JP2019103085A - Magnetic resistance effect device - Google Patents

Abstract

To provide a magnetic resistance effect device capable of reducing a capacitance component existed in between a coil used as a magnetic field application mechanism and a high frequency signal line pass.SOLUTION: A magnetic resistance effect device 100 comprises: a magnetic resistance effect element 101 formed by laminating so that a spacer 101C is arranged to between a first ferromagnetic layer 101A and a second ferromagnetic layer 101B; a coil 102 that is arranged on one side of the magnetic resistance effect element 101 in a direction parallel to a lamination direction L, and applies a magnetic field to the magnetic resistance effect element 101; and a high frequency signal line pass 103 that is arranged on the other side of the magnetic resistance effect element 101 the direction parallel to the lamination direction L.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetoresistive effect device using a magnetoresistive effect element.

  In recent years, with the advancement of mobile communication terminals such as mobile phones, speeding up of wireless communication has been promoted. Since the communication speed is proportional to the bandwidth of the frequency used, the frequency band required for communication increases, and accordingly, the number of high frequency filters required for the mobile communication terminal also increases. In addition, research in the field of spintronics, which is expected to be applied to new high frequency components, is actively conducted. Among them, one of the phenomena that has attracted attention is the spin torque resonance phenomenon due to the magnetoresistance effect element (see Non-Patent Document 1).

  For example, ferromagnetic resonance can be generated in the magnetization of the magnetization free layer included in the magnetoresistive element by applying a static magnetic field using a magnetic field application mechanism simultaneously with flowing an alternating current to the magnetoresistive element. The resistance value of the magnetoresistive element vibrates periodically at a frequency corresponding to the ferromagnetic resonance frequency. Further, the resistance value of the magnetoresistive element is similarly vibrated by applying a high frequency magnetic field to the magnetization free layer of the magnetoresistive element. The ferromagnetic resonance frequency changes depending on the strength of the static magnetic field applied to the magnetoresistive element, and the resonance frequency is generally included in a high frequency band of several to several tens of GHz.

  Patent Document 1 discloses a technology for changing the ferromagnetic resonance frequency by changing the strength of the magnetic field applied to the magnetoresistive effect element, and a device such as a high frequency filter using this technology is proposed. There is.

JP, 2017-63397, A

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

  Although the electromagnet type and the strip line type are mentioned as an example of a magnetic field application mechanism for applying a magnetic field to a magnetoresistive effect element in patent documents 1, about the detailed composition, it is not indicated. Generally as a method of applying a magnetic field to a magnetoresistive effect element, the method of applying the magnetic field generated using soft magnetic bodies, such as a yoke, and a coil to a magnetoresistive effect element can be considered. However, it has been found by this inventor's research that in this method, there is a possibility that the high frequency characteristics of the device may be deteriorated due to the capacitance component existing between the coil and the high frequency signal line.

  The present invention has been made in view of the above circumstances, and provides a magnetoresistance effect device that can reduce the capacitance component, which is present between a coil used as a magnetic field application mechanism and a high frequency signal line. With the goal.

  The present invention provides the following means in order to solve the above problems.

(1) A magnetoresistive effect element according to an aspect of the present invention is a magnetoresistive effect element formed by laminating such that a spacer layer is disposed between a first ferromagnetic layer and a second ferromagnetic layer. A coil disposed on one side of the magnetoresistive element in a direction parallel to the stacking direction for applying a magnetic field to the magnetoresistive element, and the magnetoresistive element in a direction parallel to the stacking direction And a high frequency signal line disposed on the other side of

(2) In the magnetoresistance effect device according to (1), the coil includes a first magnetic member disposed on the one side of the magnetoresistance effect element and having a protrusion on the magnetoresistance effect element side, the coil May be wound around the protrusion.

(3) In the magnetoresistive device according to any one of (1) and (2), the second magnetic member may be located at a position farther from the high frequency signal line to the other side when viewed from the magnetoresistive element. May be arranged.

  In the magnetoresistive device of the present invention, the high frequency signal line is disposed on the side opposite to the coil, not on the coil side in the direction parallel to the stacking direction, as viewed from the magnetoresistive element. Therefore, the distance between the high frequency signal line and the coil is increased compared to the case where the high frequency signal line is disposed on the coil side, and the capacitance component existing between the high frequency signal line and the coil increases the distance. Correspondingly smaller. Therefore, in the magnetoresistance effect device of the present invention, deterioration of high frequency characteristics can be suppressed.

It is a sectional view showing typically the composition of the magnetoresistive effect device concerning a first embodiment of the present invention. (A), (b) is a top view which shows typically the example of a structure of the magnetoresistive effect device based on 1st embodiment of this invention. It is sectional drawing which shows typically the structure of the magnetoresistive effect device which concerns on the modification 1 of 1st embodiment of this invention. It is sectional drawing which shows typically the structure of the magnetoresistive effect device which concerns on the modification 2 of 1st embodiment of this invention. It is a figure which shows the structural example of the circuit of a high frequency device to which the magnetoresistive effect device of this invention is applied.

  Hereinafter, the present invention will be described in detail with reference to the drawings as appropriate. The drawings used in the following description may show enlarged features for convenience for the purpose of making the features of the present invention easier to understand, and the dimensional ratio of each component may be different from the actual one. is there. The materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited to them, and can be appropriately modified and implemented within the scope of the effects of the present invention.

First Embodiment
FIG. 1 is a cross-sectional view schematically showing a configuration example of a magnetoresistance effect device 100 according to a first embodiment of the present invention. The magnetoresistance effect device 100 includes at least a magnetoresistance effect element (MR element) 101, a coil 102 for applying a magnetic field to the magnetoresistance effect element, and a high frequency signal line 103 through which a high frequency current flows. The magnetoresistive effect device 100 is configured such that a magnetic field (static magnetic field) generated from the coil 102 and a magnetic field (high frequency magnetic field) generated from the high frequency signal line 103 are applied to the magnetoresistive effect element 101.

  The magnetoresistance effect element 101 is stacked such that a spacer layer (nonmagnetic layer or the like) 101C is disposed between the first ferromagnetic layer 101A and the second ferromagnetic layer 101B. One of the first ferromagnetic layer 101A and the second ferromagnetic layer 101B functions as a magnetization fixed layer, and the other functions as a magnetization free layer. In this case, the magnetization direction of the magnetization free layer changes relatively to the magnetization direction of the magnetization fixed layer. The first ferromagnetic layer 101A and the second ferromagnetic layer 101B have different coercivities, and the coercivity of the layer functioning as the magnetization fixed layer is larger than the coercivity of the layer functioning as the magnetization free layer. . The thickness of the first ferromagnetic layer 101A and the second ferromagnetic layer 101B is preferably about 1 to 10 nm.

  When one of the first ferromagnetic layer 101A and the second ferromagnetic layer 101B is a magnetization free layer and the other is a magnetization fixed layer, the magnetization free layer is closer to the high frequency signal line 103 than the magnetization fixed layer. Are preferably arranged to be short.

  The first ferromagnetic layer 101A and the second ferromagnetic layer 101B are known materials having ferromagnetism, for example, metals such as Cr, Mn, Co, Fe, Ni, and the like so that the coercive forces are different from each other. And a material selected from a ferromagnetic alloy or the like containing one or more of them. The first ferromagnetic layer 101A and the second ferromagnetic layer 101B are alloys containing these metals and at least one or more elements of B, C, and N (specifically, Co—Fe). And Co-Fe-B).

Moreover, in order to obtain a higher output, it is preferable to use a Heusler alloy such as Co ₂ FeSi. The Heusler alloy comprises an intermetallic compound having a chemical composition of X ₂ YZ. X is a transition metal element or noble metal element of Co, Fe, Ni or Cu group on the periodic table, Y is a transition metal of Mn, V, Cr or Ti group or the same element as X, Z is a typical element of Group III to Group V. Examples of the Heusler alloy include Co ₂ FeSi, Co ₂ MnSi, and Co ₂ Mn _1-a Fe _a Al _b Si _1-b .

In order to fix the magnetization of the ferromagnetic layer (magnetization fixed layer) functioning as the magnetization fixed layer, an antiferromagnetic layer may be added to be in contact with the magnetization fixed layer. In addition, the magnetization of the magnetization fixed layer 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.

  It is preferable to use a nonmagnetic material for the spacer layer 101C. The spacer layer 101C is formed of a layer formed of a conductor, an insulator or a semiconductor, or a layer including a conduction point formed of a conductor in the insulator.

  For example, in the case where the spacer layer 101C is formed of an insulator, the magnetoresistive effect element 101 is a tunneling magnetoresistive (TMR) effect element, and in the case where the spacer layer 101C is formed of a metal, giant magnetoresistive (GMR) : Giant Magnetoresistance) It becomes an effect element.

When an insulating material is applied as the spacer layer 101C, an insulating material such as Al ₂ O ₃ or MgO can be used. A high magnetoresistance change rate can be obtained by adjusting the film thickness of the spacer layer 101C so that a coherent tunnel effect is exhibited between the first ferromagnetic layer 101A and the second ferromagnetic layer 101B. In order to use the TMR effect efficiently, the film thickness of the spacer layer 101C is preferably about 0.5 to 3.0 nm.

  When the spacer layer 101C is formed of a conductive material, a conductive material such as Cu, Ag, Au, or Ru can be used. In order to use the GMR effect efficiently, the thickness of the spacer layer 101C is preferably about 0.5 to 3.0 nm.

When the spacer layer 101C is formed of a semiconductor, a material such as ZnO, In ₂ O ₃ , SnO ₂ , ITO, GaO _x, or Ga ₂ O _x can be used. In this case, the thickness of the spacer layer 101C is preferably about 1.0 to 4.0 nm.

In the case where a layer including a conduction point constituted by a conductor in the insulator is applied as the spacer layer 101C, CoFe, CoFeB, CoFeSi, CoMnGe, CoMnSi, CoMnAl, or the like is contained in the insulator constituted by Al ₂ O ₃ or MgO. It is preferable to have a structure including a conduction point constituted by a conductor such as Fe, Co, Au, Cu, Al or Mg. In this case, the thickness of the spacer layer 101C is preferably about 0.5 to 2.0 nm.

  In the magnetoresistive element 101, both of the first ferromagnetic layer 101A and the second ferromagnetic layer 101B are magnetization free layers, and two magnetization free layers and a spacer layer disposed between the two magnetization free layers are used. It can also be a magnetoresistive effect element. In this case, the magnetization directions of the first ferromagnetic layer 101A and the second ferromagnetic layer 101B can be changed relative to each other. As an example, a magnetoresistive element in which two magnetization free layers are magnetically coupled to each other via a spacer layer can be mentioned. More specifically, there is an example in which two magnetization free layers are magnetically coupled to each other through a spacer layer such that the magnetization directions of the two magnetization free layers are antiparallel to each other in the state where no external magnetic field is applied. It can be mentioned.

  The coil 102 is disposed on one side of the magnetoresistive element 101 (above the magnetoresistive element 101 in FIG. 1) in a direction parallel to the stacking direction L. “One side of the magnetoresistance effect element 101” means a side not including the magnetoresistance effect element 101 with a plane including one end face of the magnetoresistance effect element 101 in the direction parallel to the stacking direction L as a boundary. ing. That is, when the stacking direction L is aligned in the vertical direction, “one side of the magnetoresistive effect element 101” includes not only immediately above the magnetoresistive effect element 101 but also obliquely upward.

  As the coil 102, a spiral or spirally wound metal pattern is used. FIG. 1 shows an example of a spirally wound metal pattern. Here, the illustration of the depth portion of the coil 102 is omitted. The winding direction of the coil 102 is not particularly limited, but the winding direction is preferably a direction parallel to the stacking direction L of the magnetoresistance effect element 101. In order to efficiently apply the magnetic field generated from the coil 102 to the magnetoresistive effect element 101, the center of the winding of the coil 102 is the magnetoresistive effect element 101 in plan view from the direction parallel to the stacking direction L. It is preferable to arrange so that it may overlap. By adjusting the value of the current flowing through the coil 102, the magnitude of the static magnetic field applied to the magnetoresistance effect element 101 can be changed.

  The high frequency signal line 103 is disposed on the other side in the direction parallel to the stacking direction L of the magnetoresistive effect elements 101 (under the magnetoresistive effect elements 101 in FIG. 1). “The other side of the magnetoresistance effect element 101” means a side not including the magnetoresistance effect element 101 at a plane including the other end face of the magnetoresistance effect element 101 in the direction parallel to the stacking direction L ing. That is, when the stacking direction L is aligned in the vertical direction, “the other side of the magnetoresistance effect element 101” includes not only directly below the magnetoresistance effect element 101 but also obliquely below.

  The high frequency signal line 103 extends in a predetermined direction according to the application. The extending direction of the high-frequency signal line 103 may include either a direction parallel to the stacking direction L or a direction intersecting the stacking direction L.

  The number of high frequency signal lines 103 is not limited, and may be one or plural. In the case of a plurality of lines, it is preferable that the high frequency signal lines 103 be arranged such that high frequency magnetic fields generated from the respective lines reinforce each other at the position of the magnetoresistive effect element 101.

  Lines 104 and 105 are connected to both ends of the magnetoresistive element 101 in the stacking direction L, respectively. A current or voltage is applied to the magnetoresistive element 101 through at least one of the line 104 and the line 105. Further, at least one of the line 104 and the line 105 transmits a signal output from the magnetoresistive element 101. For example, a direct current or a direct current voltage is applied to the magnetoresistive effect element 101 through the line 104 and the line 105. Further, for example, the signal line 105 transmits a signal (high frequency current or high frequency voltage) output from the magnetoresistive effect element 101.

  In order to enhance the conductivity of the magnetoresistive effect element 101, it is preferable that electrodes be provided at both ends of the magnetoresistive effect element 101. Here, an electrode provided on the upper end in the stacking direction of the magnetoresistive effect element 101 is referred to as an upper electrode 106, and an electrode provided on the lower end is referred to as a lower electrode 107. As a material of the line 104, the line 105, the upper electrode 106, and the lower electrode 107, for example, one having conductivity such as Ta, Cu, Au, AuCu, Ru, or Al can be used.

2A and 2B show the magnetoresistive effect element 101 shown in FIG. 1 in the stacking direction when the coil 102 is arranged to be wound around an axis parallel to the stacking direction L. direction parallel to the L shows a configuration example when viewed in plan from (L ₁ side or L ₂ side shown in FIG. 1). Here, only the portion in which three layers of the first ferromagnetic layer 101A, the second ferromagnetic layer 101B, and the spacer layer 101C overlap is shown as the magnetoresistive effect element 101.

  In order to efficiently apply the magnetic field generated from the coil 102 to the magnetoresistance effect element 101, at least a part of the magnetoresistance effect element 101 overlaps the area 102A surrounded by the coil in the plan view. preferable. The larger the portion where the magnetoresistive effect element 101 overlaps the area 102A surrounded by the coil, the better. As shown in FIGS. 2A and 2B, the entire magnetoresistive effect element 101 overlaps the area 102A. Most preferable.

  The high frequency signal line 103 may be arranged to overlap the magnetoresistive effect element 101 as shown in FIG. 2A in the plan view, and may not overlap as shown in FIG. 2B. It may be arranged in However, from the viewpoint of efficiently applying the magnetic field generated from the high frequency signal line 103 to the magnetoresistive effect element 101, the high frequency signal line 103 preferably overlaps the magnetoresistive effect element 101 in the plan view.

There is a path through which a high frequency current flows between the coil and the high frequency signal line due to the influence of the capacitance component existing between the coil and the high frequency signal line, so if this capacitor component is large, the high frequency characteristics of the magnetoresistive device are It may deteriorate. For example, part of the high frequency current flowing through the high frequency signal line may be diverted to the coil side, and the strength of the high frequency magnetic field applied to the magnetoresistive element may be reduced. Therefore, when the magnetoresistance effect device is applied to, for example, a high frequency filter to be described later, the pass characteristic of the high frequency filter may be deteriorated. In FIG. 1, the high-frequency signal line when disposed on the side of the coil 102 is shown as a dotted line at a position separated by a distance d ₂ from the coil 102. In this case, since the capacitance component existing between the coil and the high frequency signal line is large, the deterioration of the high frequency characteristics of the magnetoresistance effect device becomes large.

On the other hand, in the magnetoresistance effect device 100 according to this embodiment, the high frequency signal line 103 is not the coil 102 side (one side) in the direction parallel to the lamination direction L when viewed from the magnetoresistance effect element 101. The coil 102 is disposed on the opposite side (the other side). Therefore, the distance d ₁ between the high frequency signal line 103 and the coil 102 is increased compared to the distance d ₂ (see FIG. 1) in the case of being disposed on the coil 102 side. The capacitance component present in C.sub.x decreases with this increase in distance. Therefore, in the magnetoresistance effect device 100 according to the present embodiment, it is possible to suppress the deterioration of the high frequency characteristics (for example, the passing characteristics) described above.

(Modifications 1 and 2)
3 and 4 are cross-sectional views schematically showing configuration examples of the magnetoresistance effect devices 110 and 120 according to the first and second modifications of the first embodiment, respectively. The same parts as in the first embodiment are indicated by the same reference numerals.

(Modification 1)
In the magnetoresistive effect device 110 of FIG. 3, the first magnetic member 108 is disposed on one side of the magnetoresistive effect element 101, that is, the same side as the coil 102 when viewed from the magnetoresistive effect element 101. The first magnetic member 108 is a member that functions as a magnetic field application mechanism for applying a static magnetic field to the magnetoresistive effect element 101. The configuration other than the first magnetic member 108 is the same as the configuration of the above-described embodiment.

  When the first magnetic member 108 is a soft magnetic material (yoke), the material may be a soft magnetic material such as a metal or alloy containing at least one of Fe, Ni and Co (for example, a NiFe alloy or CoFe alloy etc. can be used.

  A hard magnetic material (magnet) may be used as the first magnetic member 108, and in that case, a coil may be wound around the first magnetic member 108 as shown in FIG. 1 or may not be wound. Good. When a hard magnetic material is used as the first magnetic member 118, a CoPt alloy, an FePt alloy, a CoCrPt alloy or the like can be used as the material. Further, an antiferromagnetic material such as IrMn may be magnetically coupled to the soft magnetic material described above, and the direction in which the magnetization of the soft magnetic material is fixed may be used as the first magnetic member 108. In that case, the coil may or may not be wound around the first magnetic member 108 as shown in FIG.

The first magnetic member 108 is composed of a base 108B and a projection 108A that protrudes from the base 108B toward the magnetoresistive element 101. No particular limitation is imposed on the shape of the protrusion 108A, a length from the rear end 108C of the protruding portion to the tip 108D (protrusion length) _{d 4} is preferably 100nm or more. The protrusion 108A may be integral with or separate from the base 108B that is the base thereof.

  The coil 112 is wound around the protrusion 108A of the first magnetic member. The coil 112 is preferably disposed such that the central axis direction thereof substantially coincides with the projecting direction of the projecting portion 108A.

In Modification 1, since the first magnetic member 108 is applied, it is possible to apply further large magnetic field to the magnetoresistive element 101, correspondingly, the distance d ₃ between the coil 102 and the magnetoresistive element 101 It will be able to spread. As a result, the distance _{d 1} between the coil 102 and the high-frequency signal transmission line 103 can also broaden. Therefore, the capacitance component existing between the coil 102 and the high frequency signal line 103 can be further reduced, and the deterioration of the high frequency characteristic can be suppressed.

(Modification 2)
In the magnetoresistive device 120 of FIG. 4, the second magnetic member 109 is disposed together with the first magnetic member 108 having the same configuration as that of the first modification. The second magnetic member 109 is a member that functions as a magnetic field application mechanism for applying a static magnetic field to the magnetoresistive effect element 101. The first magnetic member 108 and the second magnetic member 109 are preferably connected directly or via another magnetic member in a region outside the outer peripheral portion of the coil 102.

  The second magnetic member 109 is disposed at a position farther from the high frequency signal line 103 to the other side (opposite to the coil 102) when viewed from the magnetoresistive effect element 101. Although FIG. 5 illustrates the case where the magnetoresistive effect element 101 and the high frequency signal line 103 are sandwiched by two magnetic members (the first magnetic member 108 and the second magnetic member 109), the high frequency signal line 103 is illustrated. May not be sandwiched between the two magnetic members. The configuration other than the first magnetic member 108 and the second magnetic member 109 is the same as the configuration (FIG. 1) of the embodiment described above.

  As a material of the 2nd magnetic member 109, the thing similar to what was illustrated as a material of the 1st magnetic member 108 can be used. The material of the second magnetic member 109 may be the same as or different from the material of the first magnetic member 108.

In the second modification, by disposing the second magnetic member 109, much of the magnetic flux generated from the first magnetic member 108 extends toward the second magnetic member 109, and the magnetoresistive effect element is present halfway Through 101 As a result, the stronger magnetic field to the magnetoresistive element 101 is applied, that amount can be further widened distance d ₁ between the coil 102 and the high-frequency signal transmission line 103. Therefore, the capacitance component existing between the coil 102 and the high frequency signal line 103 can be further reduced.

(Example of application)
FIG. 5 shows an example of a circuit of a high frequency device 130 to which the magnetoresistive effect device 100 is applied. The high frequency device 130 includes a magnetoresistive effect element 101, a coil (magnetic field application mechanism) 102, a high frequency signal line 103, and a DC application terminal 131. The high frequency device 130 receives a signal from the first port 132 and outputs a signal from the second port 133. The high frequency device 130 in which other circuit elements and the like are incorporated together with the above-described magnetoresistive effect element, high frequency signal line, and coil may be generically called a magnetoresistive effect device.

<Magnetoresistance effect element, magnetic field application mechanism>
As the magnetoresistance effect element 101 and the coil 102, one that satisfies the configuration of the magnetoresistance effect device 100 according to the above-described first embodiment is used as an example. In this application example, the first ferromagnetic layer 101A functions as a magnetization fixed layer, and the second ferromagnetic layer 101B functions as a magnetization free layer.

  The coil 102 can be used to set the frequency of the output signal. The frequency of the output signal changes according to the ferromagnetic resonance frequency of the second ferromagnetic layer 101B functioning as the magnetization free layer. The ferromagnetic resonance frequency of the second ferromagnetic layer 101B is changed by the effective magnetic field in the second ferromagnetic layer 101B. The effective magnetic field in the second ferromagnetic layer 101B is affected by the external magnetic field (static magnetic field). Therefore, the ferromagnetic resonance frequency of the second ferromagnetic layer 101B can be changed by changing the magnitude of the external magnetic field applied from the coil 102 to the second ferromagnetic layer 101B.

<First port and second port>
The first port 132 is an input terminal of the high frequency device 130. The first port 132 corresponds to one end of the high frequency signal line 103. By connecting an alternating current signal source (not shown) to the first port 132, an alternating current signal (high frequency signal) can be applied to the high frequency device 130. The high frequency signal applied to the high frequency device 130 is, for example, a signal having a frequency of 100 MHz or more.

  The second port 133 is an output terminal of the high frequency device 130. The second port 133 corresponds to one end of the output signal line 135 which transmits the signal output from the magnetoresistive effect element 101. The output signal line 135 corresponds to the line 105 shown in FIG.

<High frequency signal line>
One end of the high frequency signal line 103 in FIG. 5 is connected to the first port 132. Further, the high frequency device 130 is used by connecting the other end of the high frequency signal line 103 to the reference potential via the reference potential terminal 134. In FIG. 5, it is connected to the ground G as a reference potential. The ground G can be attached to the outside of the high frequency device 130. A high frequency current flows in the high frequency signal line 103 in accordance with the potential difference between the high frequency signal input to the first port 132 and the ground G. When a high frequency current flows in the high frequency signal line 103, a high frequency magnetic field is generated from the high frequency signal line 103. The high frequency magnetic field is applied to the second ferromagnetic layer 101 B of the magnetoresistive effect element 101.

<Output signal line, line>
The output signal line 135 propagates the signal output from the magnetoresistive effect element 101. The signal output from the magnetoresistive effect element 101 is a signal of a frequency selected using the ferromagnetic resonance of the second ferromagnetic layer 101B. One end of the output signal line 135 in FIG. 5 is connected to the magnetoresistive effect element 101, and the other end is connected to the second port 133. That is, the output signal line 135 connects the magnetoresistive effect element 101 and the second port 133.

  Further, an output signal line 135 between a portion forming a closed circuit formed by the power supply 136, the output signal line 135, the magnetoresistive effect element 101, the line 137, and the ground G, and the second port 133 (as an example, A capacitor may be provided on the output signal line 135) between the connection to the output signal line 135 and the second port 133. By providing a capacitor in this portion, it is possible to prevent the invariance component of the current from being added to the output signal output from the second port 133.

  One end of the line 137 is connected to the magnetoresistive element 101. The line 137 corresponds to the line 104 shown in FIG. Also, the high frequency device 130 is connected to a reference potential via a reference potential terminal 138 to which the other end of the line 137 is connected. Although the line 137 is connected to the ground G common to the reference potential of the high-frequency signal line 103 in FIG. 5, it may be connected to another reference potential. In order to simplify the circuit configuration, it is preferable that the reference potential of the high frequency signal line 103 and the reference potential of the line 137 be common.

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

<DC application terminal>
The DC application terminal 131 is connected to the power supply 136 and applies a DC current or a DC voltage in the stacking direction of the magnetoresistance effect element 101. In the present specification, a direct current is a current whose direction does not change with time, and includes a current whose magnitude changes with time. Further, the DC voltage is a voltage whose direction does not change with time, and includes a voltage whose magnitude changes with time. The power supply 136 may be a direct current source or a direct current voltage source.

  The power source 136 may be a direct current source capable of generating a constant direct current, or may be a direct current voltage source capable of generating a constant direct current voltage. Further, the power supply 136 may be a direct current source whose magnitude of the generated direct current value can change, or may be a direct current voltage source whose magnitude of the generated direct current voltage value can change.

  The current density of the current applied to the magnetoresistive element is preferably smaller than the oscillation threshold current density of the magnetoresistive element. The oscillation threshold current density of the magnetoresistive element indicates that the magnetization of the ferromagnetic layer functioning as the magnetization free layer of the magnetoresistive element starts precession motion at a constant frequency and a constant amplitude, and the magnetoresistive element oscillates. Current density at which the output (resistance value of the magnetoresistance effect element fluctuates at a constant frequency and a constant amplitude) threshold value.

  An inductor 139 is disposed between the DC application terminal 131 and the output signal line 135. The inductor 139 cuts the high frequency component of the current and passes the invariant component of the current. The output signal (high frequency signal) output from the magnetoresistive element 101 by the inductor 139 efficiently flows to the second port 133. Further, due to the inductor 139, the invariant component of the current flows in a closed circuit composed of the power supply 136, the output signal line 135, the magnetoresistive effect element 101, the line 137, and the ground G.

  For the inductor 139, a chip inductor, an inductor with a pattern line, a resistive element having an inductor component, or the like can be used. The inductance of the inductor 139 is preferably 10 nH or more.

<Function of high frequency device>
When a high frequency signal is input to the high frequency device 130 from the first port 132, a high frequency current corresponding to the high frequency signal flows in the high frequency signal line 103. A high frequency magnetic field generated by a high frequency current flowing in the high frequency signal line 103 is applied to the second ferromagnetic layer 101 B of the magnetoresistive effect element 101.

  In the magnetization of the second ferromagnetic layer 101B functioning as the magnetization free layer, the frequency of the high frequency magnetic field applied to the second ferromagnetic layer 101B by the high frequency signal line 103 is close to the ferromagnetic resonance frequency of the second ferromagnetic layer 101B. If it vibrates greatly. This phenomenon is a ferromagnetic resonance phenomenon.

  When the oscillation of the magnetization of the second ferromagnetic layer 101B becomes large, the change in resistance value of the magnetoresistance effect element 101 becomes large. For example, when a constant direct current is applied to the magnetoresistive effect element 101 from the direct current application terminal 131, the change in resistance value of the magnetoresistive effect element 101 is determined by the potential difference between the upper electrode 106 and the lower electrode 107. It is outputted from the second port 133 as a change. Further, for example, when a constant direct current voltage is applied to the magnetoresistive effect element 101 from the direct current application terminal 131, the resistance value change of the magnetoresistive effect element 101 flows between the upper electrode 106 and the lower electrode 107. It is output from the second port 133 as a change in current value.

  That is, when the frequency of the high frequency signal input from the first port 132 is a frequency close to the ferromagnetic resonance frequency of the second ferromagnetic layer 101B, the amount of fluctuation of the resistance value of the magnetoresistance effect element 101 is large. , And a large signal is output from the second port 133. On the other hand, when the frequency of the high frequency signal deviates from the ferromagnetic resonance frequency of the second ferromagnetic layer 101 B, the amount of change in the resistance value of the magnetoresistive effect element 101 is small, and the signal from the second port 133 Is hardly output. That is, the high frequency device 130 functions as a high frequency filter that can selectively pass a high frequency signal of a specific frequency.

<Other use>
Further, in the application example described above, the high frequency device 130 is used as a high frequency filter. However, the magnetoresistance effect device can be applied to high frequency devices such as an isolator, a phase shifter, and an amplifier.

  When the high frequency device 130 is used as an isolator, a signal is input from the second port 133. Even when a signal is input from the second port 133, it is not output from the first port 132, and thus functions as an isolator.

  When the high frequency device 130 is used as a phase shifter, when the output frequency band changes, the frequency of one arbitrary point in the output frequency band is focused. When the output frequency band changes, the phase at a specific frequency changes, and thus functions as a phase shifter.

  When the high frequency device 130 is used as an amplifier, the DC current or DC voltage applied from the power supply 136 is set to a predetermined value or more. By doing this, the signal output from the second port 133 becomes larger than the signal input from the first port 132, and functions as an amplifier.

  As described above, the high frequency device 130 can function as a high frequency device such as a high frequency filter, an isolator, a phase shifter, or an amplifier.

  Although the case where the number of the magnetoresistive effect elements 101 is one is illustrated in FIG. 5, the number of the magnetoresistive effect elements 101 may be plural. In this case, the plurality of magnetoresistance effect elements 101 may be connected in parallel to one another or in series. For example, by using a plurality of magnetoresistive effect elements 101 having different ferromagnetic resonance frequencies, it is possible to widen the band (pass frequency band) of the selection frequency. Further, the high frequency magnetic field generated in the output signal line 135 which outputs the output signal from one magnetoresistance effect element 100 may be applied to another magnetoresistance effect element 101. With this configuration, the output signal is filtered a plurality of times, so that the filtering accuracy of the high frequency signal can be improved.

  Further, the DC application terminal 131 may be connected between the inductor 139 and the ground G, or may be connected between the upper electrode 106 and the ground G.

  Also, instead of the inductor 139 in the above application example, a resistive element may be used. The resistance element has a function of cutting high frequency components of the current by the resistance component. This resistance element may be either a chip resistance or a resistance due to a patterned line. The resistance value of this resistance element is preferably equal to or greater than the characteristic impedance of the output signal line 135. For example, when the characteristic impedance of the output signal line 135 is 50Ω and the resistance value of the resistor is 50Ω, high frequency power of 45% can be cut by the resistor. When the characteristic impedance of the output signal line 135 is 50Ω and the resistance value of the resistor is 500Ω, high frequency power of 90% can be cut by the resistor. Also in this case, the output signal output from the magnetoresistive effect element 101 can be efficiently flowed to the second port 133.

  Further, in the above application example, when the power supply 136 connected to the DC application terminal 131 has a function of cutting the high frequency component of the current and passing the invariant component of the current, the inductor 139 may be omitted. Also in this case, the output signal output from the magnetoresistive effect element 101 can be efficiently flowed to the second port 133.

  Further, in the application example, in place of the magnetoresistive effect device 100, the magnetoresistive effect device 110 described in the first modification or the magnetoresistive effect device 120 described in the second modification may be applied.

100, 110, 120 ... Magnetoresistance effect device 101 ... Magnetoresistance effect element 101A ... First ferromagnetic layer 101B ... Second ferromagnetic layer 101C ... Spacer layer 102 ... Coil 102A ... Region 103 surrounded by coils ... High frequency signal line 104, 105 ... Line 106 ... Upper electrode 107 ... Lower electrode 108 ... First magnetic member 108A ... Projection 108B ··· Base 108C ······ Rear end 108D of projection ··· Tip of projection 109 ··· Second magnetic member 130 ··· High frequency device 131 ··· DC application terminal 132 ··· first port 133 ... second port 134, 138 ... reference potential terminal 135 ... output signal line 136 ... power supply 137 ... line 139 ... inductor _{d 1, d 2, d 3} ··· Away _d 4 · · · projection length L · · · stacking direction

Claims (3)

A magnetoresistive effect element formed by laminating such that a spacer layer is disposed between the first ferromagnetic layer and the second ferromagnetic layer;
A coil disposed on one side of the magnetoresistive element in a direction parallel to the stacking direction, for applying a magnetic field to the magnetoresistive element;
A magnetoresistive effect device comprising: a high frequency signal line disposed on the other side of the magnetoresistive effect element in a direction parallel to the stacking direction.   The magnetic sensor further includes a first magnetic member disposed on the one side of the magnetoresistive effect element and having a protrusion on the magnetoresistive effect element side, and the coil is wound around the protrusion. The magnetoresistive device according to claim 1.   3. The magnetic resistance according to claim 1, wherein a second magnetic member is disposed at a position farther from the high frequency signal line than the high frequency signal line as viewed from the magnetoresistive element. Effect device.

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