JP5951401B2 - Magnetic recording element and magnetic memory - Google Patents

Description

  The present invention relates to a magnetic recording element and a magnetic memory that use spin-polarized electrons for magnetization reversal.

  In recent years, research and development of spin electronics devices using the spin degree of freedom of electrons has been actively conducted.

  For example, in a hard disk drive, the magnetization state of a recording medium is controlled by a magnetic field from a magnetic head, and in a magnetic random access memory, the magnetization state of a magnetoresistive element is controlled by a combined magnetic field from two write lines.

  The method of controlling the magnetization state by such a magnetic field has an old history and is now an established technology.

  On the other hand, with recent advances in nanotechnology, recording units of a recording medium and miniaturization of magnetoresistive elements have progressed, and it has become necessary to control these magnetization states locally on a nanoscale.

  However, since the magnetic field has the property of spreading in space, it is difficult to localize. For this reason, a so-called “crosstalk” problem that causes erroneous writing due to the influence of the magnetic field on the recording unit and the magnetoresistive effect element other than the write target occurs. Further, if the magnetic field generation source is made small to attempt to localize the magnetic field, a magnetic field having a magnitude necessary for magnetization reversal cannot be obtained.

  Therefore, “current direct drive type magnetization reversal method” that does not cause such a problem has been noticed (for example, see Non-Patent Document 1).

  This is a technique in which a spin injection current as a write current is passed through a magnetoresistive effect element, and magnetization reversal is executed using spin-polarized electrons generated there. Specifically, the angular momentum of the spin-polarized electrons is transmitted to the electrons in the magnetic material as the magnetic recording layer, so that the magnetization of the magnetic recording layer is reversed.

  If such a current reversal magnetization reversal technique (spin injection magnetization reversal technique) is used, the magnetization state can be easily controlled locally at the nanoscale, and the value of the spin injection current can be reduced according to miniaturization. It helps to realize spin electronics devices such as high recording density hard disks and magnetic random access memories.

However, there are problems with this technology. That is, the current density Jc of the spin injection current required for the magnetization reversal becomes a large value of 1 × 10 ⁷ A / cm ² or more. When such a large value is reached, reliability problems such as deterioration of element characteristics occur due to the influence of heat generated in the magnetoresistive element.

  As countermeasures, several proposals have been made, for example, by reducing the value of the saturation magnetization Ms of the magnetic material constituting the magnetoresistive element (see, for example, Patent Documents 1 and 2). If it is made smaller, there arises a new problem that the MR (magneto-resistive) characteristic that determines the thermal fluctuation resistance of the magnetized state and the magnitude of the reproduction signal output deteriorates.

Japanese Patent Laid-Open No. 2005-93488 JP 2004-193595 A

F. J. Albert, et al., Appl. Phy. Lett. 77, 3809 (2000)

  The example of the present invention proposes a technique for reducing the current density of the spin injection current for magnetization reversal without degrading thermal fluctuation resistance and MR characteristics.

The magnetic recording element according to the example of the present invention includes a magnetic recording layer whose magnetization is variable according to the direction of the current passing through the film and whose easy axis direction is perpendicular to the film surface, and whose magnetization is perpendicular to the film surface. A magnetic pinned layer fixed in a direction, a nonmagnetic barrier layer between the magnetic recording layer and the magnetic pinned layer, and an insertion layer between the magnetic recording layer and the nonmagnetic barrier layer, In the magnetic recording layer, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfies Han> 12.57 Ms and Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness thereof is at 5nm or less, the insertion layer comprises CoFeB, FeB, CoNbZr, FeAlSi, CoTaZr, and, one of the FeTaC.

1 is a side view showing a structure of a magnetic recording element according to a first embodiment. The figure which shows the relationship between the saturation magnetization Ms of the magnetic recording layer of FIG. 1, and the anisotropic magnetic field Han. The side view which shows the structure of the magnetic-recording element of 2nd Embodiment. The figure which shows the relationship between the saturation magnetization Ms of the magnetic-recording layer of FIG. 3, and the anisotropic magnetic field Han. The side view which shows the structure of the magnetic-recording element of 3rd Embodiment. FIG. 6 is a diagram showing the relationship between the saturation magnetization Ms and the anisotropic magnetic field Han of the magnetic recording layer in FIG. 5. Sectional drawing which shows the structure of the magnetic recording element made as an experiment in 1st Example. The figure which shows the relationship between the saturation magnetization Ms of the sample of 1st Example, and the anisotropic magnetic field Han. The figure which shows the relationship between the thickness of a magnetic-recording layer, and an inversion current density. The figure which shows the mode at the time of writing. The figure which shows the evaluation result of a writing characteristic. The figure which shows the structure of the magnetic recording element made as an experiment in 2nd Example. The figure which shows the structure of the magnetic recording element made as an experiment in 2nd Example. The figure which shows the structure of the magnetic recording element made as an experiment in 2nd Example. The side view which shows the structure of the magnetic-recording element of 5th Embodiment. Sectional drawing which shows the structure of the magnetic recording element made as an experiment in 3rd Example. Sectional drawing which shows the structure of the magnetic recording element made as an experiment in 4th Example. Sectional drawing which shows the structure of the magnetic-recording element made as an experiment in 5th Example. Sectional drawing which shows the structure of the magnetic-recording element made as an experiment in 5th Example. The figure which shows the range of the magnetic-recording element made as an experiment in 5th Example. The circuit diagram which shows the magnetic random access memory as an application example. “1” —A cross-sectional view showing a state of a memory cell at the time of writing. “0” —A cross-sectional view showing a state of a memory cell at the time of writing. “1” —A cross-sectional view showing a state of a memory cell at the time of reading. “0” —A cross-sectional view showing a state of a memory cell at the time of reading. The figure which shows the example of a layout of a magnetic-recording element. The figure which shows the example of a layout of a magnetic-recording element. The figure which shows the example of a layout of a magnetic-recording element. The figure which shows the example of a layout of a magnetic-recording element. The figure which shows the basic structure of the probe memory as an application example. The figure which shows the modification of the probe memory of FIG. The figure which shows the modification of the probe memory of FIG. The figure which shows the modification of the probe memory of FIG. The figure which shows the probe memory of the multi probe structure as an application example. The figure which shows the device structure of the probe memory of FIG. The figure which shows spin FET as an application example.

  The best mode for carrying out an example of the present invention will be described below in detail with reference to the drawings.

1. Overview
The example of the present invention is premised on a magnetization reversal technique (spin injection magnetization reversal technique) by direct current driving. In this technique, the following configuration is adopted in order to reduce the current density of the spin injection current for magnetization reversal without degrading the resistance to thermal fluctuation and MR characteristics.

  First, the easy axis of magnetization of the magnetic recording layer (magnetic free layer) is set to a direction perpendicular to the film surface.

  Here, the film surface means the surface of the film when the magnetic recording layer is regarded as a “film”. Therefore, the direction perpendicular to the film surface is the direction in which the magnetic pinned layer, the magnetic recording layer, and the nonmagnetic barrier layer (for example, tunnel barrier layer) between them are stacked.

  The magnetic recording layer (magnetic material) having such a structure is called a perpendicular magnetization film. On the other hand, a magnetic recording layer (magnetic material) having an easy axis direction parallel to the film surface is referred to as an in-plane magnetization film (horizontal magnetization film).

  The perpendicular magnetization film is easier to miniaturize than the in-plane magnetization film, and the current density of the spin injection current for magnetization reversal is also small.

  In order to make the easy axis direction of the magnetic recording layer perpendicular to the film surface, the saturation magnetization Ms (emu / cc) of the magnetic material constituting the magnetic recording layer and the anisotropic magnetic field Han (Oe) The relationship should be set to Han> 12.57Ms. The anisotropic magnetic field Han is given by Han = 2 Ku / Ms using the magnetic anisotropy Ku in the direction perpendicular to the film surface.

  The magnetization of the magnetic pinned layer is fixed in a direction perpendicular to the film surface by, for example, an antiferromagnetic layer. Further, the magnetic material may be fixed by using a magnetic material having a large coercive force that becomes a permanent magnet.

Next, in order to reduce the current density of the spin injection current to 2 × 10 ⁶ A / cm ² or less, the saturation magnetization Ms (emu / cc) of the magnetic material constituting the magnetic recording layer and the anisotropic magnetic field Han (Oe) Is set to Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness is set to 5 nm or less. This numerical value has been found by experiment, and in order to realize the current density, it is necessary to satisfy both the relationship and the thickness at the same time.

As described above, according to the example of the present invention, the current density of the spin injection current for magnetization reversal can be reduced without destroying only the saturation magnetization Ms of the magnetic material as the magnetic recording layer. However, it can be reduced to 2 × 10 ⁶ A / cm ² or less, which is desirable in order to ensure the operation of wiring and peripheral circuits. For this reason, since the thermal fluctuation resistance and MR characteristics are not deteriorated, a spin electronics device such as a magnetic memory having a high recording density can be realized.

2. Embodiment
Next, some preferred embodiments will be described.

(1) First Embodiment FIG. 1 is a side view showing the structure of a magnetic recording element according to a first embodiment.

  The magnetic recording layer 11 has variable magnetization and the easy axis direction is perpendicular to the film surface. The magnetic pinned layer 12 is fixed in a direction in which the magnetization is perpendicular to the film surface. A nonmagnetic barrier layer 13 is disposed between the magnetic recording layer 11 and the magnetic pinned layer 12.

In the magnetic recording layer 11, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfies Han> 12.57 Ms, Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness is Consists of magnetic material of 5nm or less.

  The magnetic pinned layer 12 is made of a magnetic material. The magnetization direction of the magnetic recording layer 12 is fixed by, for example, an antiferromagnetic layer. The nonmagnetic barrier layer 13 is made of, for example, an insulating material as a tunnel barrier layer.

  When the spin injection current Is flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization state of the magnetic recording element is a parallel state in which the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12 are the same. become.

  Further, when the spin injection current Is flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization state of the magnetic recording element is opposite to the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12. It becomes an antiparallel state.

FIG. 2 shows the range specified in the first embodiment.
Regarding the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) of the magnetic recording layer, the thinly covered range is the range that is established as the magnetic recording element of the first embodiment.

  According to the first embodiment, the current density of the spin injection current for magnetization reversal can be reduced without degrading the resistance to thermal fluctuation and MR characteristics.

(2) Second Embodiment FIG. 3 is a side view showing the structure of a magnetic recording element according to a second embodiment.

  The magnetic recording layer 11 has variable magnetization and the easy axis direction is perpendicular to the film surface. The magnetic pinned layer 12 is fixed in a direction in which the magnetization is perpendicular to the film surface. A nonmagnetic barrier layer 13 is disposed between the magnetic recording layer 11 and the magnetic pinned layer 12.

In the magnetic recording layer 11, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfies Han> 12.57 Ms, Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness is Consists of magnetic material of 5nm or less.

  In addition, the saturation magnetization Ms of the magnetic material constituting the magnetic recording layer 11 is set to a value exceeding 600 emu / cc. This is necessary to increase the MR ratio, which is an index indicating MR characteristics, to 20% or more.

  The magnetic pinned layer 12 is made of a magnetic material. The magnetization direction of the magnetic recording layer 12 is fixed by, for example, an antiferromagnetic layer. The nonmagnetic barrier layer 13 is made of, for example, an insulating material as a tunnel barrier layer.

  When the spin injection current Is flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization state of the magnetic recording element is a parallel state in which the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12 are the same. become.

  Further, when the spin injection current Is flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization state of the magnetic recording element is opposite to the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12. It becomes an antiparallel state.

FIG. 4 shows a range specified in the second embodiment.
Regarding the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) of the magnetic recording layer, the thinly covered range is the range that is established as the magnetic recording element of the second embodiment.

  According to the second embodiment, as in the first embodiment, the current density of the spin injection current for magnetization reversal can be reduced without degrading the resistance to thermal fluctuation and MR characteristics. Also, by setting the saturation magnetization Ms of the magnetic material constituting the magnetic recording layer 11 to a value exceeding 600 emu / cc, the current density Jc required for inversion can be reduced while maintaining the thermal fluctuation resistance, and the magnetic recording element MR ratio increases and playback signal output also increases.

(3) Third Embodiment FIG. 5 is a side view showing the structure of a magnetic recording element according to a third embodiment.

  The magnetic recording layer 11 has variable magnetization and the easy axis direction is perpendicular to the film surface. The magnetic pinned layer 12 is fixed in a direction in which the magnetization is perpendicular to the film surface. A nonmagnetic barrier layer 13 is disposed between the magnetic recording layer 11 and the magnetic pinned layer 12, and an insertion layer 14 is disposed between the magnetic recording layer 11 and the nonmagnetic barrier layer 13.

In the magnetic recording layer 11, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfies Han> 12.57 Ms, Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness is Consists of magnetic material of 5nm or less.

  The insertion layer 14 is made of a magnetic material, and the saturation magnetization Ms is set to a value exceeding 600 emu / cc. As described in the second embodiment, this is necessary to set the MR ratio, which is an index indicating the MR characteristics, to 20% or more.

  The thickness of the insertion layer 14 is set to less than 2 nm, more preferably less than 0.6 nm so as not to affect the magnetization (perpendicular magnetization) of the magnetic recording layer 11.

  The magnetic pinned layer 12 is made of a magnetic material. The magnetization direction of the magnetic recording layer 12 is fixed by, for example, an antiferromagnetic layer. The nonmagnetic barrier layer 13 is made of, for example, an insulating material as a tunnel barrier layer.

  When the spin injection current Is flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization state of the magnetic recording element is a parallel state in which the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12 are the same. become.

  Further, when the spin injection current Is flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization state of the magnetic recording element is opposite to the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12. It becomes an antiparallel state.

FIG. 6 shows a range designated in the third embodiment.
Regarding the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) of the magnetic recording layer, the thinly covered range is the range that is established as the magnetic recording element of the third embodiment.

  According to the third embodiment, as in the first embodiment, the current density of the spin injection current for magnetization reversal can be reduced without degrading the resistance to thermal fluctuation and MR characteristics. Also, by setting the saturation magnetization Ms of the magnetic material constituting the insertion layer to a value exceeding 600 emu / cc, the MR ratio of the magnetic recording element is increased and the reproduction signal output is also increased.

  The MR ratio of the magnetic recording element is affected by the saturation magnetization Ms of the magnetic material at the interface between the magnetic recording layer and the nonmagnetic barrier layer.

  Therefore, instead of the insertion layer, the saturation magnetization Ms of the magnetic recording layer is changed continuously or discontinuously in the magnetic recording layer, and the saturation magnetization Ms of the magnetic recording layer at the interface between the magnetic recording layer and the nonmagnetic barrier layer is changed. The same effect can be obtained even if the value exceeds 600 emu / cc.

(4) Fourth Embodiment FIGS. 12 to 14 are diagrams showing the structure of a magnetic recording element according to a fourth embodiment.

  The magnetic recording layer 11 is composed of magnetic fine particles 101 spatially separated by a nonmagnetic material 16. The magnetization of the magnetic fine particles 101 is variable, and the easy axis direction is perpendicular to the film surface.

  The magnetic pinned layer 12 is fixed in a direction in which the magnetization is perpendicular to the film surface. A nonmagnetic barrier layer 13 is disposed between the magnetic recording layer 11 and the magnetic pinned layer 12. A cap layer 15 is disposed on the magnetic recording layer 11.

The magnetic fine particle 101 has a relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfying Han> 12.57 Ms, Han <1.2E7Ms ⁻¹ +12.57 Ms, and a thickness of 10 nm. It consists of the following magnetic materials.

  The magnetic pinned layer 12 is made of a magnetic material. The magnetization direction of the magnetic recording layer 12 is fixed by, for example, an antiferromagnetic layer. The nonmagnetic barrier layer 13 is made of, for example, an insulating material as a tunnel barrier layer.

  When the spin injection current Is flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization state of the magnetic recording element is in a parallel state in which the magnetization direction of the magnetic fine particle 101 and the magnetization direction of the magnetic pinned layer 12 are the same. Become.

  When the spin injection current Is flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization state of the magnetic recording element is opposite to the magnetization direction of the magnetic fine particles 101 and the magnetization direction of the magnetic pinned layer 12. Become parallel.

  The magnetic material in which the magnetic fine particles are formed in the fourth embodiment is in the range specified in FIG.

  Regarding the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) of the magnetic recording layer, the thinly covered range is the range that is established as the magnetic recording element of the fourth embodiment.

  According to the fourth embodiment, it is possible to obtain ultra-high density by magnetizing the magnetic fine particles independently of each other and using each as a recording unit (1 bit). Further, the characteristic variation can be reduced by forming one recording unit (1 bit) with a plurality of magnetic fine particles.

  In the fourth embodiment, as shown in the example of FIG. 14, a hetero atom 102 may exist between the magnetic fine particles and the nonmagnetic barrier material. The hetero atom 102 is made of a material that is not included in any of the magnetic fine particles 101, the nonmagnetic barrier layer 13, and the nonmagnetic material 16.

  When these materials have a thickness of 3 atomic layers or less, the arrangement of the magnetic fine particles can be controlled without greatly affecting the magnetic characteristics.

  According to the fourth embodiment, as in the first embodiment, the current density of the spin injection current for magnetization reversal can be reduced without degrading the resistance to thermal fluctuation and MR characteristics.

(5) Fifth Embodiment FIG. 15 is a diagram showing the structure of a magnetic recording element according to a fifth embodiment.

  The magnetic recording layer 11 has variable magnetization and the easy axis direction is perpendicular to the film surface. The magnetic pinned layer 12 is fixed in a direction in which the magnetization is perpendicular to the film surface. A nonmagnetic barrier layer 13 is disposed between the magnetic recording layer 11 and the magnetic pinned layer 12.

A surface of the magnetic recording layer 11 opposite to the nonmagnetic barrier layer 13 is provided with a nonmagnetic conductive layer 102,
Further, the second magnetic pinned layer 103 having a magnetization fixed in a direction perpendicular to the film surface is provided on the surface of the nonmagnetic conductive layer 102 opposite to the magnetic recording layer 11.

  In the magnetic recording layer 11, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropy magnetic field Han (Oe) satisfies Han> 12.57 Ms and Han <1.2E7Ms-1 + 12.57 Ms, and has a thickness of Consists of magnetic material of 5nm or less.

  In addition to the case where the magnetic recording layer 11 is composed of a uniform material layer, as in the fourth embodiment, the magnetization is variable, and the magnetic recording layer 11 is formed of fine particles whose easy axis is perpendicular to the film surface. Also good.

  The magnetic pinned layer 12 and the second magnetic pinned layer 103 are made of a magnetic material. The magnetization directions of the magnetic recording layer 12 and the second magnetic pinned layer 103 are fixed by, for example, an antiferromagnetic layer. At this time, if the magnetizations of the magnetic pinned layer 12 and the second magnetic pinned layer 103 are pinned so that they are antiparallel to each other, the reversal efficiency can be increased and the current density is reduced.

The nonmagnetic barrier layer 13 is made of, for example, an insulating material as a tunnel barrier layer.

The nonmagnetic conductive layer 102 is made of, for example, a conductive metal containing one or more elements selected from Cu (copper), Au (gold), Ag (silver), and Al (aluminum).

  When the spin injection current Is flows from the second magnetic pinned layer 103 toward the magnetic pinned layer 12, the magnetization direction of the magnetic recording element is the same as the magnetization direction of the magnetic recording layer 11 and the magnetic pinned layer 12. Become parallel.

  When the spin injection current Is flows from the magnetic pinned layer 12 toward the second magnetic pinned layer 103, the magnetization state of the magnetic recording element is opposite to the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12. It becomes an antiparallel state.

  Regarding the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) of the magnetic recording layer, the thinly covered range is the range that is established as the magnetic recording element of the fourth embodiment.

  According to the fifth embodiment, it is possible to obtain ultra-high density by magnetizing the magnetic fine particles independently of each other and using each as a recording unit (1 bit). Further, the characteristic variation can be reduced by forming one recording unit (1 bit) with a plurality of magnetic fine particles.

  According to the fifth embodiment, as in the first embodiment, the current density of the spin injection current for magnetization reversal can be reduced without degrading the resistance to thermal fluctuation and MR characteristics.

3. Material examples
Examples of materials for realizing the magnetic recording elements of the first to third embodiments will be described below.

(1) Magnetic recording layer and magnetic pinned layer
The magnetic recording layer and the magnetic pinned layer are, for example, a magnetic metal containing one or more elements selected from the group of Fe (iron), Co (cobalt), Ni (nickel), Mn (manganese), and Cr (chromium) It consists of.

  For the magnetic recording layer, one or more elements selected from the group of Fe, Co, Ni, Mn, and Cr, Pt (platinum), Pd (palladium), Ir (iridium), Ru (ruthenium), Rh ( When the alloy is combined with one or more elements selected from the rhodium group, the value of the anisotropic magnetic field Han of the magnetic recording layer increases, and the value of the saturation magnetization Ms of the magnetic recording layer exceeds 600 emu / cc. It becomes easy to set.

  The value of the anisotropic magnetic field Han of the magnetic recording layer can also be adjusted by the composition of the magnetic material constituting the magnetic recording layer, crystal regularity by heat treatment, and the like.

  The magnetic recording layer and the magnetic pinned layer may be composed of, for example, a rare earth-transition metal amorphous alloy such as TbFeCo or GdFeCo, or a Co / Pt laminated structure.

  The magnetic material constituting the magnetic recording layer and the magnetic pinned layer can be a continuous magnetic material or a composite structure in which fine particles made of a magnetic material are deposited in a matrix in a non-magnetic material. In particular, a composite structure including fine particles is suitable for high density because it is suitable for miniaturization of elements.

  The shape of the magnetic fine particles is, for example, a cylindrical shape or a spherical shape as shown in FIGS.

Regarding the composite structure, when the non-magnetic material is an oxide-based high resistance material such as Al ₂ O _3-x , MgO _1-x , SiOx, ZnOx, TiOx, the spin injection current as the write current is Since it concentrates on fine particles, magnetization reversal at a low current density is possible. In particular, when the nonmagnetic material is the same as that of the nonmagnetic barrier layer, crystal control and magnetic anisotropy control of the fine particles are facilitated.

(2) Insertion layer
The insertion layer is, for example, one of Fe (iron), Co (cobalt), Ni (nickel), or Fe (iron), Co (cobalt), Ni (nickel), Mn (manganese), Cr ( It is composed of an alloy containing one element selected from the group of chromium.

The insertion layer is made of soft magnetic materials such as CoNbZr, FeTaC, CoTaZr, FeAlSi, FeB, and CoFeB, Heusler alloys such as Co ₂ MnSi, and half such as CrO ₂ , Fe ₃ O ₄ , La _1-x Sr _x MnO ₃ A metal oxide or nitride, or a magnetic semiconductor may be used.

(3) Nonmagnetic barrier layer
The two types of low resistance material and high resistance material will be described.

  For the nonmagnetic barrier layer, an insulating material can be used as a tunnel barrier layer for obtaining a large reproduction signal output by the TMR (tunnel magneto resistive) effect at the time of reading.

  Specifically, Al (aluminum), Ti (titanium), Zn (zinc), Zr (zirconium), Ta (tantalum), Co (cobalt), Ni (nickel), Si (silicon), Mg (magnesium), The nonmagnetic barrier layer can be composed of an oxide, nitride or fluoride containing at least one element selected from the group of Fe (iron).

In particular, the nonmagnetic barrier layer has a large energy gap of Al ₂ O _3-x (alumina), MgO (magnesium oxide), SiO _2-x , Si-ON, Ta-O, Al-Zr-O, ZnOx, TiOx. It is preferable that the semiconductor is composed of a semiconductor (GaAlAs or the like).

  As for the nonmagnetic barrier layer, a nanocontact MR (magneto resistive) material in which a magnetic material is inserted into a pinhole provided in the insulator, or Cu is inserted into a pinhole provided in the insulator. CPP (current-perpendicular-to-plane) -CPP-MR material can be used to obtain a large reproduction signal output.

  When the nonmagnetic barrier layer is a tunnel barrier layer, the thickness is preferably set to a value in the range of 0.2 nm to 2.0 nm for obtaining a large reproduction signal output. Similarly, when the nonmagnetic barrier layer is a nanocontact MR material, the thickness is preferably set to a value within the range of 0.4 nm to 40 nm in order to obtain a large reproduction signal output.

4). Example
An example in which a sample was actually created and its characteristics were evaluated will be described.

(1) First embodiment
FIG. 7 shows the structure of the magnetic recording element manufactured as a prototype in the first embodiment.

  The magnetic recording element includes a laminated structure of a magnetic recording layer 11, a magnetic pinned layer 12, and a nonmagnetic barrier layer 13 therebetween, and is disposed between the lower electrode 21 and the upper electrode 22. A cap layer 15 having a thickness of 10 nm or less is disposed between the magnetic recording layer 11 and the upper electrode 22.

  The cap layer 15 can be composed of, for example, an oxide such as Ta, Al, Mg, Fe or a laminated structure of a nonmagnetic metal such as Cu, Ag, Au and an oxide such as Ta, Al, Mg, Fe. Protect the magnetic recording element.

  More preferably, the cap layer 15 is made of one selected from the group consisting of oxides, nitrides and fluorides having a thickness of 1 nm or less.

  The cap layer 15 may be made of a nonmagnetic metal such as Ru, Cu, Ag, Au, or Ta when a low current density of the spin injection current is realized.

  In FIG. 7, only the upper part of the magnetic pinned layer 12 has a pillar shape, but the magnetic pinned layer 12 may be narrowed down to the lower part so as to have a pillar shape below the magnetic pinned layer.

As shown in Table 1, there are 17 types of samples. In common, the magnetic pinned layer 21 is made of an FePt ordered alloy, and the nonmagnetic barrier layer 13 is made of MgO. The magnetic recording layer is composed of Fe-Pt alloy, Fe-Co-Pt alloy, Co-Pt alloy, Co-Cu-Pt alloy, Co-Ph-Pt alloy and the like.

  Samples AA1 to AA8 are magnetic recording elements according to examples of the present invention, and are within the range of the conditions presented in the first embodiment as shown in FIG. The film thickness of the magnetic recording layer is 5 nm or less.

  On the other hand, samples BB1 to BB4 are magnetic recording elements as comparative examples, and are out of the range of the conditions presented in the first embodiment as shown in FIG.

  On the other hand, in the samples CC1 to CC5, as shown in FIG. 8, the relationship between Ms and Han is within the range of the conditions presented in the first embodiment, but the magnetic recording layer 11 is composed of FeCoPt having different thicknesses. The

  These samples are manufactured by the following procedure.

First, after forming the lower electrode 21 on the wafer, the wafer is placed in an ultra-high vacuum sputtering apparatus, and the magnetic pinned layer 12, the nonmagnetic barrier layer 13, the magnetic recording layer 11, and the cap layer are formed on the lower electrode 21. 15 are sequentially deposited. For the lower electrode 21, for example, an Au (001) or Pt (001) buffer layer can be used. A magnetization pinned layer made of an FePt ordered alloy can be grown on, for example, a buffer layer heated by a substrate. After that, after forming the MgO film by lowering the substrate temperature to room temperature, the alloy material for forming the magnetic recording layer is grown in the range of the substrate temperature from 350 ° C to 700 ° C to form the magnetic recording layer having the desired Ms and Han. obtain. A cap layer is further formed on these films. The Han of the magnetic recording layer can be changed by changing the growth temperature of the alloy as in this example, but it can also be changed by the post-annealing temperature.
Next, an EB (electron beam) resist is applied and EB exposure is performed to form a mask. The shape of the mask is, for example, an ellipse of 70 nm × 100 nm, and the longitudinal direction along the long side is parallel to the direction of magnetic anisotropy of the magnetic recording layer.

  Further, the magnetic recording layer 11, the magnetic pinned layer 12, the nonmagnetic barrier layer 13 and the cap layer 15 existing in the region not covered with the mask are etched using an ion milling device. Here, the etching amount can be accurately grasped by introducing the sputtered particles into a quadrupole analyzer by differential exhaust and performing mass spectrometry.

  This etching completes the magnetic recording element.

Thereafter, the mask is peeled off, and SiO ₂ that completely covers the magnetic recording element is formed. Further, the surface of SiO ₂ is planarized by ion milling, and the upper surface of the cap layer 15 is exposed from SiO ₂ . Finally, the upper electrode 22 is formed on the cap layer 15.

  For these samples, a spin injection current (magnetization reversal current) was passed in the stacking direction of the magnetic recording element, and the reversal current density required for reversing the magnetization of the magnetic recording layer was monitored.

As a result, in samples AA1 to AA8, the reversal current density Jc obtained by averaging the absolute value of the reversal current density when reversing from antiparallel to parallel and the absolute value of the reversal current density when reversing from parallel to antiparallel is shown. As shown in FIG. 1, it was 2 × 10 ⁶ A / cm ² or less. On the other hand, in samples BB1 to BB4, the reversal current density sufficiently exceeded 2 × 10 ⁶ A / cm ² . Note that the reversal current density Jc described in this specification is the absolute value of the reversal current density when reversing from antiparallel to parallel as described above, and reversal from parallel to antiparallel unless otherwise specified. In this case, the absolute value of the reversal current density is defined as an average value.

Furthermore, in samples CC1 to CC5, as shown in FIG. 9, the reversal current density Jc is almost proportional to the thickness of the magnetic recording layer, and a reversal current density of 2 × 10 ⁶ A / cm ² is obtained to obtain good characteristics. In order to achieve this, it is understood that the magnetic recording layer is desirably 5 nm or less.

As is apparent from this result, according to the example of the present invention, it was confirmed that the current density of the spin injection current can be reduced to 2 × 10 ⁶ A / cm ² or less. The same tendency was obtained when the nonmagnetic barrier layer was Al ₂ O _{3 -X} , SiO _{2 -X} , TiOx, ZnOx.

  10 and 11 show the evaluation results of the write characteristics of sample A1.

  First, as shown in FIG. 10, the spin injection current Is is passed under the condition that the external magnetic field is zero, and the magnetization direction of the residual magnetization of the magnetic recording layer 11 is determined.

  When the spin injection current Is flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization state of the magnetic recording element is a parallel state in which the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12 are the same. become.

  Further, when the spin injection current Is flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization state of the magnetic recording element is opposite to the magnetization direction of the magnetic recording layer 11 and the magnetization direction of the magnetic pinned layer 12. It becomes an antiparallel state.

  Next, a read current is passed through the magnetic recording element, and the resistance R in the parallel / antiparallel state is measured. As a result, as shown in FIG. 11, the relationship between the spin injection current Is and the resistance R of the magnetic recording element is obtained.

  From this evaluation, it was confirmed that magnetization reversal was properly performed with a small reversal current density.

  If the minimum value of the current required for reversing the magnetization of the magnetic recording layer is the critical current Ic, writing can be performed with a current equal to or higher than the critical current Ic, and erroneous writing at the time of reading can be prevented. Therefore, the value is smaller than the critical current Ic.

(2) Second embodiment
12 to 14 show the structure of the magnetic recording element manufactured as a prototype in the second embodiment.

  The magnetic recording element has a laminated structure of a magnetic recording layer 11, a magnetic pinned layer 12, and a nonmagnetic barrier layer 13 therebetween. The magnetic recording element is characterized in that the magnetic recording layer 11 is composed of an aggregate of a plurality of magnetic fine particles 101 separated by a nonmagnetic material 16, and the magnetization direction of each magnetic fine particle 101 is determined independently. .

Here, it is preferable from the viewpoint of the manufacturing process that the nonmagnetic material 16 exists in the crystal grain boundary of the magnetic fine particles 101 constituting the magnetic recording layer 11. The nonmagnetic material 16 is made of a material containing oxygen, such as MgO _X , Al ₂ O _{3 -X} , and SiO ₂ . In particular, when the nonmagnetic material 16 is made of the same material as the nonmagnetic barrier layer 13, the crystal orientation can be easily controlled, which is preferable in terms of manufacturing and magnetic anisotropy characteristics.

  A cap layer 15 having a thickness of 10 nm or less is disposed on the magnetic recording layer 11.

  The cap layer 15 can be composed of, for example, an oxide such as Ta, Al, Mg, Fe or a laminated structure of a nonmagnetic metal such as Cu, Ag, Au and an oxide such as Ta, Al, Mg, Fe. Protect the magnetic recording element. The cap layer 15 may be made of a nonmagnetic metal such as Ru, Cu, Ag, Au, or Ta when a low current density of the spin injection current is realized.

  More preferably, the cap layer 15 is made of one selected from the group consisting of oxides, nitrides and fluorides having a thickness of 1 nm or less.

  The cap layer 15 may be made of a nonmagnetic metal such as Ru, Cu, Ag, Au, or Ta when a low current density of the spin injection current is realized.

  For the magnetic recording element having such a structure, a plurality of samples were prepared and the characteristics thereof were evaluated in the same manner as in the first example.

Specifically, in the samples AA1 to AA8 of the first embodiment, the magnetic recording layer is separated from the nonmagnetic material composed of MgO or Al ₂ O _{3 -X} , SiO _{2 -X} , TiOx, ZnOx. And AA1 to AA8 magnetic recording layer material. The magnetic recording layer can be formed, for example, by simultaneously depositing a nonmagnetic material and a magnetic fine particle material. It is also possible to finely process the magnetic film into a pattern and embed the periphery with a nonmagnetic material.

In this case, the thickness of the magnetic recording layer may be slightly thicker than the samples AA1 to AA8 of the first embodiment, which is 10 nm at the maximum. However, in this structure, since the current concentration effect occurs, it was confirmed that the magnetization reversal was properly performed at a small reversal current density of 2 × 10 ⁶ A / cm ² or less.

(3) Third embodiment
FIG. 16 shows the structure of a magnetic recording element that was prototyped in the third embodiment.

  The magnetic recording element has a laminated structure of a magnetic recording layer 11, a magnetic pinned layer 12, and a nonmagnetic barrier layer 13 therebetween. This magnetic recording element is characterized in that a layer 17 containing oxygen is formed in the magnetic pinned layer 12. The layer 17 containing oxygen has a function of stabilizing the magnetization state of the magnetic pinned layer 12.

  A cap layer 15 having a thickness of 10 nm or less is disposed on the magnetic recording layer 11.

  The cap layer 15 can be composed of, for example, an oxide such as Ta, Al, Mg, Fe or a laminated structure of a nonmagnetic metal such as Cu, Ag, Au and an oxide such as Ta, Al, Mg, Fe. Protect the magnetic recording element.

  More preferably, the cap layer 15 is made of one selected from the group consisting of oxides, nitrides and fluorides having a thickness of 1 nm or less.

  The cap layer 15 may be made of a nonmagnetic metal such as Ru, Cu, Ag, Au, or Ta when a low current density of the spin injection current is realized.

For the magnetic recording element having such a structure, as in the first embodiment, a plurality of samples were prepared and their characteristics were evaluated. As a result, when the reversal current density was 2 × 10 ⁶ A / cm ² or less, magnetization was properly performed. It was confirmed that reversal was taking place.

(4) Fourth embodiment
FIG. 17 shows the structure of the magnetic recording element manufactured in the fourth embodiment.

  The magnetic recording element has a laminated structure of a magnetic recording layer 11, a magnetic pinned layer 12, and a nonmagnetic barrier layer 13 therebetween. This magnetic recording element is characterized in that the cap layer 15 covering the upper surface of the magnetic recording layer 11 has a two-layer structure.

  The cap layer 15A is made of a nonmagnetic metal having a thickness of 3 nm or less. The cap layer 15B is composed of one selected from the group consisting of oxide, nitride and fluoride having a thickness of 1 nm or less.

For the magnetic recording element having such a structure, as in the first embodiment, a plurality of samples were prepared and their characteristics were evaluated. As a result, when the reversal current density was 2 × 10 ⁶ A / cm ² or less, magnetization was properly performed. It was confirmed that reversal was taking place.

(5) Fifth embodiment
18 and 19 show the structure of the magnetic recording element of the fifth embodiment.

  The magnetic recording element includes a laminated structure of a magnetic recording layer 11, a magnetic pinned layer 12, and a nonmagnetic barrier layer 13 therebetween, and is disposed between the lower electrode 21 and the upper electrode 22.

  An antiferromagnetic layer 18 for fixing the magnetization of the magnetic pinned layer 12 is arranged between the magnetic pinned layer 12 and the lower electrode 21. A cap layer 15 for protecting the magnetic recording element is disposed between the magnetic recording layer 11 and the upper electrode 22.

  In the fifth embodiment, the effect is compared between the case where the perpendicular magnetization film is used and the case where the in-plane magnetization film is used.

As shown in Table 2, there are four types of samples.

  In Samples A1 and A2, as shown in FIG. 18, the direction of the easy axis of magnetization of the magnetic recording layer 11 is perpendicular to the film surface. The vertical direction is the stacking direction of the magnetic recording layer 11, the magnetic pinned layer 12, and the nonmagnetic barrier layer 13. Further, the magnetization of the magnetic pinned layer 12 is fixed in the direction perpendicular to the film surface by the antiferromagnetic layer 18.

  In Samples B1 and B2, as shown in FIG. 19, the magnetization easy axis direction of the magnetic recording layer 11 is horizontal with respect to the film surface, so the magnetization direction of the residual magnetization of the magnetic recording layer 11 is also relative to the film surface. The horizontal direction is the in-plane direction of the magnetic recording layer 11. The magnetization of the magnetic pinned layer 12 is pinned in the horizontal direction with respect to the film surface by the antiferromagnetic layer 18.

  Samples A1 and A2 are magnetic recording elements according to examples of the present invention, and are within the range of the conditions presented in the first embodiment as shown in FIG.

In the sample A1, the magnetic recording layer 11 has a laminated structure of Fe (0.2 nm) / FeCuPt (1 nm), the magnetic pinned layer 12 has a laminated structure of Pt / Co, and the nonmagnetic barrier layer 13 has an Al ₂ O structure. Consists of _3-x . The number in parentheses is the thickness.

In sample A2, the magnetic recording layer 11 is made of CoPt (2 nm), the magnetic pinned layer 12 is made of a laminated structure of GdFeCo / Fe ₃ O ₄ , and the nonmagnetic barrier layer 13 is made of MgO. The number in parentheses is the thickness.

  On the other hand, samples B1 and B2 are magnetic recording elements as comparative examples, and are out of the range of conditions presented in the first embodiment as shown in FIG.

In sample B1, the magnetic recording layer 11 is made of CoFe (2.5 nm), the magnetic pinned layer 12 is made of a CoFe / Ru / CoFe SAF (synthetic anti-ferromagnetic) structure, and the nonmagnetic barrier layer 13 is made of Al ₂ O. Consists of _3-x . The number in parentheses is the thickness.

  In the sample B2, the magnetic recording layer 11 is made of CoFeB (2.5 nm), the magnetic pinned layer 12 is made of a CoFe / CoFeB laminated structure, and the nonmagnetic barrier layer 13 is made of MgO. The number in parentheses is the thickness.

  For these samples A1, A2, B1, and B2, a spin injection current (magnetization reversal current) was applied in the magnetic recording element stacking direction, and the reversal current density required to reverse the magnetization of the magnetic recording layer was monitored. .

As a result, in sample A1, the averaged reversal current density Jc of the reversal current density when reversing from antiparallel to parallel and the reversal current density when reversing from parallel to antiparallel is 8 ×. 10 ⁵ A / cm ² , and in sample A2, the reversal current density was 9 × 10 ⁵ A / cm ² . In contrast, in sample B1, the reversal current density was 4 × 10 ⁷ A / cm ² , and in sample B2, the reversal current density was 6 × 10 ⁶ A / cm ² .

As is clear from this result, according to the example of the present invention, the current density of the spin injection current can be reduced to 1/5 or less than the conventional one, and an inversion current density of 2 × 10 ⁶ A / cm ² or less can be realized. Was confirmed.

(6) Other
The effect of the example of the present invention does not vary depending on the shape and size of the magnetic recording element, the shape and size of the lower / upper electrode, the material, and the type of insulating layer such as a passivation layer. Can be appropriately selected from a known range.

  The magnetic recording layer, magnetic pinned layer, and nonmagnetic barrier layer constituting the magnetic recording element need not all have the same shape and size, and may be designed to have different shapes and sizes.

  However, in the manufacturing process, the planar shape of the magnetic recording layer may be a square, a rectangle, a polygon (for example, a hexagon), a circle, an ellipse, or a rhombus in an aspect ratio of 1: 1 to 1: 4. It is preferable to use a mold or a parallelogram.

  The size of the magnetic recording layer is preferably set to a value within a range of 5 nm to 200 nm on one side.

  As the cross-sectional shape of the magnetic recording element, it is preferable from the manufacturing process that the cross-sectional sizes of the magnetic recording layer, the magnetic pinned layer, and the nonmagnetic barrier layer are the same or continuously changed, such as a quadrangle and a trapezoid. You may change the size of the cross section discontinuously.

  In addition, each component such as an antiferromagnetic layer, a magnetic pinned layer, a nonmagnetic barrier layer, a magnetic recording layer, a cap layer, and an insulating layer may be a single layer or a plurality of layers. .

5). Application examples
An application example of the magnetic recording element according to the example of the present invention will be described.

  Here, examples of magnetic random access memory (MRAM) and probe memory as magnetic memory, and spin FET (field) for realizing a re-configurable logic circuit An example of an effect transistor) will be described.

(1) Magnetic random access memory
When the magnetic recording element according to the example of the present invention is applied to a magnetic random access memory, the type or structure of the memory cell array is not limited. In the following, a representative example is a 1 transistor-1 MTJ (magneto tunnel junction) type suitable for spin injection writing.

A. Circuit structure
FIG. 21 shows a circuit structure of a memory cell array of a magnetic random access memory according to an example of the present invention.

  Memory cell array 31 includes a plurality of memory cells MC1, MC2, MC3, MC4 arranged in an array. Each of the memory cells MC1, MC2, MC3, MC4 includes a magnetic recording element MTJ and a MOS transistor TR connected in series.

  The gate of the MOS transistor TR is connected to the word lines WL (i) and WL (i + 1). The word lines WL (i) and WL (i + 1) extend in the x direction, and one end thereof is connected to the word line driver 32 via a MOS transistor RSW as a row selection switch.

  Row selection signals RSL (i) and RSL (i + 1) for selecting one row of the memory cell array 31 are input to the gate of the MOS transistor RSW at the time of reading / writing.

  The word line driver 32 drives a word line in one selected row. For example, when the word line WL (i) is selected, the potential of the word line WL (i) is set to “H”, and the MOS transistor TR connected to the word line WL (i) is turned on.

  One end of the magnetic recording element MTJ constituting the memory cells MC1, MC2, MC3, MC4 is connected to the bit lines BLu (j), BLu (j + 1).

  The bit lines BLu (j) and BLu (j + 1) extend in the y direction crossing the x direction, and one end thereof is connected to the bit line driver / sinker 33 via the MOS transistor CSWu as a column selection switch. .

  Column selection signals CSLu (j) and CSLu (j + 1) for selecting one column of the memory cell array 31 are input to the gate of the MOS transistor CSWu at the time of reading / writing.

  One end of the MOS transistor TR constituting the memory cells MC1, MC2, MC3, MC4 is connected to the bit lines BLd (j), BLd (j + 1).

  The bit lines BLd (j) and BLd (j + 1) extend in the y direction, and one end thereof is connected to the bit line driver / sinker 34 via a MOS transistor CSWd as a column selection switch.

  Column selection signals CSLd (j) and CSLd (j + 1) for selecting one column of the memory cell array 31 are input to the gate of the MOS transistor CSWd at the time of writing.

  One end of each of the bit lines BLd (j) and BLd (j + 1) is connected to the common read line RL via the MOS transistor CSWr as a column selection switch, and the common read line RL is connected to the sense amplifier S / A. Connected.

  Column selection signals CSLr (j) and CSLr (j + 1) for selecting one column of the memory cell array 31 are input to the gate of the MOS transistor CSWr at the time of reading.

  The sense amplifier S / A determines the data value of the magnetic recording element MTJ in the selected memory cell MC based on the reference potential Vref, and outputs this as the output signal DATA.

  Here, the bit line drivers / sinkers 33 and 34 are provided to flow the spin injection current Is to the bit lines in one selected column.

  “1” is assigned when the magnetization state of the magnetic recording element MTJ is antiparallel, and “0” is assigned when it is parallel.

  When “1” is written to the memory cell MC1, the row selection signal RSL (i) is set to “H”, the word line WL (i) is set to “H”, and the MOS transistor TR in the memory cell MC1 is turned on.

  Further, the column selection signals CSLu (j) and CSLd (j) are set to “H”, and the spin injection current Is flowing from the bit line driver / sinker 33 to the bit line driver / sinker 34 via the memory cell MC1. . At this time, in the magnetic recording element MTJ in the memory cell MC1, the magnetization state becomes antiparallel due to the spin-polarized electrons, and “1” is written.

  Similarly, when “0” is written in the memory cell MC1, the row selection signal RSL (i) is set to “H”, the word line WL (i) is set to “H”, and the MOS transistor TR in the memory cell MC1 is similarly written. Turn on.

  Further, the column selection signals CSLu (j) and CSLd (j) are set to “H”, and a spin injection current Is flowing from the bit line driver / sinker 34 to the bit line driver / sinker 33 via the memory cell MC1. . At this time, in the magnetic recording element MTJ in the memory cell MC1, the magnetization state becomes parallel due to the spin-polarized electrons, and “0” is written.

  The read is performed using, for example, the sense amplifier S / A and the bit line driver / sinker 33.

  For example, when reading data from the memory cell MC1, the row selection signal RSL (i) is set to “H”, the word line WL (i) is set to “H”, and the MOS transistor TR in the memory cell MC1 is turned on.

  Further, the column selection signal CSLu (j) is set to “H”, the bit line BLu (j) is electrically connected to the bit line driver / sinker 33, the column selection signal CSLr (j) is set to “H”, and the bit line BLd (j) is electrically connected to the sense amplifier S / A.

  For example, the bit line driver / sinker 33 connects one end of the bit line BLu (j) to a ground point, and the sense amplifier S / A supplies a read current to the memory cell MC1. The sense amplifier S / A detects a resistance value when the read current flows through the magnetic recording element MTJ in the memory cell MC1, and determines a data value stored therein.

B. Device structure
22 to 25 show examples of device structures of the memory cells MC1, MC2, MC3, and MC4 of FIG.

  The memory cell includes a MOS transistor TR and a magnetic recording element (magnetoresistance effect element) MTJ according to an example of the present invention.

  The MOS transistor TR is formed on the semiconductor substrate 41. The gate electrode of the MOS transistor TR extends in the x direction (direction orthogonal to the paper surface) as the word line WL (i).

  One of the two source / drain diffusion layers of the MOS transistor TR is connected to the lower bit line BLd (j), and the other is connected to one end (lower surface) of the magnetic recording element MTJ. The other end (upper surface) of the magnetic recording element MTJ is connected to the upper bit line BLu (j).

  The upper bit line BLu (j) and the lower bit line BLd (j) each extend in the y direction.

  The magnetic recording element has a top pin structure. That is, the base layer 42, the magnetic recording layer 11, the tunnel barrier layer (insulating layer) 13, the magnetic pinned layer 12, the antiferromagnetic layer 18, and the cap layers 15A and 15B are stacked in this order from the semiconductor substrate 41 side.

  The magnetic recording element may have a bottom pin structure.

  In the memory cell having such a device structure, as shown in FIG. 22, at the time of “1” -writing, the upper bit line BLu (j) → the magnetic recording element from the current source in the bit line driver / sinker 33 of FIG. A spin injection current Is is caused to flow toward the ground point through the path MTJ → lower bit line BLd (j).

  At this time, the electron current flows from the magnetic recording layer 11 toward the magnetic pinned layer 12 inside the magnetic recording element MTJ. In general, when an electron flow flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization of the magnetic recording layer 11 is antiparallel to the magnetization of the magnetic pinned layer 12.

  Further, as shown in FIG. 23, at the time of “0” -writing, the lower bit line BLd (j) → the magnetic recording element MTJ → the upper bit line BLu (j) from the current source in the bit line driver / sinker 34 of FIG. ), The spin injection current Is flows toward the grounding point.

  At this time, the electron current flows from the magnetic pinned layer 12 toward the magnetic recording layer 11 inside the magnetic recording element MTJ. In general, when the electron flow flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization of the magnetic recording layer 11 is parallel to the magnetization of the magnetic pinned layer 12.

  At the time of reading, as shown in FIGS. 24 and 25, for example, a read current Ir is supplied from the sense amplifier S / A to the ground point via the magnetic recording element MTJ. When the read current Ir flows through the magnetic recording element MTJ, the input potential of the sense amplifier S / A changes depending on the state of the magnetic recording element MTJ.

  For example, as shown in FIG. 24, when “1” -data is stored in the magnetic recording element MTJ, the resistance value of the magnetic recording element MTJ is large (anti-parallel state), and the sense amplifier S / A Is higher than the reference potential Vref.

  Therefore, the sense amplifier S / A outputs “1” as the output signal DATA.

  As shown in FIG. 25, when “0” -data is stored in the magnetic recording element MTJ, the resistance value of the magnetic recording element MTJ is small (parallel state), and the sense amplifier S / A The input potential is lower than the reference potential Vref.

  Therefore, the sense amplifier S / A outputs “0” as the output signal DATA.

  In this example, the direction of the read current Ir is the direction from the lower bit line BLd (j) to the upper bit line BLu (j), but in the opposite direction, that is, from the upper bit line BLu (j). The direction may be toward the lower bit line BLd (j). Further, as a reading method, a method different from this example may be adopted.

  The value of the read current Ir is made sufficiently smaller than the value of the spin injection current Is in order to suppress disturbance during reading. Specifically, the value of the read current Ir may be smaller than the critical current Ic for magnetization reversal.

  In this example, “1” is assigned when the magnetization state of the magnetic recording element MTJ is antiparallel, and “0” is assigned when it is parallel, but the opposite is also possible.

  Regarding reading, in order to obtain a high signal output by increasing the MR (magneto-resistive) ratio, the tunnel barrier layer is preferably made of a high-resistance material, for example, an insulating material such as alumina or MgO.

  Instead of such a tunnel barrier layer, a CPP-CPP-MR material or a nanocontact MR material in which Cu or a magnetic material is embedded in a number of holes provided in an insulating material is magnetically fixed to the magnetic recording layer. If it is employed as a nonmagnetic barrier layer between the layers, it is more convenient for reading.

  As long as the MOS transistor TR constituting the memory cell has a function as a selection switch, there is no problem even if it is replaced with an element such as a bipolar transistor or a diode.

C. Magnetic recording element layout
Regarding the layout of the magnetic recording element MTJ, various types can be assumed including the relationship with the structure of the memory cell array.

  The memory cell array of FIGS. 22 to 25 is a one-transistor-1MTJ type in which a memory cell is composed of one transistor and one magnetic recording element. In this case, one independent magnetic recording element MTJ is assigned to one memory cell.

  On the other hand, as shown in FIG. 26, in the one-transistor-1MTJ type memory cell array, the magnetic recording element MTJ is composed of an aggregate of a plurality of magnetic particles (polycrystalline structure) separated by a nonmagnetic material, The magnetic recording elements MTJ of all the memory cells may be integrated.

  In this case, since the magnetic recording element MTJ is solidly formed on the top of the semiconductor substrate 41, the manufacturing process is simplified, and the manufacturing cost can be reduced.

  Even in such a structure, the magnetic recording element MTJ is composed of an aggregate of a plurality of magnetic particles and can determine the magnetization direction for each magnetic particle, so that only the magnetization in the region between the plugs a and b is selectively changed. It is possible.

  Therefore, the function as the magnetic memory is not different from that of the magnetic memory having the structure shown in FIGS.

  The memory cell array in FIGS. 27 to 29 is a cross-point type.

  In the structure of FIG. 27, as in the structures of FIGS. 22 to 25, one independent magnetic recording element MTJ is assigned to one memory cell.

  In the structure of FIG. 28, the magnetic recording elements MTJ are laid out along the bit lines BL (j) and BL (j + 1) immediately below the bit lines BL (j) and BL (j + 1). In this case, since the magnetic recording element MTJ is processed simultaneously with the processing of the bit lines BL (j) and BL (j + 1), the manufacturing process is simplified and the manufacturing cost can be reduced.

  In the structure of FIG. 29, the magnetic recording element MTJ is solidly formed in a region between the word lines WL (i) and BL (i + 1) and the bit lines BL (j) and BL (j + 1). In this case, since the processing of the magnetic recording element MTJ can be omitted, the manufacturing process is simplified and the manufacturing cost can be reduced.

  28 and 29, the magnetic recording element MTJ is composed of an aggregate of a plurality of magnetic particles, and can determine the magnetization direction for each magnetic particle. Therefore, the word lines WL (i), BL (i + 1) and the bit Only the magnetization at the intersections with the lines BL (j) and BL (j + 1) can be selectively changed.

  Therefore, the function as a magnetic memory is the same in all the cross-point type magnetic memories shown in FIGS.

(2) Probe memory
Probe memory is a next-generation memory that has the potential to dramatically improve recording density compared to current memories.

  The probe memory has, for example, a cantilever-shaped probe above the recording medium, and performs an access operation by controlling the positional relationship between the recording medium and the probe. In particular, if a micro electro mechanical systems (MEMS) technique is used, a recording medium and a probe can be mixedly mounted on a semiconductor chip. In fact, concrete ones such as Millipede have been proposed.

  If the magnetic recording element in the example of the present invention is used as a recording medium for such a probe memory, it can contribute to the practical use of the probe memory.

A. Basic structure
FIG. 30 shows the basic structure of the probe memory.

  A conductive layer 52 is formed on the insulating substrate 51, and a plurality of magnetic recording elements MTJ according to the example of the present invention are arranged on the conductive layer 52 in an array. Each magnetic recording element MTJ has, for example, a laminated structure of a magnetic pinned layer 53, a nonmagnetic barrier layer (for example, a tunnel barrier layer) 54, and a magnetic recording layer 55. A space between the plurality of magnetic recording elements MTJ is filled with the insulating layer 56.

  Such an array of magnetic recording elements MTJ is referred to as a “patterned medium”.

  For example, a cantilever-like probe 57 is disposed on the patterned medium. The shape of the probe 57 is not particularly limited and may be a needle shape or the like. However, in the case of a cantilever shape, for example, it is advantageous when a probe is formed on a semiconductor chip by MEMS technology. It is.

  The position of the probe 57 is controlled by a position control device 58. For example, the position controller 58 drives the probe 57 in two dimensions (x, y) or three dimensions (x, y, z), thereby performing an access operation. The probe 57 may always be in contact with the upper surface of the patterned medium, or may always be separated by a certain distance.

  The read / write circuit 59 causes a read current to flow through the magnetic recording element MTJ and reads data stored in the magnetic recording element MTJ. In addition, the read / write circuit 59 controls the magnetization state of the magnetic recording element MTJ by causing a spin injection current in a direction corresponding to the write data to flow in the magnetic recording element MTJ during writing.

  In such a probe memory, at the time of “1” -writing, the position controller 58 determines the relative position between the patterned medium and the probe 57 based on the address signal, and the read / write circuit 59 includes the conductive layer. A spin injection current Is is passed in the direction from 52 to the probe 57.

  At this time, since the electron current flows from the magnetic recording layer 55 toward the magnetic pinned layer 53 inside the magnetic recording element MTJ, the magnetization of the magnetic recording layer 55 is antiparallel to the magnetization of the magnetic pinned layer 53. Become.

  Further, at the time of “0” -writing, the position control device 58 determines the relative position between the patterned medium and the probe 57 based on the address signal, and the read / write circuit 59 is transferred from the probe 57 to the conductive layer 52. A spin injection current Is is allowed to flow in the direction toward it.

  At this time, since the electron current flows from the magnetic pinned layer 53 toward the magnetic recording layer 55 inside the magnetic recording element MTJ, the magnetization of the magnetic recording layer 55 is parallel to the magnetization of the magnetic pinned layer 53. .

  At the time of reading, the position controller 58 determines the relative position between the patterned medium and the probe 57 based on the address signal, and the read / write circuit 59 supplies a read current Ir to the magnetic recording element MTJ.

  The direction of the read current Ir is not limited, but the value of the read current Ir is made sufficiently smaller than the value of the spin injection current Is in order to suppress disturbance during reading. Specifically, the value of the read current Ir is made smaller than the critical current Ic for magnetization reversal.

  In this example, “1” is assigned when the magnetization state of the magnetic recording element MTJ is antiparallel, and “0” is assigned when it is parallel, but it may be reversed.

  Regarding reading, in order to obtain a high signal output by increasing the MR ratio, it is preferable that the nonmagnetic barrier layer 54 be a tunnel barrier layer (for example, an insulating material such as alumina or MgO).

  Instead of such a tunnel barrier layer, a CPP-CPP-MR material or a nanocontact MR material in which Cu or a magnetic material is embedded in a number of holes provided in an insulating material is magnetically fixed to the magnetic recording layer. If it is employed as a nonmagnetic barrier layer between the layers, it is more convenient for reading.

  Here, in the example of FIG. 27, the position of the patterned medium is fixed, and the position control device 58 controls the position of the probe 57. However, the relative position between the patterned medium and the probe 57 is controlled. If possible, either the probe or the insulating substrate 51 may be driven.

  For example, as shown in FIG. 31, the relative position between the patterned medium and the probe can be controlled by the position control devices 58A and 58B.

  Further, like the hard disk drive, the access operation may be performed by rotating the insulating substrate 51 and driving the probe 57 linearly.

  32 and 33 are modifications of the probe memory of FIG.

  The probe memory of FIG. 32 is characterized in that the magnetic pinned layer 53 and the nonmagnetic barrier layer 54 are shared by all the magnetic recording elements MTJ. In this case, since the magnetic pinned layer 53 and the nonmagnetic barrier layer 54 are solidly formed on the conductive layer 52 and only the magnetic recording layer 55 needs to be patterned, the manufacturing process can be simplified and the device characteristics can be improved. .

  The probe memory of FIG. 33 is characterized in that the upper surface of the patterned medium is covered with a protective layer 60. The protective layer 60 is made of, for example, an extremely thin insulator. In this case, since the probe 57 does not directly contact the magnetic recording element MTJ, it is possible to improve the reliability of the magnetic recording element MTJ and the number of reading / writing operations.

  Instead of the protective layer 60, the probe 57 may be separated from the magnetic recording element MTJ by a certain distance, and a space may be provided between the probe 57 and the magnetic recording element MTJ. Further, the protective layer 60 may be provided, and the probe 57 may be separated from the protective layer 60 by a certain distance.

B. Multi-probe structure
An example of a probe memory having a multi-probe structure suitable for increasing the recording density will be described.

  FIG. 34 shows a circuit structure of the probe memory according to the example of the present invention.

  Blocks BK11,... BKij are arranged in a matrix. Each of the blocks BK11,... BKij may be physically separated or integrated. Each of the blocks BK11,... BKij is composed of a patterned medium composed of a plurality of magnetic recording elements, for example, as shown in FIG.

  When the blocks BK11,... BKij are arranged in a matrix of 32.times.32 as a whole, and each of the blocks BK11,... BKij is composed of 32.times.32 magnetic recording elements, 1 The storage capacity of one block is 1 kilobit, and the probe memory is 1 megabit.

  The probes 57 are arranged in a matrix like the blocks BK11,... BKij, and the probes 57 and the blocks BKij have a one-to-one correspondence.

  The probe 57 is connected to the bit lines BLu (1),... BLu (j) via the MOS transistor TR.

  The gate of MOS transistor TR is connected to word lines WL (1),... WL (i). Word lines WL (1),... WL (i) extend in the x direction, and one end thereof is connected to the word line driver 32 via a MOS transistor RSW as a row selection switch.

  The row selection signals RSL (1),... RSL (i) for selecting one of the blocks BK11,... BKij are input to the gate of the MOS transistor RSW at the time of reading / writing.

  The word line driver 32 drives a word line in one selected row. For example, when the word line WL (1) is selected, the potential of the word line WL (1) is set to “H”, and the MOS transistor TR connected to the word line WL (1) is turned on.

  The bit lines BLu (1),... BLu (j) extend in the y direction, and one end thereof is connected to the bit line driver / sinker 33 via a MOS transistor CSWu as a column selection switch.

  Column selection signals CSLu (1),... CSLu (j) for selecting one of the blocks BK11,... BKij are input to the gate of the MOS transistor CSWu at the time of reading / writing.

  One end of the block BK11,... BKij (corresponding to the conductive layer 52 in FIG. 25) is connected to the bit lines BLd (1),... BLd (j).

  The bit lines BLd (1),... BLd (j) extend in the y direction, and one end thereof is connected to the bit line driver / sinker 34 via a MOS transistor CSWd as a column selection switch.

  Column selection signals CSLd (1),... CSLd (j) for selecting one of the blocks BK11,... BKij are input to the gate of the MOS transistor CSWd at the time of writing.

  In addition, one end of each of the bit lines BLd (1),... BLd (j) is connected to the common read line RL via the MOS transistor CSWr as a column selection switch, and the common read line RL is connected to the sense amplifier S. / A.

  The column selection signals CSLr (1),... CSLr (j) for selecting one of the blocks BK11,... BKij are input to the gate of the MOS transistor CSWr at the time of reading.

  The sense amplifier S / A determines the data value of the selected magnetic recording element in the selected block BKij based on the reference potential Vref, and outputs this as the output signal DATA.

  Here, the bit line drivers / sinkers 33 and 34 are provided to flow the spin injection current Is to the selected magnetic recording element in the selected one block BKij.

  “1” is assigned when the magnetization state of the magnetic recording element is antiparallel, and “0” is assigned when it is parallel.

  When “1” is written to the magnetic recording element in the block BK11, the row selection signal RSL (1) is set to “H”, the word line WL (1) is set to “H”, and the MOS transistor TR corresponding to the block BK11 is set. turn on.

  Further, the column selection signals CSLu (1) and CSLd (1) are set to “H”, and spin injection from the bit line driver / sinker 33 toward the bit line driver / sinker 34 via the magnetic recording element in the block BK11 is performed. The current Is is passed. At this time, the magnetization state of the magnetic recording element in the block BK11 is antiparallel, and “1” is written.

  When “0” is written to the magnetic recording element in the block BK11, the row selection signal RSL (1) is set to “H”, the word line WL (1) is set to “H”, and the MOS transistor TR corresponding to the block BK11 is set. turn on.

  Further, the column selection signals CSLu (1) and CSLd (1) are set to “H”, and spin injection from the bit line driver / sinker 34 toward the bit line driver / sinker 33 via the magnetic recording element in the block BK11 is performed. The current Is is passed. At this time, the magnetization states of the magnetic recording elements in the block BK11 are parallel, and “0” is written.

  The read is performed using, for example, the sense amplifier S / A and the bit line driver / sinker 33.

  For example, when reading the data of the magnetic recording element in the block BK11, the row selection signal RSL (1) is set to “H”, the word line WL (1) is set to “H”, and the MOS transistor TR corresponding to the block BK11 is set. turn on.

  Further, the column selection signal CSLu (1) is set to “H”, the bit line BLu (1) is electrically connected to the bit line driver / sinker 33, the column selection signal CSLr (1) is set to “H”, and the bit line BLd (1) is electrically connected to the sense amplifier S / A.

  For example, the bit line driver / sinker 33 connects one end of the bit line BLu (1) to the ground point, and the sense amplifier S / A supplies a read current to the magnetic recording elements in the block BK11. The sense amplifier S / A detects a resistance value when a read current flows through the magnetic recording element, and determines a data value stored in the resistance value.

  FIG. 35 shows an example of a device structure of a probe memory having a multi-probe structure.

  In this probe memory, a patterned medium as a recording medium is formed in the center of the semiconductor chip 61, and the patterned medium is divided into a plurality of blocks BK. A plurality of probes 57 are arranged on the plurality of blocks BK corresponding to the plurality of blocks BK.

  In the peripheral portion of the semiconductor chip 61, for example, a servo region 62 in which the position control device 58 in FIG. 30 is formed and a peripheral circuit region 63 in which the read / write circuit 59 in FIG. 30 is formed are provided.

  This device structure is characterized in that all systems shown in FIG. 30 are mounted on the semiconductor chip 61. Such a semiconductor device is made possible by using MEMS technology.

(3) Spin FET
The magnetic recording element according to the example of the present invention can be applied to a spin FET.

  The spin FET can be used as a memory cell of a magnetic memory, and has attracted attention as a component of a re-configurable logic circuit.

  FIG. 36 shows an example of the device structure of the spin FET.

  This example relates to a tunnel barrier type spin FET that performs data writing by a spin injection writing method.

  A source / drain region composed of a ferromagnetic layer is formed in the semiconductor substrate 70. One of the source / drain regions is a magnetic recording layer 11 whose magnetization direction changes, and the other is a magnetic pinned layer 12. The magnetization of the magnetic pinned layer 12 is pinned by the antiferromagnetic layer 18.

  A nonmagnetic barrier layer (tunnel barrier layer) 13A is formed between the semiconductor substrate 70 and the magnetic recording layer 11 and between the semiconductor substrate 70 and the magnetic pinned layer 12. A gate electrode 72 is formed on the channel region between the magnetic recording layer 11 and the magnetic pinned layer 12 via a gate insulating layer 71.

  Source / drain electrodes 73 and 74 are formed on the antiferromagnetic layer 18 and the magnetic recording layer 11, respectively.

  The source / drain electrode 73 is connected to a driver / sinker for generating a spin injection current, that is, a P channel MOS transistor P1 and an N channel MOS transistor N1.

  Similarly, the source / drain electrode 74 is connected to a driver / sinker for generating a spin injection current, that is, a P channel MOS transistor P2 and an N channel MOS transistor N2.

  In the spin FET having such a structure, data writing is performed by applying a write gate voltage W to the gate electrode 72 and passing a spin injection current through the magnetic recording layer 11 as a source / drain region.

  The value of the write data is determined by the direction of the spin injection current, and the direction of the spin injection current is determined by turning on / off the P-channel MOS transistors P1, P2 and the N-channel MOS transistors N1, N2 according to the control signals A, B, C, D. Controlled by turning off.

  For example, when the magnetization states of the source / drain regions 11 and 12 are made antiparallel, a spin injection current is passed from the P channel MOS transistor P1 toward the N channel MOS transistor N2. At this time, since the electron flow flows from the magnetic recording layer 11 toward the magnetic pinned layer 12, the magnetization direction of the magnetic recording layer 11 is opposite to the magnetization direction of the magnetic pinned layer 12.

  When the magnetization states of the source / drain regions 11 and 12 are made parallel, a spin injection current is passed from the P channel MOS transistor P2 toward the N channel MOS transistor N1. At this time, since the electron flow flows from the magnetic pinned layer 12 toward the magnetic recording layer 11, the magnetization direction of the magnetic recording layer 11 is the same as the magnetization direction of the magnetic pinned layer 12.

  In this example, the tunnel barrier type spin FET has been described. However, the spin FET may be a Schottky barrier type without the tunnel barrier layer 13A.

(4) Other
Although three application examples have been described above, the example of the present invention can be applied to other spin electronics devices.

6). Summary
According to the example of the present invention, in the magnetization reversal technology by direct current drive, the reversal current density Jc can be reduced without deterioration of thermal fluctuation and MR characteristics, thereby reducing the plane size (maximum width) of 20 nm or less. A highly reliable magnetic recording element that is less damaged by heat generated by electric power can be realized, and can be applied to various spin electronics devices.

  The examples of the present invention are tremendous in terms of effects such as higher functionality of magnetic recording elements, higher density of magnetic memory (storage device), lower power consumption, etc., promoting the practical application of magnetization reversal technology by direct current drive The industrial merit is great.

  The example of the present invention is not limited to the above-described embodiment, and can be embodied by modifying each component without departing from the scope of the invention. Various inventions can be configured by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some constituent elements may be deleted from all the constituent elements disclosed in the above-described embodiments, or constituent elements of different embodiments may be appropriately combined.

  11, 55: Magnetic recording layer, 12, 53: Magnetic pinned layer, 13, 13A, 54: Nonmagnetic barrier layer, 14: Insertion layer, 15, 15A, 15B: Cap layer, 16: Nonmagnetic material, 17: Oxygen 18: antiferromagnetic layer, 21: lower electrode, 22: upper electrode, 31: memory cell array, 32: word line driver, 33, 34: bit line driver / sinker, 41, 70: semiconductor substrate, 51 : Insulating substrate, 52: Conductive layer, 56: Insulating layer, 57: Probe, 58, 58A, 58B: Position controller, 59: Read / write circuit, 60: Protective layer, 61: Semiconductor chip, 62: Servo area, 63: Peripheral circuit region 71: Gate insulating layer 72: Gate electrode 73, 74: Source / drain Electrode, 101: magnetic fine particles, 102: nonmagnetic conductive layer, 103: magnetic pinned layer.

Claims (12)

A magnetic recording layer in which the magnetization is variable and the easy axis direction is perpendicular to the film surface, and a magnetic pinned layer in which the magnetization is fixed in a direction perpendicular to the film surface; A nonmagnetic barrier layer between the magnetic recording layer and the magnetic pinned layer, and an insertion layer between the magnetic recording layer and the nonmagnetic barrier layer,
In the magnetic recording layer, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfies Han> 12.57 Ms and Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness thereof Is 5 nm or less,
The magnetic recording element, wherein the insertion layer includes one of CoFeB, FeB, CoNbZr, FeAlSi, CoTaZr, and FeTaC. A magnetic recording layer in which the magnetization is variable and the easy axis direction is perpendicular to the film surface, and a magnetic pinned layer in which the magnetization is fixed in a direction perpendicular to the film surface; A nonmagnetic barrier layer between the magnetic recording layer and the magnetic pinned layer, and an insertion layer between the magnetic recording layer and the nonmagnetic barrier layer,
In the magnetic recording layer, the relationship between the saturation magnetization Ms (emu / cc) and the anisotropic magnetic field Han (Oe) satisfies Han> 12.57 Ms and Han <1.2E7Ms ⁻¹ +12.57 Ms, and the thickness thereof Is 5 nm or less,
The magnetic recording element, wherein the insertion layer includes Co ₂ MnSi. The thickness of the insertion layer, a magnetic recording device according to claim 1 or 2 is less than 2 nm. The magnetic recording layer is, Fe, and a magnetic recording element according to claim 1 or 2 comprising one or more elements selected from a group of Co, an alloy in combination with Pt elements. Saturation magnetization of the insertion layer, a magnetic recording device according to claim 1 or 2 exceeds 600 emu / cc. The magnetic recording element according to claim 1 or 2 ,
A cap layer disposed on the magnetic recording element;
The magnetic layer according to claim 1, wherein the cap layer includes an oxide of Ta, Al, Mg, or Fe. The magnetic recording element according to claim 1 or 2 ,
A cap layer disposed on the magnetic recording element;
The cap layer includes one of Ru, Cu, Ag, Au, and Ta. The magnetic recording element according to claim 1 or 2 ,
A cap layer disposed on the magnetic recording element;
The cap layer includes a laminated structure of a nonmagnetic metal and an oxide of Ta, Al, Mg, or Fe, and the nonmagnetic metal is selected from the group of Cu, Ag, and Au. . The magnetic recording element according to claim 1 or 2 ,
A lower electrode disposed under the magnetic recording element;
An upper electrode disposed on the magnetic recording element;
A current source for passing the current through the magnetic recording element via the lower electrode and the upper electrode;
And a current path for guiding the current to the magnetic recording element. The current path includes a bit line connected to one of the lower electrode and the upper electrode, and a MOS transistor connected to the other of the lower electrode and the upper electrode, and the gate of the MOS transistor The magnetic memory according to claim 9 , connected to a word line intersecting the bit line. The current path includes a bit line connected to one of the lower electrode and the upper electrode, and a word line connected to the other of the lower electrode and the upper electrode, and the bit line and the The magnetic memory according to claim 9 , wherein the word lines intersect each other. The magnetic memory according to claim 9 , wherein the current path includes a probe disposed on the magnetic recording element and having a movable relative position to the magnetic recording element.

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