current to the output signal output from the second port 2.

One end of the wiring 51 is connected to the magnetoresistance effect element 10. The other end of the line 51 of the high-frequency device 200 is connected to a reference potential via a reference potential terminal 52.

In fig. 16, the line 51 is connected to the ground G having the same reference potential as that of the first signal line 30, but may be connected to another reference potential. In order to simplify the circuit configuration, the reference potential of the first signal line 30 is preferably the same as the reference potential of the line 51.

The shapes of the lines and the ground G are preferably defined as a microstrip line (MSL) type or a coplanar waveguide (CPW) type. When the line width and the ground distance are designed to be microstrip line (MSL) type or coplanar waveguide (CPW) type, it is preferable to design the line width and the ground distance so that the characteristic impedance of the line is equal to the impedance of the circuit system. By such a design, transmission loss of the line can be suppressed.

DC applying terminal

The dc application terminal 40 is connected to a power supply 41, and applies a dc current or a dc voltage in the stacking direction of the magnetoresistive element 10. In this specification, a direct current is a current whose direction does not change with time, and includes a current whose magnitude changes with time. The dc voltage is a voltage whose direction does not change with time, and includes a voltage whose magnitude changes with time. The power source 41 may be a dc current source or a dc voltage source.

The power source 41 may be a dc power source that can generate a constant dc current, or may be a dc power source that can generate a constant dc voltage. The power source 41 may be a dc current source that generates a variable dc current value, or may be a dc voltage source that generates a variable dc voltage value.

The current density of the current applied to the magnetoresistance effect element 10 is preferably smaller than the oscillation threshold current density of the magnetoresistance effect element 10. The oscillation threshold current density of the magnetoresistive element 10 is a current density of a threshold value at which the magnetization of the magnetization free layer 12 of the magnetoresistive element 10 starts precessing at a constant frequency and a constant amplitude when a current having a current density equal to or higher than the above value is applied, and the magnetoresistive element 10 oscillates (the output (resistance value) of the magnetoresistive element 10 fluctuates at a constant frequency and a constant amplitude).

An inductor 42 is provided between the dc application terminal 40 and the output signal line 50.

The inductor 42 eliminates a high-frequency component of the current and passes a constant component of the current. The output signal (high-frequency signal) output from the magnetoresistive element 10 by the inductor 42 efficiently flows through the second port 2. Further, by the inductor 42, a constant component of the current flows through a closed circuit of the power source 41, the output signal line 50, the magneto-resistance effect element 10, the line 51, and the ground G.

As the inductor 42, a chip inductor, an inductor of a pattern line, a resistance element having an inductor component, or the like can be used. The inductance of the inductor 42 is preferably 10nH or more.

Function of high frequency device

When a high-frequency signal is input to the high-frequency device 200 from the first port 1, a high-frequency current corresponding to the high-frequency signal flows through the first signal line 30. A high-frequency magnetic field generated by a high-frequency current flowing through the first signal line 30 is applied to the magnetization free layer 12 of the magnetoresistance effect element 10.

The magnetization of the magnetization free layer 12 largely vibrates when the frequency of the high-frequency magnetic field applied to the magnetization free layer 12 by the first signal line 30 is in the vicinity of the ferromagnetic resonance frequency of the magnetization free layer 12.

This phenomenon is a ferromagnetic resonance phenomenon.

When the vibration of the magnetization free layer 12 becomes large, the resistance value change of the magnetoresistance effect element 10 becomes large. For example, when a constant dc current is applied to the magnetoresistance effect element 10 from the dc application terminal 40, a change in the resistance value of the magnetoresistance effect element 10 is output from the second port 2 as a change in the potential difference between the lower electrode 14 and the upper electrode 15. For example, when a constant dc voltage is applied to the magnetoresistance effect element 10 from the dc application terminal 40, a change in the resistance value of the magnetoresistance effect element 10 is output from the second port 2 as a change in the current value flowing between the lower electrode 14 and the upper electrode 15.

That is, when the frequency of the high-frequency signal input from the first port 1 is in the vicinity of the ferromagnetic resonance frequency of the magnetization free layer 12, the amount of change in the resistance value of the magnetoresistive element 10 is large, and a large signal is output from the second port 2. On the other hand, when the frequency of the high-frequency signal is shifted from the ferromagnetic resonance frequency of the magnetization free layer 12, the amount of change in the resistance value of the magnetoresistance effect element 10 is small, and a signal is hardly output from the second port 2. That is, the high-frequency device 200 functions as a high-frequency filter that can selectively pass a high-frequency signal of a specific frequency.

Other uses

In addition, although the above description has been made by taking a case where a high-frequency device is used as a high-frequency filter as an example, a magnetoresistance effect device can also be used as a high-frequency device such as an isolator, a phase shifter, an amplifier (amplifier), or the like.

In the case of using a high-frequency device as an isolator, a signal is input from the second port 2. Even if a signal is input from the second port 2, the signal is not output from the first port 1, and thus functions as an isolator.

When the output frequency band changes, attention is paid to the frequency at any point of the output frequency band when a high-frequency device is used as a phase shifter. When the frequency band of the output changes, the phase at a specific frequency changes, and therefore, the phase shifter functions as a phase shifter.

In the case of using a high-frequency device as an amplifier, the dc current or the dc voltage applied from the power supply 41 is set to a predetermined level or more. In this way, the signal output from the second port 2 becomes larger than the signal input from the first port 1, and functions as an amplifier.

As described above, the high-frequency device 200 according to the second embodiment can function as a high-frequency device such as a high-frequency filter, an isolator, a phase shifter, or an amplifier.

In addition, although fig. 16 illustrates the case where one magnetoresistance effect element 10 is provided, a plurality of magnetoresistance effect elements 10 may be provided. In this case, the plurality of magnetoresistance effect elements 10 may be connected in parallel with each other, may be connected in series, or may be connected in combination of parallel connection and series connection. For example, by using a plurality of magnetoresistive elements 10 having different ferromagnetic resonance frequencies, the band (pass band) of the selected frequency can be expanded. In addition, the high-frequency magnetic field generated in the output signal line 50 for outputting the output signal output from one magnetoresistance effect element may be applied to another magnetoresistance effect element. With this configuration, the output signal is filtered a plurality of times. Therefore, the filtering accuracy of the high-frequency signal can be improved.

In the case where a plurality of magnetoresistance effect elements 10 are provided, the magnetoresistance effect elements 10 may be arranged as shown in fig. 14 and 15. The magnetoresistance effect elements 10 are arranged so that the plurality of magnetoresistance effect elements 10 form a magnetoresistance effect element array arranged along the first side surface 25b of the opening 25 and the second side surface 21Ab of the projection portion 21A when viewed in plan from the Z direction. The respective magnetoresistive elements 10 may be connected in parallel with each other, may be connected in series, or may be connected by combining parallel connection and series connection.

In the case of the structure shown in fig. 14, a magnetic field having substantially the same magnitude and direction can be applied to the magnetization free layers 12 of the respective magnetoresistance effect elements 10. When the magnetoresistive effect elements 10 of the same characteristics are connected in parallel or in series, the S/N ratio of the output of the high-frequency device is improved. This is because the output signals from the respective magnetoresistance effect elements 10 are in phase and in a mutually intensified relationship, while the phase of noise is random and does not intensify with the output signal. Further, by connecting the magnetoresistive elements 10 in parallel or in series, the current or voltage applied to each magnetoresistive element 10 is reduced, and the current resistance or voltage resistance of the magnetoresistive element 10 is improved.

In the case of the configuration of fig. 15, the magnetoresistance effect elements 10 of different magnetoresistance effect element rows can apply magnetic fields having different magnitudes and/or directions to the magnetization free layer 12. By setting the magnetic fields applied to the respective magnetoresistive elements 10 to different magnetic fields and setting the ferromagnetic resonance frequencies of the respective magnetoresistive elements 10 to different frequencies, the bandwidth of the high-frequency device can be expanded. Further, by connecting the magnetoresistive elements 10 in parallel or in series, the current or voltage applied to each magnetoresistive element 10 is reduced, and the current resistance or voltage resistance of the magnetoresistive elements 10 is improved.

Here, the high-frequency device 200 shown in fig. 16 is a magnetic field driven high-frequency device that is driven by applying a high-frequency magnetic field from the first signal line 30 to the magnetization free layer 12. The high-frequency device is not limited to the magnetic field drive type, and may be a current drive type. Fig. 17 is a schematic diagram showing a circuit configuration of a current-driven high-frequency device using the magnetoresistive device according to the second embodiment.

The high-frequency device 300 shown in fig. 17 includes: a magnetoresistive element 10, a magnetic field applying mechanism 20, a direct current applying terminal 40, an input signal line 60, and an output signal line 70. In fig. 17, the magnetic field applying mechanism 20 is also illustrated only in a main part. The same components as those of the high-frequency device 200 shown in fig. 16 are denoted by the same reference numerals. The input signal line 60 is a line between the first port 1 and the upper electrode 15, and the output signal line 70 is a line between the second port 2 and the lower electrode 14.

The high-frequency device 300 inputs a signal from the first port 1 and outputs a signal from the second port 2. In the high-frequency device 300 shown in fig. 17, the magnetization of the magnetization free layer 12 vibrates due to the spin transfer torque generated by the current flowing in the lamination direction of the magnetoresistance effect element 10. When the input high-frequency signal is in the vicinity of the ferromagnetic resonance frequency of the magnetization free layer 12 (in this case, both referred to as the spin torque resonance frequency of the magnetoresistive element 10), the magnetization of the magnetization free layer 12 largely vibrates. The magnetization of the magnetization free layer 12 periodically vibrates, and thereby the resistance value of the magnetoresistance effect element 10 periodically changes.

That is, when the frequency of the high-frequency signal input from the first port 1 is in the vicinity of the ferromagnetic resonance frequency of the magnetization free layer 12, the amount of change in the resistance value of the magnetoresistive element 10 is large, and a large signal is output from the second port 2. On the other hand, when the frequency of the high-frequency signal is shifted from the ferromagnetic resonance frequency of the magnetization free layer 12, the amount of change in the resistance value of the magnetoresistance effect element 10 is small, and a signal is hardly output from the second port 2. That is, the high-frequency device 300 can also function as a high-frequency filter that can selectively pass a high-frequency signal of a specific frequency.

In the high-frequency device 300 of fig. 17, the frequency of the output signal can also be set by the magnetic field applying mechanism 20. The magnetic field applying mechanism 20 can apply an external magnetic field to the magnetoresistance effect element 10 from an oblique direction. Therefore, the ferromagnetic resonance frequency of the magnetization free layer 12 can be set to a higher frequency side.

As described above, according to the high- frequency devices 200 and 300 of the present embodiment, the magnetic field can be applied to the magnetization free layer 12 from an oblique direction. Therefore, a high-frequency device which can shift the ferromagnetic resonance frequency of the magnetization free layer 12 to a higher frequency side and can be driven at a high frequency can be realized.

While the embodiments of the present invention have been described in detail with reference to the drawings, the configurations of the embodiments and the combinations thereof are examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present invention.

For example, the first signal line 30 may also serve as the lower electrode 14 or the upper electrode 15 connected to the magnetoresistive element 10. Fig. 18 is a schematic diagram of a high-frequency device in which the first signal line 30 also serves as the upper electrode 15 connected to the magnetoresistive element 10. The first signal line 30 of the high-frequency device shown in fig. 18 is connected to the magnetization free layer 12 of the magnetoresistance effect element 10. In this case, the magnetization of the magnetization free layer 12 can be oscillated by a high-frequency magnetic field generated by a high-frequency current flowing through the first signal line 30 and applied to the magnetization free layer 12. The magnetization of the magnetization free layer 12 may be oscillated by the spin transfer torque generated by the high-frequency current flowing from the first signal line 30 in the lamination direction of the magnetoresistive element 10. The magnetization of the magnetization free layer 12 may be oscillated by the spin orbit torque of the spin current generated in the direction orthogonal to the direction of the high-frequency current flowing through the portion corresponding to the upper electrode 15 of the first signal line 30. That is, the magnetization of the magnetization free layer 12 can be vibrated by at least one of the high-frequency magnetic field, the spin transfer torque, and the spin orbit torque.

In the high- frequency devices 200 and 300, the dc application terminal 40 may be connected between the inductor 42 and the ground G, or between the upper electrode 15 and the ground G.

In addition, a resistance element may be used instead of the inductor 42 of the above embodiment. The resistance element has a function of eliminating a high-frequency component of a current by a resistance component. The resistance element may be any one of a chip resistance or a resistance of a pattern line. The resistance value of the resistance element is preferably equal to or greater than the characteristic impedance of the output signal line 50. For example, when the characteristic impedance of the output signal line 50 is 50 Ω and the resistance value of the resistance element is 50 Ω,45% of the high-frequency power can be eliminated by the resistance element. When the characteristic impedance of the output signal line 50 is 50 Ω and the resistance value of the resistance element is 500 Ω, 90% of the high-frequency power can be cancelled by the resistance element. Even in this case, the output signal outputted from the magnetoresistance effect element 10 can be efficiently made to flow to the second port 2.

In the above embodiment, when the power source 41 connected to the dc application terminal 40 has a function of eliminating a high-frequency component of the current and passing a constant component of the current, the inductor 42 may be omitted. Even in this case, the output signal output from the magnetoresistance effect element 10 can be efficiently flowed to the second port 2.

The magnetoresistance effect device of the present embodiment can also be applied to an oscillator using a spin torque oscillation effect in which a direct current is applied to the magnetoresistance effect element to generate vibration in magnetization of the magnetization free layer. The magnetoresistive device according to the present embodiment can also be applied to a rectifier and a detector using a spin torque diode effect in which a dc voltage is generated by magnetization vibration of a magnetization free layer when a high-frequency current (ac current) is applied to a magnetoresistive element.

Although the use as a high-frequency device is described as an example of the magnetoresistive device, the present invention is also applicable to other devices such as a magnetic sensor if it is useful to apply a magnetic field obliquely to the lamination direction and the lamination surface of the magnetoresistive device.

Examples

(example 1)

When the magnetic field applying mechanism as shown in fig. 19A to 19B is used, the magnetic field intensity at a predetermined position and the angle of the magnetic field at the position are obtained by simulation.

The magnetic field applying mechanism is composed of a first ferromagnetic body 21 having a rectangular projection 21A, a second ferromagnetic body 22 having a rectangular opening 25, and a coil 23 wound around the projection 21A. The first ferromagnetic body 21 and the second ferromagnetic body 22 have a rectangular shape of 80 μm × 80 μm in plan view.

The projection 21A has a rectangular shape of 2.5. Mu. M.times.5 μm in plan view, and the height from the first surface 21A of the projection 21A is 750nm. The shape of the opening 25 in plan view is set to 6 μm × 10 μm. The convex portion 21A of the first ferromagnetic body 21 overlaps and encloses the opening 25 in plan view. The coil 23 was 420nm thick and wound around the projection 21A for 30 windings.

The distance d1 in the z direction between the second surface 21Aa of the projection 21A and the third surface 22a of the second ferromagnetic member 22 is 800nm, and the distance d2 in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a is 800nm. Then, the magnetic field intensity and the angle of the magnetic field at a position along the inclined direction from the first end 21Ae of the second surface 21Aa to the first end 22e of the third surface 22a are determined. The magnetic field intensity and the angle of the magnetic field are determined at positions where the distance in the x direction and the distance in the z direction from the first end 21Ae of the second surface 21Aa are the same. The y-direction position is the same as the y-direction position of the center of gravity of the convex portion 21A.

Fig. 20 is a diagram showing the magnetic field intensity and the angle of the magnetic field at a position along the inclination direction from the first end 21Ae of the second surface 21Aa to the first end 22e of the third surface 22a in the arrangement of example 1. The horizontal axis represents the distance in the x direction or the distance in the z direction from the first end 21Ae of the second surface 21Aa, and the vertical axis represents the magnetic field strength or the angle of the magnetic field. The angle of the magnetic field is relative to the xy-plane. As shown in fig. 20, when the center of gravity of the magnetization free layer 12 is disposed at these positions, a magnetic field can be applied to the magnetization free layer 12 from an oblique direction in a range of about 45 ° to 55 °.

(example 2)

In example 2, the angle of application of the magnetic field applied to the magnetization free layer 12 was determined while fixing the distance d1 in the z direction between the second surface 21Aa of the projection 21A and the third surface 22a of the second ferromagnetic body 22 to 800nm and changing the distance d2 in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a. In example 2-1 and example 2-2, the first perpendicular line C1 is set so as to pass through the midpoint position in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a. In examples 2-3 to 2-7, the first perpendicular line C1 was set at the same position as the first end 21Ae of the second surface 21 Aa. The center of gravity of the magnetization free layer 12 in the z direction is located at a distance of 400nm from the second surface 21Aa and the third surface 22a, respectively. The position of the center of gravity of the magnetization free layer 12 in the y direction is the same as the position of the center of gravity of the convex portion 21A in the y direction. The other conditions were the same as in example 1, and the angle of the magnetic field at the position of the center of gravity of the magnetization free layer 12 was determined. The results are shown in table 1. The distance d2 is described as a minus sign when the second surface 21Aa of the convex portion 21A overlaps the third surface 22a of the second ferromagnetic body 22.

[ TABLE 1 ]

As shown in table 1, by changing the distance d2 in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a, the angle of application of the magnetic field to the magnetization free layer 12 can be freely designed. Further, the application angle can be set within the range of 45 to 80 ° by satisfying the | d2/d1 | equal to or less than 2.5.

(example 3)

In example 3, as in example 2, the distance d1 in the z direction between the second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic member 22 was fixed to 800nm, and the distance d2 in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a was changed. The second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic member 22 overlap each other when viewed from the z direction, and the distance d2 is set to 0.3 μm (example 3-1), 0.6 μm (example 3-2), 0.8 μm (example 3-3), and 1.0 μm (example 3-4). In order to confirm how the magnetic field intensity and the angle of the magnetic field change depending on the position in the x direction (the position in the z direction is fixed at a distance of 400nm from the second surface 21Aa and the third surface 22 a), the magnetic field intensity and the angle of the magnetic field are obtained in a range of a distance 2.0 times the distance d2 in the direction from the first end 21Ae of the second surface 21Aa to the first end 22e of the third surface 22a. Other conditions were the same as in example 1.

Fig. 21A to 21B are diagrams showing the magnetic field strength and the angle of the magnetic field generated by the magnetic field application mechanism shown in example 3. The horizontal axis is a value obtained by normalizing the distance in the x direction from the first end 21Ae of the second surface 21Aa by the distance d2 in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a. The vertical axis represents the magnetic field strength in fig. 21A and the angle of the magnetic field in fig. 21B.

As shown in fig. 21A to 21B, the angle of application of the magnetic field applied to the magnetization free layer 12 can be changed by changing the position in the x direction at which the center of gravity of the magnetization free layer 12 is provided. When the distance from the first end 21Ae of the second surface 21Aa of the convex portion 21A exceeds 1.0 times the distance d2, the magnetic field strength decreases. The center of gravity of the magnetization free layer 12 is provided at a position where the distance from the first end 21Ae of the second surface 21Aa of the protruding portion 21A exceeds 1.0 times the distance d2, and means that the third surface 22a and the magnetization free layer 12 at least partially overlap when viewed from the z direction.

(example 4)

In example 4, the distance d2 in the x direction between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a was fixed to 800nm, and the distance d1 in the z direction between the second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic member 22 was changed. The second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic body 22 do not overlap when viewed from the z direction. The distances d1 were set to 0.3 μm (example 4-1), 0.6 μm (example 4-2), 0.8 μm (example 4-3), and 1.0 μm (example 4-4). Then, in order to confirm how the magnetic field intensity and the angle of the magnetic field change depending on the position in the z direction (the position in the x direction is fixed at a position spaced apart from the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a by 400 nm), the magnetic field intensity and the angle of the magnetic field in the range from the second surface 21Aa to the third surface 22a in the z direction are determined. Other conditions were the same as in example 1.

Fig. 22A to 22B are diagrams showing the magnetic field intensity and the magnetic field angle of the magnetic field generated by the magnetic field applying mechanism shown in example 4. The horizontal axis is a value obtained by normalizing the distance in the z direction from the second surface 21Aa by the distance d1 in the z direction. The vertical axis represents the magnetic field strength in fig. 22A and the angle of the magnetic field in fig. 22B. By disposing the center of gravity of the magnetization free layer 12 at each position shown in fig. 22A to 22B, a magnetic field in an oblique direction can be applied to the magnetization free layer 12 in any of examples 4-1 to 4-4.

Industrial applicability

According to the magnetoresistive effect device of the above aspect, a magnetic field can be applied to the magnetization free layer of the magnetoresistive effect element in an oblique direction.

Claims (13)

1. A magnetoresistance effect device, comprising:

a magnetoresistance effect element having a first magnetization free layer, a magnetization fixed layer, or a second magnetization free layer, and a spacer layer interposed between the first magnetization free layer and the magnetization fixed layer or the second magnetization free layer; and

a magnetic field applying mechanism that applies a magnetic field to at least the first magnetization free layer of the magnetoresistance effect element,

the magnetic field applying mechanism includes: a first ferromagnetic body; a second ferromagnetic body sandwiching the magnetoresistance effect element together with the first ferromagnetic body; and a coil wound around the first ferromagnetic body, wherein the first ferromagnetic body has a convex portion protruding from a first surface toward the magnetoresistance effect element side in a lamination direction of the magnetoresistance effect element,

the first magnetization free layer of the magnetoresistance effect element has a portion that does not overlap with at least one of a second surface and a third surface when viewed from the stacking direction, wherein the second surface is a surface on the magnetoresistance effect element side in the stacking direction of the protruding portion, the third surface is a surface on the magnetoresistance effect element side in the stacking direction of the second ferromagnetic body, and,

the center of gravity of the first magnetization free layer of the magnetoresistance effect element is located in a region connecting the second surface and the third surface.

2. Magnetoresistive effect device according to claim 1,

the first magnetization free layer of the magnetoresistive element has a portion that does not overlap the second surface when viewed from the stacking direction.

3. Magnetoresistive effect device according to claim 1 or 2,

the first magnetization free layer of the magnetoresistive element has a portion that does not overlap the third surface when viewed from above in the stacking direction.

4. A magnetoresistance effect device according to claim 1 or 2, characterized in that,

when the magnetoresistive element is viewed from the stacking direction in plan, a first perpendicular line passing through the center of gravity of the first magnetization free layer and extending in the stacking direction does not overlap at least one of the second surface and the third surface.

5. Magnetoresistive effect device according to claim 4,

the first perpendicular line does not overlap the second surface when the magnetoresistive element is viewed from the stacking direction in plan view.

6. Magnetoresistive effect device according to claim 1 or 2,

in a cross-sectional plane that is cut along the stacking direction through the center of gravity of the convex portion and the center of gravity of the first magnetization free layer, d2/d1 is satisfied with d1 being a distance in the stacking direction between the second surface and the third surface, and d2 being a distance in a direction orthogonal to the stacking direction between the end portions of the second surface and the third surface on the magnetoresistance effect element side.

7. Magnetoresistive effect device according to claim 1 or 2,

the second ferromagnetic body has: an opening having an opening when viewed from the stacking direction; or a recess recessed from the third surface toward the opposite side of the magnetoresistance effect element.

8. Magnetoresistive effect device according to claim 7,

the center of gravity of the opening or the recess is located on the opposite side of the magnetoresistive element with respect to the center of gravity of the protrusion when viewed from the stacking direction,

the opening or the end of the recess on the magnetoresistance effect element side is located closer to the magnetoresistance effect element side than the center of gravity of the projection.

9. A magnetoresistive effect device according to claim 8,

the convex portion is included in the opening or the concave portion when viewed from the stacking direction.

10. Magnetoresistive effect device according to claim 7,

a first side surface that sandwiches the opening or the recess of the magnetoresistive element and a second side surface of the projection are parallel to each other when viewed from the stacking direction.

11. Magnetoresistive effect device according to claim 10,

the first side surface and the second side surface are straight lines when viewed from the stacking direction.

12. The magnetoresistance effect device according to claim 10,

the magnetoresistive element array includes a plurality of magnetoresistive elements arranged along the first side surface and the second side surface when viewed from the stacking direction.

13. Magnetoresistive effect device according to claim 1 or 2,

the first ferromagnetic member has a second recess portion located outside the projection portion when viewed from the stacking direction and recessed from a second opening portion or the first surface toward an opposite side of the magnetoresistive element.

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