JP2018186266A - Magnetoresistive effect device and high frequency device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetoresistive effect device which functions as a high frequency device such as a high frequency filter.SOLUTION: A magnetoresistive effect device comprises: a first port; a second port; a magnetoresistive effect element; a first signal line connected to the first port and serving to apply a high-frequency magnetic field to the magnetoresistive effect element; a second signal line connecting between the second port and the magnetoresistive effect element; and a DC-application terminal which enables the connection of a power source for applying a DC current or a DC voltage in a lamination direction of the magnetoresistive effect element. The first signal line has a plurality of high-frequency magnetic field application regions which can apply a high-frequency magnetic field to the magnetoresistive effect element. In the first signal line, the plurality of high-frequency magnetic field application regions are provided at positions which allow high-frequency magnetic fields generated in respective high-frequency magnetic field application regions to strengthen each other in the magnetoresistive effect element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetoresistive effect device and a high frequency device.

  In recent years, with the enhancement of functions of mobile communication terminals such as mobile phones, the speed of wireless communication has been increased. Since the communication speed is proportional to the bandwidth of the frequency used, the frequency band required for communication is increasing. Accordingly, the number of high frequency filters required for mobile communication terminals is also increasing.

  In recent years, spintronics has been studied as a field that may be applicable to new high-frequency components. One of the phenomena attracting attention is a ferromagnetic resonance phenomenon caused by a magnetoresistive effect element (see Non-Patent Document 1).

  By applying an alternating current to the magnetoresistive effect element and applying a magnetic field by the magnetic field applying mechanism, ferromagnetic resonance can be caused in the magnetoresistive effect element. When ferromagnetic resonance occurs, the resistance value of the magnetoresistive element periodically oscillates at a frequency corresponding to the ferromagnetic resonance frequency. The ferromagnetic resonance frequency of the magnetoresistive effect element changes depending on the strength of the magnetic field applied to the magnetoresistive effect element, and the resonance frequency is generally in a high frequency band of several to several tens GHz.

J. et al. -M. L. Beaujour et al. , Journal of Applied Physics 99, 08N503, (2006).

  As described above, studies on a high-frequency oscillation element using the ferromagnetic resonance phenomenon are in progress. However, it cannot be said that specific studies on other applications of the ferromagnetic resonance phenomenon are sufficient.

  The present invention has been made in view of the above problems, and provides a magnetoresistive effect device that functions as a high-frequency device such as a high-frequency filter using a ferromagnetic resonance phenomenon.

  In order to solve the above problems, a method of using a magnetoresistive effect device using a ferromagnetic resonance phenomenon as a high frequency device was examined. As a result, they found a magnetoresistive effect device that utilizes a change in the resistance value of the magnetoresistive effect element caused by the ferromagnetic resonance phenomenon, and found that this magnetoresistive effect device functions as a high-frequency device.

In order to improve the output characteristics of the high-frequency device, it is preferable to efficiently apply a large high-frequency magnetic field to the magnetoresistive effect element to increase the amount of change in the resistance value of the magnetoresistive effect element. Accordingly, the inventors have found a configuration of a magnetoresistive device that can efficiently apply a large high-frequency magnetic field to the magnetoresistive device.
That is, this invention provides the following means in order to solve the said subject.

(1) A magnetoresistive effect device according to a first aspect includes a first port for inputting a signal, a second port for outputting a signal, a first ferromagnetic layer, and a second ferromagnetic layer. A magnetoresistive effect element having a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and a signal connected to the first port and corresponding to a signal input from the first port A first signal line for applying a high-frequency magnetic field to the magnetoresistive effect element, a second signal line connecting the second port and the magnetoresistive effect element, and the magnetoresistive effect element A DC application terminal capable of connecting a power source for applying a DC current or DC voltage in the stacking direction, and the first signal line includes a plurality of high-frequency magnetic field application regions that can apply a high-frequency magnetic field to the magnetoresistive element. And having the first signal line Serial plurality of high-frequency magnetic field application region has a high-frequency magnetic field with each other resulting in the respective high frequency magnetic field application region provided at a position constructive in the magnetoresistive element.

(2) In the magnetoresistance effect device according to the above aspect, the first signal line surrounds the magnetoresistance effect element when the magnetoresistance effect element is viewed from a predetermined direction, and the plurality of high-frequency magnetic fields Of the application regions, at least two high-frequency magnetic field application regions may be at positions facing the magnetoresistive element as a reference.

(3) In the magnetoresistance effect device according to the above aspect, the first signal line may be wound around an axis extending through the magnetoresistance effect element in the predetermined direction.

(4) In the magnetoresistive effect device according to the above aspect, the first signal line is branched into a plurality of signal lines, and a signal line through which a high-frequency current flows in the same direction among the branched signal lines May be arranged on the same surface side of the magnetoresistive element.

(5) In the magnetoresistive effect device according to the aspect described above, a part of the first signal line is an upper portion that applies a DC current or a DC voltage input from the DC application terminal in the stacking direction of the magnetoresistive effect element. It may also serve as an electrode or a lower electrode.

(6) In the magnetoresistive effect device according to the above aspect, a resistance value of the magnetoresistive effect element may be 20Ω or more.

(7) The magnetoresistive effect device according to the above aspect may further include a magnetic field applying mechanism that applies an external magnetic field to the magnetoresistive effect element and modulates a resonance frequency of the magnetoresistive effect element.

(8) The high frequency device according to the second aspect uses the magnetoresistive effect device according to the above aspect.

  According to the magnetoresistive effect device according to the above aspect, the magnetoresistive effect device using the ferromagnetic resonance phenomenon can be used as a high frequency device such as a high frequency filter or an amplifier.

  Moreover, according to the magnetoresistive effect device concerning the said aspect, a big high frequency magnetic field can be efficiently applied to a magnetoresistive effect element.

It is a schematic diagram of the magnetoresistive effect device which concerns on 1st Embodiment. It is a perspective schematic diagram of the magnetoresistive effect element vicinity of the magnetoresistive effect device concerning 1st Embodiment. It is a figure which shows the relationship between the frequency of the high frequency signal input into a magnetoresistive effect device, and the amplitude of the output voltage when the direct current applied to a magnetoresistive effect element is constant. It is a figure which shows the relationship between the frequency of the high frequency signal input into a magnetoresistive effect device, and the amplitude of the output voltage when the external magnetic field applied to a magnetoresistive effect element is constant. It is a perspective schematic diagram of the magnetoresistive effect element vicinity of the magnetoresistive effect device concerning 2nd Embodiment. It is a perspective schematic diagram of the magnetoresistive effect element vicinity of the magnetoresistive effect device concerning 3rd Embodiment. It is a perspective schematic diagram of the magnetoresistive effect element vicinity of the magnetoresistive effect device concerning 4th Embodiment. It is a perspective schematic diagram of the magnetoresistive effect element vicinity of the magnetoresistive effect device concerning 5th Embodiment. It is a perspective schematic diagram of the magnetoresistive element vicinity of the magnetoresistive effect device concerning 6th Embodiment.

  Hereinafter, the magnetoresistive effect device will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, in order to make the features easier to understand, the portions that become the features may be shown in an enlarged manner for the sake of convenience, and the dimensional ratios of the respective components may differ from the actual ones. The materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited to these, and can be implemented with appropriate modifications within the scope of the effects of the present invention.

(First embodiment)
FIG. 1 is a schematic diagram showing a circuit configuration of the magnetoresistive effect device according to the first embodiment. A magnetoresistive effect device 100 shown in FIG. 1 includes a first port 1, a second port 2, a magnetoresistive effect element 10, a first signal line 20, a second signal line 30, and a third signal line. Signal line 31, DC application terminal 40, and magnetic field application mechanism 50.

<First port and second port>
The first port 1 is an input terminal of the magnetoresistive effect device 100. The first port 1 corresponds to one end of the first signal line 20. An AC signal can be applied to the magnetoresistive device 100 by connecting an AC signal source (not shown) to the first port 1.

  The second port 2 is an output terminal of the magnetoresistive effect device 100. The second port 2 corresponds to one end of the second signal line 30. A signal output from the magnetoresistive effect device 100 can be measured by connecting a high-frequency measuring device (not shown) to the second port 2. A network analyzer etc. can be used for a high frequency measuring device, for example.

<Magnetoresistance effect element>
The magnetoresistive effect element 10 includes a first ferromagnetic layer 11, a second ferromagnetic layer 12, and a spacer layer 13 sandwiched between the first ferromagnetic layer 11 and the second ferromagnetic layer 12. Hereinafter, although the first ferromagnetic layer is described as a magnetization fixed layer and the second ferromagnetic layer is described as a magnetization free layer, the first ferromagnetic layer and the second ferromagnetic layer may function as either. The magnetization of the magnetization fixed layer 11 is less likely to move than the magnetization of the magnetization free layer 12, and is fixed in one direction under a predetermined magnetic field environment. When the magnetization direction of the magnetization free layer 12 changes relative to the magnetization direction of the magnetization fixed layer 11, it functions as the magnetoresistive effect element 10.

  The magnetization fixed layer 11 is made of a ferromagnetic material. The magnetization fixed layer 11 is preferably made of a high spin polarizability material such as Fe, Co, Ni, an alloy of Ni and Fe, an alloy of Fe and Co, or an alloy of Fe, Co and B. By using these materials, the magnetoresistance change rate of the magnetoresistive effect element 10 is increased. The magnetization fixed layer 11 may be made of a Heusler alloy. The film thickness of the magnetization fixed layer 11 is preferably 1 to 10 nm.

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

  The magnetization free layer 12 is made of a ferromagnetic material whose magnetization direction can be changed by an externally applied magnetic field or spin-polarized electrons.

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

  The thickness of the magnetization free layer 12 is preferably about 1 to 10 nm. Further, a high spin polarizability material may be inserted between the magnetization free layer 12 and the spacer layer 13. By inserting a high spin polarizability material, a high magnetoresistance change rate can be obtained.

  Examples of the high spin polarizability material include a CoFe alloy and a CoFeB alloy. The film thickness of either the CoFe alloy or the CoFeB alloy is preferably about 0.2 to 1.0 nm.

  The spacer layer 13 is a nonmagnetic layer disposed between the magnetization fixed layer 11 and the magnetization free layer 12. The spacer layer 13 is composed of a layer formed of a conductor, an insulator, and a semiconductor, or a layer including a conduction point formed of a conductor in the insulator.

  For example, when the spacer layer 13 is made of an insulator, the magnetoresistive element 10 is a tunneling magnetoresistive (TMR) element, and when the spacer layer 13 is made of a metal, a giant magnetoresistive (GMR) element is used. It becomes.

  When the spacer layer 13 is made of a nonmagnetic conductive material, a conductive material such as Cu, Ag, Au, or Ru can be used. In order to efficiently use the GMR effect, the thickness of the spacer layer 13 is preferably about 0.5 to 3.0 nm.

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

When a layer including a conduction point constituted by a conductor in a nonmagnetic insulator is applied as the spacer layer 13, a nonmagnetic insulator constituted by Al ₂ O ₃ or MgO includes CoFe, CoFeB, CoFeSi, CoMnGe, A structure including a conduction point constituted by a conductor such as CoMnSi, CoMnAl, Fe, Co, Au, Cu, Al, or Mg is preferable. In this case, the thickness of the spacer layer 13 is preferably about 0.5 to 2.0 nm.

  In order to improve the electrical conductivity to the magnetoresistive effect element 10, it is preferable to provide electrodes on both surfaces of the magnetoresistive effect element 10 in the stacking direction. Hereinafter, the electrode provided in the lower part of the magnetoresistive effect element 10 in the stacking direction is referred to as the lower electrode 14, and the electrode provided in the upper part is referred to as the upper electrode 15. By providing the lower electrode 14 and the upper electrode 15, the contact between the second signal line 30 and the third signal line 31 and the magnetoresistive effect element 10 becomes a surface, and any position in the in-plane direction of the magnetoresistive effect element 10. The signal (current) flows along the stacking direction.

  The lower electrode 14 and the upper electrode 15 are made of a conductive material. For example, Ta, Cu, Au, AuCu, Ru, or the like can be used for the lower electrode 14 and the upper electrode 15.

  A cap layer, seed layer, or buffer layer may be disposed between the magnetoresistive element 10 and the lower electrode 14 or the upper electrode 15. Examples of the cap layer, seed layer, or buffer layer include Ru, Ta, Cu, Cr, or a laminated film thereof. The thickness of these layers is preferably about 2 to 10 nm.

As for the size of the magnetoresistive effect element 10, it is desirable that the long side is about 300 nm or less than 300 nm when the plan view shape of the magnetoresistive effect element 10 is a rectangle (including a square).
When the planar view shape of the magnetoresistive effect element 10 is not a rectangle, the long side of the rectangle circumscribing the planar view shape of the magnetoresistive effect element 10 with the minimum area is defined as the long side of the magnetoresistive effect element 10.

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

<First signal line>
The first signal line 20 has one end connected to the first port 1 and the other end connected to a reference potential. In FIG. 1, it is connected to the ground G as a reference potential. A high-frequency current flows in the first signal line 20 in accordance with the potential difference between the high-frequency signal input to the first port 1 and the ground G. When a high-frequency current flows in the first signal line 20, a high-frequency magnetic field is generated from the first signal line 20. The high frequency magnetic field is applied to the magnetoresistive effect element 10.

  FIG. 2 is a schematic perspective view of the vicinity of the magnetoresistive effect element 10 of the magnetoresistive effect device 100 according to the first embodiment. Hereinafter, the stacking direction of the magnetoresistive effect element 10 is referred to as z direction, one direction in a plane orthogonal to the z direction is referred to as x direction, and the direction orthogonal to the x direction and z direction is referred to as y direction.

  A first signal line 20 shown in FIG. 2 includes a first wiring 21 extending along the x direction at a position in the + z direction of the magnetoresistive effect element 10, and the first wiring 21 based on the magnetoresistive effect element 10. It has the 2nd wiring 23 provided in the position which opposes, and the via wiring 22 which connects the 1st wiring 21 and the 2nd wiring 23. The first signal line 20 surrounds the magnetoresistive element 10 when the magnetoresistive element 10 is viewed from the y direction.

The high-frequency current flows in the first signal line 20 in one direction. The direction of the high-frequency current I ₁ flowing in the first wiring 21 and the direction of the high-frequency current I ₂ flowing in the second wiring 23 are opposite to each other. Here, “the direction of the high-frequency current” means the direction of the current when focusing on a certain point in time of the high-frequency current that is an AC signal. The high-frequency current I ₁ flowing through the first wiring 21 generates a magnetic field H ₁ with the first wiring 21 as the central axis. Similarly, the high-frequency current I ₂ flowing through the second wiring 23 generates a magnetic field H ₂ with the second wiring 23 as a central axis.

Direction of the magnetic field H ₁ and the magnetic field H ₂ applied to the magnetoresistive element 10 are both + y direction at a certain moment, neither in another moment a -y direction. That is, the magnetic field H ₁ generated in the first wiring 21 and the magnetic field H ₂ generated in the second wiring 23 are superimposed at the position of the magnetoresistive effect element 10 and strengthen each other.

  That is, by arranging the first signal line 20 in a predetermined arrangement with respect to the magnetoresistive effect element 10, a high frequency magnetic field application region (first wiring 21 and FIG. A plurality of second wirings 23) can be provided, and a high frequency magnetic field can be applied to the magnetoresistive effect element 10 by strengthening each other's high frequency magnetic fields.

<Second signal line, third signal line>
The second signal line 30 has one end connected to the magnetoresistive effect element 10 and the other end connected to the second port 2. That is, the second signal line 30 connects the magnetoresistive effect element 10 and the second port 2. The second signal line 30 outputs a signal having a frequency selected using the ferromagnetic resonance of the magnetoresistive effect element 10 from the second port 2.

  The third signal line 31 has one end connected to the magnetoresistive effect element 10 and the other end connected to a reference potential. In FIG. 1, the third signal line 31 is connected to the ground G common to the reference potential of the first signal line 20, but may be connected to other reference potentials. In order to simplify the circuit configuration, the reference potential of the first signal line 20 and the reference potential of the third signal line 31 are preferably common.

  The shape of each signal line and ground G is preferably 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 signal line width and the ground-to-ground distance can be designed so that the characteristic impedance of the signal line is equal to the impedance of the circuit system. preferable. By designing in this way, the transmission loss of the signal line can be suppressed.

<DC application terminal>
The DC application terminal 40 is connected to a power source 41 and applies a DC current or a DC voltage in the stacking direction of the magnetoresistive effect element 10. The power supply 41 may be configured by a circuit of a combination of a fixed resistor and a DC voltage source that can generate a constant DC current. The power source 41 may be a direct current source or a direct current voltage source.

  An inductor 42 is disposed between the DC application terminal 40 and the second signal line 30. The inductor 42 cuts the high frequency component of the current and passes only the direct current component of the current. An output signal output from the magnetoresistive effect element 10 by the inductor 42 efficiently flows to the second port 2. Further, since the direct current can pass through the inductor 42, the direct current flows through a closed circuit including the direct current source 41, the second signal line 30, the magnetoresistive effect element 10, the third signal line 31, and the ground G.

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

<Magnetic field application mechanism>
The magnetic field application mechanism 50 applies an external magnetic field to the magnetoresistive effect element 10 and modulates the resonance frequency of the magnetoresistive effect element 10. The signal output from the magnetoresistive effect device 100 varies depending on the resonance frequency of the magnetoresistive effect element 10. In order to make the output signal variable, it is preferable to further have a magnetic field application mechanism.

  The magnetic field application mechanism 50 is preferably disposed in the vicinity of the magnetoresistive element 10. The magnetic field application mechanism 50 is configured, for example, as an electromagnet type or a stripline type that can variably control the applied magnetic field intensity by either voltage or current. Moreover, you may be comprised by the combination of the electromagnet type | mold or stripline type | mold which can variably control the applied magnetic field intensity | strength, and the permanent magnet which supplies only a fixed magnetic field.

"Function of magnetoresistive device"
When a high frequency signal is input to the magnetoresistive effect device 100 from the first port 1, a high frequency current corresponding to the high frequency signal flows in the first signal line 20. The high-frequency current flowing in the first signal line 20 applies a high-frequency magnetic field to the magnetoresistive element 10.

  As shown in FIG. 2, the first signal line 20 has a plurality of high-frequency magnetic field application regions (first wiring 21 and second wiring 23), and the high-frequency magnetic fields generated in the respective high-frequency magnetic field application regions are strengthened. meet. Therefore, a large high frequency magnetic field is applied to the magnetoresistive effect element 10.

  The magnetization of the magnetization free layer 12 of the magnetoresistive effect element 10 oscillates greatly when the high-frequency magnetic field applied to the magnetoresistive effect element 10 by the first signal line 20 is near the ferromagnetic resonance frequency of the magnetization free layer 12. To do. This phenomenon is a ferromagnetic resonance phenomenon.

  When the vibration of the magnetization free layer 12 increases, the resistance value change in the magnetoresistive effect element 10 increases. The change in resistance value of the magnetoresistive effect element 10 is output from the second port 2 as a potential difference between the lower electrode 14 and the upper electrode 15.

  When the high-frequency signal input from the first port 1 is in the vicinity of the resonance frequency of the magnetization free layer 12, the amount of variation in the resistance value of the magnetoresistive effect element 10 is large, and a large signal is output from the second port 2. . On the other hand, when the high-frequency signal deviates from the resonance frequency of the magnetization free layer 12, the fluctuation amount of the resistance value of the magnetoresistive effect element 10 is small, and the signal is hardly output from the second port 2. The magnetoresistive effect device 100 functions as a high frequency filter that can selectively pass only a high frequency signal of a specific frequency.

The frequency selected by the magnetoresistive device 100 can be modulated by changing the ferromagnetic resonance frequency of the magnetization free layer 12. The ferromagnetic resonance frequency changes depending on the effective magnetic field in the magnetization free layer 12. The effective magnetic field H _eff in the magnetization free layer 12 is H _E as an external magnetic field applied to the magnetization free layer 12, H _{k as} an anisotropic magnetic field in the magnetization free layer 12, and H _{D as} a demagnetizing field in the magnetization free layer 12. When the exchange coupling magnetic field in the free layer 12 is _HEX , it is expressed by the following equation.
H _eff = H _E + H _k + H _D + H _EX

As shown by the above equation, the effective magnetic field in the magnetization free layer 12 is affected by the external magnetic field H _E. The magnitude of the external magnetic field H _E can be adjusted by the magnetic field applying mechanism 50. FIG. 3 is a diagram showing the relationship between the frequency of the high-frequency signal input to the magnetoresistive effect device 100 and the amplitude of the output voltage when the direct current applied to the magnetoresistive effect element 10 is constant.

  When an arbitrary external magnetic field is applied to the magnetoresistive effect element 10, the ferromagnetic resonance frequency of the magnetization free layer 12 changes under the influence of the external magnetic field. The ferromagnetic resonance frequency at this time is assumed to be fb1. Since the ferromagnetic resonance frequency of the magnetization free layer 12 is fb1, the amplitude of the output voltage increases when the frequency of the high-frequency signal input to the magnetoresistive device 100 is fb1. Therefore, the graph of the plot line 100b1 shown in FIG. 3 is obtained.

Next, when the external magnetic field to be applied is increased, the ferromagnetic resonance frequency is shifted from fb1 to fb2 under the influence of the external magnetic field. At this time, the frequency at which the amplitude of the output voltage increases is also shifted from fb1 to fb2. As a result, the graph of the plot line 100b2 shown in FIG. 3 is obtained. In this manner, the magnetic field application mechanism 50 can adjust the effective magnetic field H _eff applied to the magnetization free layer 12 of the magnetoresistive effect element 10 to modulate the ferromagnetic resonance frequency.

  The ferromagnetic resonance frequency can also be modulated by changing the current density of the direct current applied from the power source 41 to the magnetoresistive element 10. FIG. 4 is a diagram showing the relationship between the frequency of the high-frequency signal input to the magnetoresistive effect device 100 and the amplitude of the output voltage when the external magnetic field applied to the magnetoresistive effect element 10 is constant.

  The output voltage output from the second port 2 of the magnetoresistive effect device 100 is represented by the product of the resistance value oscillating in the magnetoresistive effect element 10 and the direct current flowing through the magnetoresistive effect element 10. As the direct current flowing through the magnetoresistive element increases, the amplitude of the output voltage (output signal) increases.

When the amount of direct current flowing through the magnetoresistive effect element 10 changes, the magnetization state in the magnetization free layer 12 changes, and the anisotropic magnetic field H _k , the demagnetizing field H _D , and the magnetic exchange coupling magnetic field H _EX in the magnetization free layer 12 change. The size changes. As a result, the ferromagnetic resonance frequency decreases as the direct current increases. That is, as shown in FIG. 4, when the amount of direct current increases, the plot line 100a1 shifts to the plot line 100a2. Thus, the ferromagnetic resonance frequency can be modulated by changing the amount of current applied from the direct current source 41 to the magnetoresistive element 10.

  In the above description, the magnetoresistive effect device is used as a high frequency filter. However, the magnetoresistive effect device can also be used as a high frequency device such as an isolator, a phase shifter, and an amplifier.

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

  When the magnetoresistive effect device is used as a phase shifter, attention is paid to the frequency at an arbitrary point in the output frequency band when the output frequency band changes. Since the phase at a specific frequency changes when the output frequency band changes, it functions as a phase shifter.

  When the magnetoresistive effect device is used as an amplifier, the resistance value change amount of the magnetoresistive effect element 10 is increased. The amount of change in the resistance value of the magnetoresistive effect element 10 can be determined by increasing the direct current input from the power supply 41 to a predetermined magnitude or increasing the high-frequency magnetic field applied to the magnetoresistive effect element 10 by the first signal line 20. ,growing. When the amount of change in the resistance value of the magnetoresistive effect element 10 increases, the signal output from the second port 2 becomes larger than the signal input from the first port 1, and functions as an amplifier.

  As described above, the magnetoresistive effect device 100 according to the first embodiment can function as a high-frequency device such as a high-frequency filter, an isolator, a phase shifter, or an amplifier.

  Further, the magnetoresistive effect device 100 according to the first embodiment has a plurality of high-frequency magnetic field application regions (first wiring 21 and second wiring 23 in FIG. 2) for applying a high-frequency magnetic field to the magnetoresistive effect element 10. Yes. Since the high-frequency magnetic fields generated from these high-frequency magnetic field application regions are in positions where they are mutually strengthened, a large high-frequency magnetic field can be applied to the magnetoresistive effect element 10. As a result, the amount of change in resistance value of the magnetoresistive effect element 10 is increased, and the magnetoresistive effect device 100 having excellent output characteristics can be obtained.

(Second Embodiment)
FIG. 5 is a schematic perspective view of the vicinity of the magnetoresistive effect element 10 of the magnetoresistive effect device 101 according to the second embodiment. The magnetoresistive effect device 101 according to the second embodiment is related to the first embodiment in that the first signal line 60 surrounds the magnetoresistive effect element 10 when the magnetoresistive effect element 10 is viewed from the y direction. The magnetoresistive effect according to the first embodiment is that the first signal line 60 is wound around an axis extending through the magnetoresistive effect element 10 and extending in the y direction, although it matches the magnetoresistive effect device 100. Different from the effect device 100. In FIG. 5, the same code | symbol is attached | subjected about the structure same as the magnetoresistive effect device 100 concerning 1st Embodiment.

  As shown in FIG. 5, the first signal line 60 is based on the plurality of first wirings 61 extending along the x direction at the position in the + z direction of the magnetoresistive effect element 10 and the magnetoresistive effect element 10. A plurality of second wirings 63 provided at positions facing the first wirings 61, and each of the first wirings 61 and each of the second wirings 63 extends the magnetoresistive effect element 10 in the y-axis direction. A plurality of via wirings 62 are connected so as to be wound around an existing axis.

  The high frequency current flows in one direction in the first signal line 60. For this reason, the direction of the high-frequency current flowing in the first wiring 61 and the direction of the high-frequency current flowing in the second wiring 63 are opposite to each other. Each of the plurality of first wirings 61 applies a magnetic field in the −y direction to the magnetoresistive effect element 10 at a certain moment from Ampere's law. Similarly, each of the plurality of second wirings 63 applies a magnetic field in the −y direction to the magnetoresistive effect element 10 at a certain moment. That is, the magnetic field generated by the first wiring 61 and the magnetic field generated by the second wiring 63 are superimposed at the position of the magnetoresistive effect element 10 and strengthen each other.

  Here, the first wiring 61 and the second wiring 63 are arranged in parallel in the y direction. For this reason, the direction of the magnetic field applied to the magnetoresistive effect element 10 at a moment when a part of the first wiring 61 and the second wiring 63 is present is strictly inclined from the −y direction. Even in this case, since each magnetic field has a component in the y direction, it can be said that they are strengthening each other.

  In other words, “strengthening between magnetic fields” means that they have components in the same direction, and the direction of the vector at a given position of the magnetic field generated from one source and the source from another source. It can be said that the magnetic fields strengthen each other when the angle formed by the direction of the vector at a predetermined position of the magnetic field is an acute angle.

  Since the magnetoresistive effect device 101 according to the second embodiment exhibits the same function as the magnetoresistive effect device 100 according to the first embodiment, the magnetoresistive effect device 101 according to the second embodiment also includes a high frequency filter, an isolator, It can function as a high-frequency device such as a phase shifter or an amplifier.

  Further, the magnetoresistive effect device 100 according to the second embodiment includes high frequency magnetic field application regions (a plurality of first wirings 61 and a plurality of second wirings 63 in FIG. 5) for applying a high frequency magnetic field to the magnetoresistive effect element 10. Have more than one. Since the high-frequency magnetic fields generated from these high-frequency magnetic field application regions are in positions where they are mutually strengthened, a large high-frequency magnetic field can be applied to the magnetoresistive effect element 10. As a result, the amount of change in the resistance value of the magnetoresistive effect element 10 is increased, and the magnetoresistive effect device 101 having excellent output characteristics is obtained.

(Third embodiment)
FIG. 6 is a schematic perspective view of the vicinity of the magnetoresistive element 10 of the magnetoresistive effect device 102 according to the third embodiment. In the magnetoresistive effect device 102 according to the third embodiment, the first signal line 70 is branched into a plurality of signal lines 71, 72, 73 on the way, and the plurality of branched signal lines 71, 72, 73 are magnetic. The magnetoresistive effect device 100 according to the first embodiment is different from the magnetoresistive effect device 100 according to the first embodiment in that it exists on the same surface side (+ z direction) with respect to the resistive effect element 10. In FIG. 6, the same components as those of the magnetoresistive effect device 100 according to the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 6, the first signal line 70 extends along the x direction at a position in the + z direction of the magnetoresistive effect element 10. The first signal line 70 branches to a plurality of signal lines 71, 72, 73 on the way, and then merges. The plurality of signal lines 71, 72, and 73 are arranged in parallel at positions that overlap when the magnetoresistive element 10 is viewed from the z direction.

  The high frequency current flows in one direction in the first signal line 70. Therefore, the directions of the high-frequency currents flowing through the branched signal lines 71, 72, 73 are the same. Each of the signal lines 71, 72, 73 applies a magnetic field in the y direction to the magnetoresistive element 10 at a certain moment from Ampere's law. That is, the magnetic fields generated in the respective signal lines 71, 72, 73 are superimposed at the position of the magnetoresistive effect element 10 and strengthen each other.

  Since the magnetoresistive effect device 102 according to the third embodiment exhibits the same function as the magnetoresistive effect device 100 according to the first embodiment, the magnetoresistive effect device 101 according to the third embodiment also includes a high frequency filter, an isolator, It can function as a high-frequency device such as a phase shifter or an amplifier.

  The magnetoresistive effect device 102 according to the third embodiment has a plurality of high frequency magnetic field application regions (a plurality of signal lines 71, 72, 73 in FIG. 6) for applying a high frequency magnetic field to the magnetoresistive effect element 10. Yes. Since the high-frequency magnetic fields generated from these high-frequency magnetic field application regions are in positions where they are mutually strengthened, a large high-frequency magnetic field can be applied to the magnetoresistive effect element 10. As a result, the amount of change in resistance value of the magnetoresistive effect element 10 is increased, and the magnetoresistive effect device 102 having excellent output characteristics can be obtained.

  In the magnetoresistive effect device 102 according to the third embodiment, the first signal line 70 is branched into three signal lines 71, 72, 73. However, the number of branches is not limited to this case, and 2 It may be branched into two signal lines, or it may be branched into more than three signal lines.

(Fourth embodiment)
FIG. 7 is a schematic perspective view of the vicinity of the magnetoresistive effect element 10 of the magnetoresistive effect device 103 according to the fourth embodiment. The magnetoresistive effect device 103 according to the fourth embodiment according to the first embodiment is that the first signal line 80 surrounds the magnetoresistive effect element 10 when the magnetoresistive effect element 10 is viewed from the y direction. This is consistent with the magnetoresistive device 100. On the other hand, the magnetoresistive effect device 103 according to the fourth embodiment is different from the magnetoresistive effect device 100 according to the first embodiment in that the first signal line 80 is branched in the middle. In FIG. 7, the same code | symbol is attached | subjected about the structure same as the magnetoresistive effect device 100 concerning 1st Embodiment.

  As shown in FIG. 7, the first signal line 80 includes a first wiring 81 extending along the x direction at a position in the + z direction of the magnetoresistive effect element 10, and the first signal line 80 based on the magnetoresistive effect element 10. And a second wiring 83 provided at a position facing the wiring 81, and the first wiring 81 and the second wiring 83 are connected by a via wiring 82.

  The first wiring 81 is joined after branching to three signal lines 81a, 81b, 81c, and the second wiring 83 is joined after branching to three signal lines 83a, 83b, 83c. The three signal lines 81a, 81b, 81c from which the first wiring 81 branches are arranged at the position in the + z direction of the magnetoresistive effect element 10, and the three signal lines 83a, 83b, from which the second wiring 83 branches. 83c is arrange | positioned in the position of the -z direction of a magnetoresistive effect element.

  The high frequency current flows in one direction in the first signal line 80. For this reason, the direction of the high-frequency current flowing in the first wiring 81 and the direction of the high-frequency current flowing in the second wiring 83 are opposite to each other. On the other hand, the directions of the high-frequency currents flowing through the three signal lines 81a, 81b, 81c branched in the first wiring 81 are the same direction, and the three signal lines 83a, 83b, 83c branched in the second wiring 83 are connected. The direction of the flowing high-frequency current is the same direction. That is, high-frequency current flows in the same direction in the signal lines located on the same plane side with respect to the magnetoresistive effect element 10.

  Each of the three signal lines 81a, 81b, 81c of the first wiring 81 applies a magnetic field in the y direction to the magnetoresistive effect element 10 at a certain moment from Ampere's law. Similarly, each of the three signal lines 83a, 83b, 83c of the plurality of second wirings 83 applies a magnetic field in the y direction to the magnetoresistive effect element 10 at a certain moment. That is, the magnetic field generated in the first wiring 81 and the magnetic field generated in the second wiring 83 are superimposed at the position of the magnetoresistive element 10 and strengthen each other.

  Since the magnetoresistive effect device 103 according to the fourth embodiment exhibits the same function as the magnetoresistive effect device 100 according to the first embodiment, the magnetoresistive effect device 103 according to the fourth embodiment also includes a high frequency filter, an isolator, It can function as a high-frequency device such as a phase shifter or an amplifier.

  The magnetoresistive effect device 103 according to the fourth embodiment is a high frequency magnetic field application region (a plurality of signal lines 81a, 81b, 81c in the first wiring 81 in FIG. 7) that applies a high frequency magnetic field to the magnetoresistive effect element 10. And a plurality of signal lines 83 a, 83 b, 83 c) in the second wiring 83. Since the high-frequency magnetic fields generated from these high-frequency magnetic field application regions are in positions where they are mutually strengthened, a large high-frequency magnetic field can be applied to the magnetoresistive effect element 10. As a result, the amount of change in resistance value of the magnetoresistive effect element 10 is increased, and the magnetoresistive effect device 103 having excellent output characteristics can be obtained.

  In the magnetoresistive effect device 103 according to the fourth embodiment, the number of branches of the first wiring 81 and the second wiring 83 is not limited to the case of FIG. 7, and may be branched to two signal lines. You may branch to more signal lines than this. Further, the number of branches of the first wiring 81 and the number of branches of the second wiring 83 may be different.

(Fifth embodiment)
FIG. 8 is a schematic perspective view of the vicinity of the magnetoresistive effect element 10 of the magnetoresistive effect device 104 according to the fifth embodiment. The magnetoresistive effect device 104 according to the fifth embodiment according to the first embodiment is that the first signal line 90 surrounds the magnetoresistive effect element 10 when the magnetoresistive effect element 10 is viewed from the y direction. This is consistent with the magnetoresistive device 100. On the other hand, the magnetoresistive effect device 104 according to the fourth embodiment is different from the magnetoresistive effect device 100 according to the first embodiment in that a part of the first signal line 90 also serves as the lower electrode 14. In FIG. 8, the same code | symbol is attached | subjected about the structure same as the magnetoresistive effect device 100 concerning 1st Embodiment.

  As shown in FIG. 8, the first signal line 90 includes a first wiring 91 extending along the x direction at a position in the + z direction of the magnetoresistive effect element 10, and the first signal line 90 based on the magnetoresistive effect element 10. A second wiring 93 provided at a position facing the wiring 91, and the first wiring 91 and the second wiring 93 are connected by a via wiring 92. The second wiring 93 is connected to the magnetoresistive effect element 10, and also serves as the lower electrode 14 that allows current to flow in the stacking direction of the magnetoresistive effect element 10.

  A high-frequency signal input from the first port 1 (see FIG. 1) flows in the order of the first wiring 91, the via wiring 92, and the second wiring 93 in the first signal line 90. For this reason, the direction of the high-frequency current flowing in the first wiring 91 and the direction of the high-frequency current flowing in the second wiring 93 are opposite to each other. According to Ampere's law, the directions (y directions) of the magnetic fields applied to the magnetoresistive effect element 10 by the first wiring 91 and the second wiring 93 coincide with each other, and the respective magnetic fields strengthen each other.

  On the other hand, when outputting a signal, a current flows in the stacking direction of the magnetoresistive effect element 10, and a change in resistance value of the magnetoresistive effect element 10 is read from the second port 2 (see FIG. 1). A direct current for reading the change in resistance value flows through the upper electrode 15, the magnetoresistive effect element 10, and the lower electrode 14 (second wiring 93), and is output from the second port 2.

  When the first signal line 90 also serves as the lower electrode 14 of the magnetoresistive effect element 10, the number of wires in the magnetoresistive effect device 104 decreases. The magnetoresistive effect device 104 is manufactured using a photolithography method or the like. For this reason, when the number of wirings is reduced, the number of manufacturing steps is greatly reduced, and the manufacturing time and manufacturing cost of the magnetoresistive effect device 104 can be reduced. Further, the number of parts constituting the magnetoresistive effect device 104 is reduced, and the integration of the magnetoresistive effect device 104 is improved.

The resistance value in the stacking direction of the magnetoresistive effect element 10 is preferably larger than the resistance value of the first signal line 90. A signal input from the first port 1 is suppressed from flowing to the upper electrode 15 via the magnetoresistive effect element 10. The first signal line 90 is made of a material having excellent conductivity such as metal, and the resistance value of the first signal line 90 is about several Ω. Specifically, the resistance value in the stacking direction of the magnetoresistive element 10 is preferably 20Ω or more.
On the other hand, a part of the high-frequency current flowing through the first signal line 90 may flow to the upper electrode 15 side. In this case, the magnetization of the magnetization free layer 12 of the magnetoresistive effect element 10 includes the magnetic field generated by the high frequency current flowing through the first signal line 90 and the spin transfer torque generated by the high frequency current flowing in the stacking direction of the magnetoresistive effect element 10. , Vibrate.

  Further, it is preferable that the resistance value of the first wiring 91 or the via wiring 92 is made larger than the resistance value of the second wiring 93. It is possible to suppress a direct current that reads a change in resistance value from flowing through the via wiring 92 and the first wiring 91. That is, by setting the resistance value of the first wiring 91 or the via wiring 92 to be larger than the resistance value of the second wiring 93, it is possible to suppress the deterioration of the signal output from the second port 2.

  Here, the configuration in which the first signal line 90 also serves as the lower electrode 14 of the magnetoresistive effect element 10 has been described. However, the flow direction of the direct current is reversed, and the first signal line 90 is the upper part of the magnetoresistive effect element 10. It may be configured to also serve as the electrode 15.

  Since the magnetoresistive effect device 104 according to the fifth embodiment has the same function as the magnetoresistive effect device 100 according to the first embodiment, the magnetoresistive effect device 104 according to the fifth embodiment also includes a high frequency filter, an isolator, It can function as a high-frequency device such as a phase shifter or an amplifier.

  Further, the magnetoresistive effect device 104 according to the fifth embodiment has a plurality of high-frequency magnetic field application regions (first wiring 91 and second wiring 93 in FIG. 8) for applying a high-frequency magnetic field to the magnetoresistive effect element 10. Yes. Since the high-frequency magnetic fields generated from these high-frequency magnetic field application regions are in positions where they are mutually strengthened, a large high-frequency magnetic field can be applied to the magnetoresistive effect element 10. As a result, the amount of change in the resistance value of the magnetoresistive effect element 10 is increased, and the magnetoresistive effect device 104 having excellent output characteristics can be obtained.

  In the magnetoresistive effect device 104 according to the fifth embodiment, since the first signal line 90 also serves as the lower electrode 14 of the magnetoresistive effect element 10, the number of components is small, and the manufacture is easy. Highly integrated.

(Sixth embodiment)
FIG. 9 is a schematic perspective view of the vicinity of the magnetoresistive effect element 10 of the magnetoresistive effect device 105 according to the sixth embodiment. In the magnetoresistive effect device 105 according to the sixth embodiment, the first signal line does not have a plurality of high-frequency magnetic field application regions, but there are a plurality of first signal lines. Different from the effect device 100. In FIG. 9, the same code | symbol is attached | subjected about the structure same as the magnetoresistive effect device 100 concerning 1st Embodiment.

  The magnetoresistive effect device 105 according to the sixth embodiment includes a first signal line 110 extending in the x direction at a position in the + z direction of the magnetoresistive effect element 10 and a position in the −z direction of the magnetoresistive effect element 10. and a first signal line 111 extending in the x direction. The direction of the high frequency current flowing through the first signal line 110 is different from the direction of the high frequency current flowing through the first signal line 111.

  Both the first signal line 110 and the first signal line 111 apply a magnetic field in the + y direction of the magnetoresistive effect element 10 according to Ampere's law. That is, the magnetic fields generated by the first signal lines 110 and 111 are strengthened at the position of the magnetoresistive effect element 10.

  In the magnetoresistive effect device 105 according to the sixth exemplary embodiment, the first signal lines 110 and 111 that apply a high frequency magnetic field to the magnetoresistive effect element 10 are in positions where the high frequency magnetic fields generated thereby strengthen each other. A large high-frequency magnetic field can be applied to the magnetoresistive element 10. As a result, the amount of change in the resistance value of the magnetoresistive effect element 10 is increased, and the magnetoresistive effect device 105 having excellent output characteristics can be obtained. On the other hand, the number of wirings constituting the magnetoresistive effect device 105 is large, and it is difficult to improve the integration.

  The present invention is not necessarily limited to the configuration of the magnetoresistive device shown as the above embodiment. The magnetoresistive effect device has a plurality of high-frequency magnetic field application regions in which the first signal line applies a high-frequency magnetic field to the magnetoresistive effect element, and the plurality of high-frequency magnetic field application regions in the first signal line have their respective high-frequency magnetic field applications. Any structure may be used as long as the high-frequency magnetic field generated in the region is in a position where the magnetoresistive effect element is strengthened.

  For example, the first signal line is not limited to the configuration of FIG. 2 that surrounds the magnetoresistive effect element 10 when the magnetoresistive effect element is viewed from the y direction, and the magnetoresistive effect element when viewed from an arbitrary direction. The structure which surrounds 10 may be sufficient.

  The plurality of high-frequency magnetic field application regions do not have to be equidistant from the magnetoresistive effect element 10 and may be provided at different distances.

DESCRIPTION OF SYMBOLS 1 ... 1st port, 2 ... 2nd port, 10 ... Magnetoresistance effect element, 11 ... Magnetization fixed layer, 12 ... Magnetization free layer, 13 ... Spacer layer, 14 ... Lower electrode, 15 ... Upper electrode, 20, 60, 70, 90, 110, 111 ... first signal line, 21, 61, 81, 91 ... first wiring, 22, 62, 82, 92 ... via wiring, 23, 63, 83, 93 ... second wiring , 30 ... second signal line, 31 ... third signal line, 40 ... DC application terminal, 41 ... DC current source, 42 ... inductor, 71, 72, 73, 81a, 81b, 81c, 83a, 83b, 83c ... Signal line, G ... Ground, 100, 101, 102, 103, 104, 105 ... Magnetoresistive device

Claims (8)

A first port into which a signal is input;
A second port from which a signal is output;
A magnetoresistive element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer;
A first signal line connected to the first port, a high-frequency current corresponding to a signal input from the first port flows, and a high-frequency magnetic field is applied to the magnetoresistive element;
A second signal line connecting the second port and the magnetoresistive element;
A DC application terminal capable of connecting a power source for applying a DC current or a DC voltage in the stacking direction of the magnetoresistive effect element, and
The first signal line has a plurality of high-frequency magnetic field application regions capable of applying a high-frequency magnetic field to the magnetoresistive effect element,
In the first signal line, the plurality of high-frequency magnetic field application regions are provided at positions where high-frequency magnetic fields generated in the respective high-frequency magnetic field application regions are strengthened in the magnetoresistive effect element. The first signal line surrounds the magnetoresistive element when the magnetoresistive element is viewed from a predetermined direction.
2. The magnetoresistive effect device according to claim 1, wherein at least two high frequency magnetic field application regions of the plurality of high frequency magnetic field application regions are at positions facing each other with respect to the magnetoresistive effect element.   The magnetoresistive effect device according to claim 2, wherein the first signal line is wound around an axis extending through the magnetoresistive effect element in the predetermined direction. The first signal line branches into a plurality of signal lines;
4. The signal line through which a high-frequency current flows in the same direction among the plurality of branched signal lines is disposed on the same surface side of the magnetoresistive effect element. 5. Magnetoresistive device.   The part of the first signal line also serves as an upper electrode or a lower electrode that applies a DC current or a DC voltage input from the DC application terminal in the stacking direction of the magnetoresistive effect element. 5. The magnetoresistive effect device according to any one of 4.   The magnetoresistive effect device according to claim 5, wherein a resistance value of the magnetoresistive effect element is 20Ω or more.   The magnetoresistive effect device according to claim 1, further comprising a magnetic field application mechanism that applies an external magnetic field to the magnetoresistive effect element and modulates a resonance frequency of the magnetoresistive effect element. A high-frequency device using the magnetoresistive effect device according to claim 1.

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