JP2019102116A - Magnetoresistance effect device - Google Patents

Abstract

To provide a magnetoresistance effect device in which a magnetic field can be applied to a magnetization free layer of a magnetoresistance effect element in an oblique direction.SOLUTION: The magnetoresistance effect device includes a magnetoresistance effect element and a magnetic field application mechanism applying magnetic field to the magnetoresistance effect element. The magnetic field application mechanism includes a first ferromagnetic member having a protrusion protruding toward the side of the magnetoresistance effect element in a stacking direction of the magnetoresistance effect element, a second ferromagnetic member sandwiching the magnetoresistance effect element with the first ferromagnetic member, and a coil wound around the first ferromagnetic member. The first magnetization free layer has a portion free from overlapping with at least one of a second surface on the magnetoresistance effect element side and a third surface on the magnetoresistance effect element side of the second ferromagnetic member when viewed in the stacking direction. The center of gravity of the first magnetization free layer is positioned within a region connecting the second surface and the third surface to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to magnetoresistive devices.

  Devices using spin possessed by magnetic materials are used in various applications. For example, a magnetoresistance such as a giant magnetoresistance (GMR) element comprising a multilayer film of a ferromagnetic layer and a nonmagnetic layer, and a tunnel magnetoresistance (TMR) element using an insulating layer (tunnel barrier layer, barrier layer) as the nonmagnetic layer Effect elements are known. The magnetoresistance effect element is used for a magnetic sensor, a high frequency component, a magnetic head, a non-volatile random access memory (MRAM), and the like.

  For example, Patent Document 1 describes a high frequency device using the ferromagnetic resonance phenomenon of a magnetoresistive effect element. A high frequency signal is applied to the ferromagnetic layer included in the magnetoresistive element to cause ferromagnetic resonance of the magnetization of the ferromagnetic layer. When ferromagnetic resonance occurs, the resistance value of the magnetoresistive element periodically vibrates at the ferromagnetic resonance frequency. The high frequency device described in Patent Document 1 functions as a high frequency filter by utilizing this resistance value change.

Unexamined-Japanese-Patent No. 2017-063397

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

  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 the magnetization free layer of the magnetoresistance effect element.

A magnetoresistive effect capable of applying an oblique magnetic field to the magnetization free layer of the magnetoresistive element by controlling the positional relationship between the two ferromagnetic bodies sandwiching the magnetoresistive element and the magnetoresistive element I found that I could provide a device. It has also been found that, in a high frequency device utilizing ferromagnetic resonance phenomenon, when a magnetic field is applied obliquely to the magnetization free layer of the magnetoresistive element, the frequency band can be expanded to the high frequency side.
That is, the present invention provides the following means in order to solve the above problems.

(1) A magnetoresistance effect device according to a first aspect includes a first magnetization free layer, a magnetization fixed layer or a second magnetization free layer, the first magnetization free layer, and the magnetization fixed layer or a second And a magnetic field application mechanism for applying a magnetic field to at least the first magnetization free layer of the magnetoresistive effect element, and The magnetic field application mechanism includes: a first ferromagnetic body having a convex portion protruding from a first surface on the side of the magnetoresistive element in the stacking direction of the magnetoresistive element; and the magnetoresistive element as the first ferromagnetic body And a coil wound around the first ferromagnetic body, wherein the first magnetization free layer of the magnetoresistive element is viewed in plan from the stacking direction. The magnetoresistive effect in the stacking direction of the protrusions A portion not overlapping with at least one of the second surface on the element side and the third surface on the side of the magnetoresistive element in the stacking direction of the second ferromagnetic body, and the magnetoresistive element The center of gravity of the first magnetization free layer is located in a region connecting the second surface and the third surface.

(2) In the magnetoresistance effect device according to the above aspect, the first magnetization free layer of the magnetoresistance effect element has a portion that does not overlap with the second surface when viewed in plan from the stacking direction. It is also good.

(3) In the magnetoresistance effect device according to the above aspect, the first magnetization free layer of the magnetoresistance effect element has a portion that does not overlap with the third surface when viewed in plan from the stacking direction. It is also good.

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

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

(6) In the magnetoresistance effect device according to the above aspect, the second surface and the first surface are cut along the stacking direction, passing through the center of gravity of the convex portion and the center of gravity of the first magnetization free layer. Assuming that the distance between the three surfaces in the stacking direction is d1, and the distance between the second surface and the end of the third surface on the magnetoresistive element side in the orthogonal direction orthogonal to the stacking direction is d2. It may satisfy d2 / d1 ≦ 2.5.

(7) In the magnetoresistance effect device according to the above aspect, the second ferromagnetic body is an opening that opens when viewed in plan in the stacking direction, or an opposite side to the magnetoresistance effect element from the third surface. It may have a recess that is recessed toward the end.

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

(10) In the magnetoresistance effect device according to the above aspect, when viewed in plan from the stacking direction, the first side surface of the opening or the concave portion sandwiching the magnetoresistance effect element and the second side surface of the convex portion , May be parallel.

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

(12) In the magnetoresistance effect device according to the above aspect, when viewed in plan from the stacking direction, a plurality of the magnetoresistance effect elements are arranged side by side along the first side surface and the second side surface. It may have a resistive effect element array.

(13) In the magnetoresistance effect device according to the above aspect, the first ferromagnetic body has the magnetism from the second opening or the first surface outside the convex portion when viewed in plan from the stacking direction. You may have a 2nd recessed part dented on the opposite side to a resistive effect element.

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

It is a cross-sectional schematic diagram of the magnetoresistive effect device concerning 1st Embodiment. It is the figure which planarly viewed the magnetoresistive effect device shown in FIG. It is the cross-sectional schematic diagram which expanded the principal part of another example of the magnetoresistance effect device concerning 1st Embodiment. It is the cross-sectional schematic diagram which expanded the principal part of another example of the magnetoresistance effect device concerning 1st Embodiment. It is the cross-sectional schematic diagram which expanded the principal part of another example of the magnetoresistance effect device concerning 1st Embodiment. It is an example of the magnetoresistance effect device concerning a 1st embodiment, and is a top view of the example which changed the physical relationship between the gravity center position of a convex part, the gravity center position of an opening, and the 1st end. It is an example of the magnetoresistive device concerning 1st Embodiment, and is a cross-sectional schematic diagram of the example which changed the positional relationship of the gravity center position of a convex part, the gravity center position of an opening, and the 1st end. It is the schematic diagram which planarly viewed another example of the magnetoresistive effect device concerning 1st Embodiment. It is a cross-sectional schematic diagram of the magnetoresistive effect device in which a 2nd ferromagnetic body has a recessed part. It is a cross-sectional schematic diagram of another example of the magnetoresistance effect device in which the second ferromagnetic body has neither an opening nor a recess. It is a cross-sectional schematic diagram of the magnetoresistive effect device in which a 1st ferromagnetic body has a 2nd opening part. It is a cross-sectional schematic diagram of the magnetoresistive effect device in which a 1st ferromagnetic body has a 2nd recessed part. It is an example of the magnetoresistance effect device according to the first embodiment, and is a schematic cross-sectional view enlarging an essential part of an example including a multistage projecting structure. It is the schematic diagram which planarly viewed another example of the magnetoresistive effect device concerning 1st Embodiment. It is the schematic diagram which planarly viewed another example of the magnetoresistive effect device concerning 1st Embodiment. It is the model which showed the circuit structure of the high frequency device which used the magnetoresistive effect device concerning 2nd Embodiment. It is the model which showed the circuit configuration of another example of the high frequency device using the magnetoresistive effect device concerning 2nd Embodiment. It is the model which showed the circuit configuration of another example of the high frequency device using the magnetoresistive effect device concerning 2nd Embodiment. It is the figure which showed typically the magnetoresistive effect device concerning an Example. It is a figure which shows the magnetic field intensity of the magnetic field which the magnetic field application mechanism shown in Example 1 produces, and the angle of a magnetic field. It is a figure which shows the magnetic field intensity of the magnetic field which the magnetic field application mechanism shown in Example 3 produces, and the angle of a magnetic field. FIG. 16 is a view showing the magnetic field strength of the magnetic field generated by the magnetic field application mechanism shown in Example 4 and the angle of the magnetic field.

  Hereinafter, the magnetoresistive effect device will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, in order to make the features easy to understand, the features that are the features may be enlarged for the sake of convenience, and the dimensional ratio of each component may be different from the actual one. The materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited to them, and can be appropriately modified and implemented within the scope of the effects of the present invention.

First Embodiment
FIG. 1 is a schematic cross-sectional view of the magnetoresistive device according to the first embodiment, and an enlarged view of the main part is also illustrated. A magnetoresistive effect device 100 shown in FIG. 1 includes a magnetoresistive effect element 10 and a magnetic field application mechanism 20.
Hereinafter, in the description of the drawings, the stacking direction of the magnetoresistive effect element 10 is the z direction, and any in-plane direction of the plane perpendicular to the z direction is the direction orthogonal to any of the x direction, the x direction and the z direction. y direction.

<Magnetoresistance effect element>
The magnetoresistive effect 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 fixed layer 11 is less likely to move than the magnetization of the magnetization free layer 12, and is fixed in one direction under a predetermined magnetic field environment. The orientation of the magnetization of the magnetization free layer 12 is changed relative to the orientation of the magnetization of the magnetization fixed layer 11 to function as the magnetoresistive effect element 10.

  In the following description, as described above, the case where the first layer is a magnetization fixed layer and the second layer is a magnetization free layer will be described as an example. On the other hand, one of the first layer and the second layer does not necessarily have to be the magnetization fixed layer, and both the first layer and the second layer may be the magnetization free layer. In this case, one of the first layer and the second layer is the first magnetization free layer, and the other is the second magnetization free layer. The magnetization directions of the first and second layers can be changed relative to each other. As an example, a magnetoresistive effect element in which two magnetization free layers are magnetically coupled via a spacer layer can be mentioned. More specifically, there is an example in which two magnetization free layers are magnetically coupled to each other through a spacer layer such that the magnetization directions of the two magnetization free layers are antiparallel to each other in the state where no external magnetic field is applied. It can be mentioned.

  The magnetization fixed layer 11 is made of a ferromagnetic material. The magnetization fixed layer 11 is preferably made of a high spin polarization 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 rate of change in magnetoresistance of the magnetoresistance effect element 10 is increased. The magnetization fixed layer 11 may be made of Heusler alloy. The thickness of the magnetization fixed layer 11 is preferably 1 to 10 nm.

The magnetization fixing method of the magnetization fixed layer 11 is not particularly limited. For example, an antiferromagnetic layer may be added to be in contact with the magnetization fixed layer 11 in order to fix the magnetization of the magnetization fixed layer 11. In addition, the magnetization of the magnetization fixed layer 11 may be fixed by utilizing the magnetic anisotropy caused by the crystal structure, the shape, and the like. For the antiferromagnetic layer, FeO, CoO, NiO, CuFeS ₂ , IrMn, FeMn, PtMn, Cr or Mn can be used.

  The magnetization free layer 12 is made of a ferromagnetic material whose direction of magnetization can be changed by an external magnetic field or a spin polarization current.

  The magnetization free layer 12 can use CoFe, CoFeB, CoFeSi, CoMnGe, CoMnSi, CoMnSi or the like as a material in the case where the magnetization easy axis is in the in-plane direction perpendicular to the stacking direction in which the magnetization free layer 12 is stacked. Co, CoCr-based alloy, Co multilayer film, CoCrPt-based alloy, FePt-based alloy, SmCo-based alloy containing rare earth, TbFeCo alloy, etc. may be used as the material in the case of having the magnetization easy axis in the lamination direction it can. The magnetization free layer 12 may be made of a Heusler alloy.

  The thickness of the magnetization free layer 12 is preferably about 1 to 10 nm. A high spin polarization material may be inserted between the magnetization free layer 12 and the spacer layer 13. By inserting a high spin polarization material, it is possible to obtain a high rate of change in magnetoresistance.

  As the high spin polarization material, a CoFe alloy or a CoFeB alloy may, for example, be mentioned. The film thickness of each of the CoFe alloy or the CoFeB alloy is preferably about 0.2 to 1.0 nm.

  The spacer layer 13 is a layer disposed between the magnetization fixed layer 11 and the magnetization free layer 12. The spacer layer 13 is formed of a layer formed of a conductor, an insulator or a semiconductor, or a layer including a conduction point formed of a conductor in the 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 becomes a tunneling magnetoresistance (TMR) effect element, and when the spacer layer 13 is made of a metal, giant magnetoresistance (GMR). It becomes an effect element.

When an insulating material is applied as the spacer layer 13, an insulating material such as Al ₂ O ₃ or MgO can be used. By adjusting the film thickness of the spacer layer 13 so that a coherent tunnel effect is expressed between the magnetization fixed layer 11 and the magnetization free layer 12, a high magnetoresistance change rate can be obtained. In order to use the TMR effect efficiently, the film thickness of the spacer layer 13 is preferably about 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 use the GMR effect efficiently, the thickness of the spacer layer 13 is preferably about 0.5 to 3.0 nm.

When the spacer layer 13 is formed of a semiconductor material, a material such as ZnO, In ₂ O ₃ , SnO ₂ , ITO, GaO _x, or Ga ₂ O _x can be used. In this case, the film thickness of the spacer layer 13 is preferably about 1.0 to 4.0 nm.

In the case of applying a layer including a conduction point formed of a conductor in the insulator as the spacer layer 13, CoFe, CoFeB, CoFeSi, CoMnGe, CoMnSi, CoMnSi, CoMnSi, CoMnSi, or the like in the insulator formed of Al ₂ O ₃ or MgO. It is preferable to have a structure including a conduction point constituted by a conductor such as Fe, Co, Au, Cu, Al or Mg. In this case, the film thickness of the spacer layer 13 is preferably about 0.5 to 2.0 nm.

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

  When the long side is as small as about 300 nm, the volume of the magnetization free layer 12 is reduced, and the highly efficient ferromagnetic resonance phenomenon can be realized. Here, the “planar shape” is a shape as viewed from the stacking direction of each layer constituting the magnetoresistive effect element 10.

<Magnetic field application mechanism>
The magnetic field application mechanism 20 shown in FIG. 1 includes a first ferromagnetic body 21, a second ferromagnetic body 22 and a coil 23. The coil 23 is wound around the convex portion 21A. The coil 23 induces a magnetic flux, and the induced magnetic flux concentrates on the convex portion 21A to form a magnetic field directed to the opposing second ferromagnetic body 22. In FIG. 1, the coil 23 is a spiral coil wound in a spiral manner around the convex portion 21A. In FIG. 1, although the coil 23 is one layer in the z direction, it may be laminated in two or more layers.

  The first ferromagnetic body 21 and the second ferromagnetic body 22 are made of magnetic material. For the first ferromagnetic body 21 and the second ferromagnetic body 22, for example, Fe, Co, Ni, an alloy of Ni and Fe, an alloy of Fe and Co, or an alloy of Fe and Co and B can be used. . The coil 23 is made of a highly conductive wiring pattern, and for example, copper, aluminum or the like can be used.

  The first ferromagnetic body 21 includes a convex portion 21A which protrudes from the first surface 21a. The first ferromagnetic body 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 in FIG. 1, is a portion extending in the xy-plane direction. The support portion 21C is a portion connecting the first ferromagnetic body 21 and the second ferromagnetic body 22 and is a portion for stabilizing the flow of the magnetic field. The convex portion 21A is a portion where magnetic flux lines flow out from the surface or magnetic flux lines flow into the surface. Further, the magnetic flux lines flowing out of the convex portion 21A or the inflowing magnetic flux lines are mainly responsible for the magnetic flux lines applied from the first ferromagnetic body and the second ferromagnetic body to the magnetization free layer. Here, "supporting the main" means supporting the main in terms of the strength of the magnetic field (magnetic flux density). The number of convex portions 21A is not limited to one, and may be plural. In the example shown in FIG. 1, the first surface 21a is the surface on the second ferromagnetic body 22 side of the main portion 21B. The shape of the first surface 21a does not matter.

  The second ferromagnetic body 22 is disposed at a position sandwiching the magnetoresistive effect element 10 with the first ferromagnetic body 21. The second ferromagnetic body 22 shown in FIG. 1 has an opening 25. FIG. 2 is a plan view of the magnetoresistive device 100 shown in FIG. The opening 25 is formed inside the coil 23.

<Positional relationship between the magnetoresistance effect element 10 and the magnetic field application mechanism 20>
The magnetoresistive effect element 10 and the magnetic field application mechanism 20 are manufactured by a lamination process in the z direction. In the in-plane direction (xy plane) of the magnetoresistance effect element 10 by controlling the positional relationship between each configuration of the magnetic field application mechanism 20 and the magnetoresistance effect element 10 despite the fact that such a lamination process has been performed. On the other hand, an oblique magnetic field 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 not overlapping the second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic body 22 when viewed in plan from the z direction. Have. Here, the second surface 21Aa is a surface on the magnetoresistance effect element 10 side in the z direction (the stacking direction of the magnetoresistance effect element 10) of the convex portion 21A (see FIG. 1). The third surface 22a is the surface on the magnetoresistance effect element 10 side in the z direction of the second ferromagnetic body 22 (the lamination direction of the magnetoresistance effect element 10) (see FIG. 1). The shapes of the second surface 21Aa and the third surface 22a do not matter. The center of gravity of the magnetization free layer 12 is located in the area 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 relationship with respect to the second surface 21Aa and the third surface 22a, the direction from the first end 21Ae of the second surface 21Aa to the first end 22e of the third surface 22a A magnetic field is mainly applied to the magnetization free layer 12. In the magnetic field application mechanism 20 shown in FIG. 1, the magnetic field from the first end 21Ae to 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 oblique to the in-plane direction (xy plane) of the magnetization free layer 12.

  Here, in FIG. 1, the first end portion 21Ae and the first end portion 22e have the convex portion 21A and the second strong portion in a cross section cut along a plane including a line segment passing through the center of gravity of the convex portion 21A and the magnetization free layer 12. These are corner portions of the magnetic body 22 on the magnetoresistance effect element 10 side. Here, in FIG. 1, the first end 21 </ b> Ae and the first end 22 e are illustrated as corners of two line segments orthogonal to each other. However, in an actual element, the second surface 21Aa of the convex portion 21A and the side surface may be connected by a gentle curved surface. In this case, a portion where the inclination angle with respect to the in-plane direction (xy plane) of the tangent of the curved surface is 10 degrees is defined as the boundary between the second surface 21Aa and the side surface. The same applies to the third surface 22a.

  The magnetoresistive effect device 100 shown in FIG. 1 is an embodiment for applying a magnetic field in a direction oblique to the in-plane direction of the magnetization free layer 12, and it is not necessary to satisfy this configuration. For example, although the magnetoresistive effect device 100 shown in FIG. 1 has a configuration in which the magnetization free layer 12 does not overlap with any of the second surface 21Aa and the third surface 22a when viewed in plan from the z direction, The effect device may be configured to have a portion in which the magnetization free layer 12 does not overlap with only one of the surfaces.

  FIG. 3 is an enlarged schematic cross-sectional view of the main part of another example of the magnetoresistance effect device according to the present embodiment. The magnetization free layer 12 in the magnetoresistive effect device 101 shown in FIG. 3A has a portion that does not overlap with the second surface 21Aa in plan view from the z direction, but overlaps with the third surface 22a on the entire surface. On the other hand, the magnetization free layer 12 in the magnetoresistive device 102 shown in FIG. 3B overlaps the entire second surface 21Aa in plan view from the z direction but does not overlap the third surface 22a. . The center of gravity of the magnetization free layer 12 is located in an area A connecting the second surface 21Aa and the third surface 22a in any of FIGS. 3 (a) and 3 (b).

  In the magnetoresistive effect device 101 shown in FIG. 3A, the magnetic flux lines that flowed out from the first end 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 the direction which spreads from the first end 21Ae to the third surface 22a. The magnetic field spreading from the first end 21Ae toward the third surface 22a has a component oblique to the xy plane. Therefore, also in the magnetoresistance effect device 101 shown in FIG. 3A, the magnetic field can be applied obliquely to the magnetization free layer 12.

  Also in the magnetoresistance effect device 102 shown in FIG. 3B, the stray magnetic field between the second surface 21Aa and the third surface 22a is strong in the region A connecting the second surface 21Aa and the third surface 22a. It occurs. For example, in FIG. 3B, the magnetic flux lines that flowed out from the second end 21Af opposite to the first end 21Ae flow into the third surface 22a of the second ferromagnetic body 22. Under the condition that the center of gravity of the magnetization free layer 12 exists in the region A, when the magnetization free layer 12 and the third surface 22 a are disposed so as not to overlap with each other when viewed from the z direction, the second surface 21 Aa and the Magnetic flux lines generated in a region A connecting the three surfaces 22 a are applied to the magnetization free layer 12. Therefore, also in the magnetoresistance effect device 101 shown in FIG. 3B, a magnetic field can be applied in an oblique direction to the magnetization free layer 12.

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

  FIGS. 4 and 5 are enlarged schematic cross-sectional views of the main parts of another example of the magnetoresistive effect device according to the present embodiment. In the magnetoresistive device 103 shown in FIG. 4A, the first perpendicular C1 overlaps the second surface 21Aa and the third surface 22a in a plan view from the z direction. In the magnetoresistive device 104 shown in FIG. 4B, the first perpendicular C1 does not overlap the second surface 21Aa in plan view from the z direction, but overlaps the third surface 22a. In the magnetoresistive device 105 shown in FIG. 5A, the first perpendicular C1 overlaps the second surface 21Aa and does not overlap the third surface 22a in a plan view from the z direction. In the magnetoresistive device 106 shown in FIG. 5B, the first perpendicular C1 does not overlap with any of the second surface 21Aa and the third surface 22a in a plan view from the z direction.

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

  When the first perpendicular C1 does not overlap the second surface 21Aa in plan view from the z direction (FIG. 4B), the position of the magnetization free layer 12 at the shortest distance between the second surface 21Aa and the third surface 22a It is arrange | positioned by the position shifted from the position of the perpendicular line which went down to 3rd surface 22a from 2 surface 21Aa. Therefore, the application angle can be smaller than in the case of FIG. 4A, and the magnetic field in the oblique direction can be applied to the magnetization free layer 12 more.

  When the first perpendicular C1 does not overlap the third surface 22a in plan view from the z direction (FIG. 5A), the shortest distance between the second surface 21Aa and the third surface 22a is oblique to the xy plane . That is, the diagonal component of the stray magnetic field generated between the second surface 21Aa and the third surface 22a increases. Therefore, the application angle can be smaller than in the case of FIG. 4A, and the magnetic field in the oblique direction can be applied to the magnetization free layer 12 more.

  Finally, in the case where the first perpendicular C1 does not overlap with the second surface 21Aa and the third surface 22a in plan view from the z direction (FIG. 5B), the configuration of FIG. 4B and FIG. Therefore, the application angle is smaller. As a result, the application angle of the magnetic field to the magnetization free layer 12 can be reduced to about 45 °.

  In addition to the positional relationship between the first perpendicular C1 and the convex portion 21A and the opening 25, the z-direction distance (d1) between the second surface 21Aa and the third surface 22a, and the first end of the second surface 21Aa The application angle of the magnetic field to the magnetization free layer 12 may be controlled by the distance (d2) in the orthogonal direction (for example, the x direction) orthogonal to the z direction of the first end 22e of the third surface 22a. By adjusting the relationship between these distances, the angle (application angle) between 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. Can. In order to make the application angle in the range of 45 ° to 80 °, it is preferable to satisfy | d2 / d1 | ≦ 2.5.

  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 them and the first end 22e. The center of gravity of the opening 25 means the position of the center of gravity when the opening 25 is filled with a uniform medium. 6 and 7 show an example of the magnetoresistance effect device according to this embodiment, where 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 22e are described. Here is an example that has changed. 6 is a plan view from the z direction, and FIG. 7 is a schematic view cut along 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.

  In each of the magnetoresistance effect devices 100 and 107 shown in FIGS. 6 and 7, the center of gravity C3 of the opening 25 is located on the opposite side of the magnetoresistance effect element 10 with respect to the center of gravity C2 of the convex portion 21A. Here, “located on the opposite side” means the opening when it is orthogonal to the line connecting the center of gravity C3 of the opening 25 and the magnetoresistance effect element 10 and divided by a straight line passing through the center of gravity C2 of the convex portion 21A. This means that the center of gravity C3 of 25 and the magnetoresistance effect element 10 exist in different regions. On the other hand, in the magnetoresistive effect device 100 shown in FIGS. 6A and 7A, the end 25e of the opening 25 (the first end 22e of the third surface 22a) is the center of gravity C2 of the convex portion 21A. While the magnetoresistive effect device 107 shown in FIGS. 6B and 7B is closer to the magnetoresistive effect element 10, the end 25e of the opening 25 is closer to the magnetic center C2 of the convex portion 21A. It is on the opposite side to the resistance effect element 10.

  In the magnetoresistance effect device 100 shown in FIGS. 6A and 7A, the end 25 e of the opening 25 is close to the magnetoresistance effect element 10 side. Therefore, when viewed from the z direction, the magnetoresistive effect element 10 and the third surface 22a are not easily superimposed. That is, the diagonal component 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 included in the opening 25 when viewed from the z direction, the component of the magnetic field applied to the magnetoresistance effect element 10 in the oblique direction can be further increased.

  As described above, in the magnetoresistance effect devices 100 to 107 exemplified in the present embodiment, the magnetic field application mechanism 20 has the convex portion 21A and the opening 25 and the positional relationship between them and the magnetoresistance effect element 10 is controlled It is done. Therefore, although the magnetoresistive effect element 10 and the magnetic field application mechanism 20 are manufactured by the lamination process in the z direction, the magnetic field is applied obliquely to the in-plane direction (xy plane) of the magnetization free layer 12 can do.

  Further, although the present embodiment has been described in detail with reference to the drawings, each configuration and the combination thereof in the present embodiment are an example, and addition, omission, and replacement of the configuration are possible without departing from the spirit of the present invention. And other changes are possible.

  For example, the shape when the convex portion 21A and the opening 25 are viewed in plan from the z direction is not limited to the rectangle as shown in FIG. FIG. 8 is a schematic view of another example of the magnetoresistance effect device viewed in plan from the z direction. The plan view shape of the convex portion 21A and the opening 25 may be circular as shown in FIG. 8 (a), or may be semi-moon shaped as shown in FIG. 8 (b). In addition to these, the shape in plan view may be an elliptical shape, a polygonal shape or the like. Further, as shown in FIG. 8B, the shapes of the convex portion 21A and the opening 25 do not have to be similar.

  In the plan view shape of the convex portion 21A and the opening portion 25, it is preferable that the first side surface 25b of the opening portion 25 and the second side surface 21Ab of the convex portion 21A be parallel. Here, the first side surface 25b and the second side surface 21Ab are side surfaces sandwiching the magnetoresistive effect element 10 when viewed in plan from the z direction. As shown to Fig.8 (a), when planar view shape of convex part 21A and the opening part 25 is circular, the semicircle by the side of the magnetoresistive effect element 10 respond | corresponds to 1st side 25b and 2nd side 21Ab. That is, parallel may be either a parallel straight line or a parallel curve.

  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 between them becomes constant. That is, the magnetic field strength applied to the magnetoresistive effect element 10 is constant even if the magnetoresistive effect element 10 is provided at any position between them, and the positional accuracy of the magnetoresistive effect element 10 can be relaxed.

  The first side surface 25b and the second side surface 21Ab are preferably straight as shown in FIGS. 2 and 8 (b). When the side surfaces are straight in plan view, the magnetic field strength between the first side surface 25b and the second side surface 21Ab can be made more constant.

  In the magnetoresistive device according to the above-described embodiment, the second ferromagnetic body 22 has the opening 25. However, instead of the opening 25 as in the magnetoresistive device 110 shown in FIG. A recess 26 may be provided which is recessed from the three surfaces 22 a to the opposite side to the magnetoresistive effect element 10. As in the case of the opening 25, the center of gravity of the recess 26 is the center of gravity when filled with a uniform medium.

  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 is replaced with the recess 26, the flow of magnetic flux lines does not change significantly. That is, the magnetoresistive effect device 110 shown in FIG. 9 can apply an oblique magnetic field to the magnetization free layer 12. Also, for the preferred configuration for controlling the angle (application angle) between the in-plane direction (xy plane) of the magnetization free layer 12 and the direction in which the magnetic field is applied, the "opening 25" is replaced with the "recess 26". The same configuration can be selected.

  The second ferromagnetic body 22 may not have the opening 25 or the recess 26. FIG. 10 is a cross-sectional view schematically showing an example of the magnetoresistance effect device 111 having neither a recess nor an opening. In this case, the magnetoresistive element 10 and the third surface 22 a of the second ferromagnetic body 22 always overlap in a plan view from the z direction. Therefore, the magnetization free layer 12 of the magnetoresistive effect element 10 needs to have a portion which does not overlap with the second surface 21Aa of the convex portion 21A in plan view 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 toward the third surface 22a. That is, the stray magnetic field between the second surface 21Aa and the third surface 22a is generated in the area A connecting the second surface 21Aa and the third surface 22a.

  The magnetic field applied to the portion of the magnetoresistive element 10 not overlapping the second surface 21Aa in a plan view from the z direction is a magnetic field generated so as to spread from the second surface 21Aa to the third surface 22a. This magnetic field has a component oblique to the xy plane. Therefore, also in the magnetoresistance effect device 111 shown in FIG. 10, a magnetic field can be applied obliquely to the magnetization free layer 12.

  11 and 12 schematically show another example of the magnetoresistance effect device according to the present embodiment. The magnetoresistive effect device shown in FIG. 11 is different from the magnetoresistive effect device 100 shown in FIG. 1 in that the first ferromagnetic body 21 has a second opening 27 outside the convex portion 21A. The magnetoresistive device shown in FIG. 12 is the magnetoresistive device shown in FIG. 1 in that the first ferromagnetic body 21 has a second recess 28 recessed from the first surface 21 a to the opposite side of the magnetoresistive device 10. Different from the effect device 100. 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 magnetoresistance effect element 10 becomes uniform, and a magnetic field can be applied to the magnetoresistance effect element 10 at a desired application angle. It is considered that the flow of the magnetic flux lines becomes constant by reducing the amount of the magnetic material disposed in the vicinity of the magnetoresistance effect element 10.

  FIG. 13 is a view schematically showing another example of the magnetoresistance effect device according to the present embodiment. The magnetoresistive effect device shown in FIG. 13 has a projecting structure including two steps in the center. In the case of FIG. 13A, the density of the magnetic flux lines applied to the magnetization free layer 12 from the step portion at the first stage (the side far from the magnetoresistance effect element 10) is small, and the flux lines applied to the magnetization free layer 12 The main flow direction of does not change significantly with or without the first stage. Therefore, in the case of FIG. 13A, the portion at the second stage is the convex portion 21A, and the portion at the first stage belongs to the main portion 21B. On the other hand, in the case of FIG. 13B, the density of the magnetic flux lines applied from the first step to the magnetization free layer 12 is large, and the main flow direction of the magnetic flux lines applied to the magnetization free layer 12 is It fluctuates greatly with the presence or absence of the 1st stage. Therefore, in the case of FIG. 13B, the portions of the first and second stages become the convex portions 21A.

  As shown in FIG. 13B, in the case where the convex portion 21A has a multistage structure, the magnetization free layer 12 has a portion not overlapping the predetermined portion in the second surface 21Aa when viewed in plan from the z direction. The center of gravity of the magnetization free layer 12 is preferably located in an area A connecting a predetermined portion of the second surface 21Aa and the third surface 22a.

  For example, 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 (the surface on the magnetoresistance effect element 10 side in the z direction) and the end of the third surface 22a is In the case where the second surface 21Aa is closer or equal to the shortest distance between the surface of the (n-1) -th stage and the third surface 22a, the magnetoresistive effect element 10 in the z direction from the surface of the n-th stage from the main portion 21B side It is preferable that the surface up to the surface closest to the above be the above-mentioned predetermined part and the above relationship be satisfied. For example, when the convex portion 21A has a two-step structure, the shortest distance between the end of the surface of the second step from the main portion 21B and the end of the third surface 22a is the surface of the first step from the main portion 21B. If the distance is shorter than or equal to the shortest distance to the third surface 22a, the surface of the second step from the main portion 21B and the surface closest to the magnetoresistive element 10 in the z direction are the same surface. It is preferable that the surface of the second stage from the side of the portion 21B (the surface closest to the magnetoresistive effect element 10 in the z direction) be the above-described predetermined portion and the above relationship be satisfied.

  On the other hand, if the relationship between the shortest distances is not satisfied, for example, as in the example of FIG. 13B, the end (corner E1) of the surface S2 of the second stage and the end (corner of the third surface 22a) When the shortest distance to the part E2) is farther than the shortest distance between the surface S1 of the first step and the third surface 22a, a predetermined relationship is satisfied between the entire second surface 21Aa including the first step Is preferred.

  14 and 15 schematically show another example of the magnetoresistance effect device according to the present embodiment. The magnetoresistive effect device shown in FIGS. 14 and 15 differs from the magnetoresistive effect device 100 shown in FIG. 2 in that a plurality of magnetoresistive effect elements 10 are provided.

  The magnetoresistive effect device 112 shown in FIG. 14 has a magnetoresistive effect element row in which three magnetoresistive effect elements 10 are arranged in a line. The magnetoresistive effect device 112 shown in FIG. 15 has three magnetoresistive element rows in which three magnetoresistive effect elements 10 are arranged in a line. In the magnetoresistance effect element array, three magnetoresistance effect elements 10 are arranged side by side along the first side surface 25b of the opening 25 and the second side surface 21Ab of the convex portion 21A. The first side surface 25b and the second side surface 21Ab are parallel to each other.

  The magnetoresistive effect device 112 shown in FIG. 14 can apply a magnetic field in an oblique direction to the magnetization free layer 12 of each magnetoresistive effect element 10. Further, the magnitudes and directions of the magnetic fields applied to the three magnetoresistance effect elements 10 can be made substantially the same.

  The magnetoresistive effect device 113 shown in FIG. 15 can apply a magnetic field in an oblique direction to the magnetization free layer 12 of each magnetoresistive effect element 10. In addition, magnetic fields having different magnitudes and / or directions can be applied to the respective magnetoresistive element arrays.

  Although FIGS. 14 and 15 show an example in which one magnetoresistive element array is formed by three magnetoresistive elements 10, the number of magnetoresistive elements 10 in one magnetoresistive element array may be plural. Is optional. Further, the number of magnetoresistive element rows is also arbitrary.

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

Second Embodiment
FIG. 16 is a schematic view showing a circuit configuration of a high frequency device 200 using a magnetoresistance effect device according to the second embodiment. The high frequency device 200 shown in FIG. 16 includes a magnetoresistive effect element 10, a magnetic field application mechanism 20, a first signal line 30, and a DC application terminal 40. The high frequency device 200 receives a signal from the first port 1 and outputs a signal from the second port 2.

<Magnetoresistance effect element, magnetic field application mechanism>
As the magnetoresistance effect element 10 and the magnetic field application mechanism 20, one satisfying the configuration of the magnetoresistance effect device according to the above-mentioned first embodiment is used. Only the main part of the magnetic field application mechanism 20 shown in FIG. 16 is shown. The magnetoresistive effect element 10 is provided with a lower electrode 14 and an upper electrode 15 in order to enhance the conductivity.

  The magnetic field application mechanism 20 can set the frequency of the output signal. The frequency of the output signal varies with the ferromagnetic resonance frequency of the magnetization free layer 12. The ferromagnetic resonance frequency of the magnetization free layer 12 is changed by the effective magnetic field in the magnetization free layer 12. The effective magnetic field in the magnetization free layer 12 is affected by the external magnetic field. Therefore, by changing the magnitude of the external magnetic field (static magnetic field) applied from the magnetic field application 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 5 GHz or more, more preferably 10 GHz or more), it is necessary to shift the ferromagnetic resonance frequency of the magnetization free layer 12 to a higher frequency side. It has now been found that when an external magnetic field is applied to the magnetization free layer 12 in an oblique direction, the ferromagnetic resonance frequency of the magnetization free layer 12 can be shifted to a higher frequency side. The configuration of a preferable magnetic field application mechanism 20 capable of applying an external magnetic field to the magnetization free layer 12 in an oblique direction is the configuration shown in the first embodiment.

<First port and second port>
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. By connecting an alternating current signal source (not shown) to the first port 1, an alternating current 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, for example, a signal having a frequency of 100 MHz or more.

  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 element 10.

<First signal line>
One end of the first signal line 30 in FIG. 16 is connected to the first port 1. Further, the high frequency device 200 is used by connecting the other end of the first signal line 30 to the reference potential via the reference potential terminal 32. In FIG. 16, it is connected to the ground G as a reference potential. The ground G can be external to the high frequency device 200. A high frequency current flows in the first signal line 30 in accordance with the potential difference between the high frequency signal input to the first port 1 and the ground G. When a high frequency current flows in 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 magnetoresistive 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 to arrange a plurality of signal lines at positions where the high frequency magnetic fields generated from the respective signal lines strengthen each other at the position of the magnetoresistance effect element 10.

<Output signal line, line>
The output signal line 50 propagates the signal output from the magnetoresistive element 10. The signal output from the magnetoresistive element 10 is a signal of a frequency selected using the ferromagnetic resonance of the magnetization free layer 12. One end of the output signal line 50 in FIG. 16 is connected to the magnetoresistive element 10, and the other end is connected to the second port 2. That is, the output signal line 50 in FIG. 1 connects the magnetoresistive effect element 10 and the second port 2.

  In addition, an output signal line 50 between a portion forming a closed circuit formed by the power supply 41, the output signal line 50, the magnetoresistive effect element 10, the line 51, and the ground G and the second port 2 (as an example, the output of the inductor 42 The output signal line 50) between the connection to the signal line 50 and the second port 2 may be provided with a capacitor. By providing a capacitor in the relevant portion, it is possible to prevent the invariance component of the current from being added to the output signal output from the second port 2.

  One end of the line 51 is connected to the magnetoresistive element 10. Further, the high frequency device 200 is used by connecting the other end of the line 51 to the reference potential via the reference potential terminal 52. In FIG. 16, the line 51 is connected to the ground G common to the reference potential of the first signal line 30, but may be connected to another reference potential. In order to simplify the circuit configuration, it is preferable that the reference potential of the first signal line 30 and the reference potential of the line 51 be common.

  The shape of each line and ground G is preferably defined in a microstrip line (MSL) type or coplanar waveguide (CPW) type. When designing as a microstrip line (MSL) type or coplanar waveguide (CPW) type, it is preferable to design the line width and the distance between the grounds so that the characteristic impedance of the line and the impedance of the circuit system become equal. By designing in this manner, the transmission loss of the line can be suppressed.

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

  The power source 41 may be a direct current source capable of generating a constant direct current or a direct current voltage source capable of generating a constant direct current voltage. Further, the power supply 41 may be a direct current source whose magnitude of the generated direct current value can change, or a direct current voltage source whose magnitude of the generated direct current voltage value can change.

  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. With the oscillation threshold current density of the magnetoresistance effect element 10, the magnetization of the magnetization free layer 12 of the magnetoresistance effect element 10 is precessed with a constant frequency and a constant amplitude by applying a current having a current density higher than this value. It is a threshold current density at which movement starts and the magnetoresistance effect element 10 oscillates (the output (resistance value of the magnetoresistance effect element 10 fluctuates at a constant frequency and a constant amplitude).

  An inductor 42 is disposed between the DC application terminal 40 and the output signal line 50. The inductor 42 cuts high frequency components of the current and passes invariant components of the current. The output signal (high frequency signal) output from the magnetoresistive element 10 by the inductor 42 efficiently flows to the second port 2. Further, due to the inductor 42, the invariable component of the current flows in a closed circuit such as the power supply 41, the output signal line 50, the magnetoresistance effect element 10, the line 51, and the ground G.

  For the inductor 42, a chip inductor, an inductor with a pattern line, a resistive element having an inductor component, or the like can be used. The inductance of the inductor 42 is preferably 10 nH 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 in the first signal line 30. A high frequency magnetic field generated by a high frequency current flowing in the first signal line 30 is applied to the magnetization free layer 12 of the magnetoresistive element 10.

  The magnetization of the magnetization free layer 12 largely oscillates when the frequency of the high frequency magnetic field applied to the magnetization free layer 12 by the first signal line 30 is near the ferromagnetic resonance frequency of the magnetization free layer 12. This phenomenon is a ferromagnetic resonance phenomenon.

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

  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 variation of the resistance value of the magnetoresistance effect element 10 is large, and from the second port 2 A large signal is output. On the other hand, when the frequency of the high frequency signal deviates from the ferromagnetic resonance frequency of the magnetization free layer 12, the variation of the resistance value of the magnetoresistance effect element 10 is small, and the 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 use>
Further, although the case where the high frequency device is used as the high frequency filter has been presented as an example, the magnetoresistive effect device can also be used as a high frequency device such as an isolator, a phase shifter, and an amplifier.

  When the high frequency device is used as an isolator, a signal is input from the second port 2. Even when a signal is input from the second port 2, it is not output from the first port 1, and thus functions as an isolator.

  When the high frequency device is used as a phase shifter, when the output frequency band changes, the frequency of one arbitrary point in the output frequency band is focused. When the output frequency band changes, the phase at a specific frequency changes, and thus functions as a phase shifter.

  When a high frequency device is used as an amplifier, the DC current or DC voltage applied from the power supply 41 is set to a predetermined value or more. By doing this, 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.

  Although one magnetoresistive element 10 is illustrated in FIG. 16 as an example, a plurality of magnetoresistive elements 10 may be provided. In this case, the plurality of magnetoresistance effect elements 10 may be connected in parallel to each other, may be connected in series, or may be connected in combination of the parallel connection and the series connection. For example, by using a plurality of magnetoresistive effect elements 10 having different ferromagnetic resonance frequencies, it is possible to widen the band (pass frequency band) of the selected frequency. Further, the high frequency magnetic field generated in the output signal line 50 which outputs the output signal output from one magnetoresistive element may be applied to another magnetoresistive element. With such a configuration, the output signal is filtered a plurality of times. Therefore, the filtering accuracy of the high frequency signal can be enhanced.

  When a plurality of magnetoresistance effect elements 10 are provided, the magnetoresistance effect elements 10 may be disposed as shown in FIG. 14 and FIG. When viewed in plan from the Z direction, the plurality of magnetoresistive elements 10 are arranged along the first side surface 25b of the opening 25 and the second side surface 21Ab of the convex portion 21A. In the same manner, the magnetoresistive element 10 is disposed. The respective magnetoresistance effect elements 10 may be connected in parallel to each other, may be connected in series, or may be connected in combination of parallel connection and series connection.

  As described above, in the case of the configuration of FIG. 14, magnetic fields of 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 elements 10 having the same characteristics are connected in parallel or in series, the S / N ratio of the output of the high frequency device is improved. While the output signals from the respective magnetoresistive elements 10 are in phase and in an mutually reinforcing relationship, the phase of the noise is random and is not as strong as the output signal. Further, by connecting the magnetoresistance effect elements 10 in parallel or in series, the current or voltage applied to each of the magnetoresistance effect elements 10 is reduced, and the current resistance or voltage resistance of the magnetoresistance effect element 10 is improved. Do.

  Further, in the case of the configuration of FIG. 15, it is possible to apply a magnetic field different in at least one of the size and the direction to the magnetization free layer 12 of each of the magnetoresistance effect elements 10 of different magnetoresistance effect element rows. By making the magnetic fields applied to the respective magnetoresistive elements 10 different and making the ferromagnetic resonance frequencies of the respective magnetoresistive elements 10 different, the bandwidth of the high frequency device can be expanded. Further, by connecting the magnetoresistance effect elements 10 in parallel or in series, the current or voltage applied to each of the magnetoresistance effect elements 10 is reduced, and the current resistance or voltage resistance of the magnetoresistance effect element 10 is improved. Do.

  Here, the high frequency device 200 shown in FIG. 16 is a magnetic field drive type high frequency device 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 view showing a circuit configuration of a current drive type high frequency device using the magnetoresistance effect device according to the second embodiment.

  A high frequency device 300 shown in FIG. 17 includes a magnetoresistive effect element 10, a magnetic field application mechanism 20, a DC application terminal 40, an input signal line 60, and an output signal line 70. Also in FIG. 17, only the main part of the magnetic field application mechanism 20 is shown. The same reference numerals are given to the same components as those of the high frequency device 200 shown in FIG. The input signal line 60 is a wiring between the first port 1 and the upper electrode 15, and the output signal line 70 is a wiring between the second port 2 and the lower electrode 14.

  The high frequency device 300 receives 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 flowing a current in the stacking direction of the magnetoresistive 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, also referred to as the spin torque resonance frequency of the magnetoresistance effect element 10), the magnetization of the magnetization free layer 12 vibrates largely. By periodically vibrating the magnetization of the magnetization free layer 12, the resistance value of the magnetoresistance effect element 10 changes periodically.

  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 variation of the resistance value of the magnetoresistance effect element 10 is large, and from the second port 2 A signal is output. On the other hand, when the frequency of the high frequency signal deviates from the ferromagnetic resonance frequency of the magnetization free layer 12, the variation of the resistance value of the magnetoresistance effect element 10 is small, and the signal is hardly output from the second port 2. . That is, the high frequency device 300 can also function as a high frequency filter which can selectively pass a high frequency signal of a specific frequency.

  Also in the high frequency device 300 in FIG. 17, the frequency of the output signal can be set by the magnetic field application mechanism 20. The magnetic field application mechanism 20 can apply an external magnetic field to the magnetoresistance effect element 10 in 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 according to the present embodiment, a magnetic field can be applied to the magnetization free layer 12 from an oblique direction. Therefore, the ferromagnetic resonance frequency of the magnetization free layer 12 can be shifted to a higher frequency side, and a high frequency device which can be driven at a high frequency can be realized.

  The embodiments of the present invention have been described in detail with reference to the drawings, but the respective configurations and the combinations thereof and the like in the respective embodiments are merely examples, and additions and omissions of configurations are possible within the scope of the present invention. , Permutations, and other modifications are possible.

  For example, the first signal line 30 may double as the lower electrode 14 or the upper electrode 15 connected to the magnetoresistive effect element 10. FIG. 18 is a schematic view of a high frequency device in which the first signal line 30 doubles as the upper electrode 15 connected to the magnetoresistance effect element 10. In the high frequency device shown in FIG. 18, the first signal line 30 is connected to the magnetization free layer 12 of the magnetoresistive element 10. In this case, the magnetization of the magnetization free layer 12 can be oscillated using the high frequency magnetic field generated by the high frequency current flowing in the first signal line 30 and applied to the magnetization free layer 12. Alternatively, the magnetization of the magnetization free layer 12 may be oscillated using spin transfer torque generated by a high frequency current flowing from the first signal line 30 in the stacking direction of the magnetoresistance effect element 10. The magnetization of the magnetization free layer 12 is oscillated by using spin orbit torque due to spin current generated in a direction orthogonal to the flowing direction of the high frequency current flowing in the portion corresponding to the upper electrode 15 of the first signal line 30. It is also good. That is, the magnetization of the magnetization free layer 12 can be oscillated using 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 direct current application terminal 40 may be connected between the inductor 42 and the ground G, or may be connected between the upper electrode 15 and the ground G.

  Also, in place of the inductor 42 in the above embodiment, a resistive element may be used. The resistance element has a function of cutting high frequency components of the current by the resistance component. This resistance element may be either a chip resistance or a resistance due to a patterned 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 50Ω and the resistance value of the resistance element is 50Ω, high frequency power of 45% can be cut by the resistance element. When the characteristic impedance of the output signal line 50 is 50Ω and the resistance value of the resistor is 500Ω, high frequency power of 90% can be cut by the resistor. Also in this case, the output signal output from the magnetoresistance effect element 10 can be efficiently flowed to the second port 2.

  Further, in the above embodiment, when the power supply 41 connected to the direct current application terminal 40 has a function of cutting high frequency components of current and passing invariant components of current at the same time, the inductor 42 may be omitted. Also 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 according to this embodiment is also applicable to an oscillator using a spin torque oscillation effect in which vibration is generated in the magnetization of the magnetization free layer by applying a direct current to the magnetoresistance effect element. In the magnetoresistive device according to the present embodiment, when a high frequency current (AC current) is applied to the magnetoresistive element, a spin torque diode generates a DC voltage due to the oscillation of the magnetization of the magnetization free layer. The present invention is also applicable to rectifiers and detectors using effects.

  In addition, although the use as a high frequency device is described as an example of the magnetoresistive effect device here, if it is useful to apply a magnetic field obliquely to the stacking direction and the stacking surface of the magnetoresistive effect element, such as a magnetic sensor It is applicable also to other devices.

Example 1
When the magnetic field application mechanism as shown in FIG. 19 was used, the magnetic field strength at a predetermined position and the angle of the magnetic field at that position were obtained by simulation.
The magnetic field application mechanism includes a first ferromagnetic body 21 having a rectangular convex portion 21A, a second ferromagnetic body 22 having a rectangular opening 25 and a coil 23 wound around the convex portion 21A. The shape in plan view of the first ferromagnetic body 21 and the second ferromagnetic body 22 is a rectangle of 80 μm × 80 μm. The shape of the convex portion 21A in plan view is a rectangle of 2.5 μm × 5 μm, and the height of the convex portion 21A from the first surface 21a is 750 nm. The shape of the opening 25 in plan view is 6 μm × 10 μm. The convex portion 21A of the first ferromagnetic body 21 overlaps the opening 25 in plan view and is contained. The thickness of the coil 23 was set to 420 nm, and the coil was wound 30 times around the convex portion 21A.

  The distance d1 between the second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic body 22 in the z direction is 800 nm, and the first end 21Ae of the second surface 21Aa and the first end of the third surface 22a The distance d2 in the x direction with 22e is 800 nm. Then, the magnetic field strength and the angle of the magnetic field at a position along the diagonal direction from the first end 21Ae of the second surface 21Aa to the first end 22e of the third surface 22a were determined. The magnetic field strength and the angle of the magnetic field were determined at a position where the distance in the x direction from the first end 21Ae of the second surface 21Aa was the same as the distance in the z direction. The position in the y direction 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 strength at a position along the diagonal 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, and the angle of the magnetic field It is. The horizontal axis is 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 is the magnetic field strength or the angle of the magnetic field. The angle of the magnetic field is the angle 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 the range of about 45 ° to 55 °.

(Example 2)
In the second embodiment, the distance d1 in the z direction between the second surface 21Aa of the protrusion 21A and the third surface 22a of the second ferromagnetic body 22 is fixed at 800 nm, and the first end 21Ae of the second surface 21Aa and the second end 21Ae are fixed. When the distance d2 in the x direction with the first end 22e of the three faces 22a was changed, the application angle of the magnetic field applied to the magnetization free layer 12 was determined. In Example 2-1 and Example 2-2, the first perpendicular C1 is 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. Set to pass through. In Examples 2-3 to 2-7, the first perpendicular C1 is at the same position as the first end 21Ae of the second surface 21Aa. The position of the center of gravity of the magnetization free layer 12 in the z direction is 400 nm from the second surface 21Aa and the third surface 22a. 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 represented as minus when the second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic body 22 overlap.

  As shown in Table 1 above, the magnetic field applied to the magnetization free layer 12 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. Can be designed freely. Further, by satisfying | d2 / d1 | ≦ 2.5, the application angle can be in the range of 45 ° to 80 °.

(Example 3)
In the third embodiment, as in the second embodiment, the distance d1 between the second surface 21Aa of the convex portion 21A and the third surface 22a of the second ferromagnetic body 22 in the z direction is fixed at 800 nm, and the second surface 21Aa The distance d2 in the x direction between the first end 21Ae 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 do not overlap when viewed from the z direction, and the distance d2 is 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). Then, depending on the position in the x direction (the position in the z direction is fixed at a position of 400 nm from the second surface 21Aa and the third surface 22a), to confirm how the magnetic field strength and the magnetic field angle change The magnetic field strength and the angle of the magnetic field in a range of 2.0 times the distance d2 from the first end 21Ae of the two surfaces 21Aa to the first end 22e of the third surface 22a were determined. The other conditions were the same as in Example 1.

  FIG. 21 is a diagram showing the magnetic field strength of the magnetic field generated by the magnetic field application mechanism shown in Example 3 and the angle of the magnetic field. The horizontal axis is the distance d2 between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a in the x direction from the first end 21Ae of the second surface 21Aa. It is a standardized value. The vertical axis is the magnetic field strength in FIG. 21 (a) and the angle of the magnetic field in FIG. 21 (b).

  As shown in FIG. 21, the application angle of the magnetic field applied to the magnetization free layer 12 can be changed by changing the position in the x direction where the center of gravity of the magnetization free layer 12 is set. 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. Placing the center of gravity of the magnetization free layer 12 at a position where the distance from the first end 21Ae of the second surface 21Aa of the convex portion 21A exceeds 1.0 times the distance d2 corresponds to the third surface 22a and the magnetization free layer It means that 12 and at least one part overlap in the z direction.

(Example 4)
In the fourth embodiment, the distance d2 between the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a is fixed at 800 nm, and the second surface 21Aa of the convex portion 21A and the second surface 21Aa are fixed. The distance d1 in the z direction with the third surface 22a of the ferromagnetic body 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 distance d1 was 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). And depending on the position in the z direction (the position in the x direction is fixed at a position 400 nm from the first end 21Ae of the second surface 21Aa and the first end 22e of the third surface 22a) In order to confirm whether the change occurred, the magnetic field strength and the angle of the magnetic field in the range of the z direction from the second surface 21Aa to the third surface 22a were determined. The other conditions were the same as in Example 1.

  FIG. 22 is a diagram showing the magnetic field strength of the magnetic field and the angle of the magnetic field generated by the magnetic field application mechanism shown in the fourth embodiment. The horizontal axis is a value obtained by standardizing the distance in the z direction from the second surface 21Aa by the distance d1 in the z direction. The vertical axis is the magnetic field strength in FIG. 22 (a) and the angle of the magnetic field in FIG. 22 (b). By arranging the center of gravity of the magnetization free layer 12 at each position shown in FIG. 22, it is possible to apply an oblique magnetic field to the magnetization free layer 12 in any of the embodiments 4-1 to 4-4.

1 first port 2 second port 10 magnetoresistance effect element 11 magnetization fixed layer 12 magnetization free layer 13 spacer layer 20 magnetic field application mechanism 21 first ferromagnetic body 21a first surface 21A convex portion 21Aa second surface 21Ae first End portion 21B Flat portion 21C Support portion 22 Second ferromagnetic body 22a Third surface 22e First end 23 Coil 25 Opening 26 Recess 27 Second opening 28 Second opening 30 First signal line 32, 52 Reference potential Terminal 40 DC applied 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 A area C1 first perpendicular C2, C3 center of gravity

Claims (13)

A first magnetization free layer, a magnetization fixed layer or a second magnetization free layer, and a spacer layer sandwiched between the first magnetization free layer and the magnetization fixed layer or the second magnetization free layer A magnetoresistance effect element,
A magnetic field application mechanism for applying a magnetic field to at least the first magnetization free layer of the magnetoresistive element;
The magnetic field application mechanism includes: a first ferromagnetic body having a convex portion protruding from a first surface on a side of the magnetoresistive element in the stacking direction of the magnetoresistive element; and the magnetoresistive element as the first ferromagnetic material A second ferromagnetic body sandwiching the body, and a coil wound around the first ferromagnetic body,
The first magnetization free layer of the magnetoresistance effect element has a second surface on the magnetoresistance effect element side in the lamination direction of the convex portion when viewed in plan from the lamination direction, and the second ferromagnetism And a portion not overlapping with at least one of the third surface on the magnetoresistive element side in the stacking direction of the body, and
The magnetoresistive effect device, wherein a center of gravity of the first magnetization free layer of the magnetoresistive effect element is located in a region connecting the second surface and the third surface.   2. The magnetoresistive effect device according to claim 1, wherein the first magnetization free layer of the magnetoresistive effect element has a portion that does not overlap with the second surface when viewed in plan from the stacking direction.   3. The magnetoresistive effect device according to claim 1, wherein the first magnetization free layer of the magnetoresistive effect element has a portion that does not overlap with the third surface when viewed in plan from the stacking direction.   When the magnetoresistive effect element is viewed in plan from the stacking direction, a first perpendicular extending in the stacking direction through the center of gravity of the first magnetization free layer is at least one of the second surface and the third surface. The magnetoresistive effect device as described in any one of Claims 1-3 which does not overlap with one side.   The magnetoresistance effect device according to claim 4, wherein the first perpendicular does not overlap with the second surface when the magnetoresistance effect element is viewed in plan from the stacking direction. In a cut surface cut along the stacking direction, passing through the center of gravity of the convex portion and the center of gravity of the first magnetization free layer,
The distance in the stacking direction between the second surface and the third surface is d1, and the distance in the orthogonal direction orthogonal to the stacking direction between the second surface and the end of the third surface on the side of the magnetoresistive element The magnetoresistance effect device according to any one of claims 1 to 5, wherein d2 / d112.5 is satisfied, where d2 is d2.   The second ferromagnetic body has an opening that opens when viewed in plan from the stacking direction, or a concave that is recessed from the third surface to the opposite side to the magnetoresistive element. 6. The magnetoresistive device according to any one of 6. When viewed in plan from the stacking direction, 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,
The magnetoresistance effect device according to claim 7, wherein an end of the opening or the recess on the side of the magnetoresistance effect element is positioned closer to the magnetoresistance effect element than a center of gravity of the projection.   The magnetoresistance effect device according to claim 8, wherein the convex portion is included in the opening or the concave portion when viewed in plan from the stacking direction.   10. The method according to claim 7, wherein the first side face of the opening or the recess sandwiching the magnetoresistive element and the second side face of the protrusion are parallel to each other when viewed in plan from the stacking direction. The magnetoresistance effect device according to one item.   The magnetoresistance effect device according to claim 10, wherein the first side surface and the second side surface are straight when viewed in plan from the stacking direction.   The magnetoresistance effect element array according to claim 10, further comprising a magnetoresistive effect element array in which a plurality of the magnetoresistive effect elements are arranged side by side along the first side surface and the second side surface when viewed in plan from the stacking direction. Magnetoresistive device as described.   The first ferromagnetic body is recessed outward of the protrusion from the second opening or the first surface toward the opposite side of the magnetoresistive element when viewed in plan from the stacking direction. The magnetoresistance effect device according to any one of claims 1 to 12, having a recess.

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