JP6717137B2 - Resonant element, resonator and magnetoresistive device - Google Patents

Description

The present invention relates to a resonance element, a resonator and a magnetoresistive effect device using a magnetoresistive effect element.

2. Description of the Related Art In recent years, as mobile communication terminals such as mobile phones have become more sophisticated, 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, and the number of high frequency filters required for mobile communication terminals is increasing accordingly. Recently, spintronics has been studied as a field that has a possibility of being applied to new high frequency components, and one of the phenomena attracting attention is the spin torque resonance phenomenon due to a magnetoresistive effect element ( Non-Patent Document 1). By applying an alternating current to the magnetoresistive effect element, spin torque resonance can be generated in the magnetoresistive effect element, and the resistance value of the magnetoresistive effect element periodically oscillates at a frequency corresponding to the spin torque resonance frequency. The spin torque resonance frequency of the magnetoresistive element changes depending on the strength of the magnetic field applied to the magnetoresistive element, and the resonance frequency is generally in a high frequency band of several to several tens GHz.

Nature, Vol. 438, no. 7066, pp. 339-342, 17 November 2005

The magnetoresistive effect element may be applied to a high frequency device by utilizing the spin torque resonance phenomenon, but a specific configuration for applying it to a high frequency device such as a high frequency filter has not been shown so far. An object of the present invention is to provide a magnetoresistive effect device capable of realizing a high frequency device such as a high frequency filter using a magnetoresistive effect element.

A resonator according to the present invention for achieving the above object is a magnetoresistive effect element having a magnetization fixed layer, a magnetization free layer, and a spacer layer arranged therebetween, and a magnetization free layer to which the magnetization free layer is connected. A layer connection electrode and a magnetization fixed layer connection electrode to which the magnetization fixed layer is connected, wherein the magnetoresistive effect element is arranged between the magnetization free layer connection electrode and the magnetization fixed layer connection electrode, The magnetization free layer connection electrode has a first electrode end portion and a second electrode end portion with a connection portion where the magnetization free layer connection electrode is connected to the magnetization free layer sandwiched between the magnetization free layer connection electrode and the magnetization free layer connection electrode. A first electrode end of the electrode is connected to a first reference voltage terminal, and a second electrode end of the magnetization free layer connecting electrode is a DC voltage input for inputting a DC voltage to the magnetization free layer connecting electrode. The first feature is that it is connected to a terminal.

According to the resonator having the above characteristics, since the magnetoresistive effect element has a large change in impedance of the magnetoresistive effect element at the spin torque resonance frequency, the resonator having the above characteristics may have frequency characteristics as a resonator. It will be possible.

Further, the resonator according to the present invention is provided with a resonance element and a signal line, and the second feature is that the magnetoresistive effect element is connected in series to the signal line.

According to the resonator having the above characteristics, with respect to the resonance of the magnetoresistive effect element at the spin torque resonance frequency, the high frequency signal is cut off to the second port at the non-resonance frequency, and is cut off to the second port side at the resonance frequency. Since it can be passed, the resonator having the above characteristics can have frequency characteristics as a high frequency filter.

Further, the resonator according to the present invention includes a resonance element, a signal line, and a second reference voltage terminal, and the magnetoresistive effect element is connected in parallel to the signal line. It is a feature.

According to the resonator having the above characteristics, with respect to the resonance of the magnetoresistive effect element at the spin torque resonance frequency, a high-frequency signal passes to the second port at the non-resonance frequency and is transmitted to the second port side at the resonance frequency. Since it can be cut off, the resonator having the above characteristics can have frequency characteristics as a high frequency filter.

Further, the magnetoresistive effect device according to the present invention is a magnetoresistive effect element having a magnetization fixed layer, a magnetization free layer, and a spacer layer arranged between these, and a magnetization free layer connection electrode to which the magnetization free layer is connected. A magnetization fixed layer connection electrode to which the magnetization fixed layer is connected, a first port to which a high frequency signal is input, a second port to output a high frequency signal, a signal line, a first inductor or A resistance element, a second inductor or a resistance element, a DC voltage input terminal, and a first reference voltage terminal, wherein the magnetoresistive effect element includes the magnetization free layer connection electrode and the magnetization fixed layer connection electrode. And the magnetization free layer connecting electrode has a first electrode end and a second electrode end sandwiching a connecting part where the magnetization free layer connecting electrode is connected to the magnetization free layer. In the magnetoresistive effect element, the first electrode end of the magnetization free layer connection electrode and the magnetization fixed layer connection electrode are connected in series to the first port and the second port via the signal line. And a second electrode end of the magnetization free layer connecting electrode is connected to the DC voltage input terminal, and a first reference voltage terminal is connected to a first electrode end of the magnetization free layer connecting electrode. The signal connected to the magnetization fixed layer connection electrode, the second inductor or the second resistance element being connected to the signal line via the first inductor or the first resistance element. The fourth feature is that the line is connected to the ground.

The magnetoresistive device having the above characteristics induces a spin orbit torque (SOT) by a direct current flowing through a magnetization free layer connecting electrode in a plane, and spin transfer is performed by a direct current flowing from the magnetization free layer connecting electrode to a magnetization fixed layer connecting electrode. Since the torque (STT) can be induced, the resonance characteristic of the magnetoresistive effect element at the spin torque resonance frequency is improved, and the magnetoresistive effect device with the above characteristics has a good pass characteristic and a range between the pass characteristic and the cutoff characteristic. Can function as a large high-frequency filter.

Further, the magnetoresistive effect device according to the present invention is a magnetoresistive effect element having a magnetization fixed layer, a magnetization free layer, and a spacer layer arranged between these, and a magnetization free layer connection electrode to which the magnetization free layer is connected. A magnetization fixed layer connection electrode to which the magnetization fixed layer is connected, a first port to which a high frequency signal is input, a second port to output a high frequency signal, a signal line, a first inductor or The magnetoresistive effect element has a resistance element, a DC voltage input terminal, a first reference voltage terminal, and a second reference voltage terminal, and the magnetoresistive effect element includes the magnetization free layer connection electrode and the magnetization fixed layer connection electrode. And the magnetization free layer connecting electrode has a first electrode end and a second electrode end sandwiching a connection part where the magnetization free layer connecting electrode is connected to the magnetization free layer. In the magnetization free layer connection electrode, a first electrode end of the magnetization free layer connection electrode and a second electrode end of the magnetization free layer connection electrode are connected to the first port and the first port via the signal line. The first reference voltage terminal is connected in series to a second port, and the first reference voltage terminal is connected to the signal line to which the first electrode end of the magnetization free layer connecting electrode is connected to the first inductor or the first resistor. Connected via an element, the DC voltage input terminal is connected to the signal line to which the second electrode end of the magnetization free layer connection electrode is connected, and the magnetization fixed layer connection electrode is connected to the second line. The fifth feature is that the connection is made to the reference voltage terminal.

The magnetoresistive effect device having the above characteristics is a magnetoresistive effect device having the above characteristics, in which a spin orbit torque is induced by a direct current flowing in a plane through the magnetization free layer connection electrode, and the magnetization free layer connection electrode is changed to a magnetization fixed layer connection electrode. Since the spin transfer torque can be induced by the flowing DC current, the resonance characteristics of the magnetoresistive effect element at the spin torque resonance frequency are improved, and the magnetoresistive effect device with the above characteristics has a good cutoff characteristic, a pass characteristic and a cutoff characteristic. It is possible to function as a high frequency filter having a wide characteristic range.

A sixth feature of the magnetoresistive effect device according to the present invention is that it has a frequency setting mechanism capable of setting the spin torque resonance frequency.

According to the magnetoresistive effect device having the above characteristics, since the spin torque resonance frequency of the magnetoresistive effect element can be set to an arbitrary frequency, the magnetoresistive effect device having the above characteristics can function as a filter in an arbitrary frequency band. Is possible.

Further, in the magnetoresistive effect device according to the present invention, the frequency setting mechanism is an effective magnetic field setting mechanism capable of setting an effective magnetic field in the magnetization free layer, and the effective magnetic field is changed to spin the magnetoresistive element. The seventh feature is that the torque resonance frequency can be changed.

According to the magnetoresistive effect device having the above characteristics, since the spin torque resonance frequency of the magnetoresistive effect element can be variably controlled, the magnetoresistive effect device having the above characteristics can function as a frequency variable filter.

According to the present invention, it is possible to provide a magnetoresistive effect device capable of realizing a high-frequency device such as a high-frequency filter using a magnetoresistive effect element.

It is a cross-sectional schematic diagram which showed the structure of the magnetoresistive effect device which concerns on 1st Embodiment. 3 is a graph showing a relationship between impedance and frequency of the magnetoresistive effect element of the magnetoresistive effect device according to the first embodiment. 3 is a graph showing the relationship between the frequency and the attenuation amount of the magnetoresistive effect device according to the first embodiment. It is a cross-sectional schematic diagram which showed the structure of the magnetoresistive effect device which concerns on 2nd Embodiment. 9 is a graph showing the relationship between the frequency and the attenuation amount of the magnetoresistive effect device according to the second embodiment. It is a cross-sectional schematic diagram which showed the structure of the magnetoresistive effect device which concerns on 3rd Embodiment. It is a graph which showed the frequency of the direct current of the magnetoresistive effect device concerning a 3rd embodiment, and the relation of the amount of attenuation. 9 is a graph showing the relationship between the frequency and the amount of attenuation with respect to the magnetic field strength of the magnetoresistive effect device according to the third embodiment. It is a cross-sectional schematic diagram which showed the structure of the magnetoresistive effect device which concerns on 4th Embodiment. It is the graph which showed the frequency with respect to the direct current of the magnetoresistive effect device which concerns on 4th Embodiment, and the relationship of attenuation amount. 11 is a graph showing the relationship between the frequency and the amount of attenuation with respect to the magnetic field strength of the magnetoresistive effect device according to the fourth embodiment. It is a cross-sectional schematic diagram which showed the structure of the magnetoresistive effect device which concerns on 5th Embodiment. It is the graph which showed the frequency with respect to the direct current of the magnetoresistive effect device which concerns on 5th Embodiment, and the relationship of attenuation amount. 9 is a graph showing the relationship between the frequency and the amount of attenuation with respect to the magnetic field strength of the magnetoresistive effect device according to the fifth embodiment. It is a cross-sectional schematic diagram which showed the structure of the magnetoresistive effect device which concerns on 6th Embodiment. It is the graph which showed the frequency with respect to the direct current of the magnetoresistive effect device which concerns on 6th Embodiment, and the relationship of attenuation amount. It is a graph which showed the frequency of the magnetic field intensity of the magnetoresistive effect device which concerns on 6th Embodiment, and the relationship of attenuation amount.

Preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the embodiments below. Further, the components described below include those that can be easily conceived by those skilled in the art, those that are substantially the same, and those that are within the equivalent range. Furthermore, the components described below can be combined as appropriate. Further, various omissions, substitutions or changes of the constituent elements can be made without departing from the scope of the present invention.

(First embodiment)
FIG. 1 is a schematic cross-sectional view of a magnetoresistive effect device 101 according to the first embodiment of the present invention. The magnetoresistive effect device 101 includes a magnetoresistive effect element 1 having a magnetization fixed layer 2, a magnetization free layer 4, and a spacer layer 3 arranged therebetween, and a magnetization free layer connection electrode 5 to which the magnetization free layer 4 is connected. And the magnetization fixed layer connection electrode 6 to which the magnetization fixed layer 2 is connected, and the first magnetization free layer connection electrode which is one end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4. A high frequency signal is input to the electrode end 5a, the second electrode end 5b of the magnetization free layer connecting electrode which is the other end of the magnetization free layer connecting electrode 5 sandwiching the connecting portion connected to the magnetization free layer 4, and the high frequency signal. It has a first port 9a for outputting a high frequency signal, a second port 9b for outputting a high frequency signal, a signal line 7, a DC voltage input terminal 11, and a first reference voltage terminal 14a. The first port 9a, the magnetization free layer connection electrode 5, the magnetoresistive effect element 1, the magnetization fixed layer connection electrode 6 and the second port 9b are connected in series in this order via the signal line 7. Further, the first electrode end 5a of the magnetization free layer connecting electrode is connected to the ground 8 via the first reference voltage terminal 14a, and the second electrode end 5b of the magnetization free layer connecting electrode is connected to the DC voltage input terminal. It is connected to the DC voltage source 13 via 11.

The first port 9a is an input port to which a high frequency signal which is an AC signal is input, and the second port 9b is an output port to which a high frequency signal is output. The magnetoresistive effect element 1 is electrically connected to the signal line 7 via the magnetization free layer connection electrode 5 and the magnetization fixed layer connection electrode 6. The high frequency signal input from the first port 9a passes through the magnetoresistive effect element 1 and is output to the second port 9b. In addition, the attenuation amount (S21), which is the dB value of the power ratio (output power/input power) when the high-frequency signal passes from the first port 9a to the second port 9b, is measured by a high-frequency measuring device such as a network analyzer. It can be measured.

The magnetization free layer connection electrode 5 and the magnetization fixed layer connection electrode 6 have a role as a pair of electrodes, and are arranged via the magnetoresistive effect element 1 in the stacking direction of the layers forming the magnetoresistive effect element 1. There is. That is, the magnetization free layer connection electrode 5 and the magnetization fixed layer connection electrode 6 transmit a signal (current) to the magnetoresistive effect element 1 in a direction intersecting the plane of each layer constituting the magnetoresistive effect element 1, for example, in the magnetic field. It has a function as a pair of electrodes for flowing in a direction (stacking direction) perpendicular to the main surface of each layer constituting the resistance effect element 1. The magnetoresistive effect element 1 has one end (on the magnetization free layer 4 side) electrically connected to the signal line 7 via the magnetization free layer connection electrode 5, and the other end (on the magnetization fixed layer 2 side) is the magnetization fixed layer connection electrode. It is electrically connected to the signal line 7 via 6.

The magnetization fixed layer connection electrode 6 is preferably made of an electric conductor metal. The electric conductor metal is composed of, for example, Ta, Cu, Au, AuCu, Ru, or a film of two or more of any of these materials.

The magnetization free layer connection electrode 5 is preferably made of a heavy metal. The heavy metal is composed of a heavy metal having a large spin-orbit interaction, for example, Hf, Ta, W, Re, Os, Ir, Pt, Pb, or an alloy thereof. Further, as the heavy metal, a conductive material doped with these heavy metals or alloys may be used. Further, in order to obtain desired electrical characteristics and structure, materials such as B, C, N, O, Al, Si, P, Ga and Ge may be added to the heavy metal as appropriate.

The ground 8 functions as a reference potential. The shapes of the signal line 7 and the ground 8 are preferably defined as a microstrip line (MSL) type or a coplanar waveguide (CPW) type. When designing the microstrip line shape and the coplanar waveguide shape, the signal line 7 and the ground line distance are designed so that the characteristic impedance of the signal line 7 and the impedance of the circuit system become equal. Can be a transmission line with less transmission loss.

The DC voltage input terminal 11 is connected to the magnetization free layer connection electrode 5 with the second electrode end 5b of the magnetization free layer connection electrode interposed therebetween. By connecting the DC voltage source 13 to the DC voltage input terminal 11, it becomes possible to apply a DC voltage to the magnetoresistive effect element 1 and flow a DC current. Further, an inductor or a resistance element for cutting a high frequency signal may be connected in series between the DC voltage input terminal 11 and the DC voltage source 13.

The DC voltage source 13 is connected to the ground 8 and the DC voltage input terminal 11, and the ground 8, the first reference voltage terminal 14a, the first electrode end portion 5a of the magnetization free layer connection electrode, the magnetization free layer connection electrode 5, A closed circuit including the second electrode end portion 5b of the magnetization free layer connecting electrode and the DC voltage input terminal 11 is formed. The DC voltage source 13 applies a DC voltage to the closed circuit from the DC voltage input terminal 11 and inputs a DC current. The DC voltage source 13 is configured by, for example, a circuit of a combination of a variable resistor and a DC voltage source, and is configured to change the voltage value of the DC voltage. The DC voltage source 13 may be configured by a circuit that is a combination of a fixed resistor and a DC voltage source that can generate a constant voltage and current.

The magnetization fixed layer 2 is made of a ferromagnetic material, and its magnetization direction is substantially fixed in one direction. The magnetization fixed layer 2 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. Thereby, a high magnetoresistance change rate can be obtained. The magnetization fixed layer 2 may be made of a Heusler alloy. The film thickness of the magnetization fixed layer 2 is preferably 1 to 10 nm. Further, an antiferromagnetic layer may be added so as to be in contact with the magnetization fixed layer 2 in order to fix the magnetization of the magnetization fixed layer 2. Alternatively, the magnetization of the magnetization fixed layer 2 may be fixed by utilizing the magnetic anisotropy caused by the crystal structure, the shape, and the like. For the antiferromagnetic layer, FeO, CoO, NiO, CuFeS ₂ , IrMn, FeMn, PtMn, Cr or Mn can be used.

The spacer layer 3 is arranged between the magnetization fixed layer 2 and the magnetization free layer 4, and the magnetization of the magnetization fixed layer 2 and the magnetization of the magnetization free layer 4 interact to obtain a magnetoresistive effect. The spacer layer 3 is composed of a layer made of a conductor, an insulator, or a semiconductor, or a layer containing a conducting point in the insulator made of a conductor.

When a non-magnetic conductive material is used as the spacer layer 3, Cu, Ag, Au, or Ru is used as the material, and a giant magnetoresistive (GMR) effect is exhibited in the magnetoresistive effect element. When utilizing the GMR effect, the thickness of the spacer layer 3 is preferably about 0.5 to 3.0 nm.

When a non-magnetic insulating material is used as the spacer layer 3, Al ₂ O ₃ or MgO is used as the material, and the tunnel magnetoresistive (TMR) effect is exhibited in the magnetoresistive effect element. A high magnetoresistance change rate can be obtained by adjusting the film thickness of the spacer layer 3 so that the coherent tunnel effect is exhibited between the magnetization fixed layer 2 and the magnetization free layer 4. When utilizing the TMR effect, the thickness of the spacer layer 3 is preferably about 0.5 to 3.0 nm.

When a non-magnetic semiconductor material is used as the spacer layer 3, examples of the material include ZnO, In ₂ O ₃ , SnO ₂ , ITO, GaO _x or Ga ₂ O _x, and the thickness of the spacer layer 3 is 1.0. It is preferably about 4.0 nm.

When applying a layer comprising a conductive point constituted by the conductor of the non-magnetic insulator in a spacer layer 3, the nonmagnetic insulator during constituted by _Al 2 _{O 3} or MgO, CoFe, CoFeB, CoFeSi, CoMnGe, It is preferable that the structure includes a conduction point formed of a conductor such as CoMnSi, CoMnAl, Fe, Co, Au, Cu, Al or Mg. In this case, the spacer layer 3 preferably has a thickness of about 0.5 to 2.0 nm.

The magnetization free layer 4 can change its magnetization direction and is made of a ferromagnetic material. The magnetization direction of the magnetization free layer 4 can be changed by, for example, an externally applied magnetic field or spin polarized electrons. When the magnetization free layer 4 is a material having an easy axis of magnetization in the in-plane direction, examples of the material include CoFe, CoFeB, CoFeSi, CoMnGe, CoMnSi, and CoMnAl, and the thickness thereof is about 1 to 10 nm. preferable. When the magnetization free layer 4 is a material having an easy axis of magnetization in the direction normal to the film surface, the material is Co, CoCr alloy, Co multilayer film, CoCrPt alloy, FePt alloy, SmCo alloy containing rare earth or TbFeCo. Examples include alloys. Further, the magnetization free layer 4 may be made of a Heusler alloy. Further, a high spin polarizability material may be inserted between the magnetization free layer 4 and the spacer layer 3. This makes it possible to obtain a high magnetoresistance change rate. Examples of the high spin polarizability material include CoFe alloy and CoFeB alloy. The film thickness of each of the CoFe alloy and the CoFeB alloy is preferably set to about 0.2 to 1.0 nm.

Further, a cap layer, a seed layer or a buffer layer may be provided between the magnetization free layer connecting electrode 5 and the magnetoresistive effect element 1 and between the magnetization fixed layer connecting electrode 6 and the magnetoresistive effect element 1. .. Examples of the cap layer, seed layer, or buffer layer include Ru, Ta, Cu, Cr, or a laminated film thereof, and the film thickness of these layers is preferably about 2 to 10 nm.

When the shape of the magnetoresistive effect element is a rectangle (including a square) in a plan view, it is desirable that its long side is about 100 nm or 100 nm or less. When the shape in plan view is not a rectangle, the long side of the rectangle circumscribing the shape in plan view with the smallest area is defined as the long side of the magnetoresistive effect element. When the long side is as small as about 100 nm, the magnetic domain of the magnetization free layer 4 can be made into a single domain, and a highly efficient spin torque resonance phenomenon can be realized. Here, the “plan view shape” is a shape viewed from a plane perpendicular to the stacking direction of each layer constituting the magnetoresistive effect element.

Here, the spin torque resonance phenomenon will be described.

When a high-frequency signal having the same frequency as the spin torque resonance frequency specific to the magnetoresistive effect element is input to the magnetoresistive effect element, the magnetization of the magnetization free layer oscillates at the spin torque resonance frequency. This phenomenon is called a spin torque resonance phenomenon. The element resistance value of the magnetoresistive effect element is determined by the relative angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer. Therefore, the resistance value of the magnetoresistive effect element at the time of spin torque resonance changes periodically with the oscillation of the magnetization of the magnetization free layer. That is, the magnetoresistive effect element can be treated as a resistance oscillating element whose resistance value periodically changes at the spin torque resonance frequency.

Further, a spin transfer torque can be induced in the magnetoresistive effect element 1 by causing a direct current to flow from the magnetization free layer 4 to the magnetization fixed layer 2 or from the magnetization fixed layer 2 to the magnetization free layer 4. The spin transfer torque can increase the vibration angle of the magnetization of the vibrating magnetization free layer. That is, since the amplitude of resistance vibration can be increased, the resonator has a large resonance characteristic.

Further, the inside of the magnetization free layer connecting electrode 5 in contact with the magnetization free layer 4 is in the horizontal plane (from the first electrode end 5a of the magnetization free layer connecting electrode to the second electrode end 5b of the magnetization free layer connecting electrode or A spin orbit torque can be induced by passing a direct current from the second electrode end 5b of the free layer connecting electrode to the first electrode end 5a of the magnetization free layer connecting electrode. The spin orbit torque can increase the oscillation angle of the magnetization of the oscillating magnetization free layer. That is, since the amplitude of resistance vibration can be increased, the resonator has a large resonance characteristic.

Due to the spin torque resonance phenomenon, among the high frequency components of the high frequency signal input from the first port 9a, the frequency component that is equal to the spin torque resonance frequency of the magnetoresistive effect element 1 or near the spin torque resonance frequency is low. It easily passes through the magnetoresistive effect element 1 in the impedance state and is output to the second port 9b. On the other hand, of the high frequency components of the high frequency signal, frequency components that are not near the spin torque resonance frequency of the magnetoresistive effect element 1 are less likely to be output to the second port 9b by the magnetoresistive effect element 1 in the high impedance state. That is, the magnetoresistive effect element can be treated as a resonator.

As described above, in the magnetoresistive effect device 101, the frequency component of the high frequency signal, which is input from the first port 9a and is not in the vicinity of the spin torque resonance frequency of the magnetoresistive effect element 1, is blocked to the second port 9b. The frequency component of the high frequency signal in the vicinity of the spin torque resonance frequency passes to the second port 9b. That is, the magnetoresistive effect device 101 can have a function of a high frequency filter having a pass band at a frequency near the spin torque resonance frequency of the magnetoresistive effect element 1. That is, the magnetoresistive effect device 101 is a bandpass filter (bandpass filter).

In the magnetoresistive effect device 101, it is preferable that the magnetoresistive effect element 1 has a high impedance (that is, the resistance value of the magnetoresistive effect element 1) with respect to a high-frequency signal having a non-resonant frequency.

Further, in the magnetoresistive effect device 101, when the direct current voltage input from the direct current voltage input terminal 11 has a certain magnitude or more, the magnetoresistive effect device 1 receives the spin torque resonance frequency from the first port 9a. The output power output from the second port 9b can be made larger (the attenuation amount is 0 dB or more) than the input power of the high frequency signal. That is, the magnetoresistive effect device 101 can also function as an amplifier.

FIG. 2 is a graph showing the relationship between the frequency of the high frequency signal input to the magnetoresistive effect device 101 and the impedance of the magnetoresistive effect element of the magnetoresistive effect device 101. The vertical axis of FIG. 2 represents impedance Z (Ω), and the horizontal axis represents frequency F (Hz). The plot line 100a1 in FIG. 2 shows the impedance characteristics of the magnetoresistive effect element 1 connected in series to the first port 9a and the second port 9b.

FIG. 3 shows a graph showing the relationship between the frequency and the attenuation amount of the high frequency signal input to the magnetoresistive effect device 101. The vertical axis of FIG. 3 represents the attenuation amount IL (dB), and the horizontal axis represents the frequency F (Hz).

As shown in FIG. 3, since the impedance becomes smaller at the spin torque resonance frequency of the magnetoresistive effect element 1, the pass characteristic of the magnetoresistive effect device 101 for a high frequency signal having the same frequency as the spin torque resonance frequency is improved (attenuation amount). The absolute value of decreases).

(Second embodiment)
FIG. 4 is a schematic cross-sectional view of the magnetoresistive effect device 102 according to the second embodiment of the present invention. In the magnetoresistive effect device 102, the points different from the magnetoresistive effect device 101 of the first embodiment will be mainly described, and description of common items will be appropriately omitted. The elements common to the magnetoresistive effect device 101 of the first embodiment are denoted by the same reference numerals, and the description of the common elements is omitted. The magnetoresistive effect device 102 further has two reference voltage terminals 14b in addition to the magnetoresistive effect device 101 of the first embodiment. The first port 9a is connected to the second port 9b via the signal line 7. The magnetization free layer connection electrode 5 is connected to the signal line 7, and the magnetization fixed layer connection electrode 6 is connected to the ground 8 via the second reference voltage terminal 14b. Further, the first electrode end 5a of the magnetization free layer connecting electrode is connected to the ground 8 via the first reference voltage terminal 14a, and the second electrode end 5b of the magnetization free layer connecting electrode is connected to the DC voltage input terminal. It is connected to the DC voltage source 13 via 11. The other configurations of the magnetoresistive effect device 102 are the same as those of the magnetoresistive effect device 101 of the first embodiment.

The DC voltage source 13 is connected to the ground 8 and the DC voltage input terminal 11, and the ground 8, the first reference voltage terminal 14a, the first electrode end portion 5a of the magnetization free layer connection electrode, the magnetization free layer connection electrode 5, A closed circuit including the second electrode end portion 5b of the magnetization free layer connecting electrode and the DC voltage input terminal 11 is formed. Further, the ground 8, the second reference voltage terminal 14b, the magnetization fixed layer connection electrode 6, the magnetoresistive effect element 1, the magnetization free layer connection electrode 5, the second electrode end 5b of the magnetization free layer connection electrode, and the DC voltage input. A closed circuit including the terminal 11 is also formed.

FIG. 5 shows a graph showing the relationship between the frequency and the attenuation amount of the high frequency signal input to the magnetoresistive effect device 102. The vertical axis of FIG. 5 represents the attenuation amount IL (dB), and the horizontal axis represents the frequency F (Hz).

As shown in FIG. 5, since the impedance becomes smaller at the spin torque resonance frequency of the magnetoresistive effect element 1, the cutoff characteristic of the magnetoresistive effect device 102 with respect to a high frequency signal having the same frequency as the spin torque resonance frequency is improved (attenuation amount). The absolute value of increases).

(Third Embodiment)
FIG. 6 is a schematic cross-sectional view of the magnetoresistive effect device 103 according to the third embodiment of the present invention. In the magnetoresistive effect device 103, the points different from the magnetoresistive effect device 101 of the first embodiment will be mainly described, and description of common items will be appropriately omitted. The elements common to the magnetoresistive effect device 101 of the first embodiment are denoted by the same reference numerals, and the description of the common elements is omitted. The magnetoresistive effect device 103 further includes a first inductor 10a and a second inductor 10b in addition to the magnetoresistive effect device 101 of the first embodiment. The magnetization free layer connection electrode 5 is connected to the signal line 7 on the first port 9a side via the first electrode end 5a of the magnetization free layer connection electrode. The first inductor 10a is connected to the ground 8 via the first reference voltage terminal 14a, and the second inductor 10b is connected between the signal line 7 to which the magnetization fixed layer connecting electrode 6 is connected and the ground 8. It is connected. The magnetoresistive effect element 1 is connected to the signal line 7 so that the magnetization fixed layer 2 side faces the second port 9b side, and a direct current input from the direct current voltage input terminal 11 passes through the magnetoresistive effect element 1 inside. It is arranged so as to flow from the magnetization free layer 4 to the magnetization fixed layer 2. Further, the first reference voltage terminal 14a is connected via the first inductor 10a to the signal line 7 to which the first electrode end portion 5a of the magnetization free layer connecting electrode is connected, and input from the DC voltage input terminal 11. Is arranged so that a direct current is generated in the magnetization free layer connecting electrode 5 from the second electrode end 5b of the magnetization free layer connecting electrode toward the first electrode end 5a of the magnetization free layer connecting electrode. ing. The other configurations of the magnetoresistive effect device 103 are the same as those of the magnetoresistive effect device 101 of the first embodiment.

The magnetoresistive effect element 1 is arranged so that a DC current input from the DC voltage input terminal 11 flows through the magnetoresistive effect element 1 from the magnetization free layer 4 to the magnetization fixed layer 2.

The first inductor 10a and the second inductor 10b are connected between the signal line 7 and the ground 8 and have the function of cutting off the high frequency component of the current by the inductor component and at the same time allowing the direct current component of the current to pass. The first inductor 10a and the second inductor 10b may be chip inductors or patterned line inductors. Alternatively, a resistance element having an inductor component may be used. The inductance values of the first inductor 10a and the second inductor 10b are preferably 10 nH or more. By the first inductor 10a, the first electrode end 5a of the magnetization free layer connecting electrode, the magnetization free layer connecting electrode 5, the second electrode end 5b of the magnetization free layer connecting electrode, the signal line 7, the DC voltage input terminal. A DC current applied from the DC voltage input terminal 11 can be passed through a closed circuit including the DC voltage source 13, the DC voltage source 13, the first inductor 10a, the first reference voltage terminal 14a, and the ground 8. At the same time, by the second inductor 10b, the magnetization fixed layer connection electrode 6, the magnetoresistive effect element 1, the magnetization free layer connection electrode 5, the second electrode end 5b of the magnetization free layer connection electrode, the signal line 7, the DC voltage. The DC current applied from the DC voltage input terminal 11 can be passed through a closed circuit including the input terminal 11, the DC voltage source 13, the second inductor 10b, and the ground 8. Further, by adjusting the resistance components of the first inductor 10a and the second inductor 10b, the amount of current flowing through each closed circuit can be adjusted.

The magnetic field applying mechanism 12 is disposed near the magnetoresistive effect element 1, and can apply a magnetic field to the magnetoresistive effect element 1 to set the spin torque resonance frequency. For example, the magnetic field applying mechanism 12 is configured by an electromagnet type or a strip line type in which the applied magnetic field strength can be variably controlled by either voltage or current. The magnetic field applying mechanism 12 may be configured by a combination of an electromagnet type or a stripline type and a permanent magnet that supplies only a constant magnetic field. The magnetic field applying mechanism 12 can change the effective magnetic field in the magnetization free layer 4 by changing the magnetic field applied to the magnetoresistive effect element 1 to change the spin torque resonance frequency of the magnetoresistive effect element 1.

Here, the torque related to the spin torque resonance phenomenon will be described.

A high-frequency signal having the same frequency as the spin torque resonance frequency is applied to the magnetoresistive effect element 1 while applying a direct current flowing in the magnetoresistive effect element 1 in the direction from the magnetization free layer 4 to the magnetization fixed layer 2. , The resistance value of the magnetoresistive effect element 1 periodically changes at the spin torque resonance frequency in the same phase as the input high frequency signal due to the spin transfer torque, and the impedance for the high frequency signal decreases. .. That is, the magnetoresistive effect element 1 can be treated as a resistance element in which the impedance of the high frequency signal decreases at the spin torque resonance frequency due to the spin torque resonance phenomenon.

Further, a direct current is caused to flow from the second electrode end portion 5b of the magnetization free layer connection electrode to the first electrode end portion 5a of the magnetization free layer connection electrode in the magnetization free layer connection electrode 5 in contact with the magnetization free layer 4. Thus, the spin orbit torque can be induced in the same direction as the spin transfer torque. By combining the spin transfer torque and the spin orbit torque, the amplitude of magnetization of the vibrating magnetization free layer can be further increased. That is, since the amplitude of resistance vibration can be increased, the impedance of the high frequency signal at the spin torque resonance frequency can be treated as a resistance element that is further greatly reduced.

The spin torque resonance frequency changes depending on the effective magnetic field in the magnetization free layer 4. The effective magnetic field Heff in the magnetization free layer 4 is the external magnetic field HE applied to the magnetization free layer 4, the anisotropic magnetic field Hk in the magnetization free layer 4, the demagnetizing field HD in the magnetization free layer 4, and the exchange coupling magnetic field in the magnetization free layer 4. With HEX,
Heff=HE+Hk+HD+HEX
It is represented by. The magnetic field applying mechanism 12 is an effective magnetic field setting mechanism capable of setting an effective magnetic field Heff in the magnetization free layer 4 by applying a magnetic field to the magnetoresistive effect element 1 and applying an external magnetic field HE to the magnetization free layer 4. The magnetic field applying mechanism 12, which is an effective magnetic field setting mechanism, changes the magnetic field applied to the magnetoresistive effect element 1 to change the effective magnetic field in the magnetization free layer 4 to change the spin torque resonance frequency of the magnetoresistive effect element 1. Can be made Thus, when the magnetic field applied to the magnetoresistive effect element 1 is changed, the spin torque resonance frequency of the magnetoresistive effect element 1 changes.

Further, when a DC current is applied to the magnetoresistive effect element 1 at the time of spin torque resonance, the spin transfer torque increases and the amplitude of the oscillating resistance value increases. As the amplitude of the oscillating resistance value increases, the amount of change in the element impedance of the magnetoresistive effect element 1 increases. Further, when the current density of the applied direct current is changed, the spin torque resonance frequency changes. Therefore, the spin torque resonance frequency of the magnetoresistive effect element 1 can be changed by changing the magnetic field from the magnetic field applying mechanism 12 or changing the applied DC current input from the DC voltage input terminal 11. The current density of the DC current applied to the magnetoresistive effect element 1 is preferably smaller than the respective oscillation threshold current densities. The oscillation threshold current density of the magnetoresistive effect element, by applying a direct current of a current density of this value or more, the magnetization of the magnetization free layer of the magnetoresistive effect element starts precession at a constant frequency and a constant amplitude, It is a threshold current density at which the magnetoresistive effect element oscillates (the output (resistance value) of the magnetoresistive effect element varies at a constant frequency and a constant amplitude).

Further, when a DC current having the same magnetic field and the same current density is applied to the magnetoresistive effect element, the spin torque resonance of the magnetoresistive effect element increases as the aspect ratio of the magnetoresistive effect element in plan view increases. The frequency will be higher. Here, the “aspect ratio of the plan view shape” is the ratio of the length of the long side to the length of the short side of the rectangle circumscribing the plan view shape of the magnetoresistive effect element in the minimum area.

The magnetic field angle (the relative angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer) applied to the magnetoresistive effect element 1 from the magnetic field applying mechanism 12 is preferably 90° or more. When the magnetic field angle is 90° or more, the magnetization of the magnetization free layer can maintain the precession in the direction opposite to the spin transfer torque and the spin orbit torque. That is, since the amplitude of resistance vibration can be increased, it can be treated as a resistance element in which the impedance of the high frequency signal changes significantly at the spin torque resonance frequency.

As described above, in the magnetoresistive effect device 103, the frequency component of the high-frequency signal that is input from the first port 9a and is not in the vicinity of the spin torque resonance frequency of the magnetoresistive effect element 1 is blocked to the second port 9b. The frequency component of the high frequency signal in the vicinity of the spin torque resonance frequency passes to the second port 9b. That is, the magnetoresistive effect device 101 can have a function of a high frequency filter having a pass band at a frequency near the spin torque resonance frequency of the magnetoresistive effect element 1. That is, the magnetoresistive effect device 103 is a bandpass filter (bandpass filter).

7 and 8 are graphs showing the relationship between the frequency and the attenuation of the high frequency signal input to the magnetoresistive effect device 103. 7 and 8, the vertical axis represents the attenuation amount IL (dB) and the horizontal axis represents the frequency F (Hz). FIG. 7 is a graph when the magnetic field applied to the magnetoresistive effect element 1 is constant. A plot line 100d1 in FIG. 7 is obtained when the DC current value applied to the magnetoresistive effect element 1 from the DC voltage input terminal 11 is Id1, and a plot line 100d2 is from the DC voltage input terminal 11 to the magnetoresistive effect element 1. The value of the direct current value applied to is Id2. The relationship of the direct current values at this time is Id1<Id2. Further, FIG. 8 is a graph when the direct current applied to the magnetoresistive effect element 1 is constant. A plot line 100e1 in FIG. 8 is obtained when the magnetic field strength applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1 is He1, and a plot line 100e2 is applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1. The magnetic field strength is He2. The relationship of the magnetic field strength at this time is He1<He2.

For example, as shown in FIG. 7, when the DC current value applied from the DC voltage input terminal 11 to the magnetoresistive effect element 1 is increased from Id1 to Id2, the spin of the magnetoresistive effect element 1 changes as the current value changes. By increasing the amount of change in the element impedance of the magnetoresistive effect element 1 at a frequency near the torque resonance frequency (passband frequency), the high-frequency signal output from the second port 9b is further increased and the pass The loss is small. Therefore, the magnetoresistive effect device 103 can realize a high-frequency filter having a wide range of cutoff characteristics and pass characteristics. When the DC current value is increased from Id1 to Id2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fd1 to fd2. That is, the pass frequency band shifts to the low frequency side. That is, the magnetoresistive effect device 103 can also function as a high frequency filter capable of changing the frequency of the pass frequency band.

Further, for example, as shown in FIG. 8, when the magnetic field strength applied from the magnetic field applying mechanism 12 is increased from He1 to He2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fe1 to fe2. That is, the pass frequency band shifts to the high frequency side. Further, changing the magnetic field strength (effective magnetic field H _eff in the magnetization free layer 4) can shift the pass frequency band more than changing the direct current value. That is, the magnetoresistive effect device 103 can function as a high frequency filter capable of changing the frequency of the pass frequency band.

As the external magnetic field H _E (effective magnetic field H _eff in the magnetization free layer 4) applied to the magnetoresistive effect element 1 increases, the amplitude of the oscillating resistance value of the magnetoresistive effect element 1 decreases. It is preferable to increase the current density of the direct current applied to the magnetoresistive effect element 1 as the external magnetic field H _E (effective magnetic field H _eff in the magnetization free layer 4) applied to the effect element is increased.

As described above, in the magnetoresistive effect device 103, the magnetoresistive effect element 1 having the magnetization fixed layer 2, the magnetization free layer 4, and the spacer layer 3 arranged therebetween, and the magnetization free layer 4 are connected to each other. The connection electrode 5, the magnetization fixed layer connection electrode 6 to which the magnetization fixed layer 2 is connected, and the magnetization free layer connection electrode which is one end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4 A first electrode end portion 5a, a second electrode end portion 5b of the magnetization free layer connection electrode which is the other end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4, and a high frequency signal. , A second port 9b for outputting a high frequency signal, a signal line 7, a DC voltage input terminal 11, a first reference voltage terminal 14a, and a first inductor 10a. The second inductor 10b has a second inductor 10b, the first inductor 10a is connected to the ground 8 via the first reference voltage terminal 14, and the second inductor 10b is connected to the magnetization fixed layer connection electrode 6. It is connected between the signal line 7 and the ground 8. The magnetoresistive effect element 1 is connected to the signal line 7 so that the magnetization fixed layer 2 side faces the second port 9b side, and a direct current input from the direct current voltage input terminal 11 passes through the magnetoresistive effect element 1 inside. It is arranged so as to flow from the magnetization free layer 4 to the magnetization fixed layer 2. Further, the first reference voltage terminal 14a is connected via the first inductor 10a to the signal line 7 to which the first electrode end portion 5a of the magnetization free layer connecting electrode is connected, and input from the DC voltage input terminal 11. Is arranged so that the generated direct current flows through the magnetization free layer connecting electrode 5 from the second electrode end 5b of the magnetization free layer connecting electrode toward the first electrode end 5a of the magnetization free layer connecting electrode. ing.

Therefore, by inputting a high frequency signal from the first port 9a to the magnetoresistive effect element 1 via the signal line 7, spin torque resonance can be induced in the magnetoresistive effect element 1. At the same time as this spin torque resonance, a DC current flows from the magnetization free layer 4 to the magnetization fixed layer 2 in the magnetoresistive effect element 1, whereby spin transfer torque can be induced, and the magnetoresistive effect element 1 is , And can be treated as an element whose resistance value periodically oscillates at a frequency corresponding to the spin torque resonance frequency in the same phase as the high frequency signal input from the first port. Further, a direct current is passed through the magnetization free layer connecting electrode 5 from the second electrode end 5b of the magnetization free layer connecting electrode to the first electrode end 5a of the magnetization free layer connecting electrode, whereby the spin transfer torque is increased. Spin orbital torque can be induced in the same direction as, and the amplitude of the oscillating resistance can be increased. Due to this effect, the element impedance of the magnetoresistive effect element 1 for the same frequency as the spin torque resonance frequency of the magnetoresistive effect element 1 is greatly reduced. That is, the magnetoresistive effect device 103 can have frequency characteristics as a high frequency filter.

Further, in order to increase the range of the cutoff characteristic and the pass characteristic, the magnetization free layer 4 has an easy axis of magnetization in the normal direction to the film surface, and the fixed magnetization layer 2 has an easy axis of magnetization in the film surface direction. Preferably.

Further, since the spin torque resonance frequency of the magnetoresistive effect element 1 can be variably controlled by changing the DC current applied from the DC voltage input terminal 11, the magnetoresistive effect device 103 functions as a frequency variable filter. It is also possible to do.

Further, since the magnetoresistive effect device 103 has the magnetic field applying mechanism 12 as a frequency setting mechanism capable of setting the spin torque resonance frequency of the magnetoresistive effect element 1, the spin torque resonance frequency of the magnetoresistive effect element 1 is set to an arbitrary frequency. Can be Therefore, the magnetoresistive effect device 103 can function as a filter in an arbitrary frequency band.

Further, in the magnetoresistive effect device 103, the magnetic field applying mechanism 12 is an effective magnetic field setting mechanism capable of setting the effective magnetic field in the magnetization free layer 4, and the effective magnetic field in the magnetization free layer 4 is changed to change the effective magnetic field in the magnetoresistive effect element 1. Since the spin torque resonance frequency can be changed, it can function as a frequency variable filter.

In the magnetoresistive device 103, the signal line 7 on the side of the first port 9a has been described as an example connected to the first electrode end portion 5a of the magnetization free layer connecting electrode. It may be connected to the magnetization free layer connection electrode 5.

(Fourth Embodiment)
FIG. 9 is a schematic cross-sectional view of the magnetoresistive effect device 104 according to the fourth embodiment of the present invention. In the magnetoresistive effect device 104, the points different from the magnetoresistive effect device 103 of the third embodiment will be mainly described, and common items will not be described as appropriate. The elements common to the magnetoresistive effect device 103 of the third embodiment are denoted by the same reference numerals, and the description of the common elements is omitted. The magnetoresistive effect device 104 is different from the magnetoresistive effect device 103 of the third embodiment in that the direct current input from the direct current voltage input terminal 11 moves from the magnetization fixed layer 2 to the magnetization free layer in the magnetoresistive effect element 1. It is arranged so as to flow in the direction of 4. Further, a direct current input from the DC voltage input terminal 11 passes through the magnetization free layer connecting electrode 5 from the first electrode end 5a of the magnetization free layer connecting electrode to the second electrode end of the magnetization free layer connecting electrode. It is arranged so as to flow in the direction of 5b. The other configuration of the magnetoresistive effect device 104 is the same as that of the magnetoresistive effect device 103 of the third embodiment.

The magnetoresistive effect element 1 is arranged so that a DC current input from the DC voltage input terminal 11 flows through the magnetoresistive effect element 1 from the magnetization fixed layer 2 to the magnetization free layer 4.

Here, the torque related to the spin torque resonance phenomenon will be described.

A high-frequency signal having the same frequency as the spin torque resonance frequency is applied to the magnetoresistive effect element 1 while applying a direct current flowing in the magnetoresistive effect element 1 in the direction from the magnetization fixed layer 2 to the magnetization free layer 4. , The resistance value of the magnetoresistive effect element 1 periodically changes at the spin torque resonance frequency in a state in which the phase is different by 180° from the input high frequency signal due to the spin transfer torque. Will increase. That is, the magnetoresistive effect element 1 can be treated as a resistance element in which the impedance of the high frequency signal increases at the spin torque resonance frequency due to the spin torque resonance phenomenon.

Further, a direct current is caused to flow from the first electrode end portion 5a of the magnetization free layer connection electrode to the second electrode end portion 5b of the magnetization free layer connection electrode in the magnetization free layer connection electrode 5 in contact with the magnetization free layer 4. Thus, the spin orbit torque can be induced in the same direction as the spin transfer torque. By combining the spin transfer torque and the spin orbit torque, the amplitude of magnetization of the vibrating magnetization free layer can be further increased. That is, since the amplitude of the resistance vibration can be increased, the impedance of the high frequency signal at the spin torque resonance frequency can be treated as a resistance element that further increases.

The magnetic field angle (relative angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer) applied to the magnetoresistive effect element 1 from the magnetic field applying mechanism 12 is preferably 90° or less. When the magnetic field angle is 90° or less, the magnetization of the magnetization free layer can maintain the precession in the direction opposite to the spin transfer torque and the spin orbit torque. That is, since the amplitude of resistance vibration can be increased, it can be treated as a resistance element in which the impedance of the high frequency signal changes significantly at the spin torque resonance frequency.

As described above, in the magnetoresistive effect device 104, the frequency component of the high-frequency signal that is input from the first port 9a and is not near the spin torque resonance frequency of the magnetoresistive effect element 1 is passed to the second port 9b. , The frequency component of the high frequency signal in the vicinity of the spin torque resonance frequency is blocked to the second port 9b. That is, the magnetoresistive effect device 104 can have a function of a high frequency filter in which the frequency near the spin torque resonance frequency of the magnetoresistive effect element 1 has a stop band. That is, the magnetoresistive effect device 104 is a band cutoff type filter (band elimination filter).

10 and 11 are graphs showing the relationship between the frequency and the attenuation amount of the high frequency signal input to the magnetoresistive effect device 104. 10 and 11, the vertical axis represents the attenuation amount IL (dB) and the horizontal axis represents the frequency F (Hz). FIG. 10 is a graph when the magnetic field applied to the magnetoresistive effect element 1 is constant. The plot line 100g1 of FIG. 10 is when the DC current value applied to the magnetoresistive effect element 1 from the DC voltage input terminal 11 is Ig1, and the plot line 100g2 is from the DC voltage input terminal 11 to the magnetoresistive effect element 1. The value of the applied direct current is Ig2. The relationship of the direct current values at this time is Ig1<Ig2. Further, FIG. 11 is a graph when the direct current applied to the magnetoresistive effect element 1 is constant. The plot line 100h1 in FIG. 11 is when the magnetic field intensity applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1 is Hh1, and the plot line 100h2 is applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1. The magnetic field strength is Hh2. The relationship between the magnetic field strengths at this time is Hh1<Hh2.

For example, as shown in FIG. 11, when the DC current value applied from the DC voltage input terminal 11 to the magnetoresistive effect element 1 is increased from Ig1 to Ig2, the spin of the magnetoresistive effect element 1 changes as the current value changes. By increasing the amount of change in the element impedance of the magnetoresistive effect element 1 at a frequency near the torque resonance frequency (frequency in the cutoff band), the high frequency signal output from the second port 9b is further reduced and passes through. The loss will increase. Therefore, the magnetoresistive effect device 104 can realize a high frequency filter having a wide range of the cutoff characteristic and the pass characteristic. When the DC current value is increased from Ig1 to Ig2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fg1 to fg2. That is, the pass frequency band shifts to the low frequency side. That is, the magnetoresistive effect device 104 can also function as a high frequency filter capable of changing the frequency in the cutoff frequency band.

Further, for example, as shown in FIG. 11, when the magnetic field strength applied from the magnetic field applying mechanism 12 is increased from Hh1 to Hh2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fh1 to fh2. That is, the cutoff frequency band shifts to the high frequency side. Further, changing the magnetic field strength (effective magnetic field H _eff in the magnetization free layer 4) can shift the cut-off frequency band more than changing the DC current value. That is, the magnetoresistive effect device 104 can function as a high frequency filter capable of changing the frequency of the cutoff frequency band.

As described above, in the magnetoresistive effect device 104, the magnetoresistive effect element 1 having the magnetization fixed layer 2, the magnetization free layer 4, and the spacer layer 3 arranged therebetween, and the magnetization free layer 4 are connected. The connection electrode 5, the magnetization fixed layer connection electrode 6 to which the magnetization fixed layer 2 is connected, and the magnetization free layer connection electrode which is one end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4 A first electrode end portion 5a, a second electrode end portion 5b of the magnetization free layer connection electrode which is the other end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4, and a high frequency signal. , A second port 9b for outputting a high frequency signal, a signal line 7, a DC voltage input terminal 11, a first reference voltage terminal 14a, and a first inductor 10a. It has a second inductor 10b, the first inductor 10a is connected to the ground 8 via the first reference voltage terminal 14a, and the second inductor 10b is connected to the magnetization fixed layer connection electrode 6. It is connected between the signal line 7 and the ground 8. The magnetoresistive effect element 1 is connected to the signal line 7 so that the magnetization fixed layer 2 side faces the second port 9b side, and a direct current input from the direct current voltage input terminal 11 passes through the magnetoresistive effect element 1 inside. It is arranged so as to flow from the magnetization fixed layer 2 to the magnetization free layer 4. Further, the first reference voltage terminal 14a is connected via the first inductor 10a to the signal line 7 to which the first electrode end portion 5a of the magnetization free layer connecting electrode is connected, and input from the DC voltage input terminal 11. Is arranged so that a direct current is generated in the magnetization free layer connection electrode 5 from the first electrode end 5a of the magnetization free layer connection electrode toward the second electrode end 5b of the magnetization free layer connection electrode. ing.

Therefore, by inputting a high frequency signal from the first port 9a to the magnetoresistive effect element 1 via the signal line 7, spin torque resonance can be induced in the magnetoresistive effect element 1. At the same time as this spin torque resonance, a DC current flows from the magnetization fixed layer 2 to the magnetization free layer 4 in the magnetoresistive effect element 1, whereby spin transfer torque can be induced, and the magnetoresistive effect element 1 is , 180° out of phase with the high frequency signal input from the first port, it can be treated as an element whose resistance value periodically oscillates at a frequency corresponding to the spin torque resonance frequency. Further, a direct current is passed through the magnetization free layer connecting electrode 5 from the first electrode end 5a of the magnetization free layer connecting electrode to the second electrode end 5b of the magnetization free layer connecting electrode, whereby the spin transfer torque is increased. Spin orbital torque can be induced in the same direction as, and the amplitude of the oscillating resistance can be increased. Due to this effect, the element impedance of the magnetoresistive effect element 1 with respect to the same frequency as the spin torque resonance frequency of the magnetoresistive effect element 1 is greatly increased. That is, the magnetoresistive effect device 104 can have frequency characteristics as a high frequency filter.

(Fifth Embodiment)
FIG. 12 is a schematic cross-sectional view of the magnetoresistive effect device 105 according to the fifth embodiment of the present invention. In the magnetoresistive effect device 105, differences from the magnetoresistive effect device 102 of the second embodiment will be mainly described, and common items will not be described as appropriate. The elements common to the magnetoresistive effect device 102 of the second embodiment are denoted by the same reference numerals, and the description of the common elements is omitted. The magnetoresistive effect device 105 further includes a first inductor 10a and a second reference voltage terminal 14b, unlike the magnetoresistive effect device 103 of the second embodiment. The first port 9a, the first electrode end 5a of the magnetization free layer connection electrode, the magnetization free layer connection electrode 5, the second electrode end 5b of the magnetization free layer connection electrode and the second port 9b are the signal line 7 Are connected in series in this order. The first reference voltage terminal 14a is connected via the first inductor 10a to the signal line 7 to which the first electrode end 5a of the magnetization free layer connecting electrode is connected, and the DC voltage input terminal 11 is The second electrode end 5b of the free layer connection electrode is connected to the connected signal line 7. The first inductor 10a is connected to the ground 8 via the first reference voltage terminal 14a. In the magnetoresistive effect element 1, the magnetization fixed layer 2 side is connected to the ground 8 via the second reference voltage terminal 14b, and the direct current input from the direct current voltage input terminal 11 magnetizes the inside of the magnetoresistive effect element 1. It is arranged so as to flow from the free layer 4 to the magnetization fixed layer 2. Further, the direct current input from the DC voltage input terminal 11 passes through the magnetization free layer connecting electrode 5 from the second electrode end 5b of the magnetization free layer connecting electrode to the first electrode end of the magnetization free layer connecting electrode. It is arranged so as to flow in the direction of 5a. Other configurations of the magnetoresistive effect device 105 are the same as those of the magnetoresistive effect device 102 of the second embodiment.

The magnetoresistive effect element 1 is arranged so that a DC current input from the DC voltage input terminal 11 flows through the magnetoresistive effect element 1 from the magnetization free layer 4 to the magnetization fixed layer 2.

The first inductor 10a is connected between the signal line 7 and the ground 8 and has a function of cutting off the high frequency component of the current by the inductor component and at the same time allowing the direct current component of the current to pass. The first inductor 10a may be either a chip inductor or a pattern line inductor. Alternatively, a resistance element having an inductor component may be used. The inductance value of the first inductor 10a is preferably 10 nH or more. By the first inductor 10a, the first electrode end 5a of the magnetization free layer connecting electrode, the magnetization free layer connecting electrode 5, the second electrode end 5b of the magnetization free layer connecting electrode, the signal line 7, the DC voltage input terminal. A DC current applied from the DC voltage input terminal 11 can be passed through a closed circuit including the DC voltage source 13, the DC voltage source 13, the first inductor 10a, the first reference voltage terminal 14a, and the ground 8. Further, by adjusting the resistance component of the first inductor 10a and the resistance component between the magnetoresistive effect element 1, the magnetization fixed layer connection electrode 6 and the ground 8, the amount of current flowing in the magnetization free layer connection electrode is adjusted. You can also do it.

The magnetic field applying mechanism 12 is disposed near the magnetoresistive effect element 1, and can apply a magnetic field to the magnetoresistive effect element 1 to set the spin torque resonance frequency. For example, the magnetic field applying mechanism 12 is configured by an electromagnet type or a strip line type in which the applied magnetic field strength can be variably controlled by either voltage or current. The magnetic field applying mechanism 12 may be configured by a combination of an electromagnet type or a stripline type and a permanent magnet that supplies only a constant magnetic field. The magnetic field applying mechanism 12 can change the effective magnetic field in the magnetization free layer 4 by changing the magnetic field applied to the magnetoresistive effect element 1 to change the spin torque resonance frequency of the magnetoresistive effect element 1.

Here, the torque related to the spin torque resonance phenomenon will be described.

A high-frequency signal having the same frequency as the spin torque resonance frequency is applied to the magnetoresistive effect element 1 while applying a direct current flowing in the magnetoresistive effect element 1 in the direction from the magnetization free layer 4 to the magnetization fixed layer 2. , The resistance value of the magnetoresistive effect element 1 periodically changes at the spin torque resonance frequency in the same phase as the input high frequency signal due to the spin transfer torque, and the impedance for the high frequency signal decreases. .. That is, the magnetoresistive effect element 1 can be treated as a resistance element in which the impedance of the high frequency signal decreases at the spin torque resonance frequency due to the spin torque resonance phenomenon.

Further, a direct current is caused to flow from the second electrode end portion 5b of the magnetization free layer connection electrode to the first electrode end portion 5a of the magnetization free layer connection electrode in the magnetization free layer connection electrode 5 in contact with the magnetization free layer 4. Thus, the spin orbit torque can be induced in the same direction as the spin transfer torque. By combining the spin transfer torque and the spin orbit torque, the amplitude of magnetization of the vibrating magnetization free layer can be further increased. That is, since the amplitude of resistance vibration can be increased, the impedance of the high frequency signal at the spin torque resonance frequency can be treated as a resistance element that is further greatly reduced.

The spin torque resonance frequency changes depending on the effective magnetic field in the magnetization free layer 4. The effective magnetic field Heff in the magnetization free layer 4 is the external magnetic field HE applied to the magnetization free layer 4, the anisotropic magnetic field Hk in the magnetization free layer 4, the demagnetizing field HD in the magnetization free layer 4, and the exchange coupling magnetic field in the magnetization free layer 4. With HEX,
Heff=HE+Hk+HD+HEX
It is represented by. The magnetic field applying mechanism 12 is an effective magnetic field setting mechanism capable of setting an effective magnetic field Heff in the magnetization free layer 4 by applying a magnetic field to the magnetoresistive effect element 1 and applying an external magnetic field HE to the magnetization free layer 4. The magnetic field applying mechanism 12, which is an effective magnetic field setting mechanism, changes the magnetic field applied to the magnetoresistive effect element 1 to change the effective magnetic field in the magnetization free layer 4 to change the spin torque resonance frequency of the magnetoresistive effect element 1. Can be made Thus, when the magnetic field applied to the magnetoresistive effect element 1 is changed, the spin torque resonance frequency of the magnetoresistive effect element 1 changes.

Further, when a DC current is applied to the magnetoresistive effect element 1 at the time of spin torque resonance, the spin transfer torque increases and the amplitude of the oscillating resistance value increases. As the amplitude of the oscillating resistance value increases, the amount of change in the element impedance of the magnetoresistive effect element 1 increases. Further, when the current density of the applied direct current is changed, the spin torque resonance frequency changes. Therefore, the spin torque resonance frequency of the magnetoresistive effect element 1 can be changed by changing the magnetic field from the magnetic field applying mechanism 12 or changing the applied DC current input from the DC voltage input terminal 11. The current density of the DC current applied to the magnetoresistive effect element 1 is preferably smaller than the respective oscillation threshold current densities. The oscillation threshold current density of the magnetoresistive effect element, by applying a direct current of a current density of this value or more, the magnetization of the magnetization free layer of the magnetoresistive effect element starts precession at a constant frequency and a constant amplitude, It is a threshold current density at which the magnetoresistive effect element oscillates (the output (resistance value) of the magnetoresistive effect element varies at a constant frequency and a constant amplitude).

Further, when a DC current having the same magnetic field and the same current density is applied to the magnetoresistive effect element, the spin torque resonance of the magnetoresistive effect element increases as the aspect ratio of the magnetoresistive effect element in plan view increases. The frequency will be higher. Here, the “aspect ratio of the plan view shape” is the ratio of the length of the long side to the length of the short side of the rectangle circumscribing the plan view shape of the magnetoresistive effect element in the minimum area.

The magnetic field angle (the relative angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer) applied to the magnetoresistive effect element 1 from the magnetic field applying mechanism 12 is preferably 90° or more. When the magnetic field angle is 90° or more, the magnetization of the magnetization free layer can maintain the precession in the direction opposite to the spin transfer torque and the spin orbit torque. That is, since the amplitude of resistance vibration can be increased, it can be treated as a resistance element in which the impedance of the high frequency signal changes significantly at the spin torque resonance frequency.

As described above, in the magnetoresistive effect device 105, the frequency component of the high-frequency signal that is input from the first port 9a and is not near the spin torque resonance frequency of the magnetoresistive effect element 1 is in the high impedance state. Pass through the second port 9b without passing through. Further, the frequency component of the high frequency signal in the vicinity of the spin torque resonance frequency, which is input from the first port 9a, flows through the magnetoresistive effect element 1 in the low impedance state to the ground 8 and is blocked from the second port 9b. To do. That is, the magnetoresistive effect device 105 can have a function of a high frequency filter in which the frequency near the spin torque resonance frequency of the magnetoresistive effect element 1 has a stop band. That is, the magnetoresistive effect device 105 is a band cutoff type filter (band elimination filter).

13 and 14 are graphs showing the relationship between the frequency and the attenuation amount of the high frequency signal input to the magnetoresistive effect device 105. 13 and 14, the vertical axis represents the attenuation amount IL (dB) and the horizontal axis represents the frequency F (Hz). FIG. 13 is a graph when the magnetic field applied to the magnetoresistive effect element 1 is constant. A plot line 100i1 in FIG. 13 is obtained when the DC current value applied to the magnetoresistive effect element 1 from the DC voltage input terminal 11 is Ii1, and a plot line 100i2 changes from the DC voltage input terminal 11 to the magnetoresistive effect element 1. The value of the applied direct current value is Ii2. The relationship of the direct current values at this time is Ii1<Ii2. Further, FIG. 14 is a graph when the direct current applied to the magnetoresistive effect element 1 is constant. The plot line 100j1 in FIG. 14 is when the magnetic field strength applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1 is Hj1, and the plot line 100j2 is applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1. The magnetic field strength is Hj2. The relationship of the magnetic field strength at this time is Hj1<Hj2.

For example, as shown in FIG. 13, when the DC current value applied from the DC voltage input terminal 11 to the magnetoresistive effect element 1 is increased from Ii1 to Ii2, the spin of the magnetoresistive effect element 1 changes as the current value changes. By increasing the amount of change in the element impedance of the magnetoresistive effect element 1 at a frequency near the torque resonance frequency (frequency in the cutoff band), the high-frequency signal output from the second port 9b becomes even smaller and passes through. The loss will increase. Therefore, the magnetoresistive effect device 105 can realize a high frequency filter having a wide range of the cutoff characteristic and the pass characteristic. When the DC current value is increased from Ii1 to Ii2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fi1 to fi2. That is, the pass frequency band shifts to the low frequency side. That is, the magnetoresistive effect device 105 can also function as a high frequency filter capable of changing the frequency in the cutoff frequency band.

Further, for example, as shown in FIG. 14, when the magnetic field strength applied from the magnetic field applying mechanism 12 is increased from Hj1 to Hj2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fj1 to fj2. That is, the cutoff frequency band shifts to the high frequency side. Further, changing the magnetic field strength (effective magnetic field H _eff in the magnetization free layer 4) can shift the cut-off frequency band more than changing the DC current value. That is, the magnetoresistive effect device 105 can function as a high frequency filter capable of changing the frequency in the cutoff frequency band.

As the external magnetic field H _E (effective magnetic field H _eff in the magnetization free layer 4) applied to the magnetoresistive effect element 1 increases, the amplitude of the oscillating resistance value of the magnetoresistive effect element 1 decreases. It is preferable to increase the current density of the direct current applied to the magnetoresistive effect element 1 as the external magnetic field H _E (effective magnetic field H _eff in the magnetization free layer 4) applied to the effect element is increased.

Thus, in the magnetoresistive effect device 105, the magnetoresistive effect element 1 having the magnetization fixed layer 2, the magnetization free layer 4, and the spacer layer 3 arranged therebetween, and the magnetization free layer 4 are connected. The connection electrode 5, the magnetization fixed layer connection electrode 6 to which the magnetization fixed layer 2 is connected, and the magnetization free layer connection electrode which is one end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4 A first electrode end portion 5a, a second electrode end portion 5b of the magnetization free layer connection electrode which is the other end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4, and a high frequency signal. , A second port 9b for outputting a high-frequency signal, a signal line 7, a DC voltage input terminal 11, a first reference voltage terminal 14a, and a second reference voltage terminal. 14b and the first inductor 10a, and the first inductor 10a is connected to the ground 8 via the first reference voltage terminal 14a. In the magnetoresistive effect element 1, the magnetization fixed layer 2 side is connected to the ground 8 via the second reference voltage terminal 14b, and the direct current input from the direct current voltage input terminal 11 magnetizes the inside of the magnetoresistive effect element 1. It is arranged so as to flow from the free layer 4 to the magnetization fixed layer 2. Further, the first reference voltage terminal 14a is connected via the first inductor 10a to the signal line 7 to which the first electrode end portion 5a of the magnetization free layer connecting electrode is connected, and input from the DC voltage input terminal 11. Is arranged so that a direct current is generated in the magnetization free layer connecting electrode 5 from the second electrode end 5b of the magnetization free layer connecting electrode toward the first electrode end 5a of the magnetization free layer connecting electrode. ing.

Therefore, by inputting a high frequency signal from the first port 9a to the magnetoresistive effect element 1 via the signal line 7, spin torque resonance can be induced in the magnetoresistive effect element 1. At the same time as this spin torque resonance, a DC current flows from the magnetization free layer 4 to the magnetization fixed layer 2 in the magnetoresistive effect element 1, whereby spin transfer torque can be induced, and the magnetoresistive effect element 1 is , And can be treated as an element whose resistance value periodically oscillates at a frequency corresponding to the spin torque resonance frequency in the same phase as the high frequency signal input from the first port. Further, a direct current is passed through the magnetization free layer connecting electrode 5 from the second electrode end 5b of the magnetization free layer connecting electrode to the first electrode end 5a of the magnetization free layer connecting electrode, whereby the spin transfer torque is increased. Spin orbital torque can be induced in the same direction as, and the amplitude of the oscillating resistance can be increased. Due to this effect, the element impedance of the magnetoresistive effect element 1 for the same frequency as the spin torque resonance frequency of the magnetoresistive effect element 1 is reduced. That is, the magnetoresistive effect device 105 can have frequency characteristics as a high frequency filter.

Further, in order to increase the range of the cutoff characteristic and the pass characteristic, the magnetization free layer 4 has an easy axis of magnetization in the normal direction to the film surface, and the fixed magnetization layer 2 has an easy axis of magnetization in the film surface direction. Preferably.

Further, since the spin torque resonance frequency of the magnetoresistive effect element 1 can be variably controlled by changing the direct current applied from the DC voltage input terminal 11, the magnetoresistive effect device 105 functions as a frequency variable filter. It is also possible to do.

Further, since the magnetoresistive effect device 105 has the magnetic field applying mechanism 12 as a frequency setting mechanism capable of setting the spin torque resonance frequency of the magnetoresistive effect element 1, the spin torque resonance frequency of the magnetoresistive effect element 1 is set to an arbitrary frequency. Can be Therefore, the magnetoresistive effect device 105 can function as a filter in an arbitrary frequency band.

Further, in the magnetoresistive effect device 105, the magnetic field applying mechanism 12 is an effective magnetic field setting mechanism capable of setting the effective magnetic field in the magnetization free layer 4, and the effective magnetic field in the magnetization free layer 4 is changed to change the effective magnetic field in the magnetoresistive effect element 1. Since the spin torque resonance frequency can be changed, it can function as a frequency variable filter.

In the magnetoresistive device 105, the signal line 7 on the side of the first port 9a has been described as an example connected to the first electrode end 5a of the magnetization free layer connecting electrode, but the signal line 7 is directly It may be connected to the magnetization free layer connection electrode 5.

(Sixth Embodiment)
FIG. 15 is a schematic sectional view of the magnetoresistive effect device 106 according to the sixth embodiment of the present invention. The differences between the magnetoresistive effect device 106 and the magnetoresistive effect device 105 of the fifth embodiment will be mainly described, and common items will be omitted as appropriate. The elements common to the magnetoresistive effect device 105 of the fifth embodiment are denoted by the same reference numerals, and the description of the common elements is omitted. The magnetoresistive effect device 106 is different from the magnetoresistive effect device 105 of the fifth embodiment in that the direct current input from the direct current voltage input terminal 11 moves from the magnetization fixed layer 2 to the magnetization free layer in the magnetoresistive effect element 1. It is arranged so as to flow in the direction of 4. Further, a direct current input from the DC voltage input terminal 11 passes through the magnetization free layer connecting electrode 5 from the first electrode end 5a of the magnetization free layer connecting electrode to the second electrode end of the magnetization free layer connecting electrode. It is arranged so as to flow in the direction of 5b. The other configurations of the magnetoresistive effect device 106 are the same as those of the magnetoresistive effect device 105 of the fifth embodiment.

The magnetoresistive effect element 1 is arranged so that a DC current input from the DC voltage input terminal 11 flows through the magnetoresistive effect element 1 from the magnetization fixed layer 2 to the magnetization free layer 4.

Here, the torque related to the spin torque resonance phenomenon will be described.

A high-frequency signal having the same frequency as the spin torque resonance frequency is applied to the magnetoresistive effect element 1 while applying a direct current flowing in the magnetoresistive effect element 1 in the direction from the magnetization fixed layer 2 to the magnetization free layer 4. , The resistance value of the magnetoresistive effect element 1 periodically changes at the spin torque resonance frequency in a state in which the phase is different by 180° from the input high frequency signal due to the spin transfer torque. Will increase. That is, the magnetoresistive effect element 1 can be treated as a resistance element in which the impedance of the high frequency signal increases at the spin torque resonance frequency due to the spin torque resonance phenomenon.

Further, in the magnetization free layer connecting electrode 5 in contact with the magnetization free layer 4, a direct current is caused to flow from the first electrode end 5a of the magnetization free layer connecting electrode to the second electrode end 5b of the magnetization free layer connecting electrode. Thus, the spin orbit torque can be induced in the same direction as the spin transfer torque. By combining the spin transfer torque and the spin orbit torque, the amplitude of magnetization of the vibrating magnetization free layer can be further increased. That is, since the amplitude of the resistance vibration can be increased, the impedance of the high frequency signal at the spin torque resonance frequency can be treated as a resistance element that further increases.

The magnetic field angle (relative angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer) applied to the magnetoresistive effect element 1 from the magnetic field applying mechanism 12 is preferably 90° or less. When the magnetic field angle is 90° or less, the magnetization of the magnetization free layer can maintain the precession in the direction opposite to the spin transfer torque and the spin orbit torque. That is, since the amplitude of resistance vibration can be increased, it can be treated as a resistance element in which the impedance of the high frequency signal changes significantly at the spin torque resonance frequency.

As described above, in the magnetoresistive effect device 106, the frequency component of the high-frequency signal that is input from the first port 9a and is not near the spin torque resonance frequency of the magnetoresistive effect element 1 is in the low impedance state. To the ground 8 and cut off for the second port 9b. Further, the frequency component of the high frequency signal in the vicinity of the spin torque resonance frequency, which is input from the first port 9a, passes to the second port 9b without passing through the magnetoresistive effect element 1 in the high impedance state. That is, the magnetoresistive effect device 106 can have a function of a high frequency filter having a pass band at a frequency near the spin torque resonance frequency of the magnetoresistive effect element 1. That is, the magnetoresistive effect device 106 is a bandpass filter (bandpass filter).

16 and 17 are graphs showing the relationship between the frequency and the amount of attenuation of the high frequency signal input to the magnetoresistive effect device 106. 16 and 17, the vertical axis represents the attenuation amount IL (dB) and the horizontal axis represents the frequency F (Hz). FIG. 16 is a graph when the magnetic field applied to the magnetoresistive effect element 1 is constant. The plot line 100k1 of FIG. 16 is when the DC current value applied to the magnetoresistive effect element 1 from the DC voltage input terminal 11 is Ik1, and the plot line 100k2 is from the DC voltage input terminal 11 to the magnetoresistive effect element 1. The value of the applied DC current value is Ik2. The relationship of the direct current values at this time is Ik1<Ik2. In addition, FIG. 17 is a graph when the direct current applied to the magnetoresistive effect element 1 is constant. A plot line 100l1 in FIG. 17 is when the magnetic field strength applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1 is Hl1, and a plot line 100l2 is applied from the magnetic field applying mechanism 12 to the magnetoresistive effect element 1. The magnetic field strength is H12. The relationship of the magnetic field strength at this time is Hl1<Hl2.

For example, as shown in FIG. 16, when the DC current value applied from the DC voltage input terminal 11 to the magnetoresistive effect element 1 is increased from Ik1 to Ik2, the spin of the magnetoresistive effect element 1 changes as the current value changes. By increasing the amount of change in the element impedance of the magnetoresistive effect element 1 at a frequency near the torque resonance frequency (passband frequency), the high-frequency signal output from the second port 9b is further increased and the pass The loss is small. Therefore, the magnetoresistive effect device 106 can realize a high frequency filter having a wide range of the cutoff characteristic and the pass characteristic. When the DC current value is increased from Ik1 to Ik2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fk1 to fk2. That is, the pass frequency band shifts to the low frequency side. That is, the magnetoresistive effect device 106 can also function as a high frequency filter capable of changing the frequency of the pass frequency band.

Further, for example, as shown in FIG. 17, when the magnetic field strength applied from the magnetic field applying mechanism 12 is increased from Hl1 to Hl2, the spin torque resonance frequency of the magnetoresistive effect element 1 shifts from fl1 to fl2. That is, the pass frequency band shifts to the high frequency side. Further, changing the magnetic field strength (effective magnetic field H _eff in the magnetization free layer 4) can shift the pass frequency band more than changing the direct current value. That is, the magnetoresistive effect device 106 can function as a high frequency filter capable of changing the frequency of the pass frequency band.

As described above, in the magnetoresistive effect device 106, the magnetoresistive effect element 1 having the magnetization fixed layer 2, the magnetization free layer 4, and the spacer layer 3 arranged therebetween, and the magnetization free layer 4 are connected. The connection electrode 5, the magnetization fixed layer connection electrode 6 to which the magnetization fixed layer 2 is connected, and the magnetization free layer connection electrode which is one end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4 A first electrode end portion 5a, a second electrode end portion 5b of the magnetization free layer connection electrode which is the other end of the magnetization free layer connection electrode 5 sandwiching the connection portion connected to the magnetization free layer 4, and a high frequency signal. , A second port 9b for outputting a high-frequency signal, a signal line 7, a DC voltage input terminal 11, a first reference voltage terminal 14a, and a second reference voltage. It has a terminal 14b and a first inductor 10a, and the first inductor 10a is connected to the ground 8 via the first reference voltage terminal 14a. In the magnetoresistive effect element 1, the magnetization fixed layer 2 side is connected to the ground 8, and a direct current input from the direct current voltage input terminal 11 passes through the magnetoresistive effect element 1 from the magnetization fixed layer 2 to the magnetization free layer 4. It is arranged to flow into. Further, the first reference voltage terminal 14a is connected via the first inductor 10a to the signal line 7 to which the first electrode end portion 5a of the magnetization free layer connecting electrode is connected, and input from the DC voltage input terminal 11. Is arranged so that a direct current is generated in the magnetization free layer connection electrode 5 from the first electrode end 5a of the magnetization free layer connection electrode toward the second electrode end 5b of the magnetization free layer connection electrode. ing.

Therefore, by inputting a high frequency signal from the first port 9a to the magnetoresistive effect element 1 via the signal line 7, spin torque resonance can be induced in the magnetoresistive effect element 1. At the same time as this spin torque resonance, a DC current flows from the magnetization fixed layer 2 to the magnetization free layer 4 in the magnetoresistive effect element 1, whereby spin transfer torque can be induced, and the magnetoresistive effect element 1 is , 180° out of phase with the high frequency signal input from the first port, it can be treated as an element whose resistance value periodically oscillates at a frequency corresponding to the spin torque resonance frequency. Further, a direct current is passed through the magnetization free layer connecting electrode 5 from the first electrode end 5a of the magnetization free layer connecting electrode to the second electrode end 5b of the magnetization free layer connecting electrode, whereby the spin transfer torque is increased. Spin orbital torque can be induced in the same direction as, and the amplitude of the oscillating resistance can be increased. Due to this effect, the element impedance of the magnetoresistive effect element 1 with respect to the same frequency as the spin torque resonance frequency of the magnetoresistive effect element 1 is greatly increased. That is, the magnetoresistive effect device 106 can have frequency characteristics as a high frequency filter.

Although the preferred embodiment of the present invention has been described above, it is possible to make changes and add components other than the above-described embodiment. For example, in order to prevent a DC signal from flowing in the high-frequency circuit connected to the first port 9a, the connection between the first inductor 10a and the signal line 7 in the first to sixth embodiments and the first port A capacitor for cutting a DC signal may be connected in series to the signal line 7 between the signal line 9a and 9a. Further, in order to prevent a DC signal from flowing in the high frequency circuit connected to the second port 9b, the connection portion between the DC voltage input terminal 11 and the signal line 7 in the first to sixth embodiments and the second port A capacitor for cutting a DC signal may be connected in series to the signal line 7 between the signal line 9b and 9b.

Further, in the third to sixth embodiments, the example using the inductor 10 has been described, but a resistor element may be used instead of the inductor 10. In this case, the resistance element is connected between the signal line 7 and the ground 8 and has a function of cutting off the high frequency component of the current by the resistance component. This resistance element may be either a chip resistance or a resistance by a patterned line. The resistance value of this resistance element is preferably equal to or larger than the characteristic impedance of the signal line 7. For example, when the characteristic impedance of the signal line 7 is 50Ω, 45% of high frequency power is cut by the resistance element when the resistance value of the resistance element is 50Ω, and 90% of high frequency power when the resistance value of the resistance element is 500Ω. Can be cut by a resistance element. With this resistance element, a closed circuit including the magnetoresistance effect element 1, the signal line 7, the resistance element, the ground 8 and the DC voltage input terminal 11 can be formed without deteriorating the characteristics of the high frequency signal passing through the magnetoresistance effect element 1. A DC current applied from the DC voltage input terminal 11 can flow.

When a resistance element is used instead of the inductor 10, a DC signal is applied to the signal line 7 between the connection portion of the resistance element (or the first reference voltage terminal 14a) to the signal line 7 and the first port 9a. A capacitor for cutting is connected in series, and a DC signal is applied to the signal line 7 between the connection portion of the DC voltage input terminal 11 (or resistance element) to the signal line 7 and the second port 9b. Connecting a capacitor for cutting in series is a direct current applied from the DC voltage input terminal 11 to a closed circuit including the magnetoresistive effect element 1, the signal line 7, the resistance element, the ground 8 and the DC voltage input terminal 11. It is preferable in that an electric current can be efficiently passed.

In addition, in the first to sixth embodiments, the orientation of the high-frequency signal flowing in the magnetoresistive effect element with respect to the magnetoresistive effect element is the same as the orientation illustrated in the description of the first to sixth embodiments. The magnetoresistive effect element may be arranged so as to be opposite. For example, in the first, third and fourth embodiments, the magnetization free layer 4 side of the magnetoresistive effect element 1 is connected to the first port 9a side, and the magnetization fixed layer 2 side is connected to the second port 9b side. However, the magnetization fixed layer 2 side of the magnetoresistive effect element 1 may be connected to the first port 9a side, and the magnetization free layer 4 side may be connected to the second port 9b side.

Further, in the third to sixth embodiments, the magnetoresistive effect device 103 (104, 105, 106) is described as an example having the magnetic field applying mechanism 12 as a frequency setting mechanism (effective magnetic field setting mechanism). The setting mechanism (effective magnetic field setting mechanism) may be another example as described below. For example, by applying an electric field to the magnetoresistive effect element and changing the electric field, the anisotropic magnetic field H _k in the magnetization free layer is changed to change the effective magnetic field in the magnetization free layer, and the spin of the magnetoresistive effect element is changed. The torque resonance frequency can be changed. In this case, the mechanism for applying the electric field to the magnetoresistive effect element is the frequency setting mechanism (effective magnetic field setting mechanism). Further, by providing a piezoelectric body near the magnetization free layer and applying an electric field to the piezoelectric body to deform the piezoelectric body to distort the magnetization free layer, the anisotropic magnetic field H _k in the magnetization free layer is changed. By changing the effective magnetic field in the magnetization free layer, the spin torque resonance frequency of the magnetoresistive effect element can be changed. In this case, the mechanism for applying an electric field to the piezoelectric body and the piezoelectric body serve as a frequency setting mechanism (effective magnetic field setting mechanism). Further, a control film, which is an antiferromagnetic material or a ferrimagnetic material having an electromagnetic effect, is provided so as to be magnetically coupled to the magnetization free layer, a magnetic field and an electric field are applied to the control film, and a magnetic field applied to the control film and By changing at least one of the electric fields, the exchange coupling magnetic field H _EX in the magnetization free layer is changed to change the effective magnetic field in the magnetization free layer, and the spin torque resonance frequency of the magnetoresistive effect element can be changed. In this case, the mechanism for applying a magnetic field to the control film, the mechanism for applying an electric field to the control film, and the control film serve as a frequency setting mechanism (effective magnetic field setting mechanism).

Further, even if there is no frequency setting mechanism (even if the magnetic field from the magnetic field applying mechanism 12 is not applied), if the spin torque resonance frequency of the magnetoresistive effect element is a desired frequency, the frequency setting mechanism (magnetic field applying The mechanism 12) may be omitted.

DESCRIPTION OF SYMBOLS 1 Magnetoresistive effect element 2 Magnetization fixed layer 3 Spacer layer 4 Magnetization free layer 5 Magnetization free layer connection electrode 5a 1st electrode end part of magnetization free layer connection electrode 5b 2nd electrode end part of magnetization free layer connection electrode 6 Magnetization Fixed layer connection electrode 7 Signal line 8 Ground 9a First port 9b Second port 10a First inductor 10b Second inductor 11 DC voltage input terminal 12 Magnetic field applying mechanism 13 DC voltage source 14a First reference voltage terminal 14b Second reference voltage terminal 101, 102, 103, 104, 105, 106 Magnetoresistive device

Claims (7)

Magnetoresistive element having a magnetization fixed layer, a magnetization free layer, and a spacer layer arranged therebetween, a magnetization free layer connecting electrode to which the magnetization free layer is connected, and a magnetization fixed to which the magnetization fixed layer is connected. A layer connection electrode, the magnetoresistive effect element is arranged between the magnetization free layer connection electrode and the magnetization fixed layer connection electrode, and the magnetization free layer connection electrode is the magnetization free layer connection electrode. The magnetic free layer has a first electrode end and a second electrode end sandwiching a connection part connected to the magnetization free layer, and the first electrode end of the magnetization free layer connection electrode has a first reference voltage. And a second electrode end of the magnetization free layer connecting electrode connected to a DC voltage input terminal for inputting a DC voltage to the magnetization free layer connecting electrode ,
A resonance element in which the magnetization free layer connection electrode is connected to a first port for inputting a high frequency signal . A resonator comprising: the resonance element according to claim 1; and a second port that is connected to the magnetization fixed layer connection electrode and outputs a high frequency signal . A resonator comprising: the resonance element according to claim 1; and a second port that is connected to the magnetization free layer connection electrode and outputs a high-frequency signal . Magnetoresistive element having a magnetization fixed layer, a magnetization free layer, and a spacer layer arranged therebetween, a magnetization free layer connecting electrode to which the magnetization free layer is connected, and a magnetization fixed to which the magnetization fixed layer is connected. A layer connection electrode, a first port for inputting a high frequency signal, a second port for outputting a high frequency signal, a signal line, a first inductor or a first resistance element, a second inductor or A second resistance element, a DC voltage input terminal, and a first reference voltage terminal,
The magnetoresistive effect element is arranged between the magnetization free layer connection electrode and the magnetization fixed layer connection electrode, and the magnetization free layer connection electrode has the magnetization free layer connection electrode connected to the magnetization free layer. Having a first electrode end and a second electrode end with the connection part interposed therebetween,
In the magnetoresistive effect element, the first electrode end of the magnetization free layer connection electrode and the magnetization fixed layer connection electrode are connected in series to the first port and the second port via the signal line, The second electrode end of the magnetization free layer connecting electrode is connected to the DC voltage input terminal, and the first reference voltage terminal is connected to the first electrode end of the magnetization free layer connecting electrode. The signal line is connected to the signal line via the first inductor or the first resistance element, and the second inductor or the second resistance element is connected to the signal line to which the magnetization fixed layer connection electrode is connected. A magnetoresistive effect device characterized by being connected to the ground. Magnetoresistive element having a magnetization fixed layer, a magnetization free layer, and a spacer layer arranged therebetween, a magnetization free layer connecting electrode to which the magnetization free layer is connected, and a magnetization fixed to which the magnetization fixed layer is connected. A layer connection electrode, a first port for inputting a high frequency signal, a second port for outputting a high frequency signal, a signal line, a first inductor or a first resistance element, and a DC voltage input terminal. , Having a first reference voltage terminal and a second reference voltage terminal,
The magnetoresistive effect element is arranged between the magnetization free layer connection electrode and the magnetization fixed layer connection electrode, and the magnetization free layer connection electrode has the magnetization free layer connection electrode connected to the magnetization free layer. Having a first electrode end and a second electrode end with the connection part interposed therebetween,
In the magnetization free layer connection electrode, a first electrode end of the magnetization free layer connection electrode and a second electrode end of the magnetization free layer connection electrode are connected to the first port and the first port via the signal line. 2 is connected in series to the first reference voltage terminal, and the first reference voltage terminal is connected to the signal line to which the first electrode end of the magnetization free layer connection electrode is connected to the first inductor or the first resistance element. The DC voltage input terminal is connected to the signal line to which the second electrode end of the magnetization free layer connection electrode is connected, and the magnetization fixed layer connection electrode is connected to the second reference line. A magnetoresistive device characterized by being connected to a voltage terminal. The magnetoresistive effect device according to claim 4 or 5, further comprising a frequency setting mechanism capable of setting a spin torque resonance frequency of the magnetoresistive effect element. The frequency setting mechanism is an effective magnetic field setting mechanism capable of setting an effective magnetic field in the magnetization free layer, and the spin torque resonance frequency of the magnetoresistive effect element can be changed by changing the effective magnetic field. The magnetoresistive effect device according to claim 6.

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