JP2018195791A - Magnetic element, magnetic storage device, and oscillation device - Google Patents

Abstract

To provide a magnetic element, a magnetic storage device, and an oscillation device, capable of being improved in characteristics.SOLUTION: According to an embodiment, a magnetic element includes a laminate including a first layer. The first layer includes: a first region including Mn and Ga; a second region including at least one selected from the group consisting of Fe, Co, Ni and Mn; and a third region provided between the first region and the second region. The third region includes Ga and at least one selected from the group consisting of Fe, Co, Ni and Mn.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a magnetic element, a magnetic storage device, and an oscillation device.

  For example, there is a magnetic element including two magnetic layers and an intermediate layer provided therebetween. The direction of magnetization of at least one of the two magnetic layers changes due to various external forces applied to the magnetic element. As a result, the relative angles of the magnetization directions of the two magnetic layers change, and the electric resistance of the magnetic element changes. Such a magnetic element having a magnetoresistive effect can be applied to, for example, a magnetic storage device (for example, MRAM: Magnetoresistive Random Access Memory). The magnetic element can be applied to an oscillation device, for example. Improvement of characteristics is desired in the magnetic element.

JP 2010-232499 A

  Embodiments of the present invention provide a magnetic element, a magnetic storage device, and an oscillation device capable of improving characteristics.

  According to the embodiment of the present invention, the magnetic element includes a stacked body including the first layer. The first layer includes a first region including Mn and Ga, a second region including at least one selected from the group consisting of Fe, Co, Ni, and Mn, the first region, and the second region. 3rd area | region provided between these. The third region includes Ga and at least one selected from the group consisting of Fe, Co, Ni, and Mn.

  According to the embodiments of the present invention, it is possible to provide a magnetic element, a magnetic storage device, and an oscillation device capable of improving characteristics.

FIG. 1A and FIG. 1B are schematic perspective views illustrating a magnetic element according to the embodiment. FIG. 2 is a schematic cross-sectional view illustrating a sample of a magnetic element. FIG. 3A to FIG. 3D are graphs illustrating measurement results of magnetic element samples. FIG. 4A and FIG. 4B are schematic views illustrating the characteristics and magnetization states of the magnetic element according to the embodiment. FIG. 5A and FIG. 5B are graphs illustrating measurement results of characteristics of another sample of the magnetic element. FIG. 6A and FIG. 6B are graphs illustrating characteristics of the magnetic element according to the embodiment. FIG. 7 is a schematic view illustrating a magnetic memory device according to the second embodiment. FIG. 8A to FIG. 8C are schematic views illustrating the operation of the magnetic memory device according to the second embodiment. FIG. 9 is a schematic perspective view illustrating another magnetic memory device according to the second embodiment. FIG. 10 is a schematic perspective view illustrating another magnetic memory device according to the second embodiment. FIG. 11A to FIG. 11E are schematic views illustrating another magnetic storage device according to the second embodiment. FIG. 12 is a schematic view illustrating another magnetic memory device according to the second embodiment. FIG. 13 is a schematic view illustrating an oscillation device according to the third embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Even in the case of representing the same part, the dimensions and ratios may be represented differently depending on the drawings.
In the present specification and drawings, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

FIG. 1A and FIG. 1B are schematic perspective views illustrating a magnetic element according to the embodiment.
As shown in FIG. 1A, the magnetic element 110 according to the embodiment includes a first layer 10. In this example, the magnetic element 110 further includes a second layer 20 and an intermediate layer 30. The first layer 10, the second layer 20, and the intermediate layer 30 are included in the stacked body SB.

  The first layer 10 includes a first region 11, a second region 12, and a third region 13. The first region 11 includes Mn and Ga. The first region 11 is, for example, a MnGa film. The second region 12 includes at least one selected from the group consisting of Fe, Co, Ni, and Mn. The second region 12 is, for example, an Fe film, Co film, Ni film, FeCo film, FeNi film, CoNi film, or FeCoNi film. The second region 12 may contain other elements. The third region 13 is provided between the first region 11 and the second region 12. The third region 13 includes at least one selected from the group consisting of Fe, Co, Ni, and Mn, and Ga. For example, the third region 13 includes Co and Ga. The third region 13 is a CoGa film. For example, the second region 12 includes at least one selected from the group consisting of Fe, Co, Ni, and Mn, and the third region 13 is selected from the group consisting of Fe, Co, Ni, and Mn. Further, at least one of the above and Ga may be included.

  A direction from the first region 11 to the second region 12 is defined as a first direction (Z-axis direction).

  The first region 11 is, for example, a perpendicular magnetization film. For example, the component along the Z-axis direction of the magnetization of the first region 11 is larger than the component along the direction perpendicular to the Z-axis direction of the magnetization of the first region 11.

  The second region 12 is, for example, a perpendicular magnetization film. For example, the component along the Z-axis direction of the magnetization of the second region 12 is larger than the component along the direction perpendicular to the Z-axis direction of the magnetization of the second region 12.

  The magnetization of the first region 11 (first magnetization) and the magnetization of the second region 12 (second magnetization) are along the first direction (the direction from the first region 11 toward the second region 12). The component along the first direction of the first magnetization direction is opposite to the component along the first direction of the second magnetization direction.

  For example, the magnetization of the first region 11 (first magnetization) and the magnetization of the second region 12 (second magnetization) are antiferromagnetically magnetically coupled.

  It is understood that by providing the third region 13 (CoGa film) between the first region 11 and the second region 12, antiferromagnetic magnetic coupling occurs in the first region 11 and the second region 12. It was. Examples of magnetization in these regions will be described later. When the third region 13 (CoGa film) is not provided between the first region 11 and the second region 12, antiferromagnetic magnetic coupling cannot be obtained.

  For example, the first layer 10 functions as one magnetic layer. In the first region 11 and the second region 12 provided in one magnetic layer, strong antiferromagnetic magnetic coupling (interlayer coupling) is obtained. Thereby, for example, the thermal stability is improved as compared with the case where there is no antiferromagnetic magnetic coupling. For example, when the temperature increases, the MR ratio decreases. For example, by obtaining strong antiferromagnetic coupling in the first region 11 and the second region 12, the temperature at which the MR ratio decreases can be maintained high. For example, even when the element size is reduced, a high MR ratio can be obtained.

  For example, the first layer 10 according to the embodiment can be used as a magnetoresistive element. For example, when the first layer 10 is used as a storage layer (free layer), high thermal stability is obtained. For example, a high MR ratio can be obtained in the stacked body SB including the first layer 10. For example, the leakage magnetic field can be suppressed. For example, the first layer 10 may be used as a reference layer. In this case, for example, high thermal stability can be obtained. For example, a high MR ratio can be obtained. For example, the leakage magnetic field can be suppressed.

  Generally, the reference layer is thickened to obtain high thermal stability. However, if the reference layer is thick, the leakage magnetic field increases. In the embodiment, the thin first layer 10 can suppress the leakage magnetic field while obtaining high thermal stability.

  The magnetic element according to the embodiment can be applied to various write-type MRAMs as described later. The magnetic element according to the embodiment can be applied to, for example, a spin torque oscillator or a spin torque diode.

  As already described, the stacked body SB further includes the second layer 20 and the intermediate layer 30 in addition to the first layer 10. For example, the second layer 20 includes at least one selected from the group consisting of Fe, Co, and Ni. The second layer 20 may contain other elements. The second layer 20 is, for example, an FeCoB layer. For example, the second layer 20 functions as a ferromagnetic layer.

The intermediate layer 30 is provided between the first layer 10 and the second layer 20. The intermediate layer 30 is nonmagnetic. The intermediate layer 30 includes, for example, at least one selected from the group consisting of Mg and Al, and oxygen. The intermediate layer 30 has, for example, a NaCl structure (such as MgO) or a spinel structure (such as MgAl ₂ O ₄ ). The intermediate layer 30 includes, for example, MgO. The intermediate layer 30 includes, for example, a nonmagnetic material.

  For example, the third region 13 is located between the first region 11 and the second layer 20. For example, the second region 12 is located between the third region 13 and the second layer 20. For example, the intermediate layer 30 is located between the second region 12 and the second layer 20.

  As shown in FIG. 1B, in the magnetic element 111, the intermediate layer 30 may include a high oxygen concentration region 33 and a low oxygen concentration region 34. The high oxygen concentration region 33 contains MgO. The low oxygen concentration region 34 is provided between the high oxygen concentration region 33 and the first layer 10. The low oxygen concentration region 34 includes Mg. The low oxygen concentration region 34 does not contain oxygen, for example. Alternatively, the oxygen concentration in the low oxygen concentration region 34 is lower than the oxygen concentration in the high oxygen concentration region 33. The low oxygen concentration region 34 is, for example, an Mg layer. Other configurations of the magnetic element 111 are the same as those of the magnetic element 110. The boundary between the high oxygen concentration region 33 and the low oxygen concentration region 34 may not be observed. For example, these regions may be mixed by heat treatment after forming a film to be these regions.

  In the magnetic elements 110 and 111, a first conductive layer 41, a second conductive layer 42, and a metal layer 45 are further provided. The first layer 10 is provided between the first conductive layer 41 and the second conductive layer 42. An intermediate layer 30 is provided between the first layer 10 and the second conductive layer 42. The second layer 20 is provided between the intermediate layer 30 and the second conductive layer 42.

  The metal layer 45 is located between the first conductive layer 41 and the intermediate layer 30. The first layer 10 is located between the metal layer 45 and the intermediate layer 30. The metal layer 45 includes, for example, at least one selected from the group consisting of Fe, Co, and Ni, and Ga. The metal layer 45 includes, for example, Co and Ga. The metal layer 45 is, for example, a CoGa film. The metal layer 45 functions as a base layer, for example.

  The magnetic elements 110 and 111 include, for example, a film to be the first conductive layer 41, a film to be the metal layer 45, a film to be the first layer 10, a film to be the intermediate layer 30, and a film to be the second layer 20. And it forms by forming the laminated film containing the film | membrane used as the 2nd conductive layer 42, and heat-processing. The film that becomes the first layer 10 is formed, for example, by forming the first region 11, the third region 13, and the second region 12. The above laminated film can be formed by, for example, a sputtering method, a vacuum evaporation method, a chemical vapor deposition method, or the like.

  In this example, the first wiring 70 a is electrically connected to the first conductive layer 41. The second wiring 70 b is electrically connected to the second conductive layer 42. The first wiring 70 a is electrically connected to the first layer 10. The second wiring 70 b is electrically connected to the second layer 20. A switch element or the like may be provided on at least one of these wirings.

  In the magnetic elements 110 and 111, for example, a voltage (electric field) applied between the first conductive layer 41 and the second conductive layer 42 and a supply between the first conductive layer 41 and the second conductive layer 42. The electrical resistance of the magnetic elements 110 and 111 (the electrical resistance of the stacked body SB) varies depending on at least one of the currents to be generated. The change in electrical resistance corresponds to, for example, a change in electrical resistance between the first layer 10 and the second layer 20. The change in electrical resistance corresponds to, for example, a change in electrical resistance between the first conductive layer 41 and the second conductive layer 42. The change in electrical resistance corresponds to, for example, a change in electrical resistance between the first wiring 70a and the second wiring 70b.

  This change in electrical resistance is considered to be based on the magnetoresistive effect, for example. The magnetization of the first layer 10 corresponds to the combination (for example, sum) of the magnetization of the first region 11 and the magnetization of the second region 12. For example, the magnetization of the first layer 10 is, for example, the voltage (electric field) applied between the first conductive layer 41 and the second conductive layer 42, and the first conductive layer 41 and the second conductive layer 42. It varies depending on at least one of the currents supplied therebetween. On the other hand, for example, the magnetization direction of the second layer 20 does not change. For example, the relative angle between the magnetization direction of the first layer 10 and the magnetization direction of the second layer 20 changes according to at least one of voltage (electric field) and current. The electrical resistances of the magnetic element 110 and the magnetic element 111 change according to the change in angle. In this case, the second layer 20 functions as a reference layer.

  The second layer 20 may function as a free layer. At this time, the first layer 10 may also function as a free layer. The second layer 20 may function as a free layer, and the first layer 10 may function as a reference layer.

  Depending on the angle between the direction of the magnetization of the first layer 10 (the combination or sum of the first magnetization of the first region 11 and the second magnetization of the second region 12) and the magnetization of the second layer 20 The electrical resistance of the stacked body SB changes. The stacked body SB functions as, for example, an MR element.

  Hereinafter, an experiment relating to a magnetic element will be described.

FIG. 2 is a schematic cross-sectional view illustrating a sample of a magnetic element.
As shown in FIG. 2, in the first sample 111a, a Cr film (thickness: 40 nm: nanometer) to be the first conductive layer 41 is provided on the substrate 40s. The substrate 40s is an MgO (001) substrate. In this example, a Ta film 40b is provided on the lower surface of the substrate 40s.

  A CoGa film (having a thickness of 30 nm) to be the metal layer 45 is provided on the first conductive layer 41. On the first conductive layer 41, an MnGa film (thickness t1 is 3 nm) to be the first region 11 of the first layer 10 is provided. On the first region 11, a CoGa film (thickness t3 is 0.4 nm) to be the third region 13 of the first layer 10 is provided. On the third region 13, a Co film (thickness t2 is 0.4 nm) to be the second region 12 of the first layer 10 is provided.

  An Mg film (having a thickness of 0.4 nm) serving as the low oxygen concentration region 34 of the intermediate layer 30 is provided on the second region 12 (on the first layer 10). On the low oxygen concentration region 34, an MgO film (having a thickness of 2 nm) to be the high oxygen concentration region 33 of the intermediate layer 30 is provided. On the high oxygen concentration region 33, a CoFeB film (having a thickness of 1 nm) to be the second layer 20 is provided. A Ta film 42a (having a thickness of 3 nm) is provided on the second layer 20. A Ru film 42b (having a thickness of 5 nm) is provided on the Ta film 42a. A stacked film of the Ta film 42 a and the Ru film 42 b corresponds to the second conductive layer 42. The above film is formed by, for example, a sputtering method.

  After film formation, heat treatment (annealing treatment) at various temperatures is performed to complete the first sample 111a. The heat treatment temperature is 250 ° C., and the heat treatment time is 10 minutes. For the first sample 111a, the MR ratio when an external magnetic field is applied is measured. The MR ratio is, for example, a TMR (Tunnel Magneto Resistance) ratio.

FIG. 3A to FIG. 3D are graphs illustrating measurement results of magnetic element samples.
These drawings show examples of measurement results of the MR ratio of the first sample 111a. In the first sample 111a, as described above, the second region 12 is a Co film.

  The horizontal axis in FIGS. 3A to 3D is the external magnetic field Ha (kOe) applied to the stacked body SB. When the external magnetic field Ha is positive, the external magnetic field Ha goes from the first region 11 to the second region 12. When the external magnetic field Ha is negative, the external magnetic field Ha moves from the second region 12 to the first region 11. The external magnetic field Ha is perpendicular to the film surface. The vertical axis in these figures represents the MR ratio MRv (%). The MR ratio MRv is the difference (absolute value) between the resistance (first resistance) when the external magnetic field Ha is 90 kOe and the resistance (second resistance) at each external magnetic field Ha to the first resistance. Is the ratio.

  FIGS. 3A and 3B correspond to the MR ratio MRv when the external magnetic field Ha is changed from negative to positive. 3C and 3D correspond to the MR ratio MRv when the external magnetic field Ha is changed from positive to negative. 3 (b) and 3 (d) show a part of the characteristics of FIGS. 3 (a) and 3 (c) in an enlarged manner, respectively.

  As shown in FIGS. 3A and 3B, when the external magnetic field Ha is negative and the absolute value of the external magnetic field Ha is decreased, the MR ratio MRv increases. When the absolute value of the external magnetic field Ha is increased when the external magnetic field Ha is positive, the MR ratio MRv increases after decreasing once. When the absolute value of the external magnetic field Ha is further increased, the MR ratio MRv increases and then decreases again.

  For example, the MR ratio MRv in the second state ST2 is higher than the MR ratio MRv in the first state ST1 illustrated in FIG. The MR ratio MRv in the third state ST3 illustrated in FIG. 3A is lower than the MR ratio MRv in the second state ST2. The MR ratio MRv in the fourth state ST4 illustrated in FIG. 3A is higher than the MR ratio MRv in the third state ST3. The MR ratio MRv in the fifth state ST5 illustrated in FIG. 3A is lower than the MR ratio MRv in the fourth state ST4. For example, the MR ratio MRv continuously increases from the first state ST1 to the second state ST2. For example, the MR ratio MRv continuously decreases from the fourth state ST4 to the fifth state ST5. For example, in the sample 111a, the external magnetic field Ha corresponding to the second state ST2 is negative.

  As shown in FIGS. 3C and 3D, when the external magnetic field Ha is positive and the absolute value of the external magnetic field Ha is decreased, the MR ratio MRv is decreased. When the absolute value of the external magnetic field Ha is increased when the external magnetic field Ha is negative, the MR ratio MRv increases after decreasing once. When the absolute value of the external magnetic field Ha is further increased, the MR ratio MRv increases and then decreases again.

  That is, the MR ratio MRv in the sixth state ST6 illustrated in FIG. 3C is higher than the MR ratio MRv in the fifth state ST5. The MR ratio MRv in the seventh state ST7 illustrated in FIG. 3C is lower than the MR ratio MRv in the sixth state ST6. The MR ratio MRv in the eighth state ST8 illustrated in FIG. 3C is higher than the MR ratio MRv in the seventh state ST7. The MR ratio MRv in the eighth state ST8 is higher than the MR ratio MRv in the first state ST1. For example, the MR ratio MRv continuously increases from the fifth state ST5 to the sixth state ST6. For example, the MR ratio MRv continuously decreases from the eighth state ST8 to the first state ST1. For example, in the sample 111a, the external magnetic field Ha corresponding to the sixth state ST6 is positive.

  Such a characteristic is considered to occur when the first region 11 and the second region 12 provided in the first layer 10 are antiferromagnetically coupled to each other.

  As a reference example, a sample was prepared in which the first region 11 (MnGa film) and the second region 12 (Co film) were provided in the first layer 10 and the third region 13 (CoGa film) was not provided. . In the sample of the reference example, the antiferromagnetic coupling becomes weak or the antiferromagnetic coupling cannot be obtained. In the sample of the reference example, for example, the MR ratio MRv does not increase from the first state ST1 to the second state ST2 illustrated in FIG. 3A, and the fourth state ST4 to the fifth state ST5. As a result, the MR ratio MRv does not decrease gradually. In the sample of the reference example, for example, the MR ratio MRv does not increase from the fifth state ST5 to the sixth state ST6 illustrated in FIG. 3C, and the eighth state ST8 to the first state ST1. As a result, the MR ratio MRv does not decrease gradually.

In general, when the temperature of the element is high, the MR ratio decreases. In the embodiment, a decrease in MR ratio can be suppressed even when the temperature of the element is high.
As described above, by providing the third region 13 (CoGa film) between the first region 11 and the second region 12, the characteristic characteristics illustrated in FIG. 3A and FIG. Was found to be obtained. Such a characteristic is considered to be obtained when the first region 11 and the second region 12 are ferromagnetically coupled to each other.

  In the magnetic element 110 (the magnetic element 111 or the sample 111a) according to the embodiment, the following characteristic characteristics as shown in FIGS. 3A and 3C are obtained.

  When changing from the first state ST1 in which the first magnetic field is applied to the stacked body SB to the second state ST2 in which the second magnetic field is applied to the stacked body SB, the first electrical resistance in the first state ST1 is It is higher than the second electrical resistance in the second state ST2. The first magnetic field and the second magnetic field have a direction from the second layer 20 toward the first layer 10. The absolute value of the first magnetic field is larger than the absolute value of the second magnetic field.

  When the second state ST2 is changed to the third state ST3 in which the third magnetic field is applied to the stacked body SB, the third electrical resistance in the third state ST3 is lower than the second electrical resistance. The third magnetic field has a direction from the first layer 10 toward the second layer 20.

  When the state is changed from the third state ST3 to the fourth state ST4 in which the fourth magnetic field is applied to the stacked body SB, the fourth electrical resistance in the fourth state ST4 is higher than the third electrical resistance. The fourth magnetic field has a direction from the first layer 10 toward the second layer 20. The absolute value of the fourth magnetic field is larger than the absolute value of the third magnetic field.

  When the fourth state ST4 is changed to the fifth state ST5 in which the fifth magnetic field is applied to the stacked body SB, the fifth electrical resistance in the fifth state ST5 is lower than the fourth electrical resistance. The fifth magnetic field has a direction from the first layer 10 toward the second layer 20. The absolute value of the fifth magnetic field is larger than the absolute value of the fourth magnetic field.

  When the state is changed from the fifth state ST5 to the sixth state ST6 in which the sixth magnetic field is applied to the stacked body SB, the sixth electrical resistance in the sixth state ST6 is higher than the fifth electrical resistance. The sixth magnetic field has a direction from the first layer 10 toward the second layer 20. The absolute value of the sixth magnetic field is smaller than the absolute value of the fifth magnetic field.

  When the sixth state ST6 is changed to the seventh state ST7 in which the seventh magnetic field is applied to the stacked body SB, the seventh electrical resistance in the seventh state ST7 is lower than the sixth electrical resistance. The seventh magnetic field has a direction from the second layer 20 toward the first layer 10.

  When the state is changed from the seventh state ST7 to the eighth state ST8 in which the eighth magnetic field is applied to the stacked body SB, the eighth electrical resistance in the eighth state ST8 is higher than the seventh electrical resistance. The eighth magnetic field has a direction from the second layer 20 toward the first layer 10. The absolute value of the eighth magnetic field is larger than the absolute value of the seventh magnetic field and smaller than the absolute value of the first magnetic field. Said 1st magnetic field-8th magnetic field are external magnetic fields Ha when it becomes 1st state ST1-8th state ST8.

  In the above description, the first to eighth electric resistances correspond to the electric resistance between the first layer 10 and the second layer 20, for example. The first to eighth electric resistances correspond to the electric resistance between the first conductive layer 41 and the second conductive layer 42, for example. The first to eighth electric resistances correspond to, for example, the electric resistance between the first wiring 70a and the second wiring 70b.

  Hereinafter, examples of changes in MR ratio and changes in magnetization when the external magnetic field Ha is changed will be described. In the following example, the maximum value of the intensity of the external magnetic field Ha is larger than the maximum value of the intensity of the external magnetic field Ha described with reference to FIGS.

FIG. 4A and FIG. 4B are schematic views illustrating the characteristics and magnetization states of the magnetic element according to the embodiment.
These drawings schematically show changes in the MR ratio and changes in the direction of magnetization with respect to changes in the external magnetic field Ha. The horizontal axis of FIG. 4A and FIG. 4B is the external magnetic field Ha (kOe) in the stacked body SB. When the external magnetic field Ha is positive, the direction of the external magnetic field Ha is from the first region 11 to the second region 12. When the external magnetic field Ha is negative, the external magnetic field Ha is directed from the second region 12 to the first region 11. The external magnetic field Ha is perpendicular to the film surface. The vertical axis of these figures is the normalized MR ratio MRn. In these drawings, the states of magnetization in each of the first to eighth states ST1 to ST8 are schematically illustrated.

  In the following description, the direction from the first layer 10 to the second layer 20 is referred to as “upward” (+ Z direction) for convenience. The direction from the second layer 20 toward the first layer 10 is referred to as “downward” (−Z direction) for convenience. The direction from the first region 11 to the second region 12 corresponds to “upward”. The direction from the second region 12 toward the first region 11 corresponds to “downward”.

When the external magnetic field Ha changes from negative to positive as shown in FIG.
In the first state ST1, the magnetization of the first region 11 is downward, the magnetization of the second region 12 is downward, and the magnetization of the second layer 20 is downward. At this time, the MR ratio MRn is low. In this example, the MR ratio MRn is substantially zero.

  In the second state ST2, the magnetization of the first region 11 is downward, the magnetization of the second region 12 is upward, and the magnetization of the second layer 20 is downward. The MR ratio at this time is high. In this example, the MR ratio MRn is substantially 1.

  In the third state ST3, the magnetization of the first region 11 is downward, the magnetization of the second region 12 is upward, and the magnetization of the second layer 20 is upward. At this time, the MR ratio is low. In this example, the MR ratio MRn is substantially zero.

  In the fourth state ST4, the magnetization of the first region 11 is upward, the magnetization of the second region 12 is downward (may be inclined), and the magnetization of the second layer 20 is upward. The MR ratio at this time is high. In this example, the MR ratio MRn is about 0.75.

  In the fifth state ST5, the magnetization of the first region 11 is upward, the magnetization of the second region 12 is upward, and the magnetization of the second layer 20 is upward. At this time, the MR ratio is low. In this example, the MR ratio MRn is substantially zero.

As shown in FIG. 4B, when the external magnetic field Ha changes from positive to negative, the following occurs.
In the sixth state ST6, the magnetization of the first region 11 is upward, the magnetization of the second region 12 is downward (may be inclined), and the magnetization of the second layer 20 is upward. The MR ratio MRn at this time is high. In this example, the MR ratio MRn is substantially 1.

  In the seventh state ST7, the magnetization of the first region 11 is upward, the magnetization of the second region 12 is downward, and the magnetization of the second layer 20 is downward. At this time, the MR ratio MRn is low. In this example, the MR ratio MRn is substantially zero.

  In the eighth state ST8, the magnetization of the first region 11 is downward, the magnetization of the second region 12 is upward, and the magnetization of the second layer 20 is downward. The MR ratio MRn at this time is high. In this example, the MR ratio MRn is about 0.75.

  Even when the external magnetic field Ha changes from positive to negative, the first state ST1 is obtained by increasing the absolute value of the external magnetic field Ha. In the first state ST1, the magnetization of the first region 11 is downward, the magnetization of the second region 12 is downward, and the magnetization of the second layer 20 is downward. At this time, the MR ratio MRn is low. In this example, the MR ratio MRn is substantially zero.

  As shown in FIGS. 4A and 4B, when the absolute value of the external magnetic field Ha is small (second state ST2, third state ST3, seventh state ST7, eighth state ST8, etc.), the first The magnetization direction of the region 11 is opposite to the magnetization direction of the second region 12. That is, antiferromagnetic magnetization coupling occurs.

  Also in the fourth state ST4 and the sixth state ST6, the component along the Z-axis direction of the magnetization direction of the first region 11 is opposite to the component along the Z-axis direction of the magnetization direction of the second region 12. Thus, it is considered that antiferromagnetic magnetization coupling occurs even when the magnetization direction of the second region 12 is inclined with respect to the Z-axis direction.

  Sample of Reference Example (Sample in which the first region 11 (MnGa film) and the second region 12 (for example, Co film) are provided in the first layer 10 and the third region 13 (for example, CoGa film) is not provided) In this case, the temperature of the heat treatment necessary for obtaining antiferromagnetic magnetic coupling is increased to, for example, 300 ° C. or higher.

  In general, when the element becomes high temperature, the MR ratio decreases. In the magnetic element 110 according to the embodiment, the temperature at which the MR ratio decreases can be maintained higher than the temperature at which the MR ratio in the reference example decreases. For example, the difference between the temperature at which the MR ratio in the magnetic element 110 according to the embodiment decreases and the temperature at which the MR ratio in the reference example decreases is about 50 ° C.

  In the embodiment, the third region 13 is provided between the first region 11 and the second region 12. The third region 13 is considered to suppress the Co contained in the second region 12 and the Mn and Ga contained in the first region 11 from diffusing and mixing with each other. In the embodiment, it is considered that the third region 13 functions as a diffusion suppression layer.

  Thus, in the embodiment, antiferromagnetic coupling is obtained by providing the third region 13. In the embodiment, the thermal stability is improved. The heat resistance of the element is improved.

  In the embodiment, by providing the third region 13, for example, the coercive force in the first layer 10 increases. By providing the third region 13, near the zero magnetic field, the magnetization of the first region 11 (for example, MnGa) and the magnetization of the second region 12 (for example, Co film) cancel each other, for example, become smaller or zero. become. For example, the leakage flux can be made substantially zero. By providing the third region 13, for example, strong antiferromagnetic interlayer coupling occurs between the first region 11 and the second region 12. In order to make the magnetization of the second region 12 coupled with the antiferromagnetic interlayer parallel to the magnetization of the first region 11, a very strong magnetic field of, for example, 90 kOe or more is required. This indicates that the strength of the antiferromagnetic coupling is very large.

FIG. 5A and FIG. 5B are graphs illustrating measurement results of characteristics of another sample of the magnetic element.
These drawings show examples of measurement results of the MR ratio of the second sample 111b. In the second sample 111b, the second region 12 is an Fe film having a thickness of 0.4 nm. The other conditions of the second sample 111b are the same as those of the first sample 111a.

  The horizontal axis in FIGS. 5A and 5B is the external magnetic field Ha (kOe) applied to the stacked body SB. When the external magnetic field Ha is positive, the direction of the external magnetic field Ha is from the first region 11 to the second region 12. When the external magnetic field Ha is negative, the external magnetic field Ha is directed from the second region 12 to the first region 11. The external magnetic field Ha is perpendicular to the film surface. In these figures, the vertical axis represents the electrical resistance R (Ω) between the first conductive layer 41 and the second conductive layer 42.

  As can be seen from FIGS. 5A and 5B, the second sample 111b also has the same characteristics of the change in electrical resistance with respect to the external magnetic field Ha as in the first sample 111a.

  It was found that even when the first region 12 is an Fe film, characteristic characteristics can be obtained by providing the third region 13 (CoGa film) between the first region 11 and the second region 12. . Such characteristics are considered to correspond to the first region 11 and the second region 12 being ferromagnetically coupled to each other.

  In the embodiment, antiferromagnetic magnetic coupling is obtained in two regions provided in the first layer 10 and having magnetizations substantially perpendicular to each other. Thereby, for example, a leakage magnetic field can be suppressed. For example, it is possible to suppress the leakage magnetic field from acting on a magnetic layer different from the first layer 10 (for example, the second layer 20). For example, a high MR ratio can be easily obtained.

  When the leakage magnetic field is suppressed, for example, when a plurality of magnetic elements are provided, the influence of the leakage magnetic field applied from one magnetic element to another magnetic element is suppressed. This makes it easier to obtain a stable operation.

  In the above example, the third region 13 includes Co and Ga. In the embodiment, the third region 13 may include Ga and at least one selected from the group consisting of Fe, Co, Ni, and Mn. As already described, the second region 12 includes at least one selected from the group consisting of Fe, Co, Ni, and Mn. At this time, the third region 13 may include Ga and at least one selected from the group consisting of Fe, Co, Ni, and Mn.

  In the embodiment, the thickness t3 (see FIG. 2) along the first direction (the Z-axis direction and the direction from the first region 11 toward the second region 12) of the third region 13 is, for example, 0.1 nm or more. 1.0 nm or less. When the thickness t3 is less than 0.1 nm, for example, ferromagnetic coupling is likely to occur. When the thickness t3 exceeds 1.0 nm, for example, antiferromagnetic coupling becomes weak.

  A thickness t2 (see FIG. 2) along the first direction of the second region 12 is, for example, not less than 0.1 nm and not more than 2.0 nm. When the thickness t2 is less than 0.1 nm, for example, the second region 12 tends to be discontinuous, and the MR ratio decreases. When the thickness t2 exceeds 2.0 nm, for example, the magnetization of the second region 12 is easily oriented in the in-plane direction (direction along the XY plane).

  A thickness t1 (see FIG. 2) along the first direction of the first region 11 is, for example, not less than 1 nm and not more than 5 nm. When the thickness t1 is less than 1 nm, for example, the perpendicular magnetic anisotropy becomes low. When the thickness t1 exceeds 5 nm, for example, the power for reversing the magnetization of the first layer 10 increases. For example, when the first layer 10 is used as a storage layer, power consumption increases. The first layer 10 may be used as a reference layer. In this case, the thickness t1 along the first direction of the first region 11 may exceed 5 nm, and may be, for example, 1 nm or more and 10 nm or less.

  For example, the third region 13 is in contact with the first region 11 and the second region 12. For example, the second region 12 is in contact with the intermediate layer 30.

  The magnetic element (such as the magnetic element 110 or 111) according to the first embodiment can be applied to, for example, a spin torque oscillator or a spin torque diode.

FIG. 6A and FIG. 6B are graphs illustrating characteristics of the magnetic element according to the embodiment.
These drawings illustrate characteristics of the magnetic element 112 according to the embodiment. In the magnetic element 112, the coercive force of the second layer 20 is larger than the coercive force of the first layer 10 (the first region 11, the second region 12, and the third region 13). In this example, the second layer 20 includes a CoFeB film (having a thickness of 1 nm) and an FePt film. A CoFeB film is located between the FePt film and the intermediate layer 30. The thickness of the FePt film is, for example, 1 nm or more and 10 nm or less. Other configurations of the magnetic element 112 are the same as those of the sample 111a.

  6A and 6B represents the external magnetic field Ha (kOe) applied to the stacked body SB. The vertical axis represents the MR ratio MRv (arbitrary unit. FIG. 6A corresponds to the MR ratio MRv when the external magnetic field Ha is changed from negative to positive. FIG. 6B is positive. This corresponds to the MR ratio MRv when the external magnetic field Ha is changed from negative to negative.

  As shown in FIG. 6A and FIG. 6B, in the magnetic element 112, the first state ST1 to the eighth state ST8 occur as in the sample 111a. In the magnetic element 112, the external magnetic field Ha corresponding to the second state ST2 is positive, and the external magnetic field Ha corresponding to the sixth state ST6 is negative. The characteristics of the magnetic element 112 are similar to the characteristics of the sample 111a.

  For example, when changing from the first state ST1 in which the first magnetic field is applied to the stacked body SB to the second state ST2 in which the second magnetic field is applied to the stacked body SB, the first layer 10 in the first state ST1 The first electrical resistance between the second layer 20 is higher than the second electrical resistance between the first layer 10 and the second layer 20 in the second state ST2. The first magnetic field has a direction from the second layer 20 toward the first layer 10. The second magnetic field has a direction from the first layer 10 toward the second layer 20.

  When changing from the second state ST2 to the third state ST3 in which the third magnetic field is applied to the stacked body SB, the third electrical resistance between the first layer 10 and the second layer 20 in the third state ST3 is , Lower than the second electrical resistance. The third magnetic field has a direction from the first layer 10 toward the second layer 20. The absolute value of the third magnetic field is larger than the absolute value of the second magnetic field.

  When the state is changed from the third state ST3 to the fourth state ST4 in which the fourth magnetic field is applied to the stacked body SB, the fourth electrical resistance between the first layer 10 and the second layer 20 in the fourth state ST4 is , Higher than the third electrical resistance. The fourth magnetic field has a direction from the first layer 10 toward the second layer 20. The absolute value of the fourth magnetic field is larger than the absolute value of the third magnetic field.

  When the state is changed from the fourth state ST4 to the fifth state ST5 in which the fifth magnetic field is applied to the stacked body SB, the fifth electrical resistance between the first layer 10 and the second layer 20 in the fifth state ST5 is , Lower than the fourth electrical resistance. The fifth magnetic field has a direction from the first layer 10 toward the second layer 20. The absolute value of the fifth magnetic field is larger than the absolute value of the fourth magnetic field.

  When changing from the fifth state ST5 to the sixth state ST6 in which the sixth magnetic field is applied to the stacked body SB, the sixth electric resistance between the first layer 10 and the second layer 20 in the sixth state ST6 is , Higher than the fifth electrical resistance. The sixth magnetic field has a direction from the second layer 20 toward the first layer 10.

  When the state is changed from the sixth state ST6 to the seventh state ST7 in which the seventh magnetic field is applied to the stacked body SB, the seventh electrical resistance between the first layer 10 and the second layer 20 in the seventh state ST7 is , Lower than the sixth electric resistance. The seventh magnetic field has a direction from the second layer 20 toward the first layer 10. The absolute value of the seventh magnetic field is larger than the absolute value of the sixth magnetic field.

  When the state is changed from the seventh state ST7 to the eighth state ST8 in which the eighth magnetic field is applied to the stacked body SB, the eighth electrical resistance between the first layer 10 and the second layer 20 in the eighth state ST8 is , Higher than the seventh electrical resistance. The eighth magnetic field has a direction from the second layer 20 toward the first layer 10. The absolute value of the eighth magnetic field is larger than the absolute value of the seventh magnetic field and smaller than the absolute value of the first magnetic field. Said 1st magnetic field-8th magnetic field are external magnetic fields Ha when it becomes 1st state ST1-8th state ST8.

  In the magnetic element 112, the external magnetic field Ha corresponding to the second state ST2 is positive, and the external magnetic field Ha corresponding to the sixth state ST6 is negative. This corresponds to the coercive force of the second layer 20 being larger than the coercive force of the first layer 10. For example, in the example of FIG. 6B, the transition from the sixth state ST6 to the seventh state ST7 corresponds to the reversal of the magnetization of the first layer 10. The transition from the seventh state ST7 to the eighth state ST8 corresponds to the reversal of the magnetization of the second layer 20.

  In the magnetic element 112, the second layer 20 can function as a reference layer, for example. The first layer 1 can function as a free layer (for example, a storage layer), for example.

(Second Embodiment)
The magnetic elements 110 and 111 according to the first embodiment can be applied to, for example, a magnetic storage device. Hereinafter, an example of the magnetic storage device according to the embodiment will be described.

FIG. 7 is a schematic view illustrating a magnetic memory device according to the second embodiment.
As illustrated in FIG. 7, the magnetic storage device 210 according to the present embodiment includes the magnetic element according to the first embodiment (the magnetic element 110 in this example) and the control unit 70. The magnetic element 110 includes a first layer 10, a second layer 20, and an intermediate layer 30. The control unit 70 is electrically connected to the first layer 10 and the second layer 20. In this example, the magnetic element 110 further includes a first conductive layer 41 and a second conductive layer 42. The first conductive layer 41 is electrically connected to the first layer 10. The second conductive layer 42 is electrically connected to the second layer 20.

  In this example, the control unit 70 is electrically connected to the first conductive layer 41 by the first wiring 70a. In this example, the control unit 70 is electrically connected to the second conductive layer 42 by the second wiring 70b. In this example, a switch element 70s is provided in the first wiring 70a. The switch element 70s is, for example, a selection transistor. Thus, the state in which the switch element 70s and the like are provided on the current path is also included in the electrically connected state. In the following description, the switch element 70s is on. In the on state, a current flows through the wiring. The switch element 70s may be provided on the second wiring 70b.

  As described above, the magnetic storage device 210 includes the magnetic element (the magnetic elements 110 and 111 and the modifications thereof) described with respect to the first embodiment, and the switch element 70s electrically connected to the magnetic element. Including. As will be described later, the plurality of magnetic elements serve as memory cells. One of a plurality of magnetic elements is selected by the switch element 70s, and information is stored, erased or read out.

FIG. 8A to FIG. 8C are schematic views illustrating the operation of the magnetic memory device according to the second embodiment.
The horizontal axis of these figures is time ti. The vertical axis in these figures corresponds to the signal S1 applied between the first wiring 70a and the second wiring 70b. The signal S1 substantially corresponds to a signal applied between the first layer 10 and the second layer 20.

  As shown in FIG. 8A, the control unit 70 applies the first pulse P1 between the first wiring 70a and the second wiring 70b (between the first layer 10 and the second layer 20). Operation OP1 is performed. The stored information is rewritten by the first pulse P1. The electric resistance of the magnetic element 110 is changed by the first pulse P1.

  For example, the second electrical resistance between the first layer 10 and the second layer 20 after the first operation OP1 is the first electrical resistance between the first layer 10 and the second layer 20 before the first operation OP1. It is different from electrical resistance. The electrical resistance corresponds to the electrical resistance between the first wiring 70a and the second wiring 70b. This change in electrical resistance is based on, for example, a change in the direction of magnetization of at least part of the first layer 10 due to the first pulse P1. A plurality of states having different electrical resistances correspond to stored information.

  In the magnetic storage device 210, when rewriting the stored information, the control unit 70 supplies the first pulse P1 to the magnetic element 110.

  As shown in FIG. 8A, the control unit 70 may further perform the second operation OP2. In the second operation OP2, the control unit 70 performs the second pulse between the first wiring 70a and the second wiring 70b (between the first layer 10 and the second layer 20) before the first operation OP1. P2 (for example, a read pulse) is applied. The third electrical resistance between the first layer 10 and the second layer 20 obtained by the second pulse P2 is the second electrical resistance between the first layer 10 and the second layer 20 after the first operation OP1. Resistance is different. The third electrical resistance may be the same as the first electrical resistance. For example, the polarity of the second pulse P2 is opposite to the polarity of the first pulse P1 (rewrite pulse).

  For example, the first pulse P1 has a first polarity, a first pulse width T1, and a first pulse height H1. At this time, when another pulse having a second polarity opposite to the first polarity, a first pulse width T1, and a pulse height having the same absolute value as the first pulse height H1, is applied as follows: Become. The third electrical resistance between the first layer 10 and the second layer 20 after applying this other pulse between the first layer 10 and the second layer 20, and this another pulse as the first layer 10 And the absolute value of the difference between the fourth electrical resistance before being applied between the second electrical resistance and the second layer 20 is smaller than the absolute value of the difference between the second electrical resistance and the first electrical resistance. That is, information is rewritten by applying the first pulse P1, and information is not rewritten by applying another pulse.

  When the stored information is not rewritten, as shown in FIG. 8B, the control unit 70 performs the third operation OP3 after the second operation OP2. In the third operation OP3, the first pulse P1 is not applied. At this time, rewriting does not occur.

  Information can be rewritten when the appropriate first pulse P1 is applied. When an appropriate first pulse P1 is applied, the electrical resistance between the first layer 10 and the second layer 20 changes from a high resistance state to a low resistance state, or from a low resistance state to a high resistance state. To do. On the other hand, when an inappropriate pulse is applied, the desired resistance change cannot be obtained.

  The pulse width of the unsuitable pulse is, for example, about twice the appropriate first pulse width T1. If an inappropriate pulse is applied between the first layer 10 and the second layer 20, the probability of a resistance change is low.

  When another pulse P1x as shown in FIG. 8C is applied, the resistance does not change substantially. Another pulse P1x has a pulse width twice the first pulse width T1 and a first pulse height H1. After such another pulse P1x is applied between the first layer 10 and the second layer 20, the third electrical resistance between the first layer 10 and the second layer 20 and another pulse P1x are applied to the first layer 10 and the second layer 20, respectively. The absolute value of the difference between the first electric resistance before being applied between the first layer 10 and the second layer 20 is smaller than the absolute value of the difference between the second electric resistance and the first electric resistance.

  The magnetic storage device 210 is, for example, a voltage control type (electric field control type) MRAM.

FIG. 9 is a schematic perspective view illustrating another magnetic memory device according to the second embodiment.
As shown in FIG. 9, in another magnetic memory device 220 according to this embodiment, a first wiring 70a is formed on a stacked body (eg, the magnetic element 110) including the first layer 10, the second layer 20, and the intermediate layer 30. A current flows through the second wiring 70b. The current flows through the stacked body along the Z-axis direction. In the magnetic memory device 220, the electrical resistance between the first wiring 70a and the second wiring 70b (for example, between the first layer 10 and the second layer 20) changes according to the direction of current. The magnetic storage device 220 is, for example, a spin transfer type MRAM.

FIG. 10 is a schematic perspective view illustrating another magnetic memory device according to the second embodiment.
As shown in FIG. 10, another magnetic storage device 230 according to this embodiment further includes a metal-containing layer 51 in addition to the first layer 10, the second layer 20, and the intermediate layer 30.

  The metal-containing layer 51 includes a first metal. The first metal includes, for example, at least one selected from the group consisting of Pt, Pd, Au, Ru, W, Hf, and Ta. The metal-containing layer 51 includes a first portion 51a, a second portion 51b, and a third portion 51c. The third portion 51c is located between the first portion 51a and the second portion 51b. The intermediate layer 30 is located between the third portion 51 c and the second layer 20. The first layer 10 is located between the third portion 51 c and the intermediate layer 30. For example, the first layer 10 is in contact with the third portion 51c.

  A current (first current Ic1 or second current Ic2) flows through the metal-containing layer. This current is supplied from the control unit 70 described later.

  For example, the electrical resistance between the first portion 51a and the second layer 20 after the first current Ic1 flows from the first portion 51a toward the second portion 51b is defined as the first electrical resistance. For example, the electrical resistance between the first portion 51a and the second layer 20 after the second current Ic2 from the second portion 51b toward the first portion 51a flows is defined as the second electrical resistance. The value corresponding to the first electrical resistance is different from the value corresponding to the second electrical resistance. The first electrical resistance and the second electrical resistance may be electrical resistance between the second portion 51 b and the second layer 20. The electrical resistance may be an electrical resistance between the first wiring 70a and the second wiring 70b. The value corresponding to the electrical resistance is electrical resistance, voltage or current.

  For example, the spin orbit torque acts between the metal-containing layer 51 and the first layer 10 by the first current Ic1 or the second current Ic2. Thereby, the direction of magnetization of the first layer 10 is controlled. For example, the magnetization direction of the first layer 10 when the first current Ic1 flows has a component opposite to the component of the magnetization direction of the first layer 10 when the second current Ic2 flows. For example, the angle between the magnetization of the first layer 10 and the magnetization of the second layer 20 when the first current Ic1 flows is equal to the magnetization of the first layer 10 and the second layer when the second current Ic2 flows. The angle between the 20 magnetizations is different. Thereby, an electrical resistance changes. The change in electrical resistance corresponds to the stored information.

  In the magnetic memory device 230, the metal-containing layer 51 may further include Ga and at least one selected from the group consisting of Fe, Co, and Ni.

  The magnetic storage device 230 is, for example, a spin orbit torque MRAM.

FIG. 11A to FIG. 11E are schematic views illustrating another magnetic storage device according to the second embodiment.
FIG. 11A is a schematic perspective view. FIG. 11B to FIG. 11E are schematic views illustrating four operations (states).

  As shown in FIG. 11A, another magnetic storage device 230a according to this embodiment includes a metal-containing layer 51, a plurality of stacked bodies SB0, and a control unit 70. The multiple stacked bodies SB0 include, for example, a first stacked body SB1 and a second stacked body SB2. The number of the multiple stacked bodies SB0 is arbitrary.

  The first stacked body SB1 includes a first layer 10, a second layer 20, and an intermediate layer 30. The second stacked body SB2 includes a third layer 10A, a fourth layer 20A, and another intermediate layer 30A. In this example, the first stacked body SB1 further includes a second conductive layer 42. The second stacked body SB2 further includes another second conductive layer 42A.

  The metal-containing layer 51 includes first to fifth portions 51a to 51e. A third portion 51c is provided between the first portion 51a and the second portion 51b. A fourth portion 51d is provided between the third portion 51c and the second portion 51b. A fifth portion 51e is provided between the third portion 51c and the fourth portion 51d.

  The second layer 20 is provided between the third portion 51 c and the second conductive layer 42. The intermediate layer 30 is provided between the third portion 51 c and the second layer 20. The first layer 10 is provided between the third portion 51 c and the intermediate layer 30. A fourth layer 20A is provided between the fourth portion 51d and another second conductive layer 42A. Another intermediate layer 30A is provided between the fourth portion 51d and the fourth layer 20A. A third layer 10A is provided between the fourth portion 51d and another intermediate layer 30A.

  The configuration of the third layer 10A is the same as the configuration of the first layer 10. The configuration of the fourth layer 20A is the same as the configuration of the second layer 20. The configuration of another intermediate layer 30A is the same as the configuration of the intermediate layer 30A.

  The controller 70 is electrically connected to the first portion 51a, the second portion 51b, the second layer 20 (second conductive layer 42), and the fourth layer 20A (another second conductive layer 42A). . In this example, the control unit 70 and the second layer 20 are electrically connected by the first wiring 70A. The control unit 70 and the fourth layer 20A are electrically connected by the second wiring 70B. The first switch element Sw1 is provided on the current path of the first wiring 70A. The second switch element Sw2 is provided on the current path of the second wiring 70B. These switch elements are, for example, selection transistors. These switch elements are electrically connected to a drive circuit 75 provided in the control unit 70.

  In the magnetic storage device 230a, for example, first to fourth operations OQ1 to OQ4 described below are performed. These operations are controlled by the control unit 70.

  As shown in FIG. 11B, in the first operation OQ1, the control unit 70 sets the first portion 51a of the metal-containing layer 51 to the potential V0. The potential V0 is, for example, a ground potential. In the first operation OQ1, the control unit 70 sets the first potential difference between the first portion 51a and the second layer 20 as the first voltage V1 (for example, a selection voltage).

  In the first operation OQ1, the control unit 70 sets the second potential difference between the first portion 51a and the fourth layer 20A as the second voltage V2 (for example, a non-selection voltage). The second voltage V2 is different from the first voltage V1.

  In the first operation OQ1, the control unit 70 supplies the first current Ic1 to the metal-containing layer 51. The first current Ic1 has a direction from the first portion 51a to the second portion 51b.

  In such a first operation OQ1, the magnetization direction of the first layer 10 is one direction. This is due to the magnetic action from the metal-containing layer 51. On the other hand, the magnetization direction of the non-selected third layer 10A does not substantially change.

  As shown in FIG. 11C, in the second operation OQ2, the control unit 70 sets the first portion 51a of the metal-containing layer 51 to the potential V0. In the second operation OQ2, the controller 70 sets the first potential difference between the first portion 51a and the second layer 20 to the first voltage V1. In the second operation OQ2, the controller 70 sets the second potential difference between the first portion 51a and the fourth layer 20A as the second voltage V2. In the second operation OQ2, the control unit 70 supplies the second current Ic2 to the metal-containing layer 51. The second current Ic2 has a direction from the second portion 51b to the first portion 51a.

  At this time, the magnetization of the selected first layer 10 changes. This is due to, for example, a magnetic action from the metal-containing layer 51. On the other hand, the magnetization of the non-selected third layer 10A does not substantially change.

  The electrical resistance (first electrical resistance) between the second layer 20 and the first portion 51a after the first operation OQ1 is between the second layer 20 and the first portion 51a after the second operation OQ2. It is different from the electrical resistance (second electrical resistance).

  On the other hand, the electrical resistance between the fourth layer 20A and the first portion 51a after the first operation OQ1 is defined as a third electrical resistance. The electric resistance between the fourth layer 20A and the first portion 51a after the second operation OQ2 is set as a fourth electric resistance. The third electrical resistance is substantially the same as the fourth electrical resistance. This is because the magnetization of the third layer 10A does not substantially change.

  Thus, in the embodiment, the absolute value of the difference between the first electrical resistance and the second electrical resistance is larger than the absolute value of the difference between the third electrical resistance and the fourth electrical resistance.

  In the example of the third operation OQ3 illustrated in FIG. 11D, the first stacked body SB1 is set in a non-selected state, and the second stacked body SB2 is set in a selected state. As already described, in the first operation OQ1, the control unit 70 sets the first potential difference between the first portion 51a and the second layer 20 as the first voltage V1 (see FIG. 11B). Then, the control unit 70 sets the first potential difference to the first voltage V1 in the second operation OQ2 (see FIG. 11C). As illustrated in FIG. 11D, the control unit 70 sets the first potential difference between the first portion 51a and the second layer 20 to the second voltage V2 (non-selection voltage) in the third operation OQ3. The controller 70 supplies the first current Ic1 to the metal-containing layer 51 in the third operation OQ3.

  In the third operation OQ3, the magnetization of the non-selected first layer 10 does not change (same as the state of FIG. 11A). On the other hand, the magnetization of the selected third layer 10A changes from the state shown in FIG.

  Also in the fourth operation OQ4 shown in FIG. 11E, the first stacked body SB1 is set in a non-selected state, and the second stacked body SB2 is set in a selected state. In the fourth operation OQ4, the control unit 70 sets the first potential difference to the second voltage V2. In the fourth operation OQ4, the control unit 70 sets the second potential difference to the first voltage V1. The controller 70 supplies the second current Ic2 to the metal-containing layer 51 in the fourth operation OQ4.

  In the first stacked body SB1 in the non-selected state, the electrical resistance is substantially the same between the third operation OQ3 and the fourth operation OQ4. On the other hand, in the second stacked body SB2 in the selected state, the electrical resistance changes between the third operation OQ3 and the fourth operation OQ4.

  As described above, the absolute value of the difference between the first electrical resistance after the first operation OQ1 and the second electrical resistance after the second operation OQ2 is the same as that of the second layer 20 after the third operation OQ3. The absolute value of the difference between the electrical resistance between the portion 51a and the electrical resistance between the second layer 20 and the first portion 51a after the fourth operation OQ4 is larger.

  Thus, one of the multiple stacked bodies SB0 is selected. The magnetization of the magnetic layer (for example, the first layer 10 or the third layer 10A) of the selected stacked body SB0 changes according to the direction of the current flowing through the metal-containing layer 51.

FIG. 12 is a schematic view illustrating another magnetic memory device according to the second embodiment.
As shown in FIG. 12, the magnetic memory device 240 according to this embodiment includes a plurality of storage units ME, a plurality of wirings (a plurality of first bit lines BL1, a plurality of second bit lines BL2, and a plurality of word lines WL. ) And the control unit 70.

  A direction perpendicular to an arbitrary X-axis direction is taken as a Y-axis direction. A direction perpendicular to the X-axis direction and the Y-axis direction is taken as a Z-axis direction.

  In this example, the plurality of bit lines BL1 and BL2 extend in the Y-axis direction. The plurality of bit lines BL1 and BL2 are arranged in the X-axis direction. The plurality of word lines WL extend in the X-axis direction. The plurality of word lines WL are arranged in the Y-axis direction.

  One of the plurality of storage units ME includes a magnetic element 110 and a control element 70s (for example, a transistor). The control element 70s is connected in series with the magnetic element 110. One end of the magnetic element 110 is connected to one end of the control element 70s. The magnetic element 110 corresponds to one memory cell MC.

  The other end of the magnetic element 110 included in one of the plurality of storage units ME is electrically connected to one of the plurality of first bit lines BL1. The other end of the control element 70s included in one of the plurality of storage units ME is electrically connected to one of the plurality of second bit lines BL2.

  A control terminal (for example, a gate) of the control element 70s included in one of the plurality of storage units ME is electrically connected to one of the plurality of word lines WL. The third terminal of the control element 70s is electrically connected.

  The plurality of first bit lines BL1 and the plurality of second bit lines BL2 are electrically connected to at least one of the first circuit 71 and the second circuit 72. The plurality of word lines WL are electrically connected to the third circuit 73. These circuits include a selection switch (for example, a selection transistor). These circuits select a plurality of wirings and apply a predetermined voltage. A predetermined voltage pulse is applied to one of the plurality of magnetic elements 110 by these circuits and the control element 70s. Thereby, the resistance in the magnetic element 110 changes. The high resistance state or the low resistance state corresponds to “0” or “1” of the stored information. These circuits include, for example, a detection circuit (such as a sense amplifier). For example, the detection circuit detects values (voltage, current, resistance, etc.) corresponding to the resistance state of the magnetic element 110. Thereby, the stored information is read out. These circuits are included in the control unit 70.

  The magnetic storage device 240 may be, for example, a voltage control type (electric field control type) MRAM. The magnetic storage device 240 may be, for example, a spin transfer type MRAM. The magnetic storage device 240 may be, for example, a spin orbit torque MRAM.

(Third embodiment)
The present embodiment relates to an oscillation device.
FIG. 13 is a schematic view illustrating an oscillation device according to the third embodiment.
As illustrated in FIG. 13, the oscillation device 310 includes a first layer 10, a second layer 20, an intermediate layer 30, and a circuit unit 76. The first layer 10, the second layer 20, and the intermediate layer 30 have, for example, the configuration described in regard to the first embodiment. The magnetization direction of the second layer 20 is, for example, an in-plane direction and intersects the Z-axis direction.

  The circuit unit 76 is electrically connected to the first layer 10 and the second layer 20. In this example, the first conductive layer 41 and the second conductive layer 42 described in regard to the first embodiment are provided. The circuit portion 76 is electrically connected to these conductive layers via the first wiring 70a and the second wiring 70b.

  The circuit unit 76 supplies current to the stacked body including the first layer 10, the second layer 20, and the intermediate layer 30. The current flows through the stacked body along the Z-axis direction. At this time, a high frequency magnetic field is generated in the laminate. The oscillation frequency is, for example, 50 GHz or more and 300 GHz or less. For example, a high oscillation frequency can be obtained. The oscillation device 310 is, for example, a spin torque oscillator or a spin torque diode.

  According to the embodiment, it is possible to provide a magnetic element, a magnetic storage device, and an oscillation device capable of improving characteristics.

  In this specification, the state of being electrically connected includes the state where two conductors are in direct contact. The state of being electrically connected includes a state in which two conductors are connected by another conductor (for example, a wiring or the like). The electrically connected state includes a state in which a switching element (a transistor or the like) is provided between the paths between the two conductors, and a state in which a current flows in the path between the two conductors can be formed.

  In the present specification, “vertical” and “parallel” include not only strict vertical and strict parallel, but also include variations in the manufacturing process, for example, and may be substantially vertical and substantially parallel. .

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, regarding the specific configuration of each element such as a magnetic layer, an intermediate layer, a substrate, and a conductive layer included in the magnetic element, those skilled in the art can similarly implement the present invention by selecting appropriately from a well-known range. As long as the above effect can be obtained, it is included in the scope of the present invention.

  Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, all magnetic elements, magnetic storage devices, and oscillation devices that can be implemented by those skilled in the art based on the magnetic elements, magnetic storage devices, and oscillation devices described above as embodiments of the present invention are also included in this book. As long as the gist of the invention is included, it belongs to the scope of the present invention.

  In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

  DESCRIPTION OF SYMBOLS 10 ... 1st layer, 10A ... 3rd layer, 11 ... 1st area | region, 12 ... 2nd area | region, 13 ... 3rd area | region, 20 ... 2nd layer, 20A ... 4th layer, 30 ... Intermediate | middle layer, 30A ... another 33 ... High oxygen concentration region, 34 ... Low oxygen concentration region, 40b ... Ta film, 40s ... Substrate, 41 ... First conductive layer, 42 ... Second conductive layer, 42A ... Another second conductive layer, 42a ... Ta layer, 42b ... Ru layer, 45 ... metal layer, 51 ... metal-containing layer, 51a to 51e ... first to fifth parts, 70 ... control unit, 70A, 70B ... first and second wirings, 70a, 70b: 1st, 2nd wiring, 70s ... Switch element 71 ... 1st circuit 72 ... 2nd circuit 73 ... 3rd circuit 75 ... Drive circuit 76 ... Circuit part 110, 111, 112 ... Magnetic element 111a, 111b ... first and second samples, 21 0, 220, 230, 230a, 240 ... magnetic storage device, 310 ... oscillation device, BL1, BL2 ... first and second bit lines, Ha ... external magnetic field, H1 ... first pulse height, Ic1, Ic2 ... first , Second current, MC ... memory cell, ME ... memory unit, MRn, MRv ... MR ratio, OP1-OP3 ... first to third operations, OQ1-OQ4 ... first to fourth operations, P1, P2 ... first , Second pulse, P1x ... another pulse, R ... electric resistance, S1 ... signal, SB, SB0 ... laminate, SB1, SB2 ... first, second laminate, ST1 to ST8 ... first to eighth states, Sw1, Sw2 ... first and second switch elements, T1 ... first pulse width, V0 ... potential, V1, V2 ... first, second potential, WL ... word line, t1-t3 ... thickness, ti ... time

Claims (15)

A first region containing Mn and Ga;
A second region comprising at least one selected from the group consisting of Fe, Co, Ni and Mn;
A third region provided between the first region and the second region, wherein the third region includes Ga and at least one selected from the group consisting of Fe, Co, Ni, and Mn;
The magnetic element provided with the laminated body containing the 1st layer containing. The direction of the first magnetization of the first region and the direction of the second magnetization of the second region are along the direction from the first region to the second region,
2. The magnetic element according to claim 1, wherein a component of the first magnetization along the direction is opposite to a component of the second magnetization along the direction. The second region includes at least one selected from the group consisting of Fe and Co;
The magnetic element according to claim 1, wherein the third region includes Co and Ga. The laminate is
A second layer comprising at least one selected from the group consisting of Fe, Co and Ni;
A nonmagnetic intermediate layer provided between the first layer and the second layer;
The magnetic element according to claim 1, further comprising: The third region is located between the first region and the second layer;
The second region is located between the third region and the second layer;
The magnetic element according to claim 4, wherein the intermediate layer is located between the second region and the second layer. The first layer and the second layer in the first state when changing from a first state in which a first magnetic field is applied to the stacked body to a second state in which a second magnetic field is applied to the stacked body Is higher than the second electrical resistance between the first layer and the second layer in the second state, and the first magnetic field and the second magnetic field are Having an orientation from a layer toward the first layer, the absolute value of the first magnetic field being greater than the absolute value of the second magnetic field,
When changing from the second state to a third state in which a third magnetic field is applied to the stacked body, the third electrical resistance between the first layer and the second layer in the third state is: Lower than the second electrical resistance, the third magnetic field has a direction from the first layer toward the second layer;
When the third state is changed to the fourth state in which the fourth magnetic field is applied to the stacked body, the fourth electrical resistance between the first layer and the second layer in the fourth state is: The fourth electric field is higher than the third electric resistance, and the fourth magnetic field has a direction from the first layer toward the second layer, and the absolute value of the fourth magnetic field is larger than the absolute value of the third magnetic field. ,
When the fifth state is changed from the fourth state to the fifth state in which the fifth magnetic field is applied to the stacked body, the fifth electrical resistance between the first layer and the second layer in the fifth state is: The fifth electric field is lower than the fourth electric resistance, the fifth magnetic field has a direction from the first layer toward the second layer, and the absolute value of the fifth magnetic field is greater than the absolute value of the fourth magnetic field. The magnetic element according to claim 4, wherein the magnetic element is large. When changing from the fifth state to the sixth state in which the sixth magnetic field is applied to the stacked body, the sixth electrical resistance between the first layer and the second layer in the sixth state is: Higher than the fifth electric resistance, the sixth magnetic field has a direction from the first layer toward the second layer, and the absolute value of the sixth magnetic field is greater than the absolute value of the fifth magnetic field small,
When the sixth state is changed to a seventh state in which a seventh magnetic field is applied to the stacked body, a seventh electrical resistance between the first layer and the second layer in the seventh state is: Lower than the sixth electrical resistance, the seventh magnetic field has a direction from the second layer toward the first layer;
When changing from the seventh state to an eighth state in which an eighth magnetic field is applied to the laminate, the eighth electrical resistance between the first layer and the second layer in the eighth state is: The eighth electric resistance is higher than the seventh electric resistance, the eighth magnetic field has a direction from the second layer toward the first layer, and an absolute value of the eighth magnetic field is larger than an absolute value of the seventh magnetic field. The magnetic element according to claim 6, wherein the magnetic element is smaller than the absolute value of the first magnetic field. The first layer and the second layer in the first state when changing from a first state in which a first magnetic field is applied to the stacked body to a second state in which a second magnetic field is applied to the stacked body Is higher than the second electrical resistance between the first layer and the second layer in the second state, and the first magnetic field is from the second layer to the first layer. The second magnetic field has a direction from the first layer to the second layer,
When changing from the second state to a third state in which a third magnetic field is applied to the stacked body, the third electrical resistance between the first layer and the second layer in the third state is: Lower than the second electrical resistance, the third magnetic field has a direction from the first layer toward the second layer, and an absolute value of the third magnetic field is greater than an absolute value of the second magnetic field ,
When the third state is changed to the fourth state in which the fourth magnetic field is applied to the stacked body, the fourth electrical resistance between the first layer and the second layer in the fourth state is: The fourth electric field is higher than the third electric resistance, and the fourth magnetic field has a direction from the first layer toward the second layer. The absolute value of the fourth magnetic field is greater than the absolute value of the third magnetic field. big,
When the fifth state is changed from the fourth state to the fifth state in which the fifth magnetic field is applied to the stacked body, the fifth electrical resistance between the first layer and the second layer in the fifth state is: The fifth electric field is lower than the fourth electric resistance, the fifth magnetic field has a direction from the first layer toward the second layer, and the absolute value of the fifth magnetic field is greater than the absolute value of the fourth magnetic field. The magnetic element according to claim 4, wherein the magnetic element is large. When changing from the fifth state to the sixth state in which the sixth magnetic field is applied to the stacked body, the sixth electrical resistance between the first layer and the second layer in the sixth state is: Higher than the fifth electrical resistance, the sixth magnetic field has a direction from the second layer toward the first layer;
When the sixth state is changed to a seventh state in which a seventh magnetic field is applied to the stacked body, a seventh electrical resistance between the first layer and the second layer in the seventh state is: Lower than the sixth electrical resistance, the seventh magnetic field has a direction from the second layer toward the first layer, and the absolute value of the seventh magnetic field is greater than the absolute value of the sixth magnetic field ,
When changing from the seventh state to an eighth state in which an eighth magnetic field is applied to the laminate, the eighth electrical resistance between the first layer and the second layer in the eighth state is: The eighth magnetic resistance is higher than the seventh electric resistance, the eighth magnetic field has a direction from the second layer toward the first layer, and the absolute value of the eighth magnetic field is greater than the absolute value of the seventh magnetic field. The magnetic element according to claim 6, wherein the magnetic element is large and smaller than an absolute value of the first magnetic field.   10. The thickness according to claim 1, wherein a thickness of the third region along the first direction from the first region toward the second region is 0.1 nm or more and 1.0 nm or less. Magnetic element.   The magnetic element according to claim 10, wherein a thickness of the second region along the first direction is not less than 0.1 nm and not more than 2.0 nm.   The magnetic element according to claim 10 or 11, wherein a thickness of the first region along the first direction is 1 nm or more and 10 nm or less.   The magnetic element according to claim 1, wherein the third region is in contact with the first region and the second region. A magnetic element according to any one of claims 1 to 13,
A switch element electrically connected to the magnetic element;
A magnetic storage device.   An oscillation device comprising the magnetic element according to claim 1.

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