CN113497182A

CN113497182A - Magnetoresistive effect device and sensor

Info

Publication number: CN113497182A
Application number: CN202110279720.6A
Authority: CN
Inventors: 出川直通; 柴田哲也
Original assignee: TDK Corp
Current assignee: TDK Corp
Priority date: 2020-03-18
Filing date: 2021-03-16
Publication date: 2021-10-12
Also published as: JP2021152521A

Abstract

The invention provides a magnetoresistance effect device and a sensor, which are excellent in output characteristics of a direct current signal. The magnetoresistance effect device includes a magnetoresistance effect element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer interposed between the first ferromagnetic layer and the second ferromagnetic layer, a first signal line separated from the magnetoresistance effect element by an insulator, a high-frequency magnetic field generated by a first high-frequency current flowing through the first signal line being applied to the first ferromagnetic layer, a high-frequency current flowing through the magnetoresistance effect element, and a signal including a direct-current signal component generated by an output from the magnetoresistance effect element being output from the output port.

Description

Magnetoresistive effect device and sensor

Technical Field

The invention relates to a magnetoresistance effect device and a sensor.

Background

With the development of a highly information-oriented society in recent years, attention is being paid to high-frequency parts in a GHz high-frequency band. As a field that can be applied to new high-frequency components, spintronics is being studied.

For example, patent document 1 describes a spin torque diode element utilizing the spin torque diode effect. Patent document 1 describes a technique of using a spin torque diode element as a rectifier. The spin torque diode effect is a rectifying effect utilizing a resistance change of a magnetoresistance effect element.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2013/108357

Disclosure of Invention

Problems to be solved by the invention

The spin torque diode element described in patent document 1 changes the magnetization direction of the magnetic layer of the TMR element by spin transfer torque generated by an alternating current flowing through the TMR element, and outputs a direct current voltage by multiplying the changed resistance of the TMR element by the alternating current. However, the magnetization vibration using the spin transfer torque may have a small amplitude, and it may be difficult to output a large dc voltage.

The present invention has been made in view of the above problems, and an object thereof is to provide a magnetoresistive device and a magnetic sensor having excellent output characteristics of a direct current signal.

Means for solving the problems

In order to solve the above problems, the following means are provided.

(1) A magnetoresistive device according to a first aspect includes a magnetoresistive element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer interposed between the first ferromagnetic layer and the second ferromagnetic layer, a first signal line separated from the magnetoresistive element by an insulator, a high-frequency magnetic field generated by a first high-frequency current flowing through the first signal line being applied to the first ferromagnetic layer, a high-frequency current flowing through the magnetoresistive element, and an output port from which a signal including a direct-current signal component generated by an output from the magnetoresistive element is output.

(2) The magnetoresistance effect device according to the above aspect may further include a first input port connected to the first signal line, the first signal line being separated from the second signal line by an insulator, a second input port connected to the second signal line, a first high-frequency signal generating the first high-frequency current in the first signal line being input to the first input port, a second high-frequency signal generating the second high-frequency current in the second signal line being input to the second input port, the second signal line being connected to the magnetoresistance effect element, and the second high-frequency current flowing in the second signal line flowing in the magnetoresistance effect element as the high-frequency current.

(3) The magnetoresistive device according to the above aspect may further include a first input port connected to the first signal line to which a first high-frequency signal generating the first high-frequency current in the first signal line is input, the first signal line being connected to the magnetoresistive element, and the first high-frequency current flowing in the first signal line may flow as the high-frequency current in the magnetoresistive element.

(4) The magnetoresistive device according to the above aspect may further include a first input port and a second signal line, the first input port being connected to the first signal line and the second signal line, the first input port being input with a first high-frequency signal that generates the first high-frequency current in the first signal line and generates a second high-frequency current in the second signal line, the second signal line being connected to the magnetoresistive element, and the second high-frequency current flowing in the second signal line flowing as the high-frequency current in the magnetoresistive element.

(5) The magnetoresistance effect device according to the above aspect may further include a yoke that sandwiches the magnetoresistance effect element in a gap when viewed from a stacking direction of the magnetoresistance effect element, the yoke being closer to the second ferromagnetic layer than the first ferromagnetic layer, the yoke applying a magnetic field generated in the gap by an external magnetic field to the second ferromagnetic layer.

(6) The magnetoresistance effect device according to the above aspect may further include a yoke that sandwiches the magnetoresistance effect element in a gap when viewed from a stacking direction of the magnetoresistance effect element, the yoke being closer to the first ferromagnetic layer than the second ferromagnetic layer, the yoke applying a magnetic field generated in the gap by an external magnetic field to the first ferromagnetic layer.

(7) In the magnetoresistive effect device according to the above aspect, the first signal line may be closer to the first ferromagnetic layer than the second ferromagnetic layer.

(8) The magnetoresistance effect device according to the above aspect may further include one or more magnetoresistance effect elements connected to the magnetoresistance effect element, and at least two magnetoresistance effect elements may have different directions of the high-frequency magnetic field applied to the first ferromagnetic layer.

(9) In the magnetoresistive device according to the above aspect, the first signal line may have an extended portion that extends in a direction intersecting the stacking direction of the magnetoresistive elements when viewed from above in the stacking direction, the extended portion may not overlap the magnetoresistive elements when viewed from above in the stacking direction, and may partially overlap the magnetoresistive elements when viewed from above in a direction perpendicular to the stacking direction, and the high-frequency magnetic field caused by the high-frequency current flowing through the extended portion may be applied to the first ferromagnetic layer.

(10) In the magnetoresistive device according to the above aspect, the magnetoresistive element may include a plurality of the magnetoresistive elements, and one or more of the first signal lines may be provided, and an angle formed by a position overlapping with a first magnetoresistive element among the magnetoresistive elements when viewed from a stacking direction of the first magnetoresistive element, a first extending direction in which the first signal line extends, and a second extending direction overlapping with a second magnetoresistive element among the magnetoresistive elements when viewed from a stacking direction of the second magnetoresistive element, at which the first signal line extends, may be 90 °.

(11) In the magnetoresistive effect device according to the above aspect, an in-plane component of the effective magnetic field of the first ferromagnetic layer may be parallel or antiparallel to a direction of oscillation of the high-frequency magnetic field applied to the first ferromagnetic layer.

(12) The sensor of the second aspect is a sensor using the magnetoresistance effect device of the above aspect.

Effects of the invention

The magnetoresistance effect device of the above aspect is excellent in output characteristics of a direct current signal.

Drawings

Fig. 1 is a diagram schematically showing a circuit configuration of a magnetoresistive effect device according to a first embodiment.

Fig. 2 is a schematic diagram for explaining an example of the operation of the magnetoresistive effect device according to the first embodiment as a magnetic sensor.

FIG. 3 is a diagram showing an example of the magnetization states of the first ferromagnetic layer and the second ferromagnetic layer of the magnetoresistive element in the magnetic sensor.

FIG. 4 is a graph showing a phase difference Deltatheta between the magnitude of an external magnetic field applied to a magnetoresistive element and the phase of a first high-frequency current and the phase of the resistance of the magnetoresistive element₂(phase difference DeltaTheta between the phase of the second high-frequency current and the phase of the resistance of the magnetoresistive effect element₁) A graph of the relationship between.

Fig. 5 is a diagram showing an example of the magnetization states of the first ferromagnetic layer and the second ferromagnetic layer of the magnetoresistive element in the magnetic sensor for detecting the direction of the external magnetic field.

Fig. 6 is a diagram showing another example of the magnetization states of the first ferromagnetic layer and the second ferromagnetic layer of the magnetoresistive element in the magnetic sensor for detecting the direction of the external magnetic field.

Fig. 7 is a graph showing a time change in resistance of the magnetoresistance effect elements of the first pattern.

Fig. 8 is a graph showing a time change in resistance of the magnetoresistance effect elements of the second pattern.

Fig. 9 is a plan view of a modification of the magnetoresistance effect element shown in fig. 5(a) and 5 (b).

Fig. 10 is a cross-sectional view of another modification of the magnetoresistance effect element shown in fig. 5(a) and 5 (b).

Fig. 11 is a diagram showing an example of the magnetization states of the first ferromagnetic layer and the second ferromagnetic layer of the magnetoresistive element in the magnetic sensor for detecting the component in the lamination direction of the external magnetic field.

Fig. 12 is a diagram schematically showing an example of a circuit configuration when the magnetoresistive effect device of the first embodiment is used as a rectifier.

FIG. 13 is a view showing an example of the magnetization states of the first ferromagnetic layer and the second ferromagnetic layer of the magnetoresistive element in the rectifier.

Fig. 14 is a diagram showing another example of the magnetization states of the first ferromagnetic layer and the second ferromagnetic layer of the magnetoresistive element in the rectifier.

Fig. 15 is a schematic diagram for explaining a first example in the case of using a magnetoresistance effect device as a dielectric sensor.

Fig. 16 is a schematic diagram for explaining a second example when a magnetoresistance effect device is used as a dielectric sensor.

Fig. 17 is a schematic diagram for explaining a third example when a magnetoresistance effect device is used as a dielectric sensor.

Fig. 18 is a diagram schematically showing a circuit configuration of a magnetoresistive effect device according to a first modification.

Fig. 19 is a perspective view showing the vicinity of a magnetoresistance effect element of a magnetoresistance effect device according to a second modification example.

Fig. 20 is a plan view of the magnetoresistive device according to the second modification in the vicinity of the magnetoresistive element.

Fig. 21 is another example of a plan view of the magnetoresistive device according to the second modification in the vicinity of the magnetoresistive element.

Fig. 22 is another example of a perspective view showing the vicinity of the magnetoresistance effect element in the magnetoresistance effect device according to the second modification.

Fig. 23 is a diagram schematically showing a circuit configuration of a magnetoresistance effect device according to a third modification example.

Fig. 24 is a plan view of the vicinity of the magnetoresistance effect element of the magnetoresistance effect device according to the third modification example.

Fig. 25 is a diagram showing a change in value corresponding to the dc voltage output from each magnetoresistance effect element and a change in arithmetic mean of values corresponding to the dc voltages output from each magnetoresistance effect element with a change in direction of the external magnetic field.

Fig. 26 is a diagram schematically showing a circuit configuration of a magnetoresistive effect device according to a fourth modification.

Fig. 27 is a perspective view showing the vicinity of the first magnetoresistance element and the second magnetoresistance element in the magnetoresistance effect device according to the fourth modification example.

Fig. 28 is a diagram schematically showing another example of the circuit configuration of the magnetoresistive effect device according to the fourth modification.

Fig. 29 is a diagram schematically showing another example of the circuit configuration of the magnetoresistive effect device according to the fourth modification.

Fig. 30 is a perspective view showing the vicinity of a magnetoresistance effect element in a magnetoresistance effect device according to a fifth modification example.

Fig. 31 is a diagram schematically showing the circuit configuration of the magnetoresistance effect device according to the second embodiment.

Fig. 32 is a diagram schematically showing a circuit configuration of a modification of the magnetoresistive effect device according to the second embodiment.

Fig. 33 is a diagram schematically showing a circuit configuration of another modification of the magnetoresistive effect device according to the second embodiment.

Fig. 34 is a diagram schematically showing a circuit configuration of another modification of the magnetoresistive effect device according to the second embodiment.

Fig. 35 is a diagram schematically showing a circuit configuration of a magnetoresistance effect device according to a third embodiment.

Fig. 36 is a schematic view when the magnetoresistance effect device of the third embodiment is used as a dielectric sensor.

Fig. 37 is a schematic diagram of a modification when the magnetoresistance effect device of the third embodiment is used as a dielectric sensor.

Fig. 38 is a schematic view of another modification when the magnetoresistance effect device of the third embodiment is used as a dielectric sensor.

Fig. 39 is a diagram schematically showing a circuit configuration of a modification of the magnetoresistive effect device according to the third embodiment.

Fig. 40 is a diagram schematically showing a circuit configuration of another modification of the magnetoresistive effect device according to the third embodiment.

Fig. 41 is a diagram schematically showing a circuit configuration of another modification of the magnetoresistive effect device according to the third embodiment.

Detailed Description

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

"first embodiment"

Fig. 1 is a diagram showing a circuit configuration of a magnetoresistive effect device 100 according to a first embodiment. The magnetoresistance effect device 100 includes a magnetoresistance effect element 10, a first input port p1, a first signal line 20, a second input port p2, a second signal line 30, and an output port p 3. The magnetoresistive effect device 100 shown in fig. 1 further includes

wirings

40 and 42, reference potential terminals pr1 and pr2, an inductor 91, and a capacitor 92.

Magnetoresistive effect element

The magnetoresistive element 10 includes a first ferromagnetic layer 1, a second ferromagnetic layer 2, and a spacer layer 3. The spacer layer 3 is located between the first 1 and second 2 ferromagnetic layers. Hereinafter, the stacking direction of the first ferromagnetic layer 1, the second ferromagnetic layer 2, and the spacer layer 3 may be simply referred to as "stacking direction".

The first ferromagnetic layer 1 is, for example, a free magnetization layer (first free magnetization layer). The second ferromagnetic layer 2 is, for example, a fixed magnetization layer or a free magnetization layer (second free magnetization layer). When the second ferromagnetic layer 2 functions as a fixed magnetization layer, the coercivity of the second ferromagnetic layer 2 is higher than the coercivity of the first ferromagnetic layer 1, for example. The free magnetization layer is a layer made of a magnetic material whose magnetization direction changes when a predetermined external force is applied, and the fixed magnetization layer is a layer made of a magnetic material whose magnetization direction is less likely to change by the free magnetization layer when a predetermined external force is applied. The predetermined external force is, for example, an external force applied to the magnetization by an external magnetic field.

The resistance value in the stacking direction of the magnetoresistive element 10 (the resistance value when a current flows in the stacking direction) changes with a change in the relative angle between the magnetization direction of the first ferromagnetic layer 1 and the magnetization direction of the second ferromagnetic layer 2. The second ferromagnetic layer 2 may be either a fixed magnetization layer or a free magnetization layer if the relative angle of the magnetization direction of the first ferromagnetic layer 1 with respect to the magnetization direction of the second ferromagnetic layer 2 changes.

The first ferromagnetic layer 1 and the second ferromagnetic layer 2 include ferromagnetic bodies. For example, metals such as Cr, Mn, Co, Fe, and Ni, or alloys containing one or more of these metal elements can be used as the constituent materials for the first ferromagnetic layer 1 and the second ferromagnetic layer 2. Further, an alloy of the above-described metal element and at least one or more elements selected from B, C and N may be used as the first ferromagnetic layer 1 and the second ferromagnetic layer 2. For example, when the first ferromagnetic layer 1 and the second ferromagnetic layer 2 function as free magnetization layers, they may contain a CoFeB alloy as a main component. The first ferromagnetic layer 1 and the second ferromagnetic layer 2 may be formed of a plurality of layers.

Further, XYZ or X may be used for the first ferromagnetic layer 1 and the second ferromagnetic layer 2₂Intermetallic compounds (Wheatstone alloys) represented by the chemical composition YZ. X is a transition metal element or a noble metal element of Co, Fe, Ni or Cu group on the periodic table. Y is a transition metal of the Mn, V, Cr or Ti group or an element expressed by X. Z is a typical element of groups III to V. For example, Co₂FeSi、Co₂MnSi、Co₂Mn_1-aFe_aAl_bSi_1-bWheatstone alloys are known as (0 ≦ a ≦ 1, 0 ≦ b ≦ 1), and the like.

The first ferromagnetic layer 1 and the second ferromagnetic layer 2 may be in-plane magnetization films having an axis of easy magnetization in a film in-plane direction, or may be perpendicular magnetization films having an axis of easy magnetization in a direction perpendicular to the film plane.

In order to form the ferromagnetic layer as an in-plane magnetization film, a layer in contact with the ferromagnetic layer is formed of a material that hardly exhibits interfacial magnetic anisotropy. Examples of the material exhibiting the interface magnetic anisotropy include Ru, Cu, and the like. On the other hand, in order to form the ferromagnetic layer as a perpendicular magnetization film, a layer in contact with the ferromagnetic layer is formed of a material that easily exhibits interface magnetic anisotropy. Examples of the material which easily exhibits the interface magnetic anisotropy include MgO, W, Ta, and Mo. These material layers in contact with the ferromagnetic layer may be provided on one side of the ferromagnetic layer in a direction perpendicular to the film surface. Alternatively, the first ferromagnetic layer 1 or the second ferromagnetic layer 2 may be formed of a laminated film in which these material layers in contact with the ferromagnetic layers are sandwiched between a plurality of ferromagnetic layers.

In the case where the second ferromagnetic layer 2 functions as a fixed magnetization layer, an antiferromagnetic layer may be added so as to be in contact with the second ferromagnetic layer 2. In addition, the magnetization of the second ferromagnetic layer 2 may be fixed by utilizing magnetic anisotropy due to a crystal structure, a shape, or the like. As the antiferromagnetic layer, FeO, CoO, NiO, CuFeS can be used₂IrMn, FeMn, PtMn, Cr or Mn, etc.

The spacer layer 3 is a nonmagnetic layer disposed between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. The spacer layer 3 is formed of a layer made of a conductor, an insulator, or a semiconductor, or a layer in which a conductive point made of a conductor is included in an insulator.

For example, when the spacer layer 3 is made of an insulator, the Magnetoresistance effect element 10 is a Tunneling Magnetoresistance (TMR) effect element, and when the spacer layer 3 is made of a metal, it is a Giant Magnetoresistance (GMR) effect element.

When the spacer layer 3 is made of an insulating material, a material such as aluminum oxide, magnesium oxide, titanium oxide, or silicon oxide can be used. By adjusting the film thickness of the spacer layer 3 so as to exhibit a high TMR effect between the first ferromagnetic layer 1 and the second ferromagnetic layer 2, a high magnetoresistance change rate can be obtained. In order to efficiently utilize the TMR effect, the thickness of the spacer layer 3 may be set to about 0.5 to 10.0 nm.

In the case where the spacer layer 3 is formed of a nonmagnetic conductive material, a conductive material such as Cu, Ag, Au, or Ru can be used. In order to efficiently utilize the GMR effect, the thickness of the spacer layer 3 may be set to about 0.5 to 3.0 nm.

When the spacer layer 3 is formed of a nonmagnetic semiconductor material, a material such as zinc oxide, indium oxide, tin oxide, germanium oxide, gallium oxide, or ITO can be used. In this case, the thickness of the spacer layer 3 may be set to about 1.0 to 4.0 nm.

When a layer containing a conduction point formed of a conductor in a nonmagnetic insulator is used as the spacer layer 3, it is preferable to adopt a structure in which a conduction point formed of a conductor such as CoFe, CoFeB, CoFeSi, CoMnGe, CoMnSi, CoMnAl, Fe, Co, Au, Cu, Al, or Mg is contained in a nonmagnetic insulator formed of alumina or magnesia. In this case, the thickness of the spacer layer 3 may be set to about 0.5 to 2.0 nm.

In order to improve the electrical conductivity to the magnetoresistive element 10, electrodes may be provided on both surfaces of the magnetoresistive element 10 in the stacking direction. By providing electrodes on both end surfaces of the magnetoresistive element 10 in the stacking direction, the contact between each line and the magnetoresistive element 10 becomes a plane, and the signal (current) flows in the stacking direction at any position in the in-plane direction of the magnetoresistive element 10.

The magnetoresistance effect element 10 may have other layers. For example, the magnetoresistive element 10 may have a seed layer or a buffer layer on the surface of the second ferromagnetic layer 2 opposite to the first ferromagnetic layer 1. The magnetoresistive element 10 may have a cap layer on the surface of the first ferromagnetic layer 1 opposite to the second ferromagnetic layer 2. The cap layer, seed layer, and buffer layer may be made of MgO, W, Mo, Ru, Ta, Cu, Cr, or a laminated film thereof. The thicknesses of these layers may be set to about 2 to 10nm, respectively.

First input port

The first input port p1 is a first input terminal of the magnetoresistance effect device 100. The first input port p1 is connected to, for example, an ac signal source, an antenna, and the like. In the case where the antenna is integrated with the magnetoresistance effect device as a part of the magnetoresistance effect device, the antenna becomes the first input port. The first input port p1 is connected to the first signal line 20. The first input port p1 is connected to, for example, an end of the first signal line 20. The first high-frequency signal is input to the first input port p1, and the first high-frequency signal is input from the first input port p1 to the first signal line 20. The first high-frequency signal generates a first high-frequency current I in the first signal line 20_R1. The first high-frequency signal is, for example, a signal having a frequency of 100MHz or more. The first high-frequency signal may be a signal having a frequency of 1MHz or more, for example. A first high-frequency current I_R1Is identical to the frequency of the first high frequency signal.

First signal line

The first signal line 20 is used to flow the first high frequency current I_R1The signal line of (2). The first signal line 20 shown in fig. 1 is a line connecting the first input port p1 and the reference potential terminal pr 1. The first signal line 20 shown in fig. 1 electrically connects the first input port p1 and the reference potential terminal pr 1.

The first signal line 20 is separated from the magnetoresistance effect element 10 and the second signal line 30 by an insulator. The insulator may be an insulator or a space. The first signal line 20 is disposed so as to be capable of connecting the first signal line20, a first high-frequency current I flowing in_R1Generated high-frequency magnetic field H_rfTo the location of the first ferromagnetic layer 1. First high-frequency current I flowing in first signal line 20_R1Induced high frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1. Magnetization of the first ferromagnetic layer 1 in the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfThe frequency of (3) is greatly vibrated in the vicinity of the ferromagnetic resonance frequency of the first ferromagnetic layer 1. This phenomenon is a ferromagnetic resonance phenomenon. High frequency magnetic field H_rfAt a frequency of and a first high-frequency current I_R1Are consistent. The first signal line 20 is, for example, closer to the first ferromagnetic layer 1 than the second ferromagnetic layer 2.

Second input port

The second input port p2 is a second input terminal of the magnetoresistance effect device 100. An ac signal source, an antenna, and the like are connected to the second input port p2, for example. In the case where the antenna is integrated with the magnetoresistance effect device as a part of the magnetoresistance effect device, the antenna becomes the second input port. The second input port p2 is connected to the second signal line 30. The second input port p2 is connected to, for example, an end of the second signal line 30. The second high-frequency signal is input to the second input port p2, and the second high-frequency signal is input from the second input port p2 to the second signal line 30. The second high-frequency signal generates a second high-frequency current I in a second signal line 30_R2. The second high-frequency signal is, for example, a signal having a frequency of 100MHz or more. The second high-frequency signal may be a signal having a frequency of 1MHz or more, for example. A second high-frequency current I_R2Is identical to the frequency of the second high frequency signal.

Second signal line

The second signal line 30 is for flowing the second high frequency current I_R2The signal line of (2). The second signal line 30 shown in fig. 1 is a line connecting between the second input port p2 and the magnetoresistance effect element 10. The second signal line 30 shown in fig. 1 electrically connects the second input port p2 and the magnetoresistance effect element 10.

The second signal line 30 is connected to the magnetoresistance effect element 10. Second high flowing in second signal line 30Frequency current I_R2Flows through the magnetoresistance effect element 10. By a high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfThe amplitude of the magnetization vibration of the first ferromagnetic layer 1 caused by the spin transfer torque caused by the second high-frequency current I flowing through the magnetoresistive element 10 is larger than the amplitude of the magnetization vibration of the first ferromagnetic layer 1 caused by the spin transfer torque_R2And (3) the product is obtained.

Output port

The output port p3 is an output terminal of the magnetoresistance effect device 100. For example, a voltmeter for monitoring voltage or an ammeter for monitoring current is connected to the output port p 3. The output port p3 shown in fig. 1 is connected to the line 40 branched from the second signal line 30. The output port p3 is connected to the magnetoresistive element, and a signal containing a dc signal component (dc voltage or dc current) caused by the output from the magnetoresistive element 10 is output from the output port p 3.

Other structures

(reference potential terminal)

The reference potential terminals pr1 and pr2 are connected to a reference potential to determine the reference potential of the magnetoresistance effect device 100. The reference potential terminal pr1 is connected to the first signal line 20. The reference potential terminal pr2 is connected to the line 42 connected to the magnetoresistive element 10. The reference potential of fig. 1 is a ground point G. The ground point G may also be provided outside the magnetoresistance effect device 100. The reference potential may be other than the ground point G.

(line)

The terminals and the magnetoresistance effect element 10 and the terminals are connected by wiring. The shape of the line may be defined as a microstrip line (MSL) type or a coplanar waveguide (CPW) type. When the microstrip line (MSL) type or the coplanar waveguide (CPW) type is designed, the line width or the distance between the ground points may be designed so that the characteristic impedance of the line is equal to the impedance of the circuit system. By designing in this way, the transmission loss of the line can be suppressed.

The line 40 is a line branched from the second signal line 30. The line 40 connects between the second signal line 30 and the output port p 3. The wiring 42 connects between the magnetoresistive element 10 and the reference potential terminal pr 2.

(inductor, capacitor)

The inductor 91 cuts off the high-frequency component of the signal and passes the constant component of the signal. The capacitor 92 passes a high-frequency component of the signal and cuts off an invariant component of the signal. The inductor 91 is disposed in a portion where suppression of a high-frequency signal flow is desired, and the capacitor 92 is disposed in a portion where suppression of a direct-current signal flow is desired.

Inductor 91 of fig. 1 is located on line 40. Inductor 91 suppresses the second high frequency current I_R2And the high frequency component of the output from the magnetoresistive effect element 10 to the output port p 3. As the inductor 91, a chip inductor, an inductor formed by a pattern line, a resistance element having an inductor component, or the like can be used. The inductance of the inductor 91 may be 10nH or more, for example. When the voltmeter or ammeter connected to the output port p3 has a function of cutting off the high-frequency component of the signal and passing the invariant component of the signal, the inductor 91 may be eliminated.

The capacitor 92 of fig. 1 is located on the second signal line 30. The capacitor 92 in fig. 1 is located on the second input port p2 side of the second signal line 30 with respect to the branch point with the line 40. As the capacitor 92, a known capacitor can be used.

Magnetic sensor

The magnetoresistance effect device 100 can be used for a sensor, a rectifier, and the like, for example. Examples of the sensor include a magnetic sensor (magnetic field sensor) for detecting a magnetic field, a dielectric sensor using a dielectric as a measurement object, and the like. First, a case of using the sensor as a magnetic sensor will be described. Next, in the first embodiment, a dc voltage as a dc signal component output from the output port p3 will be described as an example.

Fig. 2(a) and 2(b) are schematic diagrams for explaining the operation of the magnetoresistive device 100 according to the first embodiment as a magnetic sensor. FIG. 2(a) shows a first high-frequency current I in a state where an external magnetic field of a certain magnitude is applied to the magnetoresistive element 10_R1Resistance R of the magnetoresistive element 10₁₀A second high-frequency current I_R2And a DC voltage V outputted from an output port p3_DCTime of change in time. FIG. 2(b) shows the first high-frequency current I after the external magnetic field applied to the magnetoresistive element 10 has changed (increased)_R1Resistance R of the magnetoresistive element 10₁₀A second high-frequency current I_R2And a DC voltage V outputted from an output port p3_DCTime of change in time. The external magnetic field is a magnetic field applied to the magnetoresistance effect element 10 from outside the respective structures of the magnetoresistance effect device 100. Furthermore, the first high-frequency current I shown in FIG. 1_R1And a second high-frequency current I_R2The arrows of (a) respectively indicate the forward direction of the current. The same applies to other figures described later.

First, a state before the external magnetic field applied to the magnetoresistance effect element 10 changes will be described. When a first high frequency signal is input to the first input port p1 from an alternating current signal source connected to the first input port p1, a first high frequency current I flows in the first signal line 20_R1. A first high-frequency current I_R1Generating a high-frequency magnetic field H_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 of the magnetoresistive effect element 10.

The magnetization of the first ferromagnetic layer 1 is subjected to a first high-frequency current I_R1Induced high frequency magnetic field H_rfBut vibrates. FIG. 3 is a diagram showing an example of states of magnetizations M1, M2 of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive element 10 in the magnetic sensor. The magnetization M1 of the first ferromagnetic layer 1 is induced by the high-frequency magnetic field H_rfBut vibrates (time-of-flight). The second ferromagnetic layer 2 is a fixed magnetization layer, and the direction of the magnetization M2 is fixed to the high-frequency magnetic field H_rfAre parallel to each other. External magnetic field H_exFor example in the stacking direction.

In an external magnetic field H applied to the magnetoresistance effect element 10_exIn the state before the change, for example, the ferromagnetic resonance frequency of the first ferromagnetic layer 1 is higher than the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfThe frequency of (2) is small. Resistance R of magnetoresistance effect element 10₁₀Is changed (vibrated) by the magnetization vibration of the first ferromagnetic layer 1. A first high-frequency current I_R1Phase and resistance R of magnetoresistance effect element 10₁₀May also be different in phase from each other,however, fig. 2(a) shows a similar example. A first high-frequency current I_R1And resistance R of magnetoresistance effect element 10₁₀The phase difference can be determined by the arrangement position of the first signal line 20 with respect to the magnetoresistive element 10, the arrangement positions of the first input port p1 and the reference potential terminal pr1 with respect to the first signal line 20, and the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfThe relative angle of the direction of magnetization of the second ferromagnetic layer, etc.

When a second high frequency signal is input to the second input port p2 from an ac signal source connected to the second input port p2, a second high frequency current I flows in the second signal line 30_R2. A second high-frequency current I_R2Flows through the magnetoresistance effect element 10. A second high-frequency current I_R2And the first high-frequency current I_R1Although the phases of (a) and (b) may be different, fig. 2(a) and (b) show the same example. That is, in the example shown in fig. 2(a), the second high-frequency current I_R2Phase and resistance R of magnetoresistance effect element 10₁₀Are in phase.

When a first high-frequency current I is inputted to the magneto-resistance effect device 100_R1And a second high-frequency current I_R2When the voltage is applied, the output port p3 outputs the DC voltage V caused by the output from the magnetoresistive element 10_DC。

DC voltage V_DCBy applying a first high-frequency current I_R1Induced high frequency magnetic field H_rfAnd the resistance R of the magnetoresistance effect element 10 is varied₁₀And a current (second high-frequency current I) flowing in the magnetoresistance effect element 10_R2) The product of (a) and (b) is a direct current component of the voltage V (output voltage from the magnetoresistance effect element 10).

When set to I_R2＝A·sin(2πft)、

R₁₀＝B·sin(2πft+△θ₁)+R₀When the temperature of the water is higher than the set temperature,

V＝I_R2×R₁₀＝(A·B/2)·{cos(△θ₁)－cos(4πft+△θ₁)}+A·R₀·sin(2πft)。

DC voltage V_DCIs of voltage VA DC component of (A.B/2) cos (. DELTA.. theta.)₁)。

Where A is the second high-frequency current I_R2B is the resistance R of the magnetoresistance effect element 10₁₀Amplitude of (D), R₀Is a resistance component independent of the relative angle of the magnetization of the first ferromagnetic layer 1 and the magnetization of the second ferromagnetic layer 2 in the resistance of the magnetoresistive element 10, f is the frequency, t is the time, and Δ θ₁Is the second high-frequency current I_R2Phase and resistance R of magnetoresistance effect element 10₁₀The phase difference of (1). Hereinafter, the phase difference may be abbreviated as "phase difference Δ θ₁". In addition, a first high-frequency current I is set_R1Phase and resistance R of magnetoresistance effect element 10₁₀Has a phase difference of Delta theta₂(hereinafter, it may be abbreviated as "phase difference Δ θ₂”)。

In the case shown in FIG. 2(a), Δ θ₁0(0 °), the dc voltage V output from the output port p3_DCBecomes A.B/2.

Then, the external magnetic field H applied to the magneto-resistance effect element 10 is applied_exThe state after the change (increase) will be described. When an external magnetic field H is applied to the magnetoresistance effect element 10_exWhen the change occurs, the state of magnetization vibration (chronological motion) of the first ferromagnetic layer 1 changes. As a result, the resistance R of the magnetoresistive element 10₁₀Is changed. Because of the second high-frequency current I_R2Is not changed, so that at the second high-frequency current I_R2Phase and resistance R of magnetoresistance effect element 10₁₀A phase difference Delta theta is generated between the phases₁. The ferromagnetic resonance frequency used in the first ferromagnetic layer 1 is higher than the high-frequency magnetic field H up to this point_rfFrequency (first high-frequency current I)_R1Of) is sufficiently small, the first high-frequency current I_R1Phase and resistance R of magnetoresistance effect element 10₁₀Are in phase (Delta theta)₂0(0 °)) was explained. In this example, the ferromagnetic resonance frequency of the first ferromagnetic layer 1 is higher than the high-frequency magnetic field H_rfIs sufficiently large, the phase difference Δ θ₂Becomes pi (180 °). Applied to magneto-resistive effect elementsExternal magnetic field H of element 10_exWhen the effective magnetic field inside the first ferromagnetic layer 1 becomes large, the ferromagnetic resonance frequency of the first ferromagnetic layer 1 becomes large. Therefore, in the case of this example, as shown in fig. 4, the phase difference Δ θ₂Or the phase difference Δ θ₁Varies with the magnitude of the external magnetic field applied to the magnetoresistance effect element 10.

As described above, the DC voltage V_DCIs (A.B/2) cos (. DELTA.. theta.)₁) When the phase difference is delta theta₁When changed, the DC voltage V_DCThe output value of (a) will change. That is, the magnetoresistance effect device 100 is based on the direct-current voltage V output from the output port p3_DCCapable of detecting an external magnetic field H_exWhether or not the magnitude of (b) has changed, functions as a magnetic sensor. As an example, the slave phase difference Δ θ can be detected₁A phase difference Delta theta of 0(0 DEG)₁A state change of pi (180 deg.). External magnetic field H_exBefore and after the magnitude change of (a) is detected, and a phase difference Delta theta₁The value of (2) is not limited to 0(0 °) or pi (180 °), and any value between 0 and pi (0 ° to 180 °) may be used. In the magnetoresistive effect device 100, since the current I is passed by the first high frequency_R1Induced high frequency magnetic field H_rfThe magnetization of the first ferromagnetic layer 1 is vibrated, and therefore the amplitude of the magnetization vibration of the first ferromagnetic layer 1 can be increased. When the amplitude of the magnetization vibration of the first ferromagnetic layer 1 increases, the resistance R of the magnetoresistance effect element 10 increases₁₀The amount of change (amplitude) of the voltage increases, and a large DC voltage V can be output from the output port p3_DC。

In addition, the magnetoresistance effect device 100 of the present embodiment is not limited to being capable of detecting a change in magnitude of an external magnetic field, and may be capable of detecting the magnitude or direction of an applied external magnetic field. The respective detection methods are described in detail below.

(detection of magnitude of external magnetic field)

First, a method of detecting the magnitude of the external magnetic field will be described. For example, as shown in FIG. 3, the magnetization M2 in the second ferromagnetic layer 2 is induced by a high-frequency magnetic field H_rfWhen the external magnetic field H is oriented in the vibration direction of_exBig and small hairWhen the phase difference is changed, as shown in FIG. 4, the phase difference Δ θ₂Or the phase difference Δ θ₁A change will occur. Phase difference Delta theta₂Or the phase difference Δ θ₁For example, an external magnetic field H_exIs 0(0 °) (. DELTA.Theta) when the magnitude of (D) is less than the first value₁、△θ₂0) in the external magnetic field H_exIs pi (180 DEG) (Delta theta) in the case where the magnitude of (d) is larger than the second value (the second value > the first value)₁、△θ₂Pi). Furthermore, an external magnetic field H_exWhen the magnitude of (A) is equal to or greater than a first value and equal to or less than a second value, the external magnetic field H_exIs subject to a sharp change in magnitude. Therefore, in the external magnetic field H_exIn a region where the magnitude of (A) is equal to or greater than a first value and equal to or less than a second value, the external magnetic field H_exMagnitude of (d) and phase difference Delta theta₁、△θ₂In a one-to-one relationship. I.e. if the phase difference Δ θ is known₁、△θ₂Then the external magnetic field H can be detected_exThe size of (2). As described above, the DC voltage V_DCIs (A.B/2) cos (. DELTA.. theta.)₁). Therefore, it can be based on the DC voltage V_DCValue of (d) to derive a phase difference Δ θ₁And can be based on the phase difference Delta theta₁To detect the magnitude of the external magnetic field. In addition, the DC voltage V can be used_DCThe amount of change in the magnitude of the external magnetic field is obtained. In addition, the magnetic field H is opposite to the external magnetic field_exIs a phase difference Δ θ₁、△θ₂Is abrupt, the magnetic sensor can detect the external magnetic field H with high sensitivity_exThe size difference of (2).

(detection of the direction of the external magnetic field)

Next, a method of detecting the direction of the external magnetic field will be described. FIGS. 5(a) and 5(b) show the detection of the external magnetic field H_exIn the direction of (3), the magnetization states of the first and second

ferromagnetic layers

1 and 2 of the magnetoresistive effect element 10 are shown as examples of the states of the magnetizations M1 and M2. FIG. 5(a) shows an external magnetic field H_exIs in the first direction, and FIG. 5(b) shows an external magnetic field H_exIs in a state of a direction different from the first direction.

In addition, FIGS. 6(a) andFIG. 6(b) is a diagram showing the detection of the external magnetic field H_exIn the direction of (3), the state of the magnetizations M1, M2 of the first and second

ferromagnetic layers

1, 2 of the magnetoresistive element 10 is shown in another example. FIG. 6(a) shows an external magnetic field H_exIs in the first direction, and FIG. 6(b) shows an external magnetic field H_exIs in a state of a direction different from the first direction.

The case of detecting the direction of the external magnetic field will be described with reference to two patterns, fig. 5(a) and 5(b) and fig. 6(a) and 6 (b).

First, the first pattern shown in fig. 5(a) and 5(b) will be described. In the first pattern, the magnetization M1 of the first ferromagnetic layer 1 is passed through a high-frequency magnetic field H_rfAnd vibration (time-of-flight), external magnetic field H_exIs applied to the second ferromagnetic layer 2, and the magnetization M2 of the second ferromagnetic layer 2 is induced by an external magnetic field H_exIs oriented in the direction of (a). The second ferromagnetic layer 2 is a second free magnetization layer, and the direction of the magnetization M2 of the second ferromagnetic layer 2 depends on the external magnetic field H_exIs changed. In the example of the first pattern, the first ferromagnetic layer 1 is easily passed through the high-frequency magnetic field H at the magnetization M1_rfAnd the aspect of vibration (precession) preferably has an axis of easy magnetization in a direction perpendicular to the film surface. In the example of the first pattern, the second ferromagnetic layer 2 is less likely to be subjected to the high-frequency magnetic field H at the magnetization M2_rfIt is preferable in this respect to have an axis of easy magnetization in the film in-plane direction.

The magnetic sensor detects the external magnetic field H using, for example, the magnetoresistance effect element 10 of the first pattern_exIn the direction of (a). A first high-frequency signal is input to a first input port p1 to generate a first high-frequency current I of a frequency f_R1Flows into the first signal line 20. A first high-frequency current I_R1Generating a high-frequency magnetic field H of frequency f_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 of the magnetoresistive effect element 10.

A second high-frequency signal is input to the second input port p2 to generate a second high-frequency current I having a frequency f_R2Flows into the second signal line 30. A second high-frequency current I_R2Flows through the magnetoresistance effect element 10. A second high-frequency current I_R2Example of phaseSuch as a first high-frequency current I_R1Are in phase. A second high-frequency current I_R2May also be in phase with the first high-frequency current I_R1Are different in phase.

Resistance R of magnetoresistance effect element 10₁₀As the relative angle of the magnetization M1 of the first ferromagnetic layer 1 and the magnetization M2 of the second ferromagnetic layer 2 changes. FIG. 7 shows the resistance R of the magnetoresistive element 10₁₀A graph of time variation of (a). The upper graph of FIG. 7 shows the application of the external magnetic field H in the first direction_exResistance R of the magnetoresistive effect element 10 in the state (2)₁₀The lower graph of fig. 7 shows that the external magnetic field H is applied in a direction different from the first direction_exResistance R of the magnetoresistive effect element 10 in the state (2)₁₀A graph of time variation of (a).

When an external magnetic field H_exWhen the direction of (2) is changed, the direction of the magnetization M2 of the second ferromagnetic layer 2 with respect to the central axis of vibration of the magnetization M1 of the first ferromagnetic layer 1 (rotational axis of precession, hereinafter, may be simply referred to as "rotational axis of magnetization M1") is changed. As a result, the resistance R of the magnetoresistive element 10₁₀The time when the resistance becomes maximum and minimum changes, and as shown in the lower graph of fig. 7, the resistance R of the magnetoresistance effect element 10 changes₁₀According to the example shown in the upper graph of fig. 7. When the resistance R of the magneto-resistance effect element 10₁₀When the phase of (3) is changed, the resistance R₁₀And the second high-frequency current I_R2Is a phase difference Δ θ between phases of₁The DC voltage V outputted from the output port p3 is changed_DCThe value of (c) is changed. That is, the magnetic sensor reads the dc voltage V output from the output port p3_DCCapable of detecting an external magnetic field H applied to the magnetic sensor_exIn the direction of (a).

Next, the second pattern shown in fig. 6(a) and 6(b) will be described. In the second pattern, the magnetization M1 of the first ferromagnetic layer 1 is passed through a high-frequency magnetic field H_rfBut vibrates (time-of-flight). In addition, in the second pattern, the second ferromagnetic layer 2 is a fixed magnetization layerThe direction of the magnetization M2 is fixed in the stacking direction. In the second pattern, the first ferromagnetic layer 1 and the second ferromagnetic layer 2 have an axis of easy magnetization in a direction perpendicular to the film surface.

The magnetic sensor detects the external magnetic field H, for example, using the magnetoresistance effect element 10 of the second pattern_exIn the direction of (a). A first high-frequency signal is input to a first input port p1 to generate a first high-frequency current I of a frequency f_R1Flows into the first signal line 20. A first high-frequency current I_R1Generating a high-frequency magnetic field H of frequency f_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 of the magnetoresistive effect element 10.

A second high-frequency signal is input to the second input port p2 to generate a second high-frequency current I having a frequency f_R2Flows into the second signal line 30. A second high-frequency current I_R2Flows through the magnetoresistance effect element 10. A second high-frequency current I_R2E.g. with the first high-frequency current I_R1Are in phase. A second high-frequency current I_R2May also be in phase with the first high-frequency current I_R1Are different in phase.

Resistance R of magnetoresistance effect element 10₁₀As the relative angle of the magnetization M1 of the first ferromagnetic layer 1 and the magnetization M2 of the second ferromagnetic layer 2 changes. FIG. 8 shows the resistance R of the magneto-resistive effect element 10₁₀A graph of time variation of (a). The upper graph of FIG. 8 shows the application of the external magnetic field H in the first direction_exResistance R of the magnetoresistive effect element 10 in the state (2)₁₀The lower graph in fig. 8 shows that the external magnetic field H is applied in a direction different from the first direction_exResistance R of the magnetoresistive effect element 10 in the state (2)₁₀A graph of time variation of (a).

By applying an external magnetic field H to the magnetoresistance effect element 10_exAnd an external magnetic field H is applied to the first ferromagnetic layer 1_exThe axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 is tilted. The direction of the inclination of the axis of rotation of the magnetization M1 is influenced by an external magnetic field H_exChanges in direction of (a). When the direction of the rotation axis of the magnetization M1 changes, the resistance R of the magnetoresistance effect element 10₁₀The time at which the maximum and minimum values are reached changes. As a result, as shown in the lower graph of fig. 8, the resistance R of the magnetoresistance effect element 10₁₀The phase of (b) is changed according to the example shown in the upper graph of fig. 8. When the resistance R of the magneto-resistance effect element 10₁₀When the phase of (3) is changed, the resistance R₁₀And the second high-frequency current I_R2Is a phase difference Δ θ between phases of₁The DC voltage V outputted from the output port p3 is changed_DCThe value of (c) is changed. That is, the magnetic sensor reads the dc voltage V output from the output port p3_DCCapable of detecting an external magnetic field H applied to the magnetic sensor_exIn the direction of (a).

If the magnetic sensor shown in fig. 6(a) or (b) is used, the magnetic sensor can detect the external magnetic field H_exThe size of the component in the in-plane direction (the direction perpendicular to the lamination direction of the magnetoresistive element 10). In fig. 6(a) and (b), the second ferromagnetic layer 2 is a fixed magnetization layer, and the direction of the magnetization M2 is fixed in either direction of the lamination direction. An external magnetic field H is applied to the first ferromagnetic layer 1 in the in-plane direction_ex. The axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 is passed through by an external magnetic field H_exAnd inclined from the stacking direction.

When an external magnetic field H_exWhen the magnitude of (b) is changed, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction is changed. For example, in the structure shown in fig. 6(a) or 6(b), when the external magnetic field H is applied_exWhen the magnitude of (3) is increased, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction is increased. In addition, for example, in the structure shown in fig. 6(a) or 6(b), when the external magnetic field H is applied_exWhen the magnitude of (3) is decreased, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction is decreased.

When the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes, the resistance R of the magnetoresistance effect element 10₁₀The magnitude of the amplitude of (a) changes. For example, in the case of the structure shown in fig. 6(a) or 6(b), when the inclination angle of the rotation axis of the magnetization M1 with respect to the lamination direction is decreased, the orientation direction of the magnetization M1 and the orientation of the magnetization M2The direction is close to the parallel state, the resistance R of the magneto-resistance effect element 10₁₀The magnitude of the amplitude of (c) decreases.

As described above, the resistance R of the magnetoresistance effect element 10₁₀Is to influence the DC voltage V output from the output port p3_DCThe parameter (c) of (c). As a result, when an external magnetic field H is applied to the magnetoresistive element 10_exWhen the magnitude of (b) is changed, the direct-current voltage V outputted from the output port p3_DCThe value of (c) is changed. That is, the magnetic sensor reads the dc voltage V output from the output port p3_DCCapable of detecting an external magnetic field H applied to the magnetic sensor in the in-plane direction_exThe size of (2).

Fig. 9 is a plan view of a modification of the magnetoresistive element 10 shown in fig. 5(a) and 5 (b). The first ferromagnetic layer 1 shown in FIG. 9 is smaller than the second ferromagnetic layer 2 when viewed from above in the film thickness direction. The first ferromagnetic layer 1 shown in FIG. 9 is wrapped in the second ferromagnetic layer 2 when viewed from above in the film thickness direction. Thus, the influence of the magnetization vibration of the first ferromagnetic layer 1 hardly affects the entire second ferromagnetic layer 2.

Fig. 10 is a cross-sectional view of another modification of the magnetoresistance effect element 10 shown in fig. 5(a) and 5 (b). The second ferromagnetic layer 2 shown in FIG. 10 has two ferromagnetic layers 2A, 2B and a nonmagnetic layer 2C sandwiched therebetween. The nonmagnetic layer 2C is, for example, Ru. The ferromagnetic layer 2A and the ferromagnetic layer 2B are interlayer exchange coupled via the nonmagnetic layer 2C. The magnetization M2A of the ferromagnetic layer 2A and the magnetization M2B of the ferromagnetic layer 2B are antiparallel.

The product of the film thickness and the saturation magnetization of the ferromagnetic layer 2A is different from the product of the film thickness and the saturation magnetization of the ferromagnetic layer 2B. When the product of the film thickness and the saturation magnetization is different in the two ferromagnetic layers 2A and 2B, the magnetization of the ferromagnetic layer having the large product of the film thickness and the saturation magnetization is more likely to react to a magnetic field applied from the outside than the magnetization of the ferromagnetic layer having the small product of the film thickness and the saturation magnetization, and the direction of the magnetization of the second ferromagnetic layer 2 is more likely to pass through the external magnetic field H_exBut is changed.

For example, the film thickness of the ferromagnetic layer 2A and the film thickness of the ferromagnetic layer 2B are different. When the film thicknesses of the two ferromagnetic layers 2A, 2B are different, the product of the film thicknesses and the saturation magnetizations of the two ferromagnetic layers 2A, 2B is often different. For example, the thickness of the ferromagnetic layer 2B is larger than that of the ferromagnetic layer 2A. For example, the film thickness of the ferromagnetic layer 2B is 2 times or more the film thickness of the ferromagnetic layer 2A. The product of the film thickness and the saturation magnetization of the ferromagnetic layer 2B is larger than the product of the film thickness and the saturation magnetization of the ferromagnetic layer 2A. The ferromagnetic layer 2B is located farther from the first ferromagnetic layer 1 and the first signal wiring 20 than the ferromagnetic layer 2A. When the film thickness of the ferromagnetic layer 2B is made thicker than the film thickness of the ferromagnetic layer 2A, and a ferromagnetic layer, which is easily reacted to a magnetic field applied from the outside among ferromagnetic layers included in the second ferromagnetic layer 2, is made into the ferromagnetic layer 2B, the influence of magnetization vibration of the first ferromagnetic layer 1 or the influence of a high-frequency magnetic field from the first signal line 20 can be reduced, and magnetization vibration of the second ferromagnetic layer 2 can be suppressed when viewed from the entire second ferromagnetic layer 2.

Fig. 10 illustrates an example in which the first ferromagnetic layer 1 is smaller than the second ferromagnetic layer 2 when viewed from above in the film thickness direction, but the present invention is not limited to this case. The ferromagnetic layer 2A and the ferromagnetic layer 2B may be formed of a plurality of layers.

Up to this point, the external magnetic field H is detected for the magnetic sensor_exSeveral methods of the component in the in-plane direction (the direction perpendicular to the lamination direction of the magnetoresistance effect element 10) of (a) have been described, but the magnetic sensor can also detect the external magnetic field H_exThe component in the stacking direction of (1). FIG. 11 shows the detection of an external magnetic field H_exThe component in the stacking direction of (2) is shown as an example of the magnetization states of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive element 10.

The second ferromagnetic layer 2 is a fixed magnetization layer, and the direction of magnetization M2 is fixed in either direction of the lamination direction. A static magnetic field H is applied to the first ferromagnetic layer 1_dc. The axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 passes through the static magnetic field H_dcAnd inclined from the stacking direction. Static magnetic field H_dcIs applied in a high frequency magnetic field H_rfIn parallel or anti-parallel direction. So-called high frequency magnetic field H_rfHas a flat vibration directionApplying static magnetic fields H in line or antiparallel_dcIn the first ferromagnetic layer 1 along the high-frequency magnetic field H_rfThe direction of vibration has static magnetic field H_dcThe in-plane direction component of (a). Define a high-frequency magnetic field H_rfIn the first direction among the vibration directions of (a), the static magnetic field H is applied_dcThe static magnetic field H is applied in the same direction as the first direction and is parallel to the first direction_dcThe case of being applied in a direction opposite to the first direction is set to be antiparallel.

When an external magnetic field H_exWhen the magnitude or positive-negative direction of the magnetization M1 changes, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes. For example, in the structure shown in FIG. 11, when an external magnetic field H is applied_exWhen the magnitude of (3) is increased, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction is decreased. In addition, for example, in the structure shown in fig. 11, when the external magnetic field H is applied_exIs reduced in magnitude or an external magnetic field H_exWhen the direction of (d) is in the opposite direction, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction increases.

When the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes, the resistance R of the magnetoresistance effect element 10₁₀The magnitude of the amplitude of (a) changes. For example, in the case of the structure shown in fig. 11, when the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction is decreased, the orientation direction of the magnetization M1 and the orientation direction of the magnetization M2 are close to the parallel state, and the resistance R of the magnetoresistance effect element 10 is set to be equal to the resistance R₁₀The magnitude of the amplitude of (c) decreases.

As described above, the resistance R of the magnetoresistance effect element 10₁₀Is to influence the DC voltage V output from the output port p3_DCThe parameter (c) of (c). As a result, when an external magnetic field H is applied to the magnetoresistive element 10_exWhen the magnitude of (b) is changed, the direct-current voltage V outputted from the output port p3_DCThe value of (c) is changed. That is, the magnetic sensor reads the dc voltage V output from the output port p3_DCCapable of detecting an external magnetic field H applied to the magnetic sensor_exThe size and the positive and negative directions of (a).

Here, in FIG. 11, theApplying a static magnetic field H to the first ferromagnetic layer 1_dcThe case of (c) was explained as an example. However, it is not always necessary to apply the static magnetic field H to the first ferromagnetic layer 1_dcSo long as the effective magnetic field H of the first ferromagnetic layer 1 is set_effIs set to be equal to the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfThe vibration directions of the two vibration plates are parallel or antiparallel. Effective magnetic field H of the first ferromagnetic layer 1_effAccording to an external magnetic field H applied to the first ferromagnetic layer 1_exThe anisotropic magnetic field H of the first ferromagnetic layer 1_kThe diamagnetic field H of the first ferromagnetic layer 1_DThe exchange coupling magnetic field H of the first ferromagnetic layer 1_EgBy H_eff＝H_ex+H_k+H_D+H_EgTo obtain the final product. For example, when the shape of the first ferromagnetic layer 1 viewed from the stacking direction has anisotropy, an anisotropic magnetic field H is generated in the longitudinal direction thereof_k. By orienting the longitudinal direction of the first ferromagnetic layer 1 when viewed from the stacking direction toward the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfIn addition to the static magnetic field H_dcAlternatively, the anisotropic magnetic field H may be generated in the first ferromagnetic layer 1_k。

Although an example using the dc component of the voltage V (the output voltage from the magnetoresistive element 10) has been described as an example of detecting the change in the magnitude of the external magnetic field, and the direction of the external magnetic field, the high-frequency component of the voltage may be used. Because of the high frequency component of the voltage V, i.e., - (A. B/2). cos (4 π ft +. DELTA.θ)₁) Involving a phase difference Δ θ₁Therefore, the phase difference Δ θ can be derived from the high frequency component₁. If the phase difference Δ θ is known₁Then, the phase difference Δ θ can be used₁To detect an external magnetic field.

Rectifier

The description has been made so far on the case where the magnetoresistive effect device 100 is used as a magnetic sensor. Next, a case where the magnetoresistance effect device 100 is used as a rectifier will be described.

Fig. 12 is a diagram schematically showing an example of a circuit configuration when the magnetoresistive device 100 is used as a rectifier. As an example of using the magnetoresistance effect device 100 as a rectifier, an example will be described in which an antenna at1 is connected to the first input port p1, and an antenna at2 is connected to the second input port p 2. For example, the same signal is input to the antennas at1 and at 2.

When a first high-frequency signal is input from the antenna at1 to the first input port p1, a first high-frequency current I flows in the first signal line 20_R1. When a second high-frequency signal is input from the antenna at2 to the second input port p2, a second high-frequency current I flows through the second signal line 30_R2. A first high-frequency current I_R1Generating a high-frequency magnetic field H_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 of the magnetoresistive effect element 10. A second high-frequency current I_R2Flows through the magnetoresistance effect element 10. A second high-frequency current I_R2And the first high-frequency current I_R1The phases of (a) and (b) may be different from each other, and a description will be given of the same example.

FIG. 13 is a diagram showing an example of states of magnetizations M1, M2 of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive element 10. FIG. 14 is a diagram showing another example of the states of the magnetizations M1, M2 of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive effect element 10. In the examples of fig. 13 and 14, the second ferromagnetic layer 2 functions as a fixed magnetization layer.

In a high-frequency magnetic field H_rfWhen the frequency of (a) is different from the ferromagnetic resonance frequency of the first ferromagnetic layer 1 (when the frequency is not in the vicinity of the ferromagnetic resonance frequency of the first ferromagnetic layer 1), the direction of magnetization M2 and the high-frequency magnetic field H are set, for example, as shown in fig. 13_rfAre made parallel. In a high-frequency magnetic field H_rfWhen the frequency of (3) is the ferromagnetic resonance frequency of the first ferromagnetic layer, the direction of magnetization M2 and the high-frequency magnetic field H are set as shown in FIG. 14, for example_rfIs orthogonal to the vibration direction of (b).

DC voltage V outputted from output port p3_DCMagnitude of (c) and cos (. DELTA.. theta.)₁) Is in direct proportion. In order to increase the direct currentPressure V_DCIs preferably Δ θ₁Becomes 0 (0) or + -pi (+ -180). Because of the first high-frequency current I_R1And the second high-frequency current I_R2Are in agreement, so the phase difference Δ θ₂Phase difference Delta theta₁And (5) the consistency is achieved.

In a high-frequency magnetic field H_rfWhen the frequency of (A) is not a frequency in the vicinity of the ferromagnetic resonance frequency of the first ferromagnetic layer 1, the phase difference Δ θ is obtained by adopting the structure of FIG. 13₁Will become 0 (0) or + -pi (+ -180) and the DC voltage V outputted from the output port p3_DCWill increase in size.

In contrast, the magnetic field H is high-frequency magnetic field_rfWhen the frequency of (A) is the ferromagnetic resonance frequency of the first ferromagnetic layer 1, the phase difference Δ θ is obtained by adopting the structure of FIG. 14₁Will become 0 (0) or + -pi (+ -180) and the DC voltage V outputted from the output port p3_DCWill increase in size.

In addition, fig. 14 illustrates the direction of magnetization M2 of the second ferromagnetic layer 2 and the high-frequency magnetic field H_rfIn the case where the vibration directions are orthogonal to each other, the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfIn the case of the ferromagnetic resonance frequency of the first ferromagnetic layer 1, the direction of magnetization M2 of the second ferromagnetic layer 2 and the high-frequency magnetic field H may be set in the same manner as in the configuration of fig. 13_rfIs made into a parallel structure and makes the second high-frequency current I_R2Relative to the first high-frequency current I_R1Is staggered by pi/2 (90 deg.). For example, the first high-frequency current I can be adjusted by providing a phase shifter on at least one of the first signal line 20 and the second signal line 30_R1And the second high-frequency current I_R2At least one of the phases (a) and (b).

Dielectric sensor

Next, a case where the magnetoresistance effect device 100 is used as a dielectric sensor using a dielectric as a measurement object will be described. The dielectric sensor is a sensor that determines the state of a measurement object based on, for example, a difference in dielectric constant of the measurement object. The dielectric sensor is a sensor utilizing a characteristic that a phase and an amplitude of a signal propagating through a signal line are changed by bringing a dielectric close to the signal line or providing the dielectric on a propagation path of the signal. In the case where a vegetable, grain, skin, or the like is used as a measurement object, for example, the dielectric sensor can measure the moisture content of the measurement object.

Fig. 15 is a schematic diagram for explaining a first example in the case of using the magnetoresistance effect device 100 as a dielectric sensor. The dielectric sensor shown in the first example includes the installation region a1 or the installation region a 2. A part of the first signal line 20 formed in a microstrip line type or a coplanar waveguide type, for example, is arranged in the arrangement region a 1. A part of the second signal line 30 formed in a microstrip line type or a coplanar waveguide type, for example, is arranged in the arrangement region a 2. The object to be measured having a dielectric material is set in either one of the setting region a1 and the setting region a2, and measurement is performed. The object to be measured is not particularly limited. As the magnetoresistance effect element 10 when the magnetoresistance effect device 100 is used as a dielectric sensor, for example, the same magnetoresistance effect element as shown in fig. 13 can be used.

First, the operation of the sensor when the object is placed in the placement area a1 will be described. First high-frequency current I in the state before the setting of the object to be measured_R1And a second high-frequency current I_R2As described below.

I_R2＝A·sin(2πft)

I_R1＝C·sin(2πft+△θ₃)

Here,. DELTA.theta.₃Is I_R1And I_R2Is constant.

When setting I_R1And resistance R of magnetoresistance effect element 10₁₀Has a phase difference of Delta theta₂Resistance R of the magnetoresistance effect element 10₁₀Represented by the following formula.

R₁₀＝B·sin(2πft+△θ₂+△θ₃)+R₀

Here, since the external magnetic field is measured under a certain condition, Δ θ₂Constant and unchanged.

When the object to be measured is placed in the placement area a1, I is changed by a change in dielectric constant (change from the dielectric constant of air to the dielectric constant of the object to be measured), I_R1Phase shift of (1) delta theta₄，I_R1The amplitude of (C) is changed to C'. As a result, a first high-frequency current I_R1And the resistance R of the magnetoresistance effect element 10₁₀As described below.

I_R1＝C’·sin(2πft+△θ₃+△θ₄)

R₁₀＝B’·sin(2πft+△θ₂+△θ₃+△θ₄)+R₀

Here, when I is set_R1And R₁₀Has a phase difference of Delta theta₁(＝△θ₂+△θ₃+△θ₄) When using R₁₀＝B’·sin(2πft+△θ₁)+R₀And (4) showing.

As described above, the dc voltage V output from the output port p3_DCIs the resistance R of the magnetoresistance effect element 10₁₀And a current (second high-frequency current I) flowing in the magnetoresistance effect element 10_R2) The product of (i) and (ii) the dc component of the voltage V (the output voltage from the magnetoresistive element 10) is expressed by the following equation.

V＝I_R2×R₁₀＝(A·B’/2)·{cos(△θ₁)－cos(4πft+△θ₁)}+A·R₀·sin(2πft)

DC voltage V_DCIs a DC component of the voltage V and is (A.B'/2) cos (. DELTA.. theta.)₁). Due to Delta theta₁＝△θ₂+△θ₃+△θ₄And Δ θ 2 and Δ θ₃Is constant and thus varies with the change in dielectric constant₄The dc output component corresponding to the value of B' is output from the output port p 3. Based on the result, a parameter related to the dielectric constant of the object to be measured (for example, the moisture content of the object to be measured) can be measured.

Next, the operation of the sensor when the object is placed in the placement area a2 will be described. The state before the object to be measured is installed is the same as the case where the object to be measured is installed in the installation area a1 described above.

When the object to be measured is placed in the placement area a2, I is changed by a change in dielectric constant (change from the dielectric constant of air to the dielectric constant of the object to be measured), I_R2Phase shift of (1) delta theta₄，I_R2The amplitude of (d) is changed to a'. As a result, a second high-frequency current I_R2And the resistance R of the magnetoresistance effect element 10₁₀As described below.

I_R2＝A’·sin(2πft+△θ₄)

R₁₀＝B·sin(2πft+△θ₂+△θ₃)+R₀

Here, as for the mathematical processing, I after the object to be measured is set in the setting area a2_R2The phase of (2) is described again as a reference, as follows.

I_R2＝A’·sin(2πft)

R₁₀＝B·sin(2πft+△θ₂+△θ₃－△θ₄)+R₀

I_R1＝C·sin(2πft+△θ₃－△θ₄)

Here, when I is set_R1And R₁₀Has a phase difference of Delta theta₁(＝△θ₂+△θ₃－△θ₄) When using R₁₀＝B·sin(2πft+△θ₁)+R₀And (4) showing.

As described above, the dc voltage V output from the output port p3_DCIs the resistance R of the magnetoresistance effect element 10₁₀And a current (second high-frequency current I) flowing in the magnetoresistance effect element 10_R2) The same relational expression holds for the product of (i.e., the dc component of the voltage V (the output voltage from the magnetoresistive element 10)) as in the case where the object to be measured is provided in the installation region a 1.

DC voltage V_DCIs a DC component of the voltage V and is (A'. B/2). cos (. DELTA.. theta.) (₁). Due to Delta theta₁＝△θ₂+△θ₃－△θ₄And Δ θ₂、△θ₃Is constant and therefore followsDelta theta changed by change in electric constant₄The dc output component corresponding to the value of a' is output from the output port p 3. Based on the result, a parameter related to the dielectric constant of the object to be measured (for example, the moisture content of the object to be measured) can be measured.

Fig. 16 is a schematic diagram for explaining a second example in the case of using a magnetoresistance effect device as a dielectric sensor. In the magnetoresistive effect device 100A shown in the second example, the first signal line 20A has a transmission antenna at_TAnd a receiving antenna at_RThe setting area A1 is clamped between the transmitting antenna at_TAnd a receiving antenna at_RThe area in between. Transmitting antenna at_TTransmitting the first high frequency signal transmitted in the first signal line to the receiving antenna at_R. When the object to be measured is placed in the placement area a1, I is changed by a change in dielectric constant (change from the dielectric constant of air to the dielectric constant of the object to be measured), I_R1Changes in phase and amplitude. As a result, the dc voltage V output from the output port p3_DCVaries in magnitude. This principle is the same as in the case where the object to be measured is provided in the installation area a1 in the first example. Based on the result, a parameter related to the dielectric constant of the object to be measured (for example, the moisture content of the object to be measured) can be measured.

Fig. 17 is a schematic diagram for explaining a third example in the case of using a magnetoresistance effect device as a dielectric sensor. With the magnetoresistive effect device 100B shown in the third example, the second signal line 30B has the transmitting antenna at_TAnd a receiving antenna at_RThe setting area A2 is clamped between the transmitting antenna at_TAnd a receiving antenna at_RThe area in between. Transmitting antenna at_TTransmitting the second high frequency signal transmitted in the second signal line to the receiving antenna at_R. When the object to be measured is placed in the placement area a2, I is changed by a change in dielectric constant (change from the dielectric constant of air to the dielectric constant of the object to be measured), I_R2Changes in phase and amplitude. As a result, the dc voltage V output from the output port p3_DCVaries in magnitude. This principle is applied to the first example and the installation regionThe same applies to the case where a2 is provided with the object to be measured. Based on the result, a parameter related to the dielectric constant of the object to be measured (for example, the moisture content of the object to be measured) can be measured.

As described above, the magnetoresistance effect device 100 of the first embodiment can be obtained by passing the first high-frequency current I_R1Induced high frequency magnetic field H_rfThe magnetization M1 of the first ferromagnetic layer 1 is vibrated, and therefore the vibration amplitude of the magnetization M1 can be increased. When the amplitude of vibration of the magnetization M1 increases, the resistance R of the magnetoresistance effect element 10₁₀The amount of change (amplitude) of the voltage increases, and a large direct current voltage V can be output from the output port p3_DC. As described above, the magnetoresistive device 100 according to the first embodiment can be used as a magnetic sensor, a rectifier, or a dielectric sensor using a dielectric as a measurement object.

The first embodiment has been described in detail with reference to the drawings, but the configurations and combinations of the configurations of the first embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations may be made without departing from the spirit of the invention. For example, although the magnetoresistive element 10 is an example in the first embodiment, a plurality of magnetoresistive elements 10 may be connected to the second signal line 30, and the second high-frequency current I may flow through the plurality of magnetoresistive elements 10_R2And a first high-frequency current I flowing through the first signal line 20 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive effect elements 10_R1Induced high frequency magnetic field H_rf。

(first modification)

Fig. 18 is a diagram schematically showing a circuit configuration of a magnetoresistive effect device according to a first modification. The magnetoresistance effect device 101 of the first modification example shown in fig. 18 is different from the magnetoresistance effect device 100 shown in fig. 1 in that it includes the magnetic substance section 50. In the magnetoresistance effect device 101 shown in fig. 18, the same reference numerals are given to the same structures as those of the magnetoresistance effect device 100 shown in fig. 1. Note that, in the magnetoresistive device 101 according to the first modification, the description of the configuration common to the magnetoresistive device 100 is omitted.

The magnetic body portion 50 is located between the first signal line 20 and the magnetoresistance effect element 10. The magnetic body 50 is disposed separately from the first signal line 20 and the magnetoresistance effect element 10. For example, an insulator is provided between the magnetic body 50 and the first signal line 20 and between the magnetic body 50 and the magnetoresistive element 10.

The magnetic body 50 comprises a soft magnetic body. The magnetic body 50 is, for example, an insulating magnetic body. The magnetic body 50 is made of ceramic such as ferrite. The magnetic body 50 is, for example, rare earth iron garnet (RIG). Yttrium Iron Garnet (YIG) is an example of rare earth iron garnet (RIG). The magnetic body 50 may be a metal such as permalloy.

The high-frequency magnetic field H generated by the first signal line 20 is applied to the magnetic body 50_rf1. The magnetization of the magnetic body 50 is subjected to a high-frequency magnetic field H_rf1But vibrates. Magnetization of the magnetic body 50 in the high-frequency magnetic field H_rf1When a signal having a frequency near the ferromagnetic resonance frequency of the magnetic body 50 is included, the signal vibrates largely at the frequency. The magnetization vibration of the magnetic body 50 generates a high-frequency magnetic field H_rf2。

High-frequency magnetic field H generated by magnetization vibration of the magnetic body 50_rf2Is applied to the first ferromagnetic layer 1. The magnetization of the first ferromagnetic layer 1 is induced by the high-frequency magnetic field H generated by the magnetic body 50_rf2But vibrates. I.e. by a first high-frequency current I flowing in the first signal line 20_R1Generated high-frequency magnetic field H_rf1Induced high frequency magnetic field H_rf2Is applied to the first ferromagnetic layer 1. The frequency magnetic field H generated by the magnetic body 50_rf2Is generated by a first high-frequency current I flowing in a first signal line 20_R1An example of the induced high frequency magnetic field.

Resistance R of magnetoresistance effect element 10₁₀Changes (vibrates) due to the magnetization vibration of the first ferromagnetic layer 1. When the second high-frequency signal is input to the second input port p2, a second high-frequency current I flows in the second signal line 30_R2. A second high-frequency current I_R2Flows through the magnetoresistance effect element 10. The resistance R of the magnetoresistive effect element 10 is output from the output port p3₁₀And a current (second high-frequency current I) flowing in the magnetoresistance effect element 10_R2) Product of (i) electricityDC component of voltage, i.e. DC voltage V_DC. The explanation has been made with an example in which the magnetic body portion 50 is located between the first signal wiring 20 and the magnetoresistance effect element 10, but if the high-frequency magnetic field H generated by the first signal wiring 20_rf1A high-frequency magnetic field H applied to the magnetic body 50 and generated by magnetization vibration of the magnetic body 50_rf2When the signal is applied to the first ferromagnetic layer 1, the position of the magnetic body 50 is not limited to this, and for example, the magnetic body 50 may be disposed so that the first signal line 20 is located between the magnetic body 50 and the magnetoresistive element 10. In the case of using a plurality of magnetoresistive elements 10, the high-frequency magnetic field H generated by the magnetization vibration of one magnetic body 50_rf2The first ferromagnetic layer 1 may be applied to a plurality of magnetoresistance effect elements 10, or a plurality of magnetic body portions 50 may be used, and one magnetic body portion 50 may be provided for each magnetoresistance effect element 10.

The magnetoresistance effect device 101 of the first embodiment is also caused to pass the first high-frequency current I_R1Induced high frequency magnetic field H_rf2The magnetization M1 of the first ferromagnetic layer 1 is vibrated, and therefore the vibration amplitude of the magnetization M1 can be increased. When the amplitude of vibration of the magnetization M1 increases, the resistance R of the magnetoresistance effect element 10₁₀The amount of change (amplitude) of the voltage increases, and a large direct current voltage V can be output from the output port p3_DC. The magnetoresistive device 101 according to the first modification example can be used as a magnetic sensor, a rectifier, or a dielectric sensor using a dielectric as a measurement object.

(second modification)

Fig. 19 is a perspective view showing the vicinity of the magnetoresistive element 10 of the magnetoresistive device 102 according to the second modification. Fig. 20 is a plan view showing the vicinity of the magnetoresistive element 10 of the magnetoresistive device 102 according to the second modification. In FIGS. 19 and 20, the second signal line 30 connected to the first ferromagnetic layer 1 and the line 42 connected to the second ferromagnetic layer 2 are omitted. The magnetoresistance effect device 102 of the second modification shown in fig. 19 and 20 is different from the magnetoresistance effect device 100 shown in fig. 1 in that it has the yoke 60. In the magnetoresistance effect device 102 shown in fig. 19 and 20, the same components as those of the magnetoresistance effect device 100 shown in fig. 1 are denoted by the same reference numerals. Note that, in the magnetoresistance effect device 102 of the second modification, the description of the configuration common to the magnetoresistance effect device 100 is omitted.

The yoke 60 is closer to the second ferromagnetic layer 2 than the first ferromagnetic layer 1 in the stacking direction. The first ferromagnetic layer 1 of the magnetoresistive element 10 shown in fig. 19 and 20 is smaller than the second ferromagnetic layer 2 when viewed from above in the stacking direction, and is enclosed in the second ferromagnetic layer 2. The yoke 60 is located on the opposite side of the first signal line 20 in the stacking direction, for example, with reference to the magnetoresistive element 10. The yoke 60 includes a soft magnetic body. The yoke 60 is, for example, an alloy of Fe, Co, Ni, and Fe, an alloy of Fe and Co, an alloy of Fe, Co, and B, or the like.

The yoke 60 has a first portion 61 and a second portion 62. The first portion 61 and the second portion 62 are separated from each other to form a gap GA. The first portion 61 and the second portion 62 sandwich the magnetoresistance effect element 10 in the gap when viewed from the stacking direction. The magnetic flux enters the second portion 62 from the first portion 61, or enters the first portion 61 from the second portion 62.

When an external magnetic field H is applied to the magnetoresistance effect device 102_exAt this time, the yoke 60 induces magnetic flux to be concentrated in the gap GA between the first portion 61 and the second portion 62. The yoke 60 will be influenced by the external magnetic field H_exThe magnetic field generated in the gap GA is applied to the second ferromagnetic layer 2. The second ferromagnetic layer 2 is a second free magnetization layer, and the magnetization M2 of the second ferromagnetic layer 2 changes its direction by receiving a magnetic field generated in the gap GA between the first portion 61 and the second portion 62. The direction of the magnetic field generated in the gap GA between the first portion 61 and the second portion 62 depends on the external magnetic field H_exIs changed. The magnetoresistance effect device 102 can be particularly applied to the detection of the external magnetic field H_exIn the direction of (b), the magnetic sensor using the magnetoresistance effect element 10 of the first pattern (see fig. 5 a and 5 b).

In the example shown in fig. 19, the magnetoresistive element 10 is not located in the gap GA of the yoke 60 in the stacking direction, but a part of the magnetoresistive element 10 (for example, a part or all of the second ferromagnetic layer 2) may be located in the gap GA of the yoke 60 in the stacking direction. In the example of fig. 20, the first portion 61 and the second portion 62 of the yoke 60 sandwich the magnetoresistance effect element 10 in one direction, and as shown in fig. 21, the yoke 60 may surround the magnetoresistance effect element 10 when viewed from above in the stacking direction.

As shown in fig. 22, the yoke 60 may be located closer to the first ferromagnetic layer 1 than the second ferromagnetic layer 2 in the stacking direction. Fig. 22 is a perspective view showing the vicinity of the magnetoresistive element 10 of the magnetoresistive device according to another example of the second modification. The yoke 60 will be influenced by the external magnetic field H_exThe magnetic field generated in the gap GA is applied to the first ferromagnetic layer 1. The axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 is tilted by the magnetic field generated in the gap GA between the first portion 61 and the second portion 62. The direction of the magnetic field generated in the gap GA between the first portion 61 and the second portion 62 depends on the external magnetic field H_exIs changed. The magnetoresistance effect device shown in FIG. 22 can be applied particularly to the detection of external magnetic field H_exIn the direction of (b), the magnetic sensor using the magnetoresistance effect element 10 of the second pattern (see fig. 6(a) and 6 (b)).

In the example shown in fig. 22, the magnetoresistive element 10 is not located in the gap GA of the yoke 60 in the stacking direction, but a part of the magnetoresistive element 10 (for example, a part or all of the first ferromagnetic layer 1) may be located in the gap GA of the yoke 60 in the stacking direction. In the example of fig. 22, the yoke 60 may surround the periphery of the magnetoresistive element 10 when viewed from above in the stacking direction.

(third modification)

Fig. 23 is a diagram schematically showing a circuit configuration of a magnetoresistive effect device 103 according to a third modification. The magnetoresistance effect device 103 of the third modification shown in fig. 23 is different from the magnetoresistance effect device 100 shown in fig. 1 in that it has a plurality of magnetoresistance effect elements 10. In the magnetoresistance effect device 103 shown in fig. 23, the same reference numerals are given to the same structures as those of the magnetoresistance effect device 100 shown in fig. 1. Note that, in the magnetoresistance effect device 103 according to the third modification, the description of the configuration common to the magnetoresistance effect device 100 is omitted.

The magnetoresistance effect elements 10 are connected to the second signal lines 30, respectively, and the magnetoresistance effect elements 10 are connected to each other in series. Each magnetoresistive element 10 is separated from the first signal line 20 via an insulator. The first signal line 20 is disposed so as to be able to pass a first high-frequency current I flowing through the first signal line 20_R1Generated high-frequency magnetic field H_rfThe position of the first ferromagnetic layer 1 applied to each magnetoresistive effect element 10. By a first high-frequency current I flowing in the first signal line 20_R1Induced high frequency magnetic field H_rfIs applied to each first ferromagnetic layer 1. The second ferromagnetic layer 2 of each magnetoresistive element 10 functions as a fixed magnetization layer. The magnetization directions of the second ferromagnetic layers 2 of the plurality of magnetoresistive effect elements 10 are all the same direction.

Fig. 24 is a plan view of the magnetoresistance effect device 103 according to the third modification example, which is viewed from the vicinity of the magnetoresistance effect element 10. In fig. 24, only the magnetoresistance effect element 10 and the first signal wiring 20 are illustrated. A part of the first signal line 20 shown in fig. 24 is annular when viewed from the stacking direction. The magnetoresistive elements 10 are located at positions overlapping the first signal lines 20, respectively, when viewed from above in the stacking direction. As shown in fig. 24, each magnetoresistive element 10 is located at a position shifted by a rotation angle with respect to the center of the annular first signal line 20

The position of (a). Angle of rotation

For example 60. In fig. 24, the angle α is the reference direction and the external magnetic field H_exThe angle formed by the directions of (a) and (b). In fig. 24, as an example, a high-frequency magnetic field H is applied to one magnetoresistance effect element 10 of three magnetoresistance effect elements 10_rfIs set as the reference direction.

According to the right-hand rule, a high-frequency magnetic field H_rfGenerated around the first signal line 20. High-frequency magnetic field H applied to first ferromagnetic layer 1 of each magnetoresistive element 10_rfIn directions different from each other between the plurality of magnetoresistance effect elements 10The same is true. As shown in FIG. 24, the high-frequency magnetic field H applied to the first ferromagnetic layer 1 of each magnetoresistive element 10_rfIs shifted from the rotation angle between the adjacent magnetoresistance effect elements 10

The same angle. The magnetoresistance effect device 103 can be applied particularly for detecting an external magnetic field H_exThe direction of (a) is a magnetic sensor using the magnetoresistance effect element 10 of the first pattern (see fig. 5 a and 5 b), and a magnetic sensor using the magnetoresistance effect element 10 of the second pattern (see fig. 6 a and 6 b).

High-frequency magnetic field H applied to the first ferromagnetic layer 1 due to each magnetoresistance effect element 10_rfThe relative angle between the direction of (A) and the magnetization direction of the second ferromagnetic layer 2 is different between the plurality of magnetoresistive effect elements 10, and therefore the phase difference Δ θ between the respective magnetoresistive effect elements 10₂The magnetoresistive effect elements 10 are different from one another. FIG. 25(a) shows the relationship between the magnetic field H and the external magnetic field H_exCos (. DELTA.theta.) of each magnetoresistive element 10 in terms of the change in direction of (A)₂) Fig. 25(b) is a graph showing cos ([ delta ] theta) of the three magnetoresistive elements 10₂) Is measured in a graph of the change in the arithmetic mean of (1). Fig. 25(a) and 25(b) are graphs when the three magnetoresistance effect elements 10 are arranged at different positions rotated by rotation angles of 60 ° with respect to the center of the annular first signal line 20. The numbers of the legends of the graphs of fig. 25(a) are the rotation angles of the respective magnetoresistive effect elements 10

The value of (c).

As shown in the graph of fig. 25(a), cos ([ delta ] θ) of each magnetoresistive element 10₂) Relative to the external magnetic field H_exIs not very linear. The DC voltage outputted from each magneto-resistive effect element 10 and cos (. DELTA.. theta.) of each magneto-resistive effect element 10₁) Is in direct proportion. When setting the second high frequency current I_R2And a first high-frequency current I_R1Has a phase difference of Delta theta₃Becomes Δ θ₁＝△θ₂+△θ₃Therefore, in each magnetoresistive element 10, the dc voltage output from the magnetoresistive element 10 is equal to cos ([ delta ] theta ])₂+△θ₃) Is in direct proportion. Due to phase difference Delta theta₃Is constant, and therefore, in each magnetoresistive element 10, COS (Delta theta)₂+△θ₃) Relative to the external magnetic field H_exLinear of direction change of (1) and cos ([ delta ] theta)₂) The same is true. Therefore, the change in the dc voltage output from each magnetoresistance effect element 10 with respect to the external magnetic field H_exIs not very linear.

In contrast, as shown in the graph of fig. 25(b), cos ([ delta ] θ) of the three magnetoresistive elements 10₂) The obtained value (cos (. DELTA.. theta.) of the three magnetoresistive effect elements 10₂+△θ₃) Added value) with respect to the external magnetic field H_exThe linearity of the change in direction of (a) is good. Due to the DC voltage V output from the output port p3_DCCos (. DELTA.theta.) of three magnetoresistive elements 10₂+△θ₃) The added values are proportional, so that the DC voltage V is_DCRelative to the external magnetic field H_exThe linearity of the change in direction of (a) is good.

In the examples shown in FIGS. 23 to 25, the high-frequency magnetic field H applied to the first ferromagnetic layer of the three magnetoresistive elements 10 is used_rfHas been described, but the high-frequency magnetic field H applied to the first ferromagnetic layer of at least two magnetoresistive elements 10 is set to be different_rfAre different from each other, and a direct current voltage V can be obtained_DCRelative to the external magnetic field H_exThe direction change of (2) has a certain effect of being good in linearity. By applying a high-frequency magnetic field H to the first ferromagnetic layer of at least three magnetoresistance effect elements 10_rfCan further improve the direct current voltage V_DCRelative to the external magnetic field H_exIs linear in the direction change of (a).

In addition, in order to improve the DC voltage V_DCRelative to the external magnetic field H_exThe first strength applied to each magneto-resistance effect element 10 can be madeHigh frequency magnetic field H of magnetic layer_rfThe size of (b) differs among the plurality of magnetoresistance effect elements 10. For example, the distance between the first ferromagnetic layer of each magnetoresistive element 10 and the first signal line 20 may be different between the plurality of magnetoresistive elements 10.

(fourth modification)

Fig. 26 is a diagram schematically showing a circuit configuration of a magnetoresistive effect device 104 according to a fourth modification. The magnetoresistance effect device 104 of the fourth modification example shown in fig. 26 is different from the magnetoresistance effect device 100 shown in fig. 1 in that it has a plurality of second input ports p2, a plurality of output ports p3, a plurality of magnetoresistance effect elements 10, and the like. In the magnetoresistance effect device 104 shown in fig. 26, the same reference numerals are given to the same structures as those of the magnetoresistance effect device 100 shown in fig. 1. Note that, in the magnetoresistive device 104 according to the fourth modification, the description of the configuration common to the magnetoresistive device 100 is omitted.

Fig. 27 is an enlarged perspective view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 104 according to the fourth modification. The magnetoresistance effect element 10 includes two magnetoresistance effect elements, which are referred to as a first magnetoresistance effect element 11 and a second magnetoresistance effect element 12, respectively.

For example, the first magnetoresistance element 11 and the second magnetoresistance element 12 have the same structure as the first pattern shown in fig. 5(a) and 5 (b). Specifically, in both the first magnetoresistive element 11 and the second magnetoresistive element 12, the first ferromagnetic layer 1 and the second ferromagnetic layer 2 are free magnetization layers whose magnetization directions change, and the magnetization M1 of the first ferromagnetic layer 1 is caused to pass through the high-frequency magnetic field H_rfBut vibrates (time-of-flight). The first magnetoresistance element 11 and the second magnetoresistance element 12 may have the same structure as the second pattern shown in fig. 6(a) and 6 (b).

An external magnetic field H is applied to the first magnetoresistance element 11 and the second magnetoresistance element 12_ex. External magnetic field H_exIs applied from a direction inclined with respect to the stacking direction of the first magnetoresistance element 11 or the second magnetoresistance element 12. The orientation direction of the magnetization of the second ferromagnetic layer 2 is, for example, the same as that of the applied external magnetic field H_exAre in the same direction.

The first signal line 20 is separated from the first magnetoresistance effect element 11 and the second magnetoresistance effect element 12, respectively, via an insulator. The first signal line 20 extends in the first extending direction at a position overlapping the first magnetoresistance element 11 when viewed from the stacking direction of the first magnetoresistance element 11 in plan view. The first signal line 20 extends in the second extending direction at a position overlapping the second magnetoresistance element 12 when viewed from the stacking direction of the second magnetoresistance element 12 in plan view. The first and second directions of extension are different and form an angle of 90 °.

The first magnetoresistance element 11 and the second magnetoresistance element 12 are connected to different output ports p3, respectively. Hereinafter, the output port p3 that outputs the voltage due to the output from the first magnetoresistance element 11 is referred to as a first output port p31, and the output port p3 that outputs the voltage due to the output from the second magnetoresistance element 12 is referred to as a second output port p 32.

As described above, the voltage V1 output from the first magnetoresistance element 11 is based on the resistance R of the first magnetoresistance element 11₁₁And a current (second high-frequency current I) flowing in the first magnetoresistance element 11_R2) Expressed by the product of (a), the following relationship is satisfied.

I_R2＝A·sin(2πft)、

R₁₁＝B·sin(2πft+△θ₁)+R₀

V1＝I_R2×R₁₁＝(A·B/2)·{cos(△θ₁)－cos(4πft+△θ₁)}+A·R₀·sin(2πft)

The first output port p31 outputs (A.B/2). cos (. DELTA.. theta.) as a DC component of the voltage V1₁)。

In contrast, the high-frequency magnetic field H applied to the first magnetoresistance element 11_rfWith respect to the high-frequency magnetic field H applied to the second magnetoresistance effect element 12_rfIs inclined by 90 deg.. Therefore, the resistance R of the second magnetoresistance element 12₁₂Relative to the resistance R of the first magnetoresistance effect element 11₁₁Is delayed by pi/2 (90 deg.).

As a result, the voltage V2 output from the second magnetoresistance element 12 satisfies the following relationship.

I_R2＝A·sin(2πft)、

R₁₂＝B·sin(2πft+△θ₁－π/2)+R₀＝－B·cos(2πft+△θ₁)+R₀

V2＝I_R2×R₁₂＝(A·B/2)·{sin(△θ₁)－sin(4πft+△θ₁)}+A·R₀·sin(2πft)

The second output port p32 outputs (A.B/2). sin (Delta theta) which is the DC component of the voltage V2₁)。

By using the DC component of the voltage V1 outputted from the first output port p31 and the DC component of the voltage V2 outputted from the second output port p32, (A.B/2) and [ Delta ] [ theta ] can be obtained₁Specific values of (a). Further, "- (A. B/2). cos (4 π ft +. DELTA.θ) which is a high-frequency component of the voltage V1 is used₁) "- (A. B/2). sin (4 π ft +. DELTA.θ) which is a high-frequency component of the sum voltage V2₁) ", it is also possible to determine (A.B/2) and Δ θ₁Specific values of (a).

Based on the value of (A.B/2), for example, the external magnetic field H can be detected_exThe size of (2). This is because when the external magnetic field H is changed_exWhen (A) and (B)/2) are larger, the value of (A · B/2) changes. Specifically, when changing the external magnetic field H_exWhen the value of (3) is larger, the inclination angle of the rotation axis of the magnetization M1 of the first ferromagnetic layer 1 with respect to the stacking direction changes. As a result, the resistance value R of the first magnetoresistance element 11₁₁Amplitude B of the first magnetoresistive element 12 and resistance R of the second magnetoresistive element 12₁₂The amplitude B of (A) changes, and the value of (A.B/2) changes.

In addition, according to Δ θ₁E.g. capable of detecting an external magnetic field H_exThe angle of (c). This is because when the external magnetic field H is changed_exAt the angle of (c), the direction of the magnetization M2 of the second ferromagnetic layer 2 with respect to the rotation axis of the magnetization M1 of the first ferromagnetic layer 1 changes, and the phase difference Δ θ is changed as in the first pattern shown in fig. 5(a) and 5(b)₁A change occurs. In the first magneto-resistance effect element 11 and the second magneto-resistance effect element 12In the same configuration as the second pattern shown in fig. 6(a) and 6(b), the direction of inclination of the rotation axis of the magnetization M1 is caused by the external magnetic field H in the same manner as the second pattern_exChanges according to the direction of the phase difference delta theta₁A change occurs. In the case of the fourth modification, Δ θ can be obtained₁The value of (b) itself enables detection of the direction of the external magnetic field over the entire 360-degree area of the in-plane direction.

In fig. 26, an example is shown in which two second input ports p2 are provided and one second input port p2 is connected to each of the first magnetoresistance element 11 and the second magnetoresistance element 12, but one second input port p2 may be provided as in the magnetoresistance effect device 104A shown in fig. 28. The second input port p2 in fig. 28 is connected to the first magnetoresistance effect element 11 and the second magnetoresistance effect element 12, respectively. A directional coupler 93 is provided between the first magnetoresistance effect element 11 and the second magnetoresistance effect element 12. In addition, a plurality of first signal lines 20 may be provided as in the magnetoresistive effect device 104B shown in fig. 29. In fig. 29, a high-frequency magnetic field H is applied to the first magnetoresistance element 11_rfAnd applying a high-frequency magnetic field H to the second magnetoresistance element 12_rfIs different from the first signal line 20.

Several modifications of the magnetoresistive effect device according to the first embodiment have been described so far. The modifications of the magnetoresistive effect device according to the first embodiment are not limited to these modifications, and the modifications may be combined. For example, the magnetic body 50 of the first modification may be provided in the second modification or the third modification, and the high-frequency magnetic field H generated by the magnetization vibration of the magnetic body 50 may be set_rf2Is applied to the first ferromagnetic layer 1. Further, the yoke 60 of the second modification may be provided to each magnetoresistive element 10 of the third modification, and the magnetic field generated in the gap GA may be applied to the first ferromagnetic layer 1 or the second ferromagnetic layer 2 of each magnetoresistive element 10.

In addition, as shown in FIG. 30, a high-frequency magnetic field H_rfIt may be applied in the stacking direction of the first ferromagnetic layer 1. FIG. 30 shows a magnetoresistance effect device according to a fifth modification exampleA perspective view of the vicinity of the magnetoresistive effect element 10 of the member.

The first signal line 20 has an extended portion 21. The extending portion 21 extends in a direction intersecting the stacking direction when viewed from the stacking direction of the magnetoresistive element 10. The extension portion 21 is located at a position not overlapping the magnetoresistance effect element 10 when viewed from the stacking direction. In addition, when viewed from a direction perpendicular to the stacking direction, a part of the extension portion 21 overlaps the magnetoresistance effect element 10. The magnetoresistive element 10 is not disposed at the tip of the extension portion 21 extending in the extension direction. That is, the extension portion 21 is disposed so as not to overlap with the magnetoresistance effect element 10 when viewed from the extension direction thereof. For example, the first signal line 20 includes the periphery of the first ferromagnetic layer 1 when viewed from the stacking direction of the magnetoresistive elements 10.

When a high-frequency current flows in the extension portion 21, a high-frequency magnetic field H is generated_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 from a direction crossing the in-plane direction in which the first ferromagnetic layer 1 extends. High frequency magnetic field H_rfFor example, in the stacking direction to the first ferromagnetic layer 1. In this case, the magnetization M2 of the second ferromagnetic layer 2 has a component in the in-plane direction in which the second ferromagnetic layer 2 spreads. The magnetization M2 of the second ferromagnetic layer 2 is oriented in one direction of the in-plane directions, for example. Even with this structure, the magnetoresistance effect device operates.

"second embodiment"

Fig. 31 is a diagram showing a circuit configuration of a magnetoresistive effect device according to a second embodiment. The magnetoresistance effect device 110 includes the magnetoresistance effect element 10, a first input port p11, a first signal line 70, and an output port p 12. The magnetoresistive effect device 110 shown in fig. 31 further includes

other wirings

80 and 82, a reference potential terminal pr3, an inductor 91, and a capacitor 92. In the magnetoresistance effect device 110 shown in fig. 31, the same reference numerals are given to the same structures as those of the magnetoresistance effect device 100 shown in fig. 1. Note that, in the magnetoresistive effect device 110 according to the second embodiment, a description of a structure common to the magnetoresistive effect device 100 is omitted.

The first input port p11 is an input terminal of the magnetoresistance effect device 110. The first input port p11 is connected to, for example, an ac signal source, an antenna, and the like. The first input port p11 is connected to the first signal line 70. The first input port p11 is connected to, for example, an end of the first signal line 70. The first high-frequency signal is input to the first input port p11, and the first high-frequency signal is input from the first input port p11 to the first signal line 70. The first high-frequency signal generates a first high-frequency current I in the first signal line 70_R1。

The first signal line 70 is used to flow the first high frequency current I_R1The signal line of (2). The first signal line 70 shown in fig. 31 is a line connecting the first input port p11 and the magnetoresistance effect element 10. The first signal line 70 shown in fig. 31 electrically connects the first input port p11 and the magnetoresistance effect element 10.

The first signal line 70 is disposed so as to be able to transmit the first high-frequency current I flowing through the first signal line 70_R1Generated high-frequency magnetic field H_rfTo the location of the first ferromagnetic layer 1. By a first high-frequency current I flowing in the first signal line 70_R1Induced high frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1. The magnetization of the first ferromagnetic layer 1 is passed through a high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfBut vibrates. Magnetization of the first ferromagnetic layer 1 in the high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfWhen the frequency of (2) is in the vicinity of the ferromagnetic resonance frequency of the first ferromagnetic layer 1, the vibration becomes large. The first signal line 20 mainly generates a high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfFor example, closer to the first ferromagnetic layer 1 than the second ferromagnetic layer 2.

In addition, the first signal line 70 is connected to the magnetoresistance effect element 10. First high-frequency current I flowing in first signal line 70_R1Flows through the magnetoresistance effect element 10. By a high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfThe amplitude ratio of the magnetization vibration of the first ferromagnetic layer 1 caused by the first high-frequency current I flowing through the magnetoresistive element 10_R1Induced by the generated spin transfer torqueThe amplitude of magnetization vibration of a ferromagnetic layer 1 is large.

The output port p12 is an output terminal of the magnetoresistance effect device 110. To the output port p12, for example, a voltmeter for monitoring voltage or an ammeter for monitoring current is connected. The output port p12 shown in fig. 31 is connected to the line 80 branched from the first signal line 70. A signal containing a signal component (a direct current voltage or a direct current) caused by the output from the magnetoresistive element 10 is output from the output port p 12.

The line 80 is a line branched from the first signal line 70. The line 80 connects between the first signal line 70 and the output port p 12. The wiring 82 connects between the magnetoresistive element 10 and the reference potential terminal pr 3.

In addition, the inductor 91 of fig. 31 is located on the line 80. Inductor 91 suppresses the first high frequency current I_R1And the high frequency component of the output from the magnetoresistive effect element 10 to the output port p 12. The capacitor 92 of fig. 31 is located on the first signal line 70. The capacitor 92 in fig. 31 is located on the first input port p11 side of the first signal line 70 at a branch point with respect to the line 80.

Next, the operation of the magnetoresistive effect device 110 will be described. Hereinafter, in the second embodiment, an example of a dc voltage will be described as a dc signal component output from the output port p 12. When the first high-frequency signal is input to the first input port p11, a first high-frequency current I flows in the first signal line 70_R1. A first high-frequency current I_R1Generating a high-frequency magnetic field H_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 of the magnetoresistive effect element 10.

The magnetization of the first ferromagnetic layer 1 is subjected to a first high-frequency current I_R1Induced high frequency magnetic field H_rfBut vibrates. Resistance R of magnetoresistance effect element 10₁₀Is changed (vibrated) by the magnetization vibration of the first ferromagnetic layer 1.

In addition, a first high-frequency current I_R1Flows through the magnetoresistance effect element 10. The output port p12 outputs a DC voltage V_DC. DC voltage V_DCIs the resistance R of the magnetoresistance effect element 10₁₀And in the magnetoresistance effect element 10Flowing current (first high-frequency current I)_R1) The product of (a) and (b) is a direct current component of the voltage V (output voltage from the magnetoresistance effect element 10).

The magnetoresistive device 110 of the second embodiment can be used as a magnetic sensor or a rectifier, as with the magnetoresistive device 100 of the first embodiment. In addition, also in the case where the magnetoresistance effect device 110 of the second embodiment is used as a magnetic sensor, similarly to the first embodiment, it is possible to detect a change in the magnitude of an external magnetic field, or the direction of an external magnetic field.

The operation of the magnetoresistive device 110 according to the second embodiment as a magnetic sensor and a rectifier is almost the same as that of the magnetoresistive device 100 according to the first embodiment. However, since the first signal line 70 is connected to the magnetoresistance effect element 10, the first high-frequency current I flowing in the first signal line 70_R1The second high-frequency current I of the first embodiment flowing through the magnetoresistive element 10 flows through the magnetoresistive element 10_R2In the second embodiment, the first high-frequency current I flowing in the magnetoresistance effect element 10 is replaced_R1. Phase difference Δ θ of the first embodiment₁Is replaced by a first high-frequency current I_R1Phase and resistance R of magnetoresistance effect element 10₁₀Phase difference Δ θ of₂D.c. voltage V_DCUsing (A.B/2) cos (. DELTA.. theta.) as₂) And (4) showing.

In the magnetoresistive effect device 110 of the second embodiment, since the magnetization of the first ferromagnetic layer 1 is passed by the first high-frequency current I_R1Induced high frequency magnetic field H_rfAnd vibrates, so the amplitude of the magnetization vibration can be increased. When the amplitude of the magnetization vibration increases, the resistance R of the magnetoresistance effect element 10₁₀The amount of change (amplitude) of the voltage increases, and a large direct current voltage V can be output from the output port p12_DC. In addition, the magnetoresistance effect device 110 of the second embodiment can be used as a magnetic sensor or a rectifier.

The second embodiment has been described in detail with reference to the drawings, but the configurations of the second embodiment and the combinations thereof are merely examples, and do not depart from the gist of the present inventionAdditions, omissions, substitutions, and other changes in the structure can be made without departing from the scope. For example, although the magnetoresistive element 10 is an example in the second embodiment, a plurality of magnetoresistive elements 10 may be connected to the first signal line 20, and the first high-frequency current I may flow through the plurality of magnetoresistive elements 10_R1And a first high-frequency current I flowing through the first signal line 20 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive effect elements 10_R1Induced high frequency magnetic field H_rf。

For example, in the second embodiment, the same modifications and modifications as those in the first embodiment can be applied, and the respective modifications and modifications can be combined. For example, as in the magnetoresistive device 111 shown in fig. 32, the magnetic body 50 may be provided, and a high-frequency magnetic field generated by magnetization vibration of the magnetic body 50 may be applied to the first ferromagnetic layer 1. For example, a plurality of magnetoresistive elements 10 may be provided as in the magnetoresistive device 112 shown in fig. 33, and the high-frequency magnetic field H applied to the first ferromagnetic layer 1 of each magnetoresistive element 10 may be set in the same manner as in the third modification of the first embodiment_rfThe direction of (b) differs among the plurality of magnetoresistance effect elements 10. In the magnetoresistance effect device 112 shown in fig. 33, the magnetoresistance effect elements 10 are connected to the first signal lines 70, respectively, and the magnetoresistance effect elements 10 are connected to each other in series.

For example, as in the magnetoresistive device 113 shown in fig. 34, a plurality of magnetoresistive elements (the first magnetoresistive element 11 and the second magnetoresistive element 12) may be provided, and the angle formed between the first extending direction and the second extending direction may be 90 ° as in the fourth modification of the first embodiment.

"third embodiment"

Fig. 35 is a diagram showing a circuit configuration of a magnetoresistive effect device according to a third embodiment. The magnetoresistance effect device 120 includes a magnetoresistance effect element 10, a first input port p1, a first signal line 20, a second signal line 31, a line 43, a directional coupler 93, and an output port p 3. The magnetoresistance effect device 120 shown in fig. 35 is different from the magnetoresistance effect device 100 shown in fig. 1 in that the first signal line 20 and the second signal line 31 are connected to the first input port p1 via the line 43 and the directional coupler 93, and do not have the second input port p 2. In the magnetoresistance effect device 120 shown in fig. 35, the same reference numerals are given to the same structures as those of the magnetoresistance effect device 100 shown in fig. 1. Note that, in the magnetoresistive effect device 120 according to the third embodiment, a description of a structure common to the magnetoresistive effect device 100 is omitted.

The second signal line 31 is connected to the first input port p1 and the magnetoresistance effect element 10. In the example shown in fig. 35, the first input port p1 is connected to the first signal line 20 and the second signal line 31 via the line 43 and the directional coupler 93, and the first high-frequency signal that generates the first high-frequency current I in the first signal line 20 is input to the first input port p1_R1And a second high-frequency current I is generated in a second signal line 31_R2. A second high-frequency current I flowing in the second signal line 31_R2Flows through the magnetoresistance effect element 10.

Next, the operation of the magnetoresistance effect device 120 will be described. Hereinafter, in the second embodiment, an example of a dc voltage will be described as a dc signal component output from the output port p 3.

When the first high-frequency signal is input to the first input port p1, a high-frequency current I flows in the line 43_R. Branched by a directional coupler 93 into a first signal line 20 and a second signal line 31, a high-frequency current I_RA first high-frequency current I flows in the first signal line 20_R1And a second high-frequency current I flows in the second signal line 31_R2. A first high-frequency current I_R1Generating a high-frequency magnetic field H_rf. High frequency magnetic field H_rfIs applied to the first ferromagnetic layer 1 of the magnetoresistive effect element 10.

The magnetization of the first ferromagnetic layer 1 is subjected to a first high-frequency current I_R1Induced high frequency magnetic field H_rfBut vibrates. Resistance R of magnetoresistance effect element 10₁₀Is changed (vibrated) by the magnetization vibration of the first ferromagnetic layer 1. By a high-frequency magnetic field H applied to the first ferromagnetic layer 1_rfInduced of the first ferromagnetic layer 1The amplitude ratio of the magnetization vibration is determined by the second high-frequency current I flowing in the magneto-resistance effect element 10_R2The amplitude of magnetization vibration of the first ferromagnetic layer 1 caused by the generated spin transfer torque is large.

A second high-frequency current I_R2Flows through the magnetoresistance effect element 10. The output port p3 outputs a DC voltage V_DC. DC voltage V_DCIs the resistance R of the magnetoresistance effect element 10₁₀And a current (second high-frequency current I) flowing in the magnetoresistance effect element 10_R2) The product of (a) and (b) is a direct current component of the voltage V (output voltage from the magnetoresistance effect element 10).

The magnetoresistance effect device 120 of the third embodiment can be used as a magnetic sensor or a rectifier, similarly to the magnetoresistance effect device 100 of the first embodiment. In addition, also in the case where the magnetoresistance effect device 120 of the third embodiment is used as a magnetic sensor, similarly to the first embodiment, it is possible to detect a change in the magnitude of an external magnetic field, or the direction of an external magnetic field.

The operation of the magnetoresistive device 120 according to the third embodiment as a magnetic sensor and a rectifier is almost the same as that of the magnetoresistive device 100 according to the first embodiment.

In the magnetoresistance effect device 120 of the third embodiment, since the magnetization of the first ferromagnetic layer 1 is passed by the first high-frequency current I_R1Induced high frequency magnetic field H_rfAnd vibrates, so the amplitude of the magnetization vibration can be increased. When the amplitude of the magnetization vibration increases, the resistance R of the magnetoresistance effect element 10₁₀The amount of change (amplitude) of the voltage increases, and a large direct current voltage V can be output from the output port p3_DC. In addition, the magnetoresistance effect device 120 of the third embodiment can be used as a magnetic sensor or a rectifier.

In addition, the magnetoresistance effect device 120 of the third embodiment can be used as a dielectric sensor, similarly to the magnetoresistance effect device 100 of the first embodiment. Fig. 36 is a schematic diagram when the magnetoresistance effect device 120 is used as a dielectric sensor. The dielectric sensor using the magnetoresistance effect device 120 includes the installation region a1 or the installation region a 2. In the magnetoresistive device 120, a dielectric object to be measured is provided in one of the installation region a1 and the installation region a2, and measurement is performed. The operation principle of the sensor is the same as that of the dielectric sensor of the first embodiment.

Fig. 37 and 38 are schematic views of another example of the case where the magnetoresistive device 120 is used as a dielectric sensor. With the magnetoresistive effect device 120A shown in fig. 37, the first signal line 20A has a transmitting antenna at_TAnd a receiving antenna at_RThe setting area A1 is clamped between the transmitting antenna at_TAnd a receiving antenna at_RThe area in between. With the magnetoresistive effect device 120B shown in FIG. 38, the second signal line 31B has a transmitting antenna at_TAnd a receiving antenna at_RThe setting area A2 is clamped between the transmitting antenna at_TAnd a receiving antenna at_RThe area in between. In the magnetoresistive device 120A, a measurement object of a dielectric is provided in the installation region a1 and measurement is performed. In the magnetoresistive device 120B, a measurement object of a dielectric is provided in the installation region a2 and measurement is performed. The operation principle of the sensor is the same as that of the dielectric sensor of the first embodiment.

The third embodiment has been described in detail with reference to the drawings, but the configurations of the third embodiment and the combinations thereof are merely examples, and additions, omissions, substitutions, and other modifications of the configurations may be made without departing from the spirit of the invention. For example, although the magnetoresistive element 10 is an example in the third embodiment, a plurality of magnetoresistive elements 10 may be connected to the second signal line 31, and the second high-frequency current I may flow through the plurality of magnetoresistive elements 10_R2And a first high-frequency current I flowing through the first signal line 20 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive effect elements 10_R1Induced high frequency magnetic field H_rf。

For example, in the third embodiment, the same modifications and modifications as those in the first embodiment can be applied, and the respective modifications and modifications can be combined. For example, as in the magnetoresistive device 121 shown in fig. 39, the magnetic body 50 may be provided, and a high-frequency magnetic field generated by magnetization vibration of the magnetic body 50 may be applied to the first ferromagnetic layer 1. In addition, the first and second substrates are,for example, a plurality of magnetoresistive elements 10 may be provided as in the magnetoresistive device 122 shown in fig. 40, and the high-frequency magnetic field H applied to the first ferromagnetic layer 1 of each magnetoresistive element 10 may be set in the same manner as in the third modification of the first embodiment_rfThe direction of (b) differs among the plurality of magnetoresistance effect elements 10. In the magnetoresistance effect device 122 shown in fig. 40, the magnetoresistance effect elements 10 are connected to the second signal lines 31, respectively, and the magnetoresistance effect elements 10 are connected to each other in series.

For example, as in the magnetoresistive device 123 shown in fig. 41, a plurality of magnetoresistive elements (the first magnetoresistive element 11 and the second magnetoresistive element 12) may be provided, and the angle formed by the second extending direction of the first extending direction may be 90 ° as in the fourth modification of the first embodiment.

In the first to third embodiments, a magnetic field applying unit for applying a static magnetic field to the magnetoresistive element 10 may be provided in the vicinity of the magnetoresistive element 10. The magnetic field applying unit is constituted by, for example, an electromagnet type or a strip type magnetic field applying mechanism that can variably control the applied magnetic field intensity by either a voltage or a current. The magnetic field applying unit may be constituted by a combination of an electromagnet type or a strip type magnetic field applying mechanism capable of variably controlling the intensity of the applied magnetic field and a permanent magnet for supplying only a constant magnetic field.

The magnetic sensors according to the first, second, and third embodiments can be used, for example, as a geomagnetic sensor, a reading element of a magnetic head of a magnetic recording and reproducing apparatus such as a hard disk drive, an angle sensor for detecting an angular position of an object, and the like.

Description of the symbols

1 first ferromagnetic layer

2 second ferromagnetic layer

3 spacer layer

10 magnetoresistance effect element

11 first magnetoresistance effect element

12 second magnetoresistance effect element

20. 20A, 70 first signal line

21 extension part

30. 30B, 31B second signal line

40. 42, 43, 80, 82 lines

50 magnetic body

60 magnetic yoke

61 first part

62 second part

91 inductor

92 capacitor

93 directional coupler

100. 100A, 100B, 101, 102, 103, 104A, 104B, 110, 111, 112, 113, 120A, 120B, 121, 122, 123 magnetoresistance effect device

Region for A1 and A2

G-ground point

H_rf、H_rf1、H_rf2High frequency magnetic field

I_R1A first high frequency current

I_R2Second high frequency current

M1, M2 magnetization

p1, p11 first input port

p2 second input port

p3, p12 output port

p31 first output port

Second output port of p32

pr1, pr2, pr3 reference potential terminals.

Claims

1. A magnetoresistance effect device includes a magnetoresistance effect element, a first signal line, and an output port,

the magnetoresistive element comprises a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer,

the first signal line is separated from the magnetoresistive effect element via an insulator, a high-frequency magnetic field caused by a first high-frequency current flowing in the first signal line is applied to the first ferromagnetic layer,

a high-frequency current flows in the magnetoresistance effect element,

a signal containing a direct current signal component caused by the output from the magnetoresistance effect element is output from the output port.

2. The magnetoresistance effect device according to claim 1, wherein,

further comprises a first input port, a second input port and a second signal line,

the first input port is connected to the first signal line, and a first high-frequency signal that generates the first high-frequency current in the first signal line is input to the first input port,

the first signal line is separated from the second signal line via an insulator,

the second input port is connected to the second signal line, and a second high-frequency signal that generates a second high-frequency current in the second signal line is input to the second input port,

the second signal line is connected to the magnetoresistive element, and the second high-frequency current flowing through the second signal line flows as the high-frequency current through the magnetoresistive element.

3. The magnetoresistance effect device according to claim 1, wherein,

the device is also provided with a first input port,

the first signal line is connected to the magnetoresistance effect element,

the first high-frequency current flowing in the first signal line flows as the high-frequency current in the magnetoresistance effect element.

4. The magnetoresistance effect device according to claim 1, wherein,

further comprises a first input port and a second signal line,

the first input port is connected to the first signal line and the second signal line, and a first high-frequency signal that generates the first high-frequency current in the first signal line and a second high-frequency current in the second signal line is input to the first input port,

the second signal line is connected to the magnetoresistance effect element, and the second high-frequency current flowing through the second signal line flows as the high-frequency current through the magnetoresistance effect element.

5. The magnetoresistance effect device according to any one of claims 1 to 4, wherein,

further comprising a yoke that sandwiches the magnetoresistance effect element in a gap when viewed from a stacking direction of the magnetoresistance effect element,

the yoke is closer to the second ferromagnetic layer than the first ferromagnetic layer,

the yoke applies a magnetic field generated in the gap by an external magnetic field to the second ferromagnetic layer.

6. The magnetoresistance effect device according to any one of claims 1 to 4, wherein,

the yoke is closer to the first ferromagnetic layer than the second ferromagnetic layer,

the yoke applies a magnetic field generated in the gap by an external magnetic field to the first ferromagnetic layer.

7. The magnetoresistance effect device according to any one of claims 1 to 6, wherein,

the first signal line is closer to the first ferromagnetic layer than the second ferromagnetic layer.

8. The magnetoresistance effect device according to any one of claims 1 to 7, wherein,

further comprises one or more magnetoresistance effect elements connected to the magnetoresistance effect element,

in at least two magnetoresistive effect elements, directions of the high-frequency magnetic field applied to the first ferromagnetic layer are different from each other.

9. The magnetoresistance effect device according to any one of claims 1 to 8, wherein,

the first signal line has an extended portion that extends in a direction intersecting the stacking direction of the magnetoresistive effect elements when viewed from the stacking direction,

the extension portion does not overlap the magnetoresistance effect element when viewed from above in the stacking direction, and partially overlaps the magnetoresistance effect element when viewed from above in a direction perpendicular to the stacking direction,

the high-frequency magnetic field caused by the high-frequency current flowing in the extension portion is applied to the first ferromagnetic layer.

10. The magnetoresistance effect device according to any one of claims 1 to 7, wherein,

a plurality of the magnetoresistive effect elements are also provided,

one or more of the first signal lines are provided,

an angle formed by a position overlapping with the first magnetoresistance element among the magnetoresistance effect elements when viewed from a stacking direction of the first magnetoresistance element, a first extending direction in which the first signal line extends, and a position overlapping with the second magnetoresistance element among the magnetoresistance effect elements when viewed from a stacking direction of the second magnetoresistance element, and a second extending direction in which the first signal line extends, is 90 °.

11. The magnetoresistance effect device according to any one of claims 1 to 10, wherein,

an in-plane component of the effective magnetic field of the first ferromagnetic layer is parallel or antiparallel to a vibration direction of the high-frequency magnetic field applied to the first ferromagnetic layer.

12. A sensor using the magnetoresistance effect device according to any one of claims 1 to 11.