JP2021152521A - Magnetoresistance effect device and sensor - Google Patents

Abstract

To provide a magnetoresistance effect device and a sensor with excellent output characteristics of DC signals.SOLUTION: The magnetoresistance effect device comprises a magnetoresistance effect element, a first signal line, and an output port, wherein the magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the first signal line is separated from the magnetoresistance effect element via an insulator, and 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, wherein the high-frequency current flows in the magnetoresistance effect element, and wherein a signal including a DC signal component caused by an output from the magnetoresistance effect element is output from the output port.SELECTED DRAWING: Figure 1

Description

The present invention relates to magnetoresistive devices and sensors.

With the recent advanced information society, attention is focused on high-frequency components in the high-frequency band of GHz. Spintronics is being researched as a field that has the potential to be applied to new high-frequency components.

For example, Patent Document 1 describes a spin torque diode element utilizing the spin torque diode effect. Patent Document 1 describes that a spin torque diode element is used as a rectifier. The spin torque diode effect is a rectification effect that utilizes a change in the resistance of a magnetoresistive element.

International Publication No. 2013/108357

In the spin torque diode element described in Patent Document 1, the direction of magnetization of the magnetic layer of the TMR element is changed by the spin transfer torque generated by the alternating current flowing through the TMR element, and the changing resistance of the TMR element is multiplied by the alternating current. By matching, the DC voltage is output. However, the vibration of magnetization using 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 of the present invention is to provide a magnetoresistive device and a magnetic sensor having excellent output characteristics of a DC signal.

The following means are provided to solve the above problems.

(1) The magnetic resistance effect device according to the first aspect includes a magnetic resistance effect element, a first signal line, and an output port, and the magnetic resistance effect element includes a first ferromagnetic layer and a second. A ferromagnetic layer and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer are provided, and the first signal line is separated from the magnetic resistance effect element via an insulator. A high-frequency magnetic field caused by the first high-frequency current flowing through the first signal line is applied to the first ferromagnetic layer, a high-frequency current flows through the magnetic resistance effect element, and the magnetic resistance effect is transmitted from the output port. A signal including a DC signal component resulting from the output from the element is output.

(2) The magnetic resistance effect device according to the above aspect further includes a first input port, a second input port, and a second signal line, and the first input port is connected to the first signal line. A first high-frequency signal that produces the first high-frequency current is input to the first signal line to the first input port, and 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, a second high frequency signal that generates a second high frequency current is input to the second signal line, and the second signal line is the second signal line. The second high-frequency current connected to the magnetic resistance effect element and flowing through the second signal line may flow through the magnetic resistance effect element as the high-frequency current.

(3) The magnetoresistive effect device according to the above aspect further includes a first input port, the first input port is connected to the first signal line, and the first input port is connected to the first signal line. A first high-frequency signal that produces the first high-frequency current is input, the first signal line is connected to the magnetic resistance effect element, and the first high-frequency current flowing through the first signal line is the magnetic resistance as the high-frequency current. It may flow through the effect element.

(4) The magnetic resistance effect device according to the above aspect further includes a first input port and a second signal line, and the first input port is connected to the first signal line and the second signal line. A first high-frequency signal that produces the first high-frequency current in the first signal line and a second high-frequency current that produces a second high-frequency current is input to the first input port, and the second signal line is the second signal line. The second high-frequency current connected to the magnetic resistance effect element and flowing through the second signal line may flow through the magnetic resistance effect element as the high-frequency current.

(5) The magnetic resistance effect device according to the above aspect further includes a yoke that sandwiches the magnetic resistance effect element in a gap in a plan view from the stacking direction of the magnetic resistance effect element, and the yoke is the first strong. The yoke is closer to the second ferromagnetic layer than the magnetic layer, and the yoke may apply a magnetic field generated in the gap by an external magnetic field to the second ferromagnetic layer.

(6) The magnetic resistance effect device according to the above aspect further includes a yoke that sandwiches the magnetic resistance effect element in a gap in a plan view from the stacking direction of the magnetic resistance effect element, and the yoke is the second strong. The yoke is closer to the first ferromagnetic layer than the magnetic layer, and the yoke may apply a magnetic field generated in the gap by an external magnetic field to the first ferromagnetic layer.

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

(8) The magnetoresistive device according to the above aspect further includes one or more magnetoresistive elements connected to the magnetoresistive element, and is applied to the first ferromagnetic layer in at least two magnetoresistive elements. The directions of the high-frequency magnetic fields generated may be different from each other.

(9) In the magnetoresistive effect device according to the above aspect, the first signal line has an extending portion extending in a direction intersecting the laminating direction in a plan view from the laminating direction of the magnetic resistance effect element. However, the extending portion does not overlap with the magnetoresistive sensor in the plan view from the stacking direction, and a part of the extending portion does not overlap with the magnetoresistive sensor in the plan view from the direction perpendicular to the stacking direction. The high-frequency magnetic field that overlaps and is caused by the high-frequency current flowing through the extending portion may be applied to the first ferromagnetic layer.

(10) In the magnetic resistance effect device according to the above aspect, the magnetic resistance effect element is provided, the first signal line is provided one or more, and the first magnetic resistance effect element among the magnetic resistance effect elements and the said. The first extending direction in which the first signal line extends at overlapping positions in a plan view from the stacking direction of the first reluctance effect element, and the second reluctance effect element and the second magnetism of the reluctance effect elements. The angle formed by the second extending direction in which the first signal line extends at a position where the resistance effect elements overlap in a plan view from the stacking direction may be 90 °.

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

(12) The sensor according to the second aspect uses the magnetoresistive effect device according to the above aspect.

The magnetoresistive device according to the above aspect is excellent in the output characteristics of a DC signal.

It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 1st Embodiment. It is a schematic diagram for demonstrating an example of the operation as the magnetic sensor of the magnetoresistive effect device which concerns on 1st Embodiment. It is a figure which shows an example of the state of magnetization of the 1st ferromagnetic layer and the 2nd ferromagnetic layer of the magnetoresistive element in a magnetic sensor. Phase difference between the magnitude of the external magnetic field applied to the magnetoresistive element and the phase of the first high-frequency current and the resistance phase of the magnetoresistive element Δθ ₂ (Phase of the second high-frequency current and the magnetoresistive element) It is a figure which showed the relationship with _{the phase difference Δθ 1} ) with the phase of a resistor. It is a figure which shows an example of the state of magnetization of the 1st ferromagnetic layer and the 2nd ferromagnetic layer of the magnetoresistive sensor in the magnetic sensor which detects the direction of an external magnetic field. It is a figure which shows another example of the state of the magnetization of the 1st ferromagnetic layer and the 2nd ferromagnetic layer of the magnetoresistive sensor in the magnetic sensor which detects the direction of an external magnetic field. It is a figure which showed the time change of the resistance of the magnetoresistive element of the 1st pattern. It is a figure which showed the time change of the resistance of the magnetoresistive effect element of the 2nd pattern. 5 is a plan view of a modified example of the magnetoresistive element shown in FIGS. 5A and 5B. It is sectional drawing of another modification of the magnetoresistive element shown in FIG. 5A and FIG. 5B. It is a figure which shows an example of the state of magnetization of the 1st ferromagnetic layer and the 2nd ferromagnetic layer of the magnetoresistive effect element in the magnetic sensor which detects the component of the stacking direction of an external magnetic field. It is a figure which shows typically an example of the circuit structure in the case where the magnetoresistive effect device which concerns on 1st Embodiment is used as a rectifier. It is a figure which shows an example of the state of magnetization of the 1st ferromagnetic layer and the 2nd ferromagnetic layer of the magnetoresistive element in a rectifier. It is a figure which shows another example of the state of magnetization of the 1st ferromagnetic layer and the 2nd ferromagnetic layer of the magnetoresistive element in a rectifier. It is a schematic diagram for demonstrating the first example in the case of using a magnetoresistive device as a dielectric sensor. It is a schematic diagram for demonstrating the 2nd example in the case of using a magnetoresistive device as a dielectric sensor. It is a schematic diagram for demonstrating the 3rd example in the case of using a magnetoresistive device as a dielectric sensor. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on the 1st modification. It is a perspective view which shows the vicinity of the magnetoresistive element of the magnetoresistive device which concerns on the 2nd modification. It is the figure which looked at the vicinity of the magnetoresistive element of the magnetoresistive device which concerns on the 2nd modification in plan view. This is another example of a plan view of the vicinity of the magnetoresistive element of the magnetoresistive device according to the second modification. This is another example of a perspective view showing the vicinity of the magnetoresistive element of the magnetoresistive device according to the second modification. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on the 3rd modification. It is a figure which looked at the vicinity of the magnetoresistive element of the magnetoresistive device which concerns on the 3rd modification in plan view. The change in the value corresponding to the DC voltage output from each magnetoresistive sensor and the change in the added average of the values corresponding to the DC voltage output from each magnetoresistive sensor due to the change in the direction of the external magnetic field. It is a figure which shows. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 4th modification. It is a perspective view which shows the vicinity of the 1st magnetoresistive element and the 2nd magnetoresistive element of the magnetoresistive device which concerns on 4th modification. It is a figure which shows another example of the circuit structure of the magnetoresistive effect device which concerns on 4th modification schematically. It is a figure which shows another example of the circuit structure of the magnetoresistive effect device which concerns on 4th modification schematically. It is a perspective view which shows the vicinity of the magnetoresistive element of the magnetoresistive device which concerns on 5th modification. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 2nd Embodiment. It is a figure which shows typically the circuit structure of the modification of the magnetoresistive effect device which concerns on 2nd Embodiment. It is a figure which shows typically the circuit structure of another modification of the magnetoresistive effect device which concerns on 2nd Embodiment. It is a figure which shows typically the circuit structure of another modification of the magnetoresistive effect device which concerns on 2nd Embodiment. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 3rd Embodiment. It is a schematic diagram in the case where the magnetoresistive effect device according to the 3rd Embodiment is used as a dielectric sensor. It is a schematic diagram of the modification when the magnetoresistive effect device according to the 3rd Embodiment is used as a dielectric sensor. It is a schematic diagram of another modification when the magnetoresistive effect device according to the third embodiment is used as a dielectric sensor. It is a figure which shows typically the circuit structure of the modification of the magnetoresistive effect device which concerns on 3rd Embodiment. It is a figure which shows typically the circuit structure of another modification of the magnetoresistive effect device which concerns on 3rd Embodiment. It is a figure which shows typically the circuit structure of another modification of the magnetoresistive effect device which concerns on 3rd Embodiment.

Hereinafter, the magnetoresistive device will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, the featured portion may be enlarged for convenience in order to make the feature easy to understand, and the dimensional ratio of each component may be different from the actual one. The materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately modified and carried out within the range in which the effects of the present invention are exhibited.

"First embodiment"
FIG. 1 is a diagram showing a circuit configuration of the magnetoresistive device 100 according to the first embodiment. The magnetoresistive device 100 includes a magnetoresistive 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 p3. The magnetoresistive device 100 shown in FIG. 1 also has lines 40 and 42, reference potential terminals pr1 and pr2, an inductor 91, and a capacitor 92.

<Magnetic resistance 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 ferromagnetic layer 1 and the second ferromagnetic layer 2. 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 the “stacking direction”.

The first ferromagnetic layer 1 is, for example, a magnetization free layer (first magnetization free layer). The second ferromagnetic layer 2 is, for example, a magnetization fixed layer or a magnetization free layer (second magnetization free layer). When the second ferromagnetic layer 2 functions as a magnetization fixing layer, the coercive force of the second ferromagnetic layer 2 is larger than, for example, the coercive force of the first ferromagnetic layer 1. The magnetization free layer is a layer made of a magnetic material whose magnetization direction changes when a predetermined external force is applied, and the magnetization fixed layer has a magnetization direction different from that of the magnetization free layer when a predetermined external force is applied. Is a layer made of a magnetic material that does not easily change. The predetermined external force is, for example, an external force applied to the magnetization by an external magnetic field.

The magnetoresistive element 10 causes a resistance value in the stacking direction (current flows in the stacking direction) according to 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. (Reluctance value when this is done) changes. The second ferromagnetic layer 2 may be a fixed magnetization layer or a free magnetization layer as long as the relative angle of the magnetization direction of the first ferromagnetic layer 1 to the magnetization direction of the second ferromagnetic layer 2 changes.

The first ferromagnetic layer 1 and the second ferromagnetic layer 2 include a ferromagnetic material. For example, the first ferromagnetic layer 1 and the second ferromagnetic layer 2 can use a metal such as Cr, Mn, Co, Fe, or Ni, or an alloy containing one or more of these metal elements as a constituent material. Further, an alloy of the above-mentioned metal element and at least one or more elements selected from B, C and N may be used for the first ferromagnetic layer 1 and the second ferromagnetic layer 2. For example, the first ferromagnetic layer 1 and the second ferromagnetic layer 2 may have a CoFeB alloy as a main component when functioning as a magnetization free layer. Each of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 may be composed of a plurality of layers.

The first ferromagnetic layer 1 and the second ferromagnetic layer 2, XYZ or X ₂ YZ intermetallic compound represented by the chemical composition (Heusler alloy) may be used. X is a transition metal element or a noble metal element of the group Co, Fe, Ni or Cu on the periodic table. Y is a transition metal of the group Mn, V, Cr or Ti or an element represented by X. Z is a typical element of groups III to V. For example, Co ₂ FeSi, Co ₂ MnSi, Co ₂ Mn _1-a Fe _a Al _b Si _1-b (0 ≦ a ≦ 1, 0 ≦ b ≦ 1) and the like are known as Whistler alloys.

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

In order to use the ferromagnetic layer as an in-plane magnetization film, the layer in contact with the ferromagnetic layer is made of a material that does not easily exhibit interfacial magnetic anisotropy. Examples of materials that do not easily exhibit interfacial magnetic anisotropy include Ru and Cu. On the other hand, in order to make the ferromagnetic layer a perpendicular magnetization film, the layer in contact with the ferromagnetic layer is made of a material that easily exhibits interfacial magnetic anisotropy. Examples of materials that easily exhibit interfacial magnetic anisotropy include MgO, W, Ta, and Mo. The layer of these materials in contact with the ferromagnetic layer may be provided on one side of the ferromagnetic layer in the direction perpendicular to the film surface. Further, the first ferromagnetic layer 1 or the second ferromagnetic layer 2 may be formed by a laminated film in which a layer of these materials in contact with the ferromagnetic layer is sandwiched between a plurality of ferromagnetic layers.

When the second ferromagnetic layer 2 functions as a magnetization fixing layer, an antiferromagnetic layer may be added so as to be in contact with the second ferromagnetic layer 2. Further, the magnetization of the second ferromagnetic layer 2 may be fixed by utilizing the magnetic anisotropy caused by the crystal structure, shape, and the like. For the antiferromagnetic layer, FeO, CoO, NiO, CuFeS ₂ , IrMn, FeMn, PtMn, Cr, Mn or the like can be used.

The spacer layer 3 is a non-magnetic layer arranged between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. The spacer layer 3 is composed of a layer composed of a conductor, an insulator or a semiconductor, or a layer including an energizing point formed of a conductor in the insulator.

For example, when the spacer layer 3 is made of an insulator, the magnetoresistive element 10 becomes a tunnel magnetoresistive (TMR) effect element, and when the spacer layer 3 is made of metal, it becomes a giant magnetoresistive (GMR). It becomes an 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. A high reluctance rate of change can be obtained by adjusting the film thickness of the spacer layer 3 so that a high TMR effect is exhibited between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. In order to efficiently utilize the TMR effect, the film thickness of the spacer layer 3 may be about 0.5 to 10.0 nm.

When the spacer layer 3 is made of a non-magnetic conductive material, a conductive material such as Cu, Ag, Au or Ru can be used. In order to efficiently utilize the GMR effect, the film thickness of the spacer layer 3 may be about 0.5 to 3.0 nm.

When the spacer layer 3 is made of a non-magnetic 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 film thickness of the spacer layer 3 may be about 1.0 to 4.0 nm.

When a layer including a current-carrying point composed of a conductor in a non-magnetic insulator is applied as the spacer layer 3, CoFe, CoFeB, CoFeSi, ComnGe, and ComnSi are contained in the non-magnetic insulator composed of aluminum oxide or magnesium oxide. , ComnAl, Fe, Co, Au, Cu, Al, Mg, and other conductors, preferably have a structure including a current-carrying point. In this case, the film thickness of the spacer layer 3 may be about 0.5 to 2.0 nm.

In order to increase the electrical conductivity of the magnetoresistive element 10, electrodes may be provided on both sides 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 surface, and a signal can be obtained at any position in the in-plane direction of the magnetoresistive element 10. The flow of (current) follows the stacking direction.

The magnetoresistive 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. Further, 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. Examples of the cap layer, seed layer or buffer layer include MgO, W, Mo, Ru, Ta, Cu, Cr and a laminated film thereof. The film thickness of each of these layers may be about 2 to 10 nm.

<1st input port>
The first input port p1 is the first input terminal of the magnetoresistive device 100. For example, an AC signal source, an antenna, or the like is connected to the first input port p1. If the antenna is integrated with the magnetoresistive device as part of the magnetoresistive device, the antenna will be 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, the end of the first signal line 20. A first high frequency signal is input to the first input port p1, and a first high frequency signal is input from the first input port p1 to the first signal line 20. The first high frequency signal produces a _{first high frequency current IR1 on the first signal line 20.} The frequency of the first high frequency signal is, for example, a signal having a frequency of 100 MHz or more. The frequency of the first high frequency current _IR1 coincides with the frequency of the first high frequency signal.

<1st signal line>
The first signal line 20 is a signal line through which _{the first high frequency current IR1 flows.} The first signal line 20 shown in FIG. 1 is a line connecting the first input port p1 and the reference potential terminal pr1. The first signal line 20 shown in FIG. 1 electrically connects the first input port p1 and the reference potential terminal pr1.

The first signal line 20 is separated from the magnetoresistive element 10 and the second signal line 30 via an insulator. The insulator may be an insulator or a space. The first signal line 20 is arranged at a position where the high frequency magnetic field _{Hrf generated by the first high frequency current IR1} flowing through the first signal line 20 can be applied to the first ferromagnetic layer 1. The high-frequency magnetic field _{Hrf caused by the first high-frequency current IR1} flowing through the first signal line 20 is applied to the first ferromagnetic layer 1. The magnetization of the first ferromagnetic layer 1 _{vibrates significantly when the frequency of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 is close to the ferromagnetic resonance frequency of the first ferromagnetic layer 1. This phenomenon is a ferromagnetic resonance phenomenon. The frequency of the high frequency magnetic field _Hrf coincides with the frequency of the first high frequency current _IR1. 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 the second input terminal of the magnetoresistive device 100. For example, an AC signal source, an antenna, or the like is connected to the second input port p2. If the antenna is integrated with the magnetoresistive device as part of the magnetoresistive device, the antenna will be 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, the end of the second signal line 30. A second high frequency signal is input to the second input port p2, and a second high frequency signal is input from the second input port p2 to the second signal line 30. The second high frequency signal produces a _{second high frequency current IR2 on the second signal line 30.} The frequency of the second high frequency signal is, for example, a signal having a frequency of 100 MHz or more. The frequency of the second high frequency current _IR2 coincides with the frequency of the second high frequency signal.

<Second signal line>
The second signal line 30 is a signal line through which _{the second high frequency current IR2 flows.} The second signal line 30 shown in FIG. 1 is a line connecting the second input port p2 and the magnetoresistive element 10. The second signal line 30 shown in FIG. 1 electrically connects the second input port p2 and the magnetoresistive element 10.

The second signal line 30 is connected to the magnetoresistive element 10. _{The second high-frequency current IR2} flowing through the second signal line 30 flows through the magnetoresistive element 10. The amplitude of the magnetization of the magnetization of the first ferromagnetic layer 1 by the high-frequency magnetic field _Hrf applied to the first ferromagnetic layer 1 is the spin transfer torque generated by _{the second high-frequency current IR2 flowing through the magnetic resistance effect element 10.} 1 It is larger than the vibration amplitude of the magnetization of the ferromagnetic layer 1.

<Output port>
The output port p3 is an output terminal of the magnetoresistive device 100. For example, a voltmeter for monitoring voltage or an ammeter for monitoring current is connected to the output port p3. The output port p3 shown in FIG. 1 is connected to a line 40 branching from the second signal line 30. The output port p3 is connected to the magnetoresistive effect element, and a signal including a DC signal component (DC voltage or DC current) caused by the output from the magnetoresistive effect element 10 is output from the output port p3.

<Other configurations>
(Reference potential terminal)
The reference potential terminals pr1 and pr2 are connected to the reference potential and determine the reference potential of the magnetoresistive 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 in FIG. 1 is ground G. The ground G may be provided outside the magnetoresistive device 100. The reference potential may be other than ground G.

(line)
The lines are connected between the terminals and between the magnetoresistive element 10 and each terminal. The shape of the line may be defined as a microstrip line (MSL) type or a coplanar waveguide (CPW) type. When designing a microstrip line (MSL) type or a coplanar waveguide (CPW) type, the line width and the distance between grounds may be designed so that the characteristic impedance of the line and the impedance of the circuit system are equal to each other. 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 the second signal line 30 and the output port p3. The line 42 connects the magnetoresistive element 10 and the reference potential terminal pr2.

(Inductor, capacitor)
The inductor 91 cuts the high frequency component of the signal and passes the invariant component of the signal. The capacitor 92 passes the high frequency component of the signal and cuts the invariant component of the signal. The inductor 91 is arranged in a portion where the flow of high-frequency signals is desired to be suppressed, and the capacitor 92 is arranged in a portion where the flow of DC signals is desired to be suppressed.

The inductor 91 in FIG. 1 is on the line 40. The inductor 91 suppresses the high frequency component of the output from the second high frequency current _IR2 and the magnetoresistive element 10 from reaching the output port p3. As the inductor 91, a chip inductor, an inductor with a pattern line, a resistance element having an inductor component, or the like can be used. The inductance of the inductor 91 may be, for example, 10 nH or more. If the voltmeter or ammeter connected to the output port p3 has the function of cutting the high frequency component of the signal and at the same time passing the invariant component of the signal, the inductor 91 may be omitted.

The capacitor 92 in FIG. 1 is on the second signal line 30. The capacitor 92 in FIG. 1 is on the second input port p2 side from the branch point of the second signal line 30 with the line 40. A known capacitor 92 can be used.

<Magnetic sensor>
The magnetoresistive device 100 can be used, for example, in a sensor, a rectifier, or the like. Examples of the sensor include a magnetic sensor (magnetic field sensor) that detects a magnetic field, a dielectric sensor that uses a dielectric as an object to be measured, and the like. First, a case where it is used as a magnetic sensor will be described. Hereinafter, in the first embodiment, an example of a DC voltage will be described as a DC signal component output from the output port p3.

2 (a) and 2 (b) are schematic views for explaining the operation of the magnetoresistive device 100 according to the first embodiment as a magnetic sensor. 2 (a) is a magnetoresistive element 10, the first high-frequency current _{I R1} in a state where the external magnetic field of a certain magnitude is applied, the resistance _{R 10} of the magnetoresistive effect element 10, the second high-frequency current _{I R2} , And the time change of the _{DC voltage VDC} output from the output port p3. _{FIG. 2B shows the first high-frequency current IR1} after the external magnetic field applied to the magnetoresistive sensor 10 has changed (increased), the resistance R10 of the magnetoresistive sensor ₁₀ , and the second high-frequency current I. The time change of the _{DC voltage VDC output from R2} and the output port p3 is shown. The external magnetic field is a magnetic field applied to the magnetoresistive element 10 from other than each configuration of the magnetoresistive device 100. The arrows arrows and second high-frequency current I _R2 of the first high-frequency current I _R1 shown in FIG. 1, respectively, represent the positive direction of the current. The same applies to other drawings described later.

First, the state before the change of the external magnetic field applied to the magnetoresistive element 10 will be described. When the first high frequency signal is input to the first input port p1 from the AC signal source connected to the first input port p1, the first high frequency current _IR1 flows through the first signal line 20. The first high-frequency current _{I R1} produces a high-frequency magnetic field _{H rf.} The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 of the magnetoresistive element 10.

The magnetization of the first ferromagnetic layer 1 vibrates by receiving a high-frequency magnetic field H _rf due to the first high-frequency current I _R1. FIG. 3 is a diagram showing an example of the states of the magnetizations M1 and M2 of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive sensor 10 in the magnetic sensor. The magnetization M1 of the first ferromagnetic layer 1 vibrates (precession) due _{to the high frequency magnetic field Hrf.} The second ferromagnetic layer 2 is a magnetization-fixed layer, and the direction of the magnetization M2 is fixed parallel to the vibration direction of the _{high-frequency magnetic field Hrf.} The external magnetic field _Hex is applied in the stacking direction, for example.

_{In the state before the external magnetic field Hex} applied to the magnetic resistance effect element 10 changes, as an example, the ferromagnetic resonance frequency of the first ferromagnetic layer 1 is the high frequency magnetic field H applied to the first ferromagnetic layer 1. It is smaller than the frequency of _rf. Resistance R ₁₀ of the magnetoresistive effect element 10, the first magnetization of the ferromagnetic layer 1 is changed by vibration (vibrating). Phase and the resistor R ₁₀ and the phase of the magneto-resistive element 10 of the first high-frequency current I _R1, may be different, but shows an example in which matched in FIG 2 (a). Phase difference between the resistance R ₁₀ of the first high-frequency current I _R1 and the magnetoresistive element 10, the arrangement position of the first signal line 20 from the magnetoresistive element 10, the first input port p1 and the reference to the first signal line 20 It can be changed by the arrangement position of the potential terminal pr1 _{and the relative angle between the direction of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 and the magnetization direction of the second ferromagnetic layer 1.

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 _IR2 flows through the second signal line 30. The second high-frequency current _IR2 flows through the magnetoresistive element 10. The phase of the second high-frequency current I _{R2 and} the phase of the first high-frequency current I _R1 may be different, but FIGS. 2 (a) and 2 (b) show examples of matching. That is, in the example shown in FIG. 2 (a), are coincident with the phase of the resistance R ₁₀ of phase and the magnetoresistive element 10 of the second high-frequency current I _R2.

When the first high-frequency current _IR1 and the second high-frequency current _{IR2 are input to the magnetoresistive device 100, the DC voltage VDC} caused by the output from the magnetoresistive element 10 is output from the output port p3.

DC voltage V _DC, the current flowing through the resistor R ₁₀ and the magnetoresistive element 10 of the magnetoresistive element 10 changes at a high-frequency magnetic field H _rf caused by the first high-frequency current I _R1 is applied (second high-frequency current It is a DC component of the voltage V (output voltage from the magnetic resistance effect element 10) which is the product of _{IR2).
I R2 = A · sin (2πft} ),
R ₁₀ = B · sin (2πft + Δθ ₁ ) + R ₀
Then
_{V = I R2 × R 10 =} (A · B / 2) · {cos (Δθ 1) -cos (4πft + Δθ 1)} + A · R 0 · sin (2πft)
Is.
The DC voltage V _DC is a DC component of the voltage V, and is (A · B / 2) · cos (Δθ ₁ ).
Here, A is the amplitude of the second high-frequency current I _R2 , B is the amplitude of the resistance R ₁₀ of the reluctance effect element 10, and R ₀ is the first ferromagnetic of the resistance of the reluctance effect element 10. It is a resistance component that does not depend on the relative angle between the magnetization of layer 1 and the magnetization of the second ferromagnetic layer 2, f is frequency, t is time, and Δθ ₁ is the phase and magnetoresistance of the second high-frequency current _IR2. This is the phase difference from the phase of the resistor R _{10 of the effect element 10.} Hereinafter, it may be simply referred to as “phase difference Δθ _1”. Further, the phase difference between the phase of the resistance R ₁₀ of phase and the magnetoresistive element 10 of the first high-frequency current I _R1 and [Delta] [theta] ₂ (hereinafter, simply referred to as "phase difference [Delta] [theta] _2").

In the case shown in FIG. 2A, Δθ ₁ = 0 (0 °), and the DC voltage _VDC output from the output port p3 is A / B / 2.

_{Next, the state after the external magnetic field Hex} applied to the magnetoresistive element 10 has changed (increased) will be described. _{When the external magnetic field Hex} applied to the magnetoresistive element 10 changes, the state of vibration (age difference motion) of the magnetization of the first ferromagnetic layer 1 changes. As a result, the phase _{of the resistor R 10 of the magnetoresistive element 10 changes.} Since the phase second high-frequency current I _R2 does not change, between the second high-frequency current I _R2 of the phase and of the resistance R ₁₀ of the magnetoresistive element 10 phase, occurs a phase difference [Delta] [theta] _1. So far, when the ferromagnetic resonance frequency of the first ferromagnetic layer 1 is sufficiently smaller than the _{frequency of the high frequency magnetic field Hrf} (the frequency of the first high frequency current _{IR1 ), the phase of the first high frequency current IR1} and the magnetic resistance effect element. The example has been described in which the phases of the resistors R10 of ₁₀ are in agreement (Δθ ₂ = 0 (0 °)). In the case of this example, when the ferromagnetic resonance frequency of the first ferromagnetic layer 1 is sufficiently larger than the frequency of the _{high frequency magnetic field Hrf , the phase difference Δθ 2} becomes π (180 °). _{When the external magnetic field Hex} applied to the magnetic resistance effect element 10 becomes large and 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 Δθ ₂ and the phase difference Δθ ₁ change according to the change in the magnitude of the external magnetic field applied to the magnetoresistive element 10.

As described above, the DC voltage _VDC is (A · B / 2) · cos (Δθ ₁ ), and when the phase difference Δθ ₁ changes, the output value of the _{DC voltage VDC changes.} That is, the magnetoresistive device 100 can detect that the magnitude of the external magnetic field _{Hex has changed based on the DC voltage VDC} output from the output port p3, and functions as a magnetic sensor. As an example, it is possible to detect a change _{from a state in which the phase difference Δθ 1} is 0 (0 °) to a state in which the phase difference Δθ _{1 is π (180 °). The value of the phase difference Δθ 1} before and after the change in the magnitude of the external magnetic field _Hex is not limited to 0 (0 °) or π (180 °), but can be any value between 0 and π (0 ° to 180 °). Values can be used. In Jiki resistance effect device 100, to vibrate the magnetization of the first ferromagnetic layer 1 by a high-frequency magnetic field H _rf that caused by the first high-frequency Denryu I _R1, possible to increase the amplitude of the vibration of the first ferromagnetic layer 1 magnetized. When the amplitude of the magnetization vibration of the first ferromagnetic layer 1 becomes large, the _{amount of change (amplitude) of the resistance R 10} of the magnetoresistive element 10 becomes large, and a large DC voltage _VDC can be output from the output port p3.

Further, the magnetoresistive device 100 according to the present embodiment can detect the magnitude or direction of the applied external magnetic field, not limited to the change in the magnitude of the external magnetic field. Hereinafter, each detection method will be described in detail.

(Detection of the magnitude of the 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, when the magnetization M2 of the second ferromagnetic layer 2 is oriented in the vibration direction of the _{high-frequency magnetic field Hrf , when the magnitude of the external magnetic field Hex} changes, as shown in FIG. The phase difference Δθ ₂ and the phase difference Δθ ₁ change. The phase difference Δθ ₂ and the phase difference Δθ ₁ are, for example, 0 (0 °) (Δθ ₁ , Δθ _{2 = 0) when the magnitude of the external magnetic field Hex} is less than the first value, and the external magnetic field _Hex. When the magnitude of is larger than the second value (second value> first value), it is π (180 °) (Δθ ₁ , Δθ ₂ = π). When the magnitude of the external magnetic field _Hex is equal to or greater than the first value and equal to or less than the second value, the magnitude of the _{external magnetic field Hex changes sharply.} Therefore, the magnitude of the external magnetic field H _ex is the second value following areas than the first value, magnitude and phase difference [Delta] [theta] ₁ of the external magnetic field H _ex, [Delta] [theta] ₂ are in one-to-one relationship. That is, if the phase differences Δθ ₁ and Δθ ₂ are known, the magnitude of the _{external magnetic field Hex can be detected.} As described above, the DC voltage _VDC is (A · B / 2) · cos (Δθ ₁ ). Therefore, the _{phase difference Δθ 1} can be derived from the value of the _{DC voltage VDC} , and the magnitude of the external magnetic field can be detected from the phase difference θ _1. It is also possible to obtain the amount of change in the magnitude of the external magnetic field from the amount of change in the value of the _{DC voltage VDC.} Further, the changes in the phase differences Δθ ₁ and Δθ ₂ with respect to the change in the external magnetic field _Hex are steep, and the magnetic sensor can detect the difference in the magnitude of the _{external magnetic field Hex with high sensitivity.}

(Detection of the direction of the external magnetic field)
Next, a method of detecting the direction of the external magnetic field will be described. 5 (a) and 5 (b) show the magnetizations M1 and M2 of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive sensor 10 when detecting the direction of the _{external magnetic field Hex.} It is a figure which shows an example of a state. FIG. 5A shows _{a state in which the direction of the external magnetic field Hex} is the first direction, and FIG. 5B shows a state in which _{the direction of the external magnetic field Hex} is different from the first direction.

6 (a) and 6 (b) show the magnetizations M1 and M2 of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive sensor 10 when detecting the direction of the _{external magnetic field Hex.} It is a figure which shows another example of the state of. _{FIG. 6A} shows a state in which the direction of the external magnetic field Hex is the first direction, and FIG. 6B shows a state in which _{the direction of the external magnetic field Hex} is different from the first direction.

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

First, the first pattern shown in FIGS. 5 (a) and 5 (b) will be described. In the first pattern, the magnetization M1 of the first ferromagnetic layer 1 is vibrated (aged) by the _{high-frequency magnetic field Hrf , and the external magnetic field Hex} is applied to the second ferromagnetic layer 2, and the second ferromagnetic layer 2 The magnetization M2 is oriented in the direction of the _{external magnetic field Hex.} The second ferromagnetic layer 2 is a second free magnetizing layer, and the direction of the magnetization M2 of the second ferromagnetic layer 2 changes according to _{the direction of the external magnetic field Hex.} In the example of the first pattern, it is preferable that the first ferromagnetic layer 1 has an easy magnetization axis in the direction perpendicular to the film surface because the magnetization M1 is easily vibrated (precession) by the _{high frequency magnetic field Hrf.} Further, in the example of the first pattern, it is preferable that the second ferromagnetic layer 2 has an easy magnetization axis in the in-plane direction of the film because the magnetization M2 is not easily affected by the _{high frequency magnetic field Hrf.}

The magnetic sensor detects the direction _{of the external magnetic field Hex} by, for example, the magnetoresistive element 10 of the first pattern. A first high-frequency signal is input to the first input port p1, and a first high-frequency current _IR1 having a frequency f is passed through the first signal line 20. The first high-frequency current _{I R1} produces a high frequency magnetic field _{H rf} of frequency f. The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 of the magnetoresistive element 10.

A second high-frequency signal is input to the second input port p2, and a second high-frequency current _IR2 having a frequency f is passed through the second signal line 30. The second high-frequency current _IR2 flows through the magnetoresistive element 10. The phase of the second high frequency current _IR2 is matched with, for example, the phase of the first high frequency current _IR1. The phase of the second high frequency current _IR2 may be different from the phase of the first high frequency current _IR1.

Resistance R ₁₀ of the magnetoresistive element 10 changes in response to changes in the first ferromagnetic layer 1 of the magnetization M1 relative angle of the second ferromagnetic layer 2 of the magnetization M2. FIG. 7 is a diagram showing a time change _{of the resistance R 10 of the magnetoresistive element 10.} The upper graph of _{FIG. 7 is a graph showing the time change of the resistance R 10} of the magnetoresistive sensor 10 in the state where the _{external magnetic field Hex} is applied in the first direction, and the lower graph of FIG. 7 is the graph showing the time change of the resistance R 10 in the first direction. It is a graph which shows the time change _{of the resistance R 10} of the magnetoresistive sensor 10 in the state where the _{external magnetic field Hex} is applied in the direction different from the above.

When the direction of the external magnetic field _Hex changes, the first axis with respect to the central axis of vibration of the magnetization M1 of the first ferromagnetic layer 1 (the rotation axis of the aging motion, hereinafter, may be simply referred to as the "rotation axis of the magnetization M1"). 2 The direction of the magnetization M2 of the ferromagnetic layer 2 changes. As a result, the maximum resistance R ₁₀ of the magnetoresistive element 10, the minimum and the timing is changed to become, as shown in the lower graph of FIG. 7, the phase of the resistance R ₁₀ of the magnetoresistive element 10 in FIG. 7 It changes from the example shown in the upper graph. When the phase of the resistance R ₁₀ of the magnetoresistive element 10 changes, the DC voltage phase difference [Delta] [theta] ₁ between the phase and the second high-frequency current I _R2 phase of the resistor R ₁₀ is changed, is outputted from the output port p3 The value of _{VDC changes.} That is, the magnetic sensor can detect the direction of _{the external magnetic field Hex} applied to the magnetic sensor by reading the _{DC voltage VDC output from the output port p3.}

Next, the second pattern shown in FIGS. 6 (a) and 6 (b) will be described. In the second pattern, the magnetization M1 of the first ferromagnetic layer 1 vibrates (precession) due to the _{high frequency magnetic field Hrf.} Further, in the second pattern, the second ferromagnetic layer 2 is a magnetization fixed layer, and the 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 easy magnetization axis in the direction perpendicular to the film surface.

The magnetic sensor detects the direction _{of the external magnetic field Hex} by, for example, the magnetoresistive element 10 of the second pattern. A first high-frequency signal is input to the first input port p1, and a first high-frequency current _IR1 having a frequency f is passed through the first signal line 20. The first high-frequency current _{I R1} produces a high frequency magnetic field _{H rf} of frequency f. The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 of the magnetoresistive element 10.

A second high-frequency signal is input to the second input port p2, and a second high-frequency current _IR2 having a frequency f is passed through the second signal line 30. The second high-frequency current _IR2 flows through the magnetoresistive element 10. The phase of the second high frequency current _IR2 is matched with, for example, the phase of the first high frequency current _IR1. The phase of the second high frequency current _IR2 may be different from the phase of the first high frequency current _IR1.

Resistance R ₁₀ of the magnetoresistive element 10 changes in response to changes in the first ferromagnetic layer 1 of the magnetization M1 relative angle of the second ferromagnetic layer 2 of the magnetization M2. FIG. 8 is a diagram showing a time change _{of the resistance R 10 of the magnetoresistive element 10.} The upper graph of _{FIG. 8 is a graph showing the time change of the resistance R 10} of the magnetoresistive sensor 10 in the state where the _{external magnetic field Hex} is applied in the first direction, and the lower graph of FIG. 8 is the graph showing the time change of the resistance R 10 in the first direction. It is a graph which shows the time change _{of the resistance R 10} of the magnetoresistive sensor 10 in the state where the _{external magnetic field Hex} is applied in the direction different from the above.

The external magnetic field H _ex is applied to the magnetoresistive element 10, by the external magnetic field H _ex is applied to the first ferromagnetic layer 1, the rotation axis of the first ferromagnetic layer 1 of the magnetization M1 is inclined. The inclination direction of the rotation axis of the magnetization M1 changes depending on the change in the _{direction of the external magnetic field Hex.} When the direction of the rotation axis of the magnetization M1 changes, the timing at which _{the resistance R 10 of the magnetoresistive element 10 becomes maximum or minimum changes.} As a result, as shown in the lower graph of _{FIG. 8, the phase of the resistor R 10} of the magnetoresistive element 10 changes from the example shown in the upper graph of FIG. When the phase of the resistance R ₁₀ of the magnetoresistive element 10 changes, the DC voltage phase difference [Delta] [theta] ₁ between the phase and the second high-frequency current I _R2 phase of the resistor R ₁₀ is changed, is outputted from the output port p3 The value of _{VDC changes.} That is, the magnetic sensor can detect the direction of _{the external magnetic field Hex} applied to the magnetic sensor by reading the _{DC voltage VDC output from the output port p3.}

By using the magnetic sensors shown in FIGS. 6A and 6B, the magnetic sensor can detect the size of the component in the in-plane direction of the _{external magnetic field Hex (the direction perpendicular to the laminating direction of the magnetoresistive element 10).} .. In FIGS. 6A and 6B, the second ferromagnetic layer 2 is a magnetization fixing layer, and the direction of the magnetization M2 is fixed in any of the stacking directions. _{An external magnetic field Hex} is applied to the first ferromagnetic layer 1 in the in-plane direction. The axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 is tilted from the stacking direction by _{the external magnetic field Hex.}

When the magnitude of the external magnetic field _Hex changes, the tilt angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes. For example, in the configuration shown in FIG. 6A or FIG. 6B, _{as the magnitude of the external magnetic field Hex} increases, the tilt angle of the rotation axis of the magnetization M1 with respect to the stacking direction increases. Further, for example, in the configuration shown in FIG. 6A or FIG. 6B, when _{the magnitude of the external magnetic field Hex} becomes small, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction becomes small.

When the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes, the magnitude of the amplitude of _{the resistance R 10 of the magnetoresistive element 10 changes.} For example, in the case of the configuration shown in FIG. 6A or FIG. 6B, when the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction becomes small, the orientation direction of the magnetization M1 and the orientation direction of the magnetization M2 are parallel to each other. The magnitude of the amplitude of _{the resistor R 10} of the magnetoresistive element 10 becomes smaller.

The resistance R 10 of the magnetoresistive element ₁₀ is a parameter that affects the _{DC voltage VDC} output from the output port p3 as described above. _{As a result, when the magnitude of the external magnetic field Hex} applied to the magnetoresistive sensor 10 changes, the value of the _{DC voltage VDC} output from the output port p3 changes. That is, the magnetic sensor can detect the magnitude of the in- _{plane external magnetic field Hex} applied to the magnetic sensor by reading the _{DC voltage VDC output from the output port p3.}

Further, FIG. 9 is a plan view of a modified example of the magnetoresistive element 10 shown in FIGS. 5 (a) and 5 (b). The first ferromagnetic layer 1 shown in FIG. 9 is smaller than the second ferromagnetic layer 2 in a plan view from the film thickness direction. The first ferromagnetic layer 1 shown in FIG. 9 is included in the second ferromagnetic layer 2 in a plan view from the film thickness direction. As a result, the influence of the vibration of the magnetization of the first ferromagnetic layer 1 is less likely to extend to the entire second ferromagnetic layer 2.

Further, FIG. 10 is a cross-sectional view of another modified example of the magnetoresistive element 10 shown in FIGS. 5 (a) and 5 (b). The second ferromagnetic layer 2 shown in FIG. 10 has two ferromagnetic layers 2A and 2B and a non-magnetic layer 2C sandwiched between them. The non-magnetic layer 2C is, for example, Ru. The ferromagnetic layer 2A and the ferromagnetic layer 2B are interconnected with each other via the non-magnetic 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 of the ferromagnetic layer 2A and the saturation magnetization is different from the product of the film thickness of the ferromagnetic layer 2B and the saturation magnetization. When the product of the film thickness and the saturation magnetization is different between the two ferromagnetic layers 2A and 2B, the magnetization of the ferromagnetic layer having the larger product of the film thickness and the saturation magnetization has a smaller product of the film thickness and the saturation magnetization. It is easier to react to a magnetic field applied from the outside than the magnetization of the ferromagnetic layer, and the direction of magnetization of the second ferromagnetic layer 2 is more likely to change depending on the _{external magnetic field Hex.}

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 and 2B are different, the product of the film thicknesses of the two ferromagnetic layers 2A and 2B and the saturation magnetization is often different. For example, the film thickness of the ferromagnetic layer 2B is thicker than the film thickness of the ferromagnetic layer 2A. For example, the film thickness of the ferromagnetic layer 2B is more than twice the film thickness of the ferromagnetic layer 2A. The product of the film thickness of the ferromagnetic layer 2B and the saturation magnetization is larger than the product of the film thickness of the ferromagnetic layer 2A and the saturation magnetization. The ferromagnetic layer 2B is located at a position away from the first ferromagnetic layer 1 and the first signal line 20 from the ferromagnetic layer 2A. The thickness of the ferromagnetic layer 2B is made thicker than the thickness of the ferromagnetic layer 2A, and among the ferromagnetic layers included in the second ferromagnetic layer 2, the ferromagnetic layer in which the magnetization easily reacts to the magnetic field applied from the outside. When is set to the ferromagnetic layer 2B, the influence of the vibration of the magnetization of the first ferromagnetic layer 1 and the influence of the high-frequency magnetic field from the first signal line 20 can be reduced. 2 It is possible to suppress the vibration of the magnetization of the ferromagnetic layer 2.

In FIG. 10, an example in which the first ferromagnetic layer 1 is smaller than the second ferromagnetic layer 2 in a plan view from the film thickness direction is presented, but the present invention is not limited to this case. Further, the ferromagnetic layer 2A and the ferromagnetic layer 2B may each be composed of a plurality of layers.

Up to this point, some methods have been described in which the magnetic sensor detects components in the in-plane direction of the _{external magnetic field Hex} (direction perpendicular to the stacking direction of the magnetoresistive sensor 10), but the magnetic sensor has described the stacking direction of the _{external magnetic field Hex.} The components of can also be detected. FIG. 11 is a diagram showing an example of the magnetization state of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 of the magnetoresistive sensor 10 in the magnetic sensor that detects the component in the stacking direction of _{the external magnetic field Hex.}

The second ferromagnetic layer 2 is a magnetization-fixed layer, and the direction of the magnetization M2 is fixed in any of the stacking directions. A static magnetic field H _dc is applied to the first ferromagnetic layer 1. The axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 is tilted from the stacking direction by _{the static magnetic field Hdc.} The static magnetic field H _dc is applied in a direction parallel to or antiparallel to the vibration direction of the high frequency magnetic field H _rf. A high-frequency magnetic field H parallel or anti-parallel to the static magnetic field H _dc and the vibration direction of the _rf is applied along the direction in which the high-frequency magnetic field H _rf in the first ferromagnetic layer 1 vibrates, the plane of the static magnetic field H _dc The presence of a directional component. When the first direction of the vibration direction of the high-frequency magnetic field _Hrf is specified, the case where the static magnetic field _Hdc is applied in the same direction as the first direction is parallel, and the static magnetic field _Hdc is opposite to the first direction. When applied in the direction, it is considered to be antiparallel.

When the magnitude or positive / negative direction of the external magnetic field _Hex changes, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes. For example, in the configuration shown in FIG. 11, as _{the magnitude of the external magnetic field Hex} increases, the tilt angle of the rotation axis of the magnetization M1 with respect to the stacking direction decreases. Further, for example, in the configuration shown in FIG. 11, when _{the magnitude of the external magnetic field Hex} becomes small or _{the direction of the external magnetic field Hex} is opposite, the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction becomes large.

When the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction changes, the magnitude of the amplitude of _{the resistance R 10 of the magnetoresistive element 10 changes.} For example, in the case of the configuration shown in FIG. 11, when the inclination angle of the rotation axis of the magnetization M1 with respect to the stacking direction becomes small, the orientation direction of the magnetization M1 and the orientation direction of the magnetization M2 approach a parallel state, and the magnetoresistive element 10 The magnitude of the amplitude of the resistor R _{10 becomes smaller.}

The resistance R 10 of the magnetoresistive element ₁₀ is a parameter that affects the _{DC voltage VDC} output from the output port p3 as described above. _{As a result, when the magnitude of the external magnetic field Hex} applied to the magnetoresistive sensor 10 changes, the value of the _{DC voltage VDC} output from the output port p3 changes. That is, the magnetic sensor can detect the magnitude and positive / negative directions of _{the external magnetic field Hex} applied to the magnetic sensor by reading the _{DC voltage VDC output from the output port p3.}

Here, in FIG. 11, _{a case where a static magnetic field Hdc} is applied to the first ferromagnetic layer 1 has been described as an example. However, it is not always necessary _{to apply the static magnetic field H dc} to the first ferromagnetic layer 1, and the in- _{plane component of the effective magnetic field H eff} in the first ferromagnetic layer 1 is applied to the first ferromagnetic layer 1. It may be parallel or antiparallel to the vibration direction of _Hrf. The effective magnetic field H _eff in the first ferromagnetic layer 1 is the external magnetic field _Hex applied to the first ferromagnetic layer 1, the anisotropic magnetic field H _k in the first ferromagnetic layer 1, and the anti-magnetic field H k in the first ferromagnetic layer 1. magnetic field _{H D,} the exchange coupling field _{H Eg} of the first ferromagnetic layer 1 obtained by _{H eff = H ex + H k} + H D + H Eg. For example, when the shape of the first ferromagnetic layer 1 when viewed from the stacking direction has anisotropy, an anisotropic magnetic field _Hk is generated in the longitudinal direction thereof. By directing the longitudinal direction of the first ferromagnetic layer 1 when viewed from the stacking direction to the vibration direction of the _{high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1, an anisotropic magnetic field is replaced _{with the static magnetic field Hdc.} the H _k may be generated in the first ferromagnetic layer 1.

Up to this point, an example has been shown in which the DC component of the voltage V (output voltage from the magnetic resistance effect element 10) is used to detect the change in the magnitude of the external magnetic field, the magnitude of the external magnetic field, and the direction of the external magnetic field. The high frequency component of the above may be used. Is a high frequency component of the voltage V - (A · B / 2 ) · cos (4πft + Δθ 1) , since a phase difference [Delta] [theta] _1, it is possible to derive the phase difference [Delta] [theta] ₁ from the high-frequency component. If the phase difference Δθ ₁ is known, the external magnetic field can be detected from _{the phase difference Δθ 1.}

<Rectifier>
Up to this point, the case where the magnetoresistive device 100 is used as a magnetic sensor has been described. Next, a case where the magnetoresistive 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 magnetoresistive device 100 as a rectifier, an example in which the antenna at1 is connected to the first input port p1 and the antenna at2 is connected to the second input port p2 will be described. For example, the same signal is input to the antennas at1 and at2.

When the first high-frequency signal is inputted from the antenna at1 to the first input port p1, the first high-frequency current _{I R1} flows through the first signal line 20. Also the second high-frequency signal from the antenna at2 to the second input port p2 is input, a second high-frequency current _{I R2} flows through the second signal line 30. The first high-frequency current _{I R1} produces a high-frequency magnetic field _{H rf.} The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 of the magnetoresistive element 10. The second high-frequency current _IR2 flows through the magnetoresistive element 10. The phase of the second high-frequency current I _{R2 and} the phase of the first high-frequency current I _R1 may be different, but here, as an example, a matching example will be described.

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

When the frequency of the high-frequency magnetic field _Hrf 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 figure is shown as an example. As shown in 13, the direction of the magnetization M2 and the vibration direction of the _{high-frequency magnetic field Hrf are made parallel.} When the frequency of the high-frequency magnetic field _Hrf is the ferromagnetic resonance frequency of the first ferromagnetic layer, as an example, the direction of the magnetization M2 and the vibration direction of the _{high-frequency magnetic field Hrf are orthogonal to each other, as shown in FIG.}

The magnitude of the _{DC voltage VDC} output from the output port p3 is proportional to _{cos (Δθ 1).} In order to increase the magnitude (absolute value) of the DC voltage _{VDC , it is preferable that Δθ 1} is 0 (0 °) or ± π (± 180 °). Since the phase of the first high-frequency current I _{R1 and} the phase of the second high-frequency current I _R2 match, the phase difference Δθ ₂ coincides with the phase difference Δθ _1.

When the frequency of the high-frequency magnetic field _Hrf is not in the vicinity of the ferromagnetic resonance frequency of the first ferromagnetic layer 1, the phase difference Δθ ₁ is 0 (0 °) or ± π (± 180 °) by the configuration shown in FIG. ), Therefore, the magnitude of the _{DC voltage VDC} output from the output port p3 becomes large.

On the other hand, when the frequency of the high-frequency magnetic field _Hrf is the ferromagnetic resonance frequency of the first ferromagnetic layer 1, the phase difference Δθ ₁ is 0 (0 °) or ± π (± 180 °) due to the configuration shown in FIG. ), Therefore, the magnitude of the _{DC voltage VDC} output from the output port p3 becomes large.

Further, in FIG. 14, an example is shown in which the direction of the magnetization M2 of the second ferromagnetic layer 2 is made orthogonal to the vibration direction of the _{high-frequency magnetic field Hrf in advance, but the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 is the first. In the case of the ferromagnetic resonance frequency of the ferromagnetic layer 1, the direction of the magnetization M2 of the second ferromagnetic layer 2 and _{the vibration direction of the high-frequency magnetic field Hrf} are parallel to each other, as in the configuration of FIG. the phase of the current _{I R2} No. 1 π / 2 (90 °) with respect to the phase of the high frequency current _{I R1} shifting may be. For example, by providing a phase shifter on at least one of the first signal line 20 and the second signal line 30, at least one of the phase of the first high frequency current _{IR1 and} the phase of the second high frequency current _IR2 can be adjusted. ..

<Dielectric sensor>
Next, a case where the magnetoresistive device 100 is used as a dielectric sensor using a dielectric as an object to be measured will be described. The dielectric sensor is, for example, a sensor that determines the state of the object to be measured based on the difference in the dielectric constant of the object to be measured. The dielectric sensor is a sensor that utilizes the characteristic that the phase and amplitude of a signal propagating in a signal line change by bringing the dielectric close to the signal line or installing a dielectric in the signal propagation path. The dielectric sensor can measure the water content of these objects to be measured, for example, when vegetables, grains, skin and the like are used as the objects to be measured.

FIG. 15 is a schematic diagram for explaining a first example when the magnetoresistive device 100 is used as a dielectric sensor. The dielectric sensor shown in the first example includes an installation area A1 or an installation area A2. A part of the first signal line 20 formed of, for example, a microstrip line type or a coplanar waveguide type is arranged in the installation area A1. In the installation area A2, a part of the second signal line 30 formed of, for example, a microstrip line type or a coplanar waveguide type is arranged. A dielectric object to be measured is installed in either the installation area A1 or the installation area A2, and measurement is performed. The object to be measured is not particularly limited. As the magnetoresistive element 10 when the magnetoresistive device 100 is used as a dielectric sensor, for example, the same magnetoresistive element 10 as shown in FIG. 13 can be used.

First, the operation of the sensor when the object to be measured is installed in the installation area A1 will be described.
Or less of the first high-frequency current I _R1 and the second high-frequency current I _R2 of the previous installation of the object to be measured state.
_{I R2 = A · sin (2πft} )
_{I R1 = C · sin (2πft} + Δθ 3)
Here [Delta] [theta] _{3 is} the phase difference between the _{I R1} and _{I R2,} is constant.

When the phase difference between the resistance _{R 10} of I _R1 and the magnetoresistive element 10 and [Delta] [theta] _2, the resistance _{R 10} of the magnetoresistive element 10 is expressed by the following equation.
R ₁₀ = B · sin (2πft + Δθ ₂ + Δθ ₃ ) + R _{0
Here, Δθ 2} is constant because the measurement is performed under the condition that the external magnetic field is constant.

When installing the measured object in the installation area A1, the change in dielectric constant (variation of the dielectric constant of the object to be measured from the dielectric constant of air), shift the phase of the I _R1 only [Delta] [theta] _4, the amplitude of the I _R1 is C' Changes to.
As a result, the first high-frequency current _IR1 and the resistance R10 of the magnetoresistive element ₁₀ are as follows.
_{I R1 = C'· sin (2πft} + Δθ 3 + Δθ 4)
R ₁₀ = B'・ sin (2πft + Δθ ₂ + Δθ ₃ + Δθ ₄ ) + R ₀

_Here, when the phase difference between the _{I R1} and _{R 10} and _{Δθ 1 (= Δθ 2 + Δθ} 3 + Δθ 4),
R ₁₀ = B'・ sin (2πft + Δθ ₁ ) + R ₀
It is represented by.

As described above, the DC voltage _VDC output from the output port p3 is the product of the resistance R ₁₀ of the magnetic resistance effect element 10 and the current (second high frequency current IR _{2) flowing through the magnetic resistance effect element 10.} It is a direct current component of V (output voltage from the magnetic resistance effect element 10), and has the following equation.
_{V = I R2 × R 10 =} (A · B'/ 2) · {cos (Δθ 1) -cos (4πft + Δθ 1)} + A · R 0 · sin (2πft)

The DC voltage V _DC is a DC component of the voltage V, and is (A · B ′ / 2) · cos (Δθ ₁ ). Since Δθ ₁ = Δθ ₂ + Δθ ₃ + Δθ ₄ , and Δθ ₂ and Δθ ₃ are constant, the DC output component corresponding to the values of _{Δθ 4} and B ′ that change with the change of the dielectric constant is output from the output port p3. .. Based on this result, parameters related to the dielectric constant of the object to be measured (for example, the amount of water in the object to be measured) can be measured.

Next, the operation of the sensor when the object to be measured is installed in the installation area A2 will be described. The state before installation of the object to be measured is the same as the case where the object to be measured is installed in the above-mentioned installation area A1.

When installing the measured object in the installation area A2, the change in dielectric constant (variation of dielectric constant of air into the dielectric constant of the object to be measured), phase shifted in I _R2 only [Delta] [theta] _4, the amplitude of the I _R2 is A' Changes to.
As a result, the second high-frequency current _IR2 and the resistance R10 of the magnetoresistive element ₁₀ are as follows.
_{I R2 = A'· sin (2πft} + Δθ 4)
R ₁₀ = B · sin (2πft + Δθ ₂ + Δθ ₃ ) + R ₀

Here, due to mathematical handling, the notation is rewritten with reference to the phase of _IR2 after the object to be measured is installed in the installation area A2 as follows.
_{I R2 = A'· sin (2πft} )
R ₁₀ = B · sin (2πft + Δθ ₂ + Δθ _{3 − Δθ 4} ) + R _{0
I R1 = C · sin (2πft} + Δθ 3 -Δθ 4)

_Here, when the phase difference between the _{I R1} and _{R 10} and _{Δθ 1 (= Δθ 2 + Δθ} 3 -Δθ 4),
R ₁₀ = B · sin (2πft + Δθ ₁ ) + R ₀
It is represented by.

As described above, the DC voltage _VDC output from the output port p3 is the product of the resistance R ₁₀ of the reluctance effect element 10 and the current (second high frequency current IR _{2) flowing through the reluctance effect element 10.} It is a direct current component of V (output voltage from the reluctance effect element 10), and the same relational expression as when the object to be measured is installed in the installation area A1 holds.

The DC voltage V _DC is a DC component of the voltage V, and is (A'・ B / 2) ・ cos (Δθ ₁ ). Since Δθ ₁ = Δθ ₂ + Δθ _{3 − Δθ 4} , and Δθ ₂ and Δθ ₃ are constant, the DC output component corresponding to the values of _{Δθ 4} and A ′ that change as the dielectric constant changes is output from the output port p3. NS. Based on this result, parameters related to the dielectric constant of the object to be measured (for example, the amount of water in the object to be measured) can be measured.

Further, FIG. 16 is a schematic diagram for explaining a second example when the magnetoresistive device is used as a dielectric sensor. In the magnetoresistive device 100A shown in the second example, the first signal line 20A has a transmitting antenna at _T and a receiving antenna at _R , and the installation area A1 is between the transmitting antenna at _T and the receiving antenna at _R. It is a sandwiched area. The transmitting antenna at _T transmits the first high frequency signal transmitted through the first signal line to the receiving antenna at _R. When the object to be measured is installed in the installation area A1, the phase and amplitude of _IR1 change due to the change in the permittivity (change from the permittivity of air to the permittivity of the object to be measured). As a result, the magnitude of the _{DC voltage VDC} output from the output port p3 changes. This principle is the same as the case where the object to be measured is installed in the installation area A1 in the first example described above. Based on this result, parameters related to the dielectric constant of the object to be measured (for example, the amount of water in the object to be measured) can be measured.

Further, FIG. 17 is a schematic diagram for explaining a third example when the magnetoresistive device is used as a dielectric sensor. In the magnetoresistive device 100B shown in the third example, the second signal line 30B has a transmitting antenna at _T and a receiving antenna at _R , and the installation area A2 is between the transmitting antenna at _T and the receiving antenna at _R. It is a sandwiched area. The transmitting antenna at _T transmits the second high frequency signal transmitted through the second signal line to the receiving antenna at _R. When the object to be measured is installed in the installation area A2, the phase and amplitude of _IR2 change due to the change in the permittivity (change from the permittivity of air to the permittivity of the object to be measured). As a result, the magnitude of the _{DC voltage VDC} output from the output port p3 changes. This principle is the same as the case where the object to be measured is installed in the installation area A2 in the first example described above. Based on this result, parameters related to the dielectric constant of the object to be measured (for example, the amount of water in the object to be measured) can be measured.

As described above, the magnetoresistance effect device 100 according to the first embodiment, for vibrating the first magnetization M1 of the ferromagnetic layer 1 by a high-frequency magnetic field H _rf caused by the first high-frequency current I _R1, the vibration of the magnetization M1 The amplitude of can be increased. When the amplitude of the vibration of the magnetization M1 becomes large, the _{amount of change (amplitude) of the resistance R 10} of the magnetoresistive element 10 becomes large, and a large DC voltage _VDC can be output from the output port p3. Further, as described above, the magnetoresistive device 100 according to the first embodiment can be used as a magnetic sensor, a rectifier, and a dielectric sensor using a dielectric as an object to be measured.

The first embodiment has been described in detail with reference to the drawings. However, each configuration and a combination thereof in the first embodiment are examples, and the configurations are added or omitted within a range that does not deviate from the gist of the present invention. , Replacements, and other changes are possible. For example, in the first embodiment, the magnetic resistance effect element 10 is one example, but a plurality of magnetic resistance effect elements 10 are connected to the second signal line 30, and a second high frequency current is connected to the plurality of magnetic resistance effect elements 10. Even if _IR2 is allowed to flow and a high-frequency magnetic field _{Hrf caused by the first high-frequency current IR1} flowing through the first signal line 20 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive elements 10. good.

(First modification)
FIG. 18 is a diagram schematically showing a circuit configuration of the magnetoresistive device according to the first modification. The magnetoresistive device 101 according to the first modification shown in FIG. 18 is different from the magnetoresistive device 100 shown in FIG. 1 in that it has a magnetic material portion 50. In the magnetoresistive device 101 shown in FIG. 18, the same reference numerals are given to the same configurations as the magnetoresistive device 100 shown in FIG. Further, the description of the configuration common to the magnetoresistive device 100 in the magnetoresistive device 101 according to the first modification will be omitted.

The magnetic body portion 50 is located between the first signal line 20 and the magnetoresistive element 10. The magnetic body portion 50 is arranged apart from the first signal line 20 and the magnetoresistive element 10. For example, an insulator is provided between the magnetic material portion 50 and the first signal line 20 and between the magnetic material portion 50 and the magnetoresistive element 10.

The magnetic material portion 50 includes a soft magnetic material. The magnetic material portion 50 is, for example, a magnetic material having an insulating property. The magnetic material portion 50 is, for example, a ceramic such as ferrite. The magnetic material portion 50 is, for example, a rare earth iron garnet (RIG). Yttrium iron garnet (YIG) is an example of rare earth iron garnet (RIG). The magnetic material portion 50 may be, for example, a metal such as permalloy.

_{A high-frequency magnetic field Hrf1} generated from the first signal line 20 is applied to the magnetic material portion 50. The magnetization of the magnetic body portion 50 vibrates in response to the _{high frequency magnetic field H rf1. When the high-frequency magnetic field Hrf1} contains a signal having a frequency near the ferromagnetic resonance frequency of the magnetic body portion 50, the magnetization of the magnetic body portion 50 vibrates significantly at that frequency. The vibration of the magnetization of the magnetic material portion 50 generates _{a high frequency magnetic field H rf2.}

_{The high-frequency magnetic field Hrf2} generated by the vibration of the magnetization of the magnetic material portion 50 is applied to the first ferromagnetic layer 1. The magnetization of the first ferromagnetic layer 1 is oscillated by the _{high frequency magnetic field Hrf2 generated by the magnetic body portion 50.} That is, the high frequency magnetic field _{H rf2} due to high frequency magnetic field _{H rf1} the first high-frequency current _{I R1} through the first signal line 20 produces is applied to the first ferromagnetic layer 1. High frequency magnetic field H _rf2 the magnetic unit 50 produces is an example of a high-frequency magnetic field caused by the first high-frequency current I _R1 through the first signal line 20.

Resistance R ₁₀ of the magnetoresistive effect element 10 varies with the vibration of the first ferromagnetic layer 1 magnetized (vibrates). When the second high frequency signal is input to the second input port p2, the second high frequency current _IR2 flows through the second signal line 30. The second high-frequency current _IR2 flows through the magnetoresistive element 10. From the output port p3 _{, a DC voltage VDC} which is a DC component of the voltage which is the product of _{the resistance R 10} of the magnetoresistive element 10 and the current (second high frequency current _IR2 ) flowing through the magnetoresistive element 10 is output. NS. Although the example in which the magnetic material portion 50 is located between the first signal line 20 and the magnetic resistance effect element 10 has been described, the high-frequency magnetic field _Hrf1 generated from the first signal line 20 is applied to the magnetic material portion 50 to cause magnetism. _{If the high-frequency magnetic field Hrf2} generated by the vibration of the magnetization of the body portion 50 is applied to the first ferromagnetic layer 1, the position of the magnetic material portion 50 is not limited to this, and for example, the first signal line 20 is the magnetic material portion. The magnetic material portion 50 may be arranged so as to be located between the 50 and the magnetic resistance effect element 10. Further, when a plurality of magnetoresistive elements 10 are used, a high-frequency magnetic field _Hrf2 generated by the vibration of the magnetization of one magnetic body portion 50 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive elements 10. Alternatively, a plurality of magnetic material portions 50 may be used to provide one magnetic material unit 50 for each magnetoresistive sensor 10.

Also magneto-resistance effect device 101 according to the first embodiment, for vibrating the first ferromagnetic layer 1 of the magnetization M1 by a high frequency magnetic field H _rf2 caused by the first high-frequency current I _R1, it can increase the amplitude of oscillation of the magnetization M1 .. When the amplitude of the vibration of the magnetization M1 becomes large, the _{amount of change (amplitude) of the resistance R 10} of the magnetoresistive element 10 becomes large, and a large DC voltage _VDC can be output from the output port p3. Further, the magnetoresistive device 101 according to the first modification can be used as a magnetic sensor, a rectifier, or a dielectric sensor using a dielectric as an object to be measured.

(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 magnetoresistive device 102 according to the second modification shown in FIGS. 19 and 20 is different from the magnetoresistive device 100 shown in FIG. 1 in that it has a yoke 60. In the magnetoresistive device 102 shown in FIGS. 19 and 20, the same reference numerals are given to the same configurations as the magnetoresistive device 100 shown in FIG. Further, the description of the configuration common to the magnetoresistive device 100 in the magnetoresistive device 102 according to the second modification will be 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 FIGS. 19 and 20 is smaller than the second ferromagnetic layer 2 in a plan view from the stacking direction and is included 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 contains a soft magnetic material. The yoke 60 is, for example, an alloy of Fe, Co, Ni, Ni and Fe, an alloy of Fe and Co, an alloy of Fe and Co and B, and 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 magnetoresistive element 10 in the gap in a plan view from the stacking direction. The magnetic flux lines flow from the first portion 61 to the second portion 62, or from the second portion 62 to the first portion 61.

When an external magnetic field _Hex is applied to the magnetoresistive device 102, the yoke 60 induces magnetic flux and concentrates it in the gap GA between the first portion 61 and the second portion 62. The yoke 60 applies a magnetic field generated in the gap GA by the external magnetic field _{Hex to the second ferromagnetic layer 2.} The second ferromagnetic layer 2 is a second free magnetized layer, and the magnetized M2 of the second ferromagnetic layer 2 receives a magnetic field generated in the gap GA between the first portion 61 and the second portion 62. The direction changes. The direction of the magnetic field generated in the gap GA between the first portion 61 and the second portion 62 changes depending on _{the direction of the external magnetic field Hex.} The magnetoresistive device 102 is particularly applicable to a magnetic sensor (see FIGS. 5A and 5B) using the first pattern magnetoresistive element 10 that detects the direction of the _{external magnetic field Hex.}

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 is a part of the magnetoresistive element 10 (for example, one of the second ferromagnetic layers 2). Part or all) may be located within the gap GA of the yoke 60 in the stacking direction. Further, in the example of FIG. 20, an example in which the first portion 61 and the second portion 62 of the yoke 60 sandwich the magnetoresistive element 10 in one direction is shown, but as shown in FIG. 21, a plan view from the stacking direction is shown. The yoke 60 may surround the magnetoresistive element 10.

Further, as shown in FIG. 22, the yoke 60 may be 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 of another example according to the second modification. The yoke 60 applies a magnetic field generated in the gap GA by the external magnetic field _{Hex to the first ferromagnetic layer 1.} The axis of rotation of the magnetization M1 of the first ferromagnetic layer 1 is tilted 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 changes depending on _{the direction of the external magnetic field Hex.} The magnetoresistive device shown in FIG. 22 is particularly _suitable for a magnetic sensor (see FIGS. 6A and 6B) using the magnetoresistive element 10 of the second pattern for detecting the direction of the external magnetic field Hex. Applicable.

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 is a part of the magnetoresistive element 10 (for example, one of the first ferromagnetic layers 1). Part or all) may be located within the gap GA of the yoke 60 in the stacking direction. Further, also in the example of FIG. 22, the yoke 60 may surround the magnetoresistive element 10 in a plan view from the stacking direction.

(Third modification example)
FIG. 23 is a diagram schematically showing a circuit configuration of the magnetoresistive device 103 according to the third modification. The magnetoresistive device 103 according to the third modification shown in FIG. 23 is different from the magnetoresistive device 100 shown in FIG. 1 in that it has a plurality of magnetoresistive elements 10. In the magnetoresistive device 103 shown in FIG. 23, the same reference numerals are given to the same configurations as the magnetoresistive device 100 shown in FIG. Further, the description of the configuration common to the magnetoresistive device 100 in the magnetoresistive device 103 according to the third modification will be omitted.

Each of the magnetoresistive elements 10 is connected to the second signal line 30, and the magnetoresistive elements 10 are connected in series. Each magnetoresistive element 10 is separated from the first signal line 20 via an insulator. The first signal line 20 is arranged at a position where the high-frequency magnetic field _{Hrf generated by the first high-frequency current IR1} flowing through the first signal line 20 can be applied to the first ferromagnetic layer 1 of each magnetoresistive element 10. There is. The high-frequency magnetic field _{Hrf caused by the first high-frequency current IR1} flowing through the first signal line 20 is applied to each of the first ferromagnetic layers 1. The second ferromagnetic layer 2 of each magnetoresistive element 10 functions as a magnetization fixing layer. The directions of magnetization of the second ferromagnetic layer 2 of the plurality of magnetoresistive elements 10 are the same.

FIG. 24 is a plan view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 103 according to the third modification. In FIG. 24, only the magnetoresistive element 10 and the first signal line 20 are shown. A part of the first signal line 20 shown in FIG. 24 is annular in a plan view from the stacking direction. The magnetoresistive element 10 is located at a position where it overlaps with the first signal line 20 in a plan view from the stacking direction. As shown in FIG. 24, each magnetoresistive element 10 is located at a position deviated by a rotation angle φ with respect to the center of the annular first signal line 20. The rotation angle φ is, for example, 60 °. In FIG. 24, the angle α is the angle formed by the reference direction and the direction of the external magnetic field _Hex . _{In FIG. 24, as an example, the direction in which the high-frequency magnetic field Hrf} is applied to the magnetoresistive element 10 of one of the three magnetoresistive elements 10 is set as the reference direction.

The high frequency magnetic field _Hrf is generated around the first signal line 20 according to the right-handed screw rule. _{The directions of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 of each magnetoresistive element 10 are different from each other among the plurality of magnetoresistive elements 10. _{As shown in FIG. 24, the direction of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 of each magnetoresistive sensor 10 is the same angle as the rotation angle φ with the adjacent magnetoresistive element 10. Only out of alignment. The magnetoresistive effect device 103 includes a magnetic sensor (see FIGS. 5A and 5B) using the magnetoresistive element 10 of the first pattern for detecting the direction of the _{external magnetic field Hex, and a second pattern.} It is particularly applicable to a magnetic sensor (see FIGS. 6 (a) and 6 (b)) using the magnetoresistive sensor 10 of the above.

In each magnetic resistance effect element 10, the _{relative angle between the direction of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 and the magnetization direction of the second ferromagnetic layer 2 is the relative angle of the plurality of magnetic resistance effect elements 10. Since they are different from each other, the phase difference Δθ ₂ in each magnetic resistance effect element 10 is different from each other among the plurality of magnetic resistance effect elements 10. FIG. 25 (a) is _{a graph showing a change in cos (Δθ 2} ) in each magnetoresistive element 10 with respect to a change in the direction of _{the external magnetic field Hex} , and FIG. 25 (b) shows three magnetoresistive effects. It is a graph which shows the change of the addition average of cos (Δθ _{2) of element 10.} 25 (a) and 25 (b) are graphs when the three magnetoresistive elements 10 are arranged at different positions by 60 ° with respect to the center of the annular first signal line 20. The numbers in the legend of the graph of FIG. 25A are the values of the rotation angle φ of each magnetoresistive element 10.

As shown in the graph of FIG. 25 (a), _{the change in cos (Δθ 2} ) in each magnetoresistive element 10 is not very linear with respect to the change in the direction of the external magnetic field _Hex. The DC voltage output from each magnetoresistive element 10 is proportional to _{cos (Δθ 1) in each magnetoresistive element 10. Assuming that} the phase difference between the second high-frequency current I _R2 and the first high-frequency current I _{R1 is Δθ 3} , Δθ ₁ = Δθ ₂ + Δθ ₃ , so that each magnetoresistive sensor 10 is output from the magnetoresistive element 10. The DC voltage is proportional to _{cos (Δθ 2} + Δθ _3). Since the phase difference Δθ ₃ is constant, in each magnetoresistive element 10, the _{linearity of the change of cos (Δθ 2} + Δθ ₃ ) with respect to the change in the direction of the external magnetic field _{Hex is the same as that of cos (Δθ 2} ). Become. Therefore, the linearity of the change in the DC voltage output from each magnetoresistive element 10 with respect to the change in the direction of the _{external magnetic field Hex is not very good.}

On the other hand, as shown in the graph of FIG. 25 (b), _{the value obtained by adding the cos (Δθ 2} ) of the three magnetoresistive elements 10 (cos (Δθ ₂ + Δθ ₃ ) of the three magnetoresistive elements 10) is obtained. The linearity of the change in the (added value) with respect to the change in the direction of _{the external magnetic field Hex becomes good. Since the DC voltage VDC} output from the output port p3 is proportional to the sum of the cos (Δθ ₂ + Δθ ₃ ) of the three magnetoresistive elements 10, the direction of the external magnetic field _{Hex of the change in the DC voltage VDC.} The linearity with respect to the change of is improved.

_{In the examples shown in FIGS. 23 to 25, the directions of the high-frequency magnetic fields Hrf} applied to the first ferromagnetic layer of the three magnetic resistance effect elements 10 are different from each other. _{By making the directions of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer different from each other, there is a certain effect that the linearity of the change _{of the DC voltage VDC} with respect to the change of the direction of the external magnetic field _{Hex is improved.} can get. _{By making the directions of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer of at least three magnetoresistive elements 10 different from each other, _{the change in the DC voltage VDC} is linear with respect to the change in the direction of the external magnetic field _Hex. You can improve your sex.

Further, the magnitude of the _{high-frequency magnetic field Hrf} applied to the first ferromagnetic layer of each magnetoresistive sensor 10 in order to improve the linearity of the change of the DC voltage _VDC with respect to the change in the direction of the external magnetic field _Hex. May be different among the plurality of magnetoresistive 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 among the plurality of magnetoresistive elements 10.

(Fourth modification)
FIG. 26 is a diagram schematically showing a circuit configuration of the magnetoresistive device 104 according to the fourth modification. The magnetoresistive device 104 according to the fourth modification shown in FIG. 26 is different from the magnetoresistive device 100 shown in FIG. 1 in that it has a plurality of second input ports p2, output ports p3, magnetic resistance effect elements 10, and the like. .. In the magnetoresistive device 104 shown in FIG. 26, the same reference numerals are given to the same configurations as the magnetoresistive device 100 shown in FIG. Further, the description of the configuration common to the magnetoresistive device 100 in the magnetoresistive device 104 according to the fourth modification will be 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. There are two magnetoresistive elements 10, and they are referred to as a first magnetoresistive element 11 and a second magnetoresistive element 12, respectively.

The configuration of the first magnetoresistive element 11 and the second magnetoresistive element 12 is, as an example, the same as the first pattern shown in FIGS. 5 (a) and 5 (b). Specifically, in each of the first magnetic resistance effect element 11 and the second magnetic resistance effect element 12, the first ferromagnetic layer 1 and the second ferromagnetic layer 2 are both free to magnetize in which the direction of magnetization changes. It is a layer, and the magnetization M1 of the first ferromagnetic layer 1 vibrates (age-difference motion) due to the _{high-frequency magnetic field Hrf.} The configuration of the first magnetoresistive element 11 and the second magnetoresistive element 12 may be the same as the second pattern shown in FIGS. 6 (a) and 6 (b).

_{An external magnetic field Hex} is applied to each of the first magnetoresistive element 11 and the second magnetoresistive element 12. The external magnetic field _Hex is applied from a direction inclined with respect to the stacking direction of the first magnetoresistive element 11 or the second magnetoresistive element 12. The orientation direction of the magnetization of the second ferromagnetic layer 2 _{coincides with, for example, the direction in which the external magnetic field Hex} is applied.

The first signal line 20 is separated from each of the first magnetoresistive element 11 and the second magnetoresistive element 12 via an insulator. The first signal line 20 extends in the first extending direction at a position where the first magnetoresistive element 11 and the first magnetoresistive element 11 overlap in a plan view from the stacking direction. The first signal line 20 extends in the second extending direction at a position where the second magnetoresistive element 12 and the second magnetoresistive element 12 overlap in a plan view from the stacking direction. Unlike the first extending direction and the second extending direction, the angle between them is 90 °.

The first magnetoresistive element 11 and the second magnetoresistive element 12 are connected to different output ports p3, respectively. Hereinafter, the output port p3 from which the voltage due to the output from the first magnetoresistive sensor 11 is output is the first output port p31, and the output port from which the voltage due to the output from the second magnetoresistive element 12 is output. p3 is referred to as a second output port p32.

As described above, the voltage V1 output from _{the first magnetoresistive sensor 11 is the current flowing through the resistor R 11} of the first magnetoresistive element 11 and the first magnetoresistive element 11 (second high-frequency current _IR2 ). It is expressed by the product of and satisfies the following relationship.
_{I R2 = A · sin (2πft} ),
R ₁₁ = B · sin (2πft + Δθ ₁ ) + R _{0
V1 = I R2 × R 11 =} (A · B / 2) · {cos (Δθ 1) -cos (4πft + Δθ 1)} + A · R 0 · sin (2πft)
From the first output port p31, (A · B / 2) · cos (Δθ ₁ ), which is a DC component of the voltage V1, is output.

On the other hand, the _{vibration direction of the high-frequency magnetic field Hrf} applied to the second magnetoresistive sensor 12 is tilted by 90 ° with respect to the vibration direction of the _{high-frequency magnetic field Hrf} applied to the second magnetoresistive element 12. .. _{Therefore, the phase of the resistor R 12} of the second magnetoresistive element 12 is delayed by π / 2 (90 °) with respect to the phase _{of the resistor R 11} of the first magnetoresistive element 11.

As a result, the voltage V2 output from the second magnetoresistive element 12 satisfies the following relationship.
_{I R2 = A · sin (2πft} ),
R ₁₂ = B · sin (2πft + Δθ ₁ −π / 2) + R ₀ = −B · cos (2πft + Δθ ₁ ) + R _{0
V2 = I R2 × R 12 =} (A · B / 2) · {sin (Δθ 1) -sin (4πft + Δθ 1)} + A · R 0 · sin (2πft)
From the second output port p32, (A · B / 2) · sin (Δθ ₁ ), which is a DC component of the voltage V2, is output.

If the DC component of the voltage V1 output from the first output port p31 and the DC component of the voltage V2 output from the second output port p32 are used, the specific values of _{(AB / 2) and Δθ 1 are used.} Can be sought. It should be noted that the high frequency component of the voltage V1 "-(A · B / 2) · cos (4πft + Δθ ₁ )" and the high frequency component of the voltage V2 "-(A · B / 2) · sin (4πft + Δθ ₁ )". If, by using, it is also possible to determine the specific value of (a · B / 2) and [Delta] [theta] _1.

From the values of (A and B / 2), for example, the magnitude of the _{external magnetic field Hex can be detected.} This is because the value of (A / B / 2) changes when the magnitude of the external magnetic field _{Hex changes.} Specifically, when _{the magnitude of the external magnetic field Hex} changes, the inclination angle of the magnetization M1 of the first ferromagnetic layer 1 with respect to the stacking direction changes. As a result, the _{amplitude A of the resistance value R 11} of the first magnetoresistive element 11 and the amplitude B of the resistance value R ₁₂ of the second magnetoresistive element 12 change, and the values of (A and B / 2) change. ..

Further, _{from Δθ 1} , for example, the angle of the _{external magnetic field Hex can be detected.} When the angle of the external magnetic field _Hex changes, the second ferromagnetic layer 2 with respect to the rotation axis of the magnetization M1 of the first ferromagnetic layer 1 is similar to the first pattern shown in FIGS. 5 (a) and 5 (b). This is because the direction of the magnetization M2 changes and the phase difference Δθ ₁ changes. When the configurations of the first magnetoresistive element 11 and the second magnetoresistive element 12 are the same as the second pattern shown in FIGS. 6 (a) and 6 (b), the magnetization M1 is the same as the second pattern. The tilt direction of the rotation axis of is changed by the change in the direction of the _{external magnetic field Hex , and the phase difference Δθ 1} is changed. In the case of the fourth modification, the _{value of Δθ 1} itself can be obtained, and the direction of the external magnetic field can be detected over the entire range of 360 degrees in the in-plane direction.

FIG. 26 shows an example in which there are two second input ports p2, and one second input port p2 is connected to each of the first magnetoresistive element 11 and the second magnetoresistive element 12. , The magnetoresistive device 104A shown in FIG. 28 may have one second input port p2. The second input port p2 in FIG. 28 is connected to each of the first magnetoresistive element 11 and the second magnetoresistive element 12. There is a directional coupler 93 between the first magnetoresistive element 11 and the second magnetoresistive element 12. Further, a plurality of first signal lines 20 may be provided as in the magnetoresistive device 104B shown in FIG. 29. 29, a first signal line 20 for applying a high-frequency magnetic field _{H rf} to the first magneto-resistive element 11, a first signal line 20 for applying a high-frequency magnetic field _{H rf} Second magneto-resistive element 12, the different ..

Up to this point, some modifications of the magnetoresistive device according to the first embodiment have been described. The modification of the magnetoresistive device according to the first embodiment is not limited to these, and each modification may be combined. For example, the magnetic body portion 50 of the first modified example is provided in the second modified example or the third modified example, and the high frequency magnetic field _Hrf2 generated by the vibration of the magnetization of the magnetic body portion 50 is applied to the first ferromagnetic layer 1. You may do so. Further, the yoke 60 of the second modification is provided in each magnetoresistive element 10 of the third modification, and the magnetic field generated in the gap GA is applied to the second ferromagnetic layer 2 of each magnetoresistive element 10. You may try to do it.

Further, as shown in FIG. 30, the high frequency magnetic field _Hrf may be applied in the stacking direction of the first ferromagnetic layer 1. FIG. 30 is a perspective view showing the vicinity of the magnetoresistive element 10 of the magnetoresistive device according to the fifth modification.

The first signal line 20 has an extending portion 21. The extending portion 21 extends in a direction intersecting the stacking direction in a plan view from the stacking direction of the magnetoresistive element 10. The extending portion 21 is located at a position where it does not overlap with the magnetoresistive element 10 in a plan view from the stacking direction. A part of the extending portion 21 overlaps with the magnetoresistive element 10 in a plan view from a direction perpendicular to the stacking direction. The magnetoresistive element 10 is not arranged at the end where the extending direction of the extending portion 21 is extended. That is, the extending portion 21 is arranged so as not to overlap with the magnetoresistive element 10 when viewed from the extending direction. The first signal line 20 surrounds the circumference of the first ferromagnetic layer 1 in a plan view from the stacking direction of the magnetoresistive element 10, for example.

When a high-frequency current flows through the extending portion 21, a high-frequency magnetic field _Hrf is generated. The high frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1. The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 from the direction intersecting the in-plane where the first ferromagnetic layer 1 spreads. The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 in the stacking direction, for example. In this case, the magnetization M2 of the second ferromagnetic layer 2 has an in-plane component in which the second ferromagnetic layer 2 spreads. The magnetization M2 of the second ferromagnetic layer 2 is oriented in one direction in the in-plane direction, for example. The magnetoresistive device also works in this configuration.

"Second embodiment"
FIG. 31 is a diagram showing a circuit configuration of the magnetoresistive device according to the second embodiment. The magnetoresistive device 110 includes a magnetoresistive element 10, a first input port p11, a first signal line 70, and an output port p12. The magnetoresistive device 110 shown in FIG. 31 also has lines 80 and 82, a reference potential terminal pr3, an inductor 91, and a capacitor 92. In the magnetoresistive device 110 shown in FIG. 31, the same reference numerals are given to the same configurations as the magnetoresistive device 100 shown in FIG. Further, the description of the configuration common to the magnetoresistive device 100 in the magnetoresistive device 110 according to the second embodiment will be omitted.

The first input port p11 is an input terminal of the magnetoresistive device 110. For example, an AC signal source, an antenna, or the like is connected to the first input port p11. The first input port p11 is connected to the first signal line 70. The first input port p11 is connected to, for example, the end of the first signal line 70. A first high frequency signal is input to the first input port p11, and a first high frequency signal is input from the first input port p11 to the first signal line 70. The first high frequency signal produces a _{first high frequency current IR1 on the first signal line 70.}

The first signal line 70 is a signal line through which _{the first high frequency current IR1 flows.} The first signal line 70 shown in FIG. 31 is a line connecting the first input port p11 and the magnetoresistive element 10. The first signal line 70 shown in FIG. 31 electrically connects the first input port p11 and the magnetoresistive element 10.

The first signal line 70 is arranged at a position where the high frequency magnetic field _{Hrf generated by the first high frequency current IR1} flowing through the first signal line 70 can be applied to the first ferromagnetic layer 1. The high-frequency magnetic field _{Hrf caused by the first high-frequency current IR1} flowing through the first signal line 70 is applied to the first ferromagnetic layer 1. The magnetization of the first ferromagnetic layer 1 is oscillated by _{the high frequency magnetic field Hrf applied to the first ferromagnetic layer 1.} The magnetization of the first ferromagnetic layer 1 _{vibrates significantly when the frequency of the high-frequency magnetic field Hrf} applied to the first ferromagnetic layer 1 is close to the ferromagnetic resonance frequency of the first ferromagnetic layer 1. The portion of the first signal line 20 where the high-frequency magnetic field _Hrf applied to the first ferromagnetic layer 1 is mainly generated is, for example, closer to the first ferromagnetic layer 1 than the second ferromagnetic layer 2.

The first signal line 70 is connected to the magnetoresistive element 10. _{The first high-frequency current IR1} flowing through the first signal line 70 flows through the magnetoresistive element 10. The amplitude of the magnetization of the magnetization of the first ferromagnetic layer 1 by the high-frequency magnetic field _Hrf applied to the first ferromagnetic layer 1 is the spin transfer torque generated by _{the first high-frequency current IR1 flowing through the magnetic resistance effect element 10.} 1 It is larger than the vibration amplitude of the magnetization of the ferromagnetic layer 1.

The output port p12 is an output terminal of the magnetoresistive device 110. For example, a voltmeter for monitoring voltage or an ammeter for monitoring current is connected to the output port p12. The output port p12 shown in FIG. 31 is connected to a line 80 branching from the first signal line 70. From the output port p12, a signal including a signal component (DC voltage or DC current) caused by the output from the magnetoresistive element 10 is output.

The line 80 is a line branched from the first signal line 70. The line 80 connects the first signal line 70 and the output port p12. The line 82 connects the magnetoresistive element 10 and the reference potential terminal pr3.

Further, the inductor 91 in FIG. 31 is on the line 80. The inductor 91 suppresses the high frequency component of the output from the first high frequency current _IR1 and the magnetoresistive element 10 from reaching the output port p12. The capacitor 92 in FIG. 31 is on the first signal line 70. The capacitor 92 in FIG. 31 is on the first input port p11 side from the branch point of the first signal line 70 with the line 80.

Next, the operation of the magnetoresistive 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 p3. When the first high frequency signal is input to the first input port p11, the first high frequency current _IR1 flows through the first signal line 70. The first high-frequency current _{I R1} produces a high-frequency magnetic field _{H rf.} The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 of the magnetoresistive element 10.

The magnetization of the first ferromagnetic layer 1 vibrates by receiving a high-frequency magnetic field H _rf due to the first high-frequency current I _R1. Resistance R ₁₀ of the magnetoresistive effect element 10, the first magnetization of the ferromagnetic layer 1 is changed by vibration (vibrating).

Further, the first high frequency current _IR1 flows through the magnetoresistive element 10. _{A DC voltage VDC} is output from the output port p12. The DC voltage V _DC is the voltage V (output voltage from the magnetic resistance effect element 10) which is the product of the resistance R ₁₀ of the magnetic resistance effect element 10 and the current (first high frequency current _{IR 1) flowing through the magnetic resistance effect element 10.} It is a DC component of.

The magnetoresistive device 110 of the second embodiment can be used as a magnetic sensor or a rectifier like the magnetoresistive device 100 of the first embodiment. Also, when the magnetoresistive device 110 of the second embodiment is used as a magnetic sensor, it is possible to detect a change in the magnitude of the external magnetic field, the magnitude of the external magnetic field, or the direction of the external magnetic field, as in the first embodiment.

The operation of the magnetoresistive device 110 of 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 magnetoresistive element 10 and the first high-frequency current _IR1 flowing through the first signal line 70 flows through the magnetoresistive element 10, the magnetoresistive element 10 in the first embodiment In the second embodiment, the second high frequency current _IR2 flowing through the inside is replaced with _{the first high frequency current IR1} flowing through the magnetoresistive element 10. The phase difference [Delta] [theta] ₁ of the first embodiment is replaced with a phase difference [Delta] [theta] ₂ and the phase of resistance _{R 10} of phase and the magnetoresistive element 10 of the first high-frequency current _{I R1,} the DC voltage _{V DC} is (A · B / 2) · cos (Δθ ₂ ).

In the magnetoresistance effect device 110 according to the second embodiment, since the high-frequency magnetic field H _rf by the first magnetization of the ferromagnetic layer 1 caused by the first high-frequency current I _R1 is vibrated, can increase the amplitude of oscillation of the magnetization. When the amplitude of the magnetization vibration becomes large, the _{amount of change (amplitude) of the resistance R 10} of the magnetoresistive element 10 becomes large, and a large DC voltage _VDC can be output from the output port p12. Further, the magnetoresistive device 110 according to 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. However, each configuration and a combination thereof in the second embodiment are examples, and the configurations are added or omitted within a range that does not deviate from the gist of the present invention. , Replacements, and other changes are possible. For example, in the second embodiment, the magnetic resistance effect element 10 is one example, but a plurality of magnetic resistance effect elements 10 are connected to the first signal line 20 and the first high frequency current is connected to the plurality of magnetic resistance effect elements 10. Even if the _IR1 is allowed to flow and the high-frequency magnetic field _{Hrf caused by the first high-frequency current IR1} flowing through the first signal line 20 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive elements 10. good.

For example, in the second embodiment, the same modifications and modifications as 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 portion 50 may be provided so that a high-frequency magnetic field generated by the vibration of the magnetization of the magnetic body portion 50 is applied to the first ferromagnetic layer 1. good. Further, for example, as in the magnetic resistance effect device 112 shown in FIG. 33, a plurality of magnetic resistance effect elements 10 are provided, and the first strength of each magnetic resistance effect element 10 is the same as in the third modification of the first embodiment. _{The directions of the high-frequency magnetic field Hrf} applied to the magnetic layer 1 may be different from each other among the plurality of magnetoresistive elements 10. In the magnetoresistive device 112 shown in FIG. 33, the magnetoresistive element 10 is connected to the first signal line 70, and the magnetoresistive elements 10 are connected in series.

Further, for example, as in the magnetic resistance effect device 113 shown in FIG. 34, a plurality of magnetic resistance effect elements are provided (the first magnetic resistance effect element 11 and the second magnetic resistance effect element 12 are provided), and the first embodiment is provided. Similar to the fourth modification, the angle formed by the first extending direction and the second extending direction may be 90 °.

"Third embodiment"
FIG. 35 is a diagram showing a circuit configuration of the magnetoresistive device according to the third embodiment. The magnetoresistive device 120 includes a magnetoresistive 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 p3. In the magnetoresistive device 120 shown in FIG. 35, 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 have a second input port p2. It differs from the magnetoresistive device 100 shown in FIG. 1 in that it does not. In the magnetoresistive device 120 shown in FIG. 35, the same reference numerals are given to the same configurations as the magnetoresistive device 100 shown in FIG. Further, the description of the configuration common to the magnetoresistive device 100 in the magnetoresistive device 120 according to the third embodiment will be omitted.

The second signal line 31 is connected to the first input port p1 and the magnetoresistive 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 signal is connected to the first input port p1. _{A first high-frequency signal that produces a first high-frequency current IR1} on the line 20 and a second high-frequency current IR2 that produces a second high-frequency current _IR2 is input to the second signal line 31. _{The second high-frequency current IR2} flowing through the second signal line 31 flows through the magnetoresistive element 10.

Next, the operation of the magnetoresistive 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 p3.

When inputting the first high-frequency signal to the first input port p1, the high-frequency current I _R flows through the line 43. High frequency current _{I R} is branched into a first signal line 20 by the directional coupler 93 and the second signal line 30, the first signal line 20 first high-frequency current _{I R1,} the second signal line 31 first 2 High frequency current _IR2 flows. The first high-frequency current _{I R1} produces a high-frequency magnetic field _{H rf.} The high-frequency magnetic field _Hrf is applied to the first ferromagnetic layer 1 of the magnetoresistive element 10.

The magnetization of the first ferromagnetic layer 1 vibrates by receiving a high-frequency magnetic field H _rf due to the first high-frequency current I _R1. Resistance R ₁₀ of the magnetoresistive effect element 10, the first magnetization of the ferromagnetic layer 1 is changed by vibration (vibrating). The amplitude of the magnetization of the magnetization of the first ferromagnetic layer 1 by the high-frequency magnetic field _Hrf applied to the first ferromagnetic layer 1 is the spin transfer torque generated by _{the second high-frequency current IR2 flowing through the magnetic resistance effect element 10.} 1 It is larger than the vibration amplitude of the magnetization of the ferromagnetic layer 1.

The second high-frequency current _IR2 flows through the magnetoresistive element 10. _{A DC voltage VDC} is output from the output port p3. The DC voltage V _DC is the voltage V (output voltage from the magnetic resistance effect element 10) which is the product of the resistance R ₁₀ of the magnetic resistance effect element 10 and the current (second high frequency current IR _{2) flowing through the magnetic resistance effect element 10.} It is a DC component of.

The magnetoresistive device 120 of the third embodiment can be used as a magnetic sensor or a rectifier like the magnetoresistive device 100 of the first embodiment. Also, when the magnetoresistive device 120 of the third embodiment is used as a magnetic sensor, it is possible to detect a change in the magnitude of the external magnetic field, the magnitude of the external magnetic field, or the direction of the external magnetic field, as in the first embodiment.

The operation of the magnetoresistive device 110 of 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 according to the third embodiment, since the high-frequency magnetic field H _rf by the first magnetization of the ferromagnetic layer 1 caused by the first high-frequency current I _R1 is vibrated, can increase the amplitude of oscillation of the magnetization. When the amplitude of the magnetization vibration becomes large, the _{amount of change (amplitude) of the resistance R 10} of the magnetoresistive element 10 becomes large, and a large DC voltage _VDC can be output from the output port p3. Further, the magnetoresistive device 120 according to the third embodiment can be used as a magnetic sensor and a rectifier.

Further, the magnetoresistive device 120 of the third embodiment can be used as a dielectric sensor like the magnetoresistive device 100 of the first embodiment. FIG. 36 is a schematic view when the magnetoresistive device 120 is used as a dielectric sensor. The dielectric sensor using the magnetoresistive device 120 includes an installation area A1 or an installation area A2. In the magnetoresistive device 120, a dielectric object to be measured is installed in either the installation area A1 or the installation area A2, and measurement is performed. The operating principle of the sensor is the same as that of the dielectric sensor of the first embodiment.

Further, FIGS. 37 and 38 are schematic views of another example in which the magnetoresistive device 120 is used as a dielectric sensor. In the magnetoresistive device 120A shown in FIG. 37, the first signal line 20A has a transmitting antenna at _T and a receiving antenna at _R , and the installation area A1 is sandwiched between the _{transmitting antenna at T} and the receiving antenna at _R. Area. In the magnetoresistive device 120B shown in FIG. 38, the second signal line 31B has a transmitting antenna at _T and a receiving antenna at _R , and the installation area A2 is sandwiched between the _{transmitting antenna at T} and the receiving antenna at _R. Area. In the magnetoresistive device 120A, a dielectric object to be measured is placed in the installation area A1 to perform measurement. In the magnetoresistive device 120B, a dielectric object to be measured is installed in the installation area A2 to perform measurement. The operating 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. However, each configuration and a combination thereof in the third embodiment are examples, and the configurations are added or omitted within a range that does not deviate from the gist of the present invention. , Replacements, and other changes are possible. For example, in the third embodiment, the magnetic resistance effect element 10 is one example, but a plurality of magnetic resistance effect elements 10 are connected to the second signal line 31 to connect the plurality of magnetic resistance effect elements 10 to the second high frequency current. Even if _IR2 is allowed to flow and a high-frequency magnetic field _{Hrf caused by the first high-frequency current IR1} flowing through the first signal line 20 is applied to the first ferromagnetic layer 1 of the plurality of magnetoresistive elements 10. good.

For example, in the third embodiment, the same modifications and modifications as 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, even if the magnetic body portion 50 is provided so that a high-frequency magnetic field generated by the vibration of the magnetization of the magnetic body portion 50 is applied to the first ferromagnetic layer 1. good. Further, for example, as in the magnetic resistance effect device 122 shown in FIG. 40, a plurality of magnetic resistance effect elements 10 are provided, and the first strength of each magnetic resistance effect element 10 is the same as in the third modification of the first embodiment. _{The directions of the high-frequency magnetic field Hrf} applied to the magnetic layer 1 may be different from each other among the plurality of magnetoresistive elements 10. In the magnetoresistive device 122 shown in FIG. 40, the magnetoresistive element 10 is connected to the second signal line 31, and the magnetoresistive elements 10 are connected in series.

Further, for example, as in the magnetic resistance effect device 123 shown in FIG. 41, a plurality of magnetic resistance effect elements are provided (the first magnetic resistance effect element 11 and the second magnetic resistance effect element 12 are provided), and the first embodiment is provided. Similar to the fourth modification, the angle formed by the first extending direction and the second extending direction may be 90 °.

Further, in the first to third embodiments, a magnetic field application unit that applies a static magnetic field to the magnetoresistive element 10 may be provided in the vicinity of the magnetoresistive element 10. The magnetic field application unit is composed of, for example, an electromagnet type or stripline type magnetic field application mechanism capable of variably controlling the applied magnetic field strength by either voltage or current. Further, the magnetic field application unit may be configured by a combination of an electromagnet type or strip line type magnetic field application mechanism capable of variably controlling the applied magnetic field strength and a permanent magnet that supplies only a constant magnetic field.

The magnetic sensors of the first embodiment, the second embodiment and the third embodiment include, for example, a geomagnetic sensor, a reading element of a magnetic head of a magnetic recording / reproducing device such as a hard disk drive, an angle sensor for detecting an angular position of an object, and the like. Can be used for.

1 1st ferromagnetic layer 2 2nd ferromagnetic layer 3 Spacer layer 10 Magnetic resistance effect element 11 1st magnetic resistance effect element 12 2nd magnetic resistance effect element 20, 20A, 70 1st signal line 21 Extended portion 30, 30B , 31, 31B 2nd signal line 40, 42, 43, 80, 82 Line 50 Magnetic material part 60 York 61 1st part 62 2nd part 91 inductor 92 Condenser 93 Directional coupler 100, 100A, 100B, 101, 102 , 103,104,104A, 104B, 110,111,112,113,120,120A, 120B , 121,122,123 magnetoresistive devices A1, A2 installation area G ground _{H rf, H rf1, H rf2} high frequency magnetic field I _R1 1st high frequency current I _R2 2nd high frequency current M1, M2 Magnetism p1, p11 1st input port p2 2nd input port p3, p12 Output port 1st output port p31
2nd output port p32
pr1, pr2, pr3 reference potential terminal

Claims (12)

It is equipped with a magnetoresistive element, a first signal line, and an output port.
The magnetoresistive sensor includes 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 element via an insulator, and a high-frequency magnetic field caused by a first high-frequency current flowing through the first signal line is applied to the first ferromagnetic layer.
A high-frequency current flows through the magnetoresistive element,
A magnetoresistive device in which a signal including a DC signal component resulting from an output from the magnetoresistive element is output from the output port. Further provided with 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 produces the first high frequency current 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 produces a second high frequency current is input to the second input port.
The magnetoresistive device according to claim 1, wherein the second signal line is connected to the magnetoresistive element, and the second high-frequency current flowing through the second signal line flows through the magnetoresistive element as the high-frequency current. .. Equipped with a first input port
The first input port is connected to the first signal line, and a first high frequency signal that produces the first high frequency current is input to the first input port.
The first signal line is connected to the magnetoresistive element, and the first signal line is connected to the magnetoresistive element.
The magnetoresistive device according to claim 1, wherein the first high-frequency current flowing through the first signal line flows through the magnetoresistive element as the high-frequency current. Further equipped with 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 the first input port generates the first high frequency current in the first signal line and the second signal line. 2 The first high frequency signal that produces high frequency current is input,
The magnetoresistive effect according to claim 1, wherein the second signal line is connected to the magnetoresistive element, and the second high-frequency current flowing through the second signal line flows through the magnetoresistive element as the high-frequency current. device. A yoke for sandwiching the magnetoresistive element in the gap is further provided in a plan view from the stacking direction of the magnetoresistive element.
The yoke is closer to the second ferromagnetic layer than the first ferromagnetic layer.
The magnetoresistive device according to any one of claims 1 to 4, wherein the yoke applies a magnetic field generated in the gap by an external magnetic field to the second ferromagnetic layer. A yoke for sandwiching the magnetoresistive element in the gap is further provided in a plan view from the stacking direction of the magnetoresistive element.
The yoke is closer to the first ferromagnetic layer than the second ferromagnetic layer.
The magnetoresistive device according to any one of claims 1 to 4, wherein the yoke applies a magnetic field generated in the gap by an external magnetic field to the first ferromagnetic layer. The magnetoresistive 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. Further having one or more magnetoresistive elements connected to the magnetoresistive element,
The magnetoresistive device according to any one of claims 1 to 7, wherein in at least two magnetoresistive elements, the directions of the high-frequency magnetic fields applied to the first ferromagnetic layer are different from each other. The first signal line has an extending portion extending in a direction intersecting the stacking direction in a plan view from the stacking direction of the magnetoresistive element.
The extending portion does not overlap with the magnetoresistive element in a plan view from the stacking direction, and a part thereof overlaps with the magnetoresistive element in a plan view from a direction perpendicular to the stacking direction.
The magnetoresistive device according to any one of claims 1 to 8, wherein the high-frequency magnetic field caused by the high-frequency current flowing through the extending portion is applied to the first ferromagnetic layer. A plurality of the magnetoresistive elements are provided.
With one or more of the first signal lines,
The first extending direction in which the first signal line extends at a position where the first magnetic resistance effect element of the magnetic resistance effect elements and the first magnetic resistance effect element overlap in a plan view from the stacking direction, and the magnetic resistance. The angle formed by the second magnetoresistive element of the effect elements and the second extending direction in which the first signal line extends at a position where they overlap in a plan view from the stacking direction of the second magnetoresistive element is 90 °. The magnetoresistive sensor according to any one of claims 1 to 7. One of claims 1 to 10, wherein the in-plane component of the effective magnetic field in the first ferromagnetic layer is parallel or antiparallel to the vibration direction of the high-frequency magnetic field applied to the first ferromagnetic layer. The magnetoresistive effect device described. A sensor using the magnetoresistive device according to any one of claims 1 to 11.

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