JP2009043993A - Magnetoresistance effect device, magnetic storage unit, magnetic memory unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-output and high-sensitivity magnetoresistance effect device and, a magnetic head, a magnetic storage unit, and a magnetic memory unit that use the magnetoresistance effect device. <P>SOLUTION: This magnetoresistance effect device comprises a fixed magnetic layer, a free magnetic layer, and a nonmagnetic layer sandwiched between the free magnetic layer and the fixed magnetic layer. At least one of the free magnetic layer and the fixed magnetic layer contains Co and/or Fe as a component, and is composed of a CoFeMg alloy film that further contains Mg. The foregoing CoFeMg alloy film has a composition with a composition range of (Co<SB>x</SB>Fe<SB>100-x</SB>)Mgy (where 0≤x≤100, 0<y<30 at%). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a magnetoresistive effect element, a magnetic head, a magnetic memory device, and a magnetic memory device used for reproducing information in a magnetic memory device, and in particular, senses in a stacking direction of a laminated film constituting the magnetoresistive effect element. The present invention relates to a so-called CPP type magnetoresistive effect element having a CPP (Current-Perpendicular-to-Plane) type structure through which a current flows.

  In recent years, magnetoresistive elements have been used in magnetic heads of magnetic storage devices as reproducing elements for reproducing information recorded on magnetic recording media. The magnetoresistive effect element reproduces information recorded on the magnetic recording medium using a magnetoresistive effect that converts a change in the direction of the signal magnetic field leaking from the magnetic recording medium into a change in electrical resistance. With the increase in recording density of magnetic storage devices, those having a spin valve film have become mainstream.

  A spin valve film is composed of a fixed magnetic layer whose magnetization is fixed in a predetermined direction, a nonmagnetic layer, and a free magnetic layer whose magnetization direction changes depending on the direction and strength of the leakage magnetic field from the magnetic recording medium. Has been. The electric resistance value of the spin valve film changes according to the angle formed by the magnetization of the fixed magnetization layer and the magnetization of the free magnetization layer. A change in electrical resistance value is detected as a voltage change by passing a constant sense current through the spin valve film, so that the magnetoresistive element reproduces a bit recorded on the magnetic recording medium.

  At present, the magnetoresistive effect element is a CPP (Current-Perpendicular-to-Plane) type in which a sense current flows in the direction in which the spin valve film is laminated, that is, the direction in which the fixed magnetic layer, the nonmagnetic layer, and the free magnetic layer are laminated. Structure is used. The CPP type spin valve film has a feature that the output hardly changes even when the core width (the width of the spin valve film corresponding to the track width of the magnetic recording medium) is reduced. Therefore, the CPP type spin valve film is suitable for increasing the recording density. .

  The output of the CPP type spin valve film is determined by the amount of change in magnetoresistance of a unit area when an external magnetic field is applied to the spin valve film by sweeping the magnetic field from one direction to the opposite direction. The amount of change in magnetoresistance per unit area is the product of the amount of change in magnetoresistance of the spin valve film and the area of the film surface of the spin valve film. In order to increase the amount of change in magnetoresistance per unit area, it is necessary to use a material having a large product of the spin-dependent bulk scattering coefficient and the specific resistance for the free magnetic layer and the fixed magnetic layer. Spin-dependent bulk scattering is a phenomenon in which the degree to which conduction electrons scatter within the free magnetic layer and the fixed magnetic layer depends on the spin direction of the conduction electrons, and the larger the spin-dependent bulk scattering coefficient, The amount of change in magnetoresistance increases. In addition to the amount of change in magnetoresistance, the coercive force (hereinafter referred to as Hcf) must be lowered in order for the free layer to rotate with high sensitivity to the signal magnetic field from the medium.

  However, when a general magnetic material such as a CoFe alloy or NiFe alloy is used for the free magnetic layer or the fixed magnetic layer (see, for example, Japanese Patent Laid-Open No. 2002-92829), the element size is reduced toward a future high recording density. Then, it is considered that the amount of change in magnetoresistance is insufficient.

  Accordingly, the present invention has been made in view of the above problems, and provides a high-output and high-sensitivity magnetoresistive effect element, a magnetic head using the same, a magnetic storage device, and a magnetic memory device.

According to one aspect, the present invention is a CPP magnetoresistive element including a fixed magnetic layer, a free magnetic layer, and a nonmagnetic layer inserted between the fixed magnetic layer and the free magnetic layer, At least one of the free magnetic layer and the fixed magnetic layer is composed of a CoFeMg alloy film including Co and / or Fe as a constituent component and further including Mg, and the CoFeMg alloy film is (Co _x Fe _100-x ) Mg. Provided is a magnetoresistive element having a composition in the composition range of _y (where 0 ≦ x ≦ 100, 0 <y <30 at%). Here, the contents of Co, Fe and Mg are expressed in atomic%. Since the specific resistance of such a CoFeMg alloy film is more than three times the specific resistance of the CoFe alloy film, by using the CoFeMg alloy film as a free magnetic layer or a fixed magnetic layer, the spin-dependent bulk scattering coefficient and the specific resistance can be reduced. The amount of change in magnetoresistance depending on the product can be made extremely large as compared with the conventional CoFe film, and as a result, the output of the magnetoresistive element can be greatly increased. According to the present invention, a magnetoresistive effect element includes a CoFeMg alloy film having a composition of (Co _x Fe _(100−x) ) M _y (where 0 ≦ x ≦ 100, 0 <y <30 at%) in a free magnetic layer. Is used, the magnetoresistive change ΔRA per unit area is increased, and the output of the magnetoresistive element is increased. On the other hand, in the present invention, it is possible to increase the specific resistance value by increasing the Mg composition in the CoFeMg alloy film as described above. However, when the Mg composition exceeds 30 atomic%, the magnetic moment rapidly decreases, so the MR ratio Will fall. For this reason, in the CoFeMg alloy film, the Mg composition preferably does not exceed 30 at% (atomic%).

  In another aspect, the present invention provides a magnetic head including any one of the above magnetoresistive elements. According to the present invention, since the magnetoresistive element has a high output, the magnetic head can cope with magnetic recording with a higher recording density.

  According to another aspect, the present invention provides a magnetic storage device including a magnetic head having any one of the magnetoresistive elements and a magnetic recording medium. According to the present invention, since the magnetoresistive element has a high output, it is possible to increase the recording density of the magnetic storage device.

In another aspect, the present invention provides a memory composed of a CPP type magnetoresistive film having a fixed magnetic layer, a free magnetic layer, and a nonmagnetic layer inserted between the fixed magnetic layer and the free magnetic layer. Writing means for arranging the magnetization of the free magnetic layer in a predetermined direction by passing a current through the element, the bit line and the word line and applying a magnetic field by a current magnetic field, or by passing a spin-polarized current through the magnetoresistive film And reading means for detecting a resistance value by supplying a sense current to the magnetoresistive film, wherein at least one of the free magnetic layer and the fixed magnetic layer contains Co and / or Fe as a constituent component, and Mg. further comprising _{(Co x Fe (100-x} )) Mg y ( where 0 ≦ x ≦ 100,0 <y < 30at%) magnetic memory instrumentation characterized by comprising from CoFeMg alloy film having a composition of To provide. According to the present invention, by using the CoFeMg alloy film as the free magnetic layer, the magnetoresistance change amount ΔRA per unit area of the magnetoresistive effect film is increased, and “0” retained when reading information is obtained. And the difference between the magnetoresistance values corresponding to “1” increases, so that accurate reading can be performed.

  According to the present invention, a magnetoresistive effect element having high output and good sensitivity for detecting a magnetic field, a magnetic head using the same, a magnetic storage device, and a magnetic memory device are provided.

Embodiments will be described below with reference to the drawings. For convenience of explanation, unless otherwise specified, “magnetic resistance change amount ΔRA of unit area” is abbreviated as “magnetic resistance change amount ΔRA” or simply “ΔRA”.
(First embodiment)
A composite magnetic head including a magnetoresistive effect element according to a first embodiment of the present invention and an inductive recording element will be described.

  FIG. 1 is a diagram showing the main part of the medium facing surface of a composite magnetic head. However, in FIG. 1, the direction of the arrow X indicates the moving direction of a magnetic recording medium (not shown) facing the magnetoresistive element.

Referring to FIG. 1, a composite magnetic head 10 is roughly composed of a magnetoresistive effect element 20 formed on a flat ceramic substrate 11 such as Al ₂ O ₃ —TiC serving as a base of a head slider, The inductive recording element 13 is formed thereon.

The inductive recording element 13 includes an upper magnetic pole 14 having a width corresponding to the track width of the magnetic recording medium on the medium facing surface, and a lower magnetic pole 16 facing the upper magnetic pole 14 with a recording gap layer 15 made of a nonmagnetic material interposed therebetween. A yoke (not shown) that magnetically connects the upper magnetic pole 14 and the lower magnetic pole 16, a coil (not shown) that winds the yoke and induces a recording magnetic field by a recording current, and the like. The upper magnetic pole 14, the lower magnetic pole 16, and the yoke are made of a soft magnetic material. Examples of the soft magnetic material include a material having a high saturation magnetic flux density to ensure a recording magnetic field, for example, a material such as an alloy having a composition such as Ni ₈₀ Fe ₂₀ , CoZrNb, FeN, FeSiN, FeCo, or CoNiFe. . The inductive recording element 13 is not limited to this, and an inductive recording element having a known structure can be used.

  The magnetoresistive effect element 20 includes a lower electrode 21, a magnetoresistive effect film 30 (hereinafter referred to as “GMR film 30”), an alumina film 25, an upper electrode on an alumina film 12 formed on the surface of the ceramic substrate 11. 22 has a laminated structure. The GMR film 30 is electrically connected to the lower electrode 21 and the upper electrode 22, respectively.

  Magnetic domain control films 24 are provided on both sides of the GMR film 30 with an insulating film 23 interposed therebetween. Here, the magnetic domain control film 24 is composed of, for example, a laminate of a Cr film and a ferromagnetic CoCrPt film. The magnetic domain control film 24 makes the free magnetic layer (shown in FIG. 2) constituting the GMR film 30 a single magnetic domain and prevents the occurrence of Barkhausen noise. On the other hand, the lower electrode 21 and the upper electrode 22 have a function as a magnetic shield in addition to a function as a flow path of the sense current Is. Therefore, the lower electrode 21 and the upper electrode 22 are made of a soft magnetic alloy, for example, an alloy such as NiFe or CoFe. Further, a conductive film, such as a Cu film, a Ta film, or a Ti film, may be provided at the interface between the lower electrode 21 and the GMR film 30. The magnetoresistive effect element 20 and the inductive recording element 13 are covered with an alumina film, a hydrogenated carbon film, or the like in order to prevent corrosion or the like.

  By the way, the sense current Is flows, for example, from the upper electrode 22 through the GMR film 30 substantially perpendicular to the film surface and reaches the lower electrode 21. At that time, the GMR film 30 changes the electric resistance value, so-called magnetoresistance value, corresponding to the intensity and direction of the signal magnetic field leaking from the magnetic recording medium. Therefore, the magnetoresistive effect element 20 detects a change in the magnetoresistance value of the GMR film 30 in the form of a voltage change caused by passing a sense current Is of a predetermined current amount. Thus, the magnetoresistive effect element 20 can reproduce the information recorded on the magnetic recording medium. The direction in which the sense current Is flows is not limited to the direction shown in FIG. Further, the moving direction of the magnetic recording medium may be reversed.

  FIG. 2 is a cross-sectional view of a first example GMR film 30 constituting the magnetoresistive effect element according to the first embodiment.

  Referring to FIG. 2, the GMR film 30 of the first example has a base layer 31, an antiferromagnetic layer 32, a fixed magnetization stack 33, a nonmagnetic metal layer 37, a free magnetization layer 38, and a protective layer 39 stacked in order. It has what is called a single spin valve structure.

  The underlayer 31 is formed on the surface of the lower electrode 21 shown in FIG. 1 by sputtering or the like. For example, a NiCr alloy film, a Ta film (for example, a film thickness of 5 nm) and a NiFe alloy film (for example, a film thickness of 5 nm) It is composed of a laminate or the like. This NiFe alloy film preferably has a Fe content in the range of 17 atomic% to 25 atomic%. By using the NiFe alloy film having such a composition, the antiferromagnetic layer 32 is epitaxially grown on the surface of the (111) crystal plane which is the crystal growth direction of the NiFe film and the crystallographically equivalent crystal plane. Thereby, the crystallinity of the antiferromagnetic layer 32 can be improved.

  The antiferromagnetic layer 32 is made of, for example, a Mn-TM alloy having a film thickness of 4 nm to 30 nm (preferably 4 nm to 10 nm) (TM includes at least one of Pt, Pd, Ni, Ir, and Rh). . Examples of the Mn-TM alloy include alloys having a composition of PtMn, PdMn, NiMn, IrMn, and PtPdMn. The antiferromagnetic layer 32 exerts an exchange interaction on the first pinned magnetization layer 34 of the pinned magnetization stack 33 to pin the magnetization of the first pinned magnetization layer 34 in a predetermined direction. The fixed magnetization stack 33 has a so-called stacked ferrimagnetic structure in which a first fixed magnetization layer 34, a nonmagnetic coupling layer 35, and a second fixed magnetization layer 36 are sequentially stacked from the antiferromagnetic layer 32 side. In the fixed magnetization stack 33, the magnetization of the first fixed magnetization layer 34 and the magnetization of the second fixed magnetization layer 36 are antiferromagnetically exchange-coupled, and the magnetization directions are antiparallel to each other.

  The first and second pinned magnetic layers 34 and 36 are each made of a ferromagnetic material containing at least one of Co, Ni, and Fe having a film thickness of 1 to 10 nm. Examples of suitable ferromagnetic materials for the first and second pinned magnetic layers 34 and 36 include alloy films having a composition of CoFe, CoFeB, CoFeAl, CoFeMg, NiFe, FeCoCu, CoNiFe, and the like. Each of the first and second pinned magnetic layers 34 and 36 may be not only one layer but also a laminate of two or more layers, and each of the layers may be a combination of the same elements. And you may comprise with the material from which a composition ratio mutually differs, or you may comprise from the material which combined the mutually different element.

  On the other hand, as the second pinned magnetic layer 36, it is particularly preferable to use an alloy film having a composition of CoFeAl or CoFeMg. This is due to the following reason.

That is, the specific resistance of the alloy film material having a composition of CoFeAl or CoFeMg is much larger than the specific resistance of an alloy film having a composition of CoFe. For example, in the case of an alloy film having a specific composition ratio of Co ₉₀ Fe ₁₀ , the specific resistance In contrast, the alloy film having a composition ratio of Co ₅₀ Fe ₂₀ Al ₃₀ has a specific resistance of 130 μΩcm, which is about six times that of the alloy film having the composition Co ₉₀ Fe ₁₀ . Further, in the case of an alloy film having a composition ratio of Co ₅₀ Fe ₂₅ Mg ₂₅ , it is 65 μΩcm, which is three times or more. Since the magnetoresistance change depends on the product of the spin-dependent bulk scattering coefficient and the specific resistance, the magnetoresistance change ΔRA is greater when the CoFeAl alloy film or the CoFeMg alloy film is used than when the CoFe alloy film is used. Will be much larger. Therefore, by using an alloy film having a composition of CoFeAl or CoFeMg for the second pinned magnetization layer 36, the magnetoresistance change ΔRA can be significantly increased.

  Furthermore, since the specific resistance of the CoFeAl alloy and the CoFeMg alloy film is less dependent on the composition ratio of the CoFeAl alloy film and the CoFeMg alloy film, there is an advantage that the composition management at the time of manufacture becomes easy. The CoFeMg alloy is also preferably used for the free magnetic layer 38 described below because of these advantages.

In the second pinned magnetization layer 36, the CoFeMg alloy film has a particularly large magnetoresistance change ΔRA, and as will be described later in Example 1, further includes Co and / or Fe as a constituent component, and further includes Mg. _{(Co x Fe (100-x} )) Mg y preferably has a composition of (where 0 ≦ x ≦ 100,0 <y < 30at%). However, each content of Co, Fe, and Mg is expressed in atomic%.

Also, examples of the soft magnetic material suitable for the first pinned magnetic layer 34 include a CoFe alloy having a composition ratio of Co ₆₀ Fe ₄₀ or a NiFe alloy having a NiFe composition in terms of low specific resistance. This is because the magnetization of the first pinned magnetic layer 34 is opposite to the magnetization direction of the second pinned magnetic layer 36, so that the first pinned magnetic layer 34 acts in a direction to reduce the magnetoresistance change ΔRA. On the other hand, the use of a ferromagnetic material having a low specific resistance can compensate for a decrease in the magnetoresistance change ΔRA.

  The thickness of the nonmagnetic coupling layer 35 is set in a range where the first pinned magnetic layer 34 and the second pinned magnetic layer 36 are antiferromagnetically exchange coupled. The range is 0.4 nm to 1.5 nm (preferably 0.4 nm to 0.9 nm). The nonmagnetic coupling layer 35 is made of a nonmagnetic material such as Ru, Rh, Ir, Ru-based alloy, Rh-based alloy, or Ir-based alloy. As the Ru-based alloy, one of Ru, Co, Cr, Fe, Ni, and Mn, or a nonmagnetic material with these alloys is suitable. Thereby, it is possible to avoid the problem that the magnetization direction of the first pinned magnetic layer 34 is displaced or reversed from a predetermined direction.

  Further, although not shown, a ferromagnetic junction layer made of a ferromagnetic material having a saturation magnetic flux density higher than that of the first pinned magnetization layer 34 may be provided between the first pinned magnetization layer 34 and the antiferromagnetic layer 32. Good.

  The nonmagnetic metal layer 37 is made of, for example, a nonmagnetic conductive material having a thickness of 1.5 nm to 10 nm. Suitable conductive materials for the nonmagnetic metal layer 37 include Cu, Al, Cr and the like.

  The free magnetic layer 38 is provided on the surface of the nonmagnetic metal layer 37 and is made of, for example, a CoFeMg alloy having a thickness of 2 nm to 12 nm. As described above, this CoFeMg alloy has a much higher specific resistance than that of a conventional CoFe alloy. Therefore, in the free magnetic layer 38, the magnetoresistance change ΔRA is much larger than when the alloy CoFe is used.

  Here, when the CoFeMg alloy film having the above composition range used for either the fixed ferromagnetic layer or the free magnetic layer is formed by sputtering, it is formed using a CoFeMg alloy target having a predetermined composition. In addition, it is also possible to use a total of three types of targets of Co, Fe, and Mg alone, and simultaneously sputter, and further sequentially sputter the three types of single targets to obtain Co. It is also possible to form a laminated film in which a layer, an Fe layer, and an Mg layer are laminated. In the present invention, the “CoFeMg alloy film” includes not only an alloy film of Co, Fe and Mg but also such a laminated film or a superlattice structure film. Further, the CoFeMg alloy film is a method of simultaneously discharging a combination of an alloy target of two kinds of elements and a single target, such as a target composed of a single Co target and a FeMg alloy, and similarly, for example, a single Mg target and a CoFe alloy target, A method of forming a film by stacking an alloy target of two kinds of elements and a single target can be applied. The CoFeMg alloy film may contain other elements such as Al, Ge, Sb, and Cu as the fourth element.

  The protective layer 39 is made of a nonmagnetic conductive material, and is made of, for example, a metal film containing any one of Ru, Cu, Ta, Au, Al, and W, and is made of a laminate of these metal films. May be. The protective layer 39 can prevent the free magnetic layer 38 from being oxidized during the heat treatment for causing the antiferromagnetism of the antiferromagnetic layer 32 described below to appear.

  Next, a method for forming the GMR film 30 of the first example will be described with reference to FIG.

  Referring to FIG. 2, first, each layer from the base layer 31 to the protective layer 39 is formed by using the above-described materials by sputtering, vapor deposition, CVD, or the like.

  Next, the laminated body thus obtained is heat-treated in a magnetic field. The heat treatment is performed in a vacuum atmosphere, for example, with a heating temperature of 250 ° C. to 320 ° C., a heating time of about 2 to 4 hours, and an applied magnetic field of 1592 kA / m. By this heat treatment, a part of the Mn-TM alloy described above is ordered and antiferromagnetism appears. Further, by applying a magnetic field in a predetermined direction during the heat treatment, the magnetization direction of the antiferromagnetic layer 32 is oriented in a predetermined direction, and fixed magnetization is generated by exchange interaction between the antiferromagnetic layer 32 and the fixed magnetization layer 33. The magnetization of the layer 33 can be fixed in a predetermined direction.

  Next, the laminate from the base layer 31 to the protective layer 39 is patterned into a predetermined shape as shown in FIG. The GMR films of the second to fifth examples described below are formed in substantially the same manner as the GMR film 30 of the first example. The GMR film 30 of the first example has a large magnetoresistance change ΔRA because the free magnetic layer 38 is made of CoFeMg. Therefore, a high-output magnetoresistive element can be realized.

  Next, a second example GMR film constituting the magnetoresistive effect element according to the first embodiment will be described. In the second example, the GMR film of the second example shown in FIG. 3 is applied instead of the GMR film 30 of the magnetoresistive effect element 10 shown in FIG. However, FIG. 3 is a cross-sectional view of a second example GMR film constituting the magnetoresistive effect element according to the first embodiment. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 3, the GMR film 40 of the second example includes an underlayer 31, a lower antiferromagnetic layer 32, a lower fixed magnetization stack 33, a lower nonmagnetic metal layer 37, a free magnetic layer 38, and an upper nonmagnetic metal. The layer 47, the upper fixed magnetization stack 43, the upper antiferromagnetic layer 42, and the protective layer 39 are sequentially stacked. That is, the GMR film 40 includes an upper nonmagnetic metal layer 47, an upper fixed magnetization stack 43, and an upper antiferromagnetic layer between the free magnetic layer 38 and the protective layer 39 of the GMR film of the first example shown in FIG. 42, a so-called dual spin valve structure. The lower antiferromagnetic layer 32, the lower pinned magnetization stack 33, and the lower nonmagnetic metal layer 34 are respectively an antiferromagnetic layer 32, a pinned magnetization layer 33, and a GMR film of the first example shown in FIG. Since the same material and film thickness as the nonmagnetic metal layer 34 are used, the same reference numerals are used. The upper nonmagnetic metal layer 47 and the upper antiferromagnetic layer 42 can be made of the same material as the lower nonmagnetic metal layer 37 and the lower antiferromagnetic layer 32, respectively, and the film thicknesses are also set in the same range. . The upper pinned magnetization stack 43 is formed by stacking an upper first pinned magnetization layer 44, an upper nonmagnetic coupling layer 45, and an upper second pinned magnetization layer 46 in this order from the upper antiferromagnetic layer 42 side. It has a structure. The upper first pinned magnetization layer 44, the upper nonmagnetic coupling layer 45, and the upper second pinned magnetization layer 46 are the same as the lower first pinned magnetization layer 34, the lower nonmagnetic coupling layer 35, and the lower second pinned magnetization layer 36, respectively. These materials can be used, and the film thickness is set in the same range.

  In the GMR film 40, the free magnetic layer 38 is selected from the same CoFeMg composition range as the free magnetic layer 38 of the GMR film of the first example shown in FIG. Therefore, the magnetoresistive effect element has a large magnetoresistance change ΔRA for the same reason as in the case of the GMR film of the first example.

  Further, the GMR film 40 includes a spin valve structure including a lower fixed magnetization stack 33, a lower nonmagnetic metal layer 37, and a free magnetization layer 38, a free magnetization layer 38, an upper nonmagnetic metal layer 47, and an upper fixed magnetization stack. The spin valve structure consisting of Therefore, in the GMR film 40, the magnetoresistance change ΔRA increases to about twice the magnetoresistance change ΔRA of the first example GMR film. As a result, the second example GMR film 40 is changed into the magnetoresistive effect element. As a result, it is possible to realize a magnetoresistive element having a higher output than when the GMR film of the first example is used. Note that the method for forming the GMR film 40 is substantially the same as the method for forming the GMR film of the first example, and a description thereof will be omitted.

  Next, a third example GMR film constituting the magnetoresistive effect element according to the first embodiment will be described. In this third example, the GMR film 50 of the third example whose sectional view is shown in FIG. 4 is applied instead of the GMR film 30 of the magnetoresistive effect element 10 shown in FIG. FIG. 4 is a cross-sectional view of a third example GMR film constituting the magnetoresistive effect element according to the first embodiment. The GMR film 50 according to the third example is a modification of the GMR film 40 according to the second example. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

Referring to FIG. 4, the GMR film 50 of the third example includes an underlayer 31, a lower antiferromagnetic layer 32, a lower fixed magnetization stack 33, a lower nonmagnetic metal layer 37, a free magnetization stack 51, and an upper nonmagnetic layer. The metal layer 47, the upper fixed magnetization stack 43, the upper antiferromagnetic layer 42, and the protective layer 39 are sequentially stacked. That is, the GMR film 50 has a configuration in which a free magnetic layered body 51 is provided instead of the free magnetic layer 38 of the GMR film of the second example shown in FIG. The free magnetization laminate 51 is formed by laminating a first interface magnetic layer 52, a free magnetization layer 38, and a second interface magnetic layer 53 in this order from the lower nonmagnetic metal layer 37 side. The free magnetic layer 38 is made of CoFeMg having the same composition range as the free magnetic layer 38 of the GMR film 30 of the first example shown in FIG. The first interface magnetic layer 52 and the second interface magnetic layer 53 are each set to a thickness in the range of, for example, 0.2 nm to 2.5 nm, are made of a soft magnetic material, and function as a diffusion prevention layer.

  The first interface magnetic layer 52 and the second interface magnetic layer 53 are preferably selected from materials having a spin-dependent interface scattering coefficient larger than that of the CoFeMg alloy film, for example, a CoFe alloy film and a NiFe alloy film. Examples of the CoFe alloy film include alloys having a composition such as CoFeNi, CoFeCu, CoFeCr, and CoFeAl in addition to an alloy having a CoFe composition. Further, as the NiFe alloy film, an alloy having a composition such as NiFeCu, NiFeCr, or the like can be cited other than an alloy having a NiFe composition. In the free magnetic layered body 51, the magnetoresistive change ΔRA can be increased by sandwiching the free magnetic layer 38 with a soft magnetic material film having a large spin-dependent interface scattering coefficient. The first interface magnetic layer 52 and the second interface magnetic layer 53 may be made of materials having the same composition, may be made of materials containing the same elements and having different composition ratios, and materials made of elements different from each other. It may be used.

  Furthermore, a CoFeMg alloy film having a composition ratio different from that of the free magnetic layer 38 may be used for the first interface magnetic layer 52 and the second interface magnetic layer 53. For example, the first interfacial magnetic layer 52 and the second interfacial magnetic layer 53 may be made of a material having a higher coercive force than the free magnetic layer 38.

  The GMR film 50 of the third example has the same effect as that of the GMR film of the second example, and further, the first interface magnetic layer 52 and the second interface magnetic layer 53 are provided on both surfaces of the free magnetic layer 38, thereby The resistance change amount ΔRA can be further increased as compared with the GMR film 40 of the second example.

  Next, a fourth example GMR film constituting the magnetoresistive effect element according to the first embodiment will be described. In the fourth example, instead of the GMR film 30 of the magnetoresistive effect element 10 shown in FIG. 1, a GMR film 60 shown in a sectional view in the fourth example is applied. The GMR film 60 of the fourth example is a modification of the GMR film 40 of the second example. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 5, the GMR film 60 of the fourth example includes an underlayer 31, a lower antiferromagnetic layer 32, a lower fixed magnetization stack 61, a lower nonmagnetic metal layer 37, a free magnetic layer 38, and an upper nonmagnetic metal. The layer 47, the upper pinned magnetic laminate 62, the upper antiferromagnetic layer 42, and the protective layer 39 are sequentially laminated. That is, the GMR film 60 includes a lower fixed magnetization stack 61 and an upper fixed magnetization stack 62 instead of the lower fixed magnetization stack 33 and the upper fixed magnetization stack 43 of the GMR film 40 of the second example shown in FIG. The configuration is provided.

  The lower pinned magnetization stack 61 includes a third interface magnetic layer 63 on the lower nonmagnetic metal layer 37 side of the lower second pinned magnetization layer 36, and the upper pinned magnetization stack 62 includes an upper second pinned magnetization layer 46. A fourth interfacial magnetic layer 64 is provided on the upper nonmagnetic metal layer 47 side. The third interface magnetic layer 63 and the fourth interface magnetic layer 64 are each set to a thickness in the range of 0.2 nm to 2.5 nm, for example, and are made of a ferromagnetic material. Each of the third interface magnetic layer 63 and the fourth interface magnetic layer 64 is preferably selected from materials whose spin-dependent interface scattering is larger than that of CoFeMg, for example, a CoFe alloy film or an alloy film. Examples of the CoFe alloy include alloys having a composition such as CoFeNi, CoFeCu, CoFeCr, and CoFeAl in addition to an alloy having a CoFe composition. In addition to NiFe element alloys, NiFe alloys include alloys having compositions such as NiFeCu and NiFeCr. Thereby, the magnetoresistance change ΔRA can be increased. The third interface magnetic layer 63 and the fourth interface magnetic layer 64 may be made of materials having the same composition, may be made of materials containing the same elements and having different composition ratios, and materials made of elements different from each other. It may be used.

  The GMR film 60 of the fourth example has the same effect as that of the GMR film of the second example. Further, by providing the third interface magnetic layer 63 and the fourth interface magnetic layer 64, the magnetoresistance change ΔRA is set to the second example. It can be further increased than that of the GMR film.

  Next, a fifth example GMR film constituting the magnetoresistive effect element according to the first embodiment will be described. In this fifth example, a GMR film 65 whose cross-sectional view is shown in FIG. 6 is applied instead of the GMR film 30 of the magnetoresistive effect element 10 shown in FIG. The GMR film of the fifth example is a modification of the GMR film of the fourth example. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 6, the GMR film 65 of the fifth example includes an underlayer 31, a lower antiferromagnetic layer 32, a lower fixed magnetization stack 66, a lower nonmagnetic metal layer 37, a free magnetic layer 38, and an upper nonmagnetic metal. The layer 47, the upper pinned magnetization stack 67, the upper antiferromagnetic layer 42, and the protective layer 39 are sequentially stacked. That is, in the GMR film 65, the lower pinned magnetization stack 66 has the first ferromagnetic junction layer 68 on the lower nonmagnetic coupling layer 35 side of the lower second pinned magnetization layer 36, and the upper pinned magnetization stack 67 has the upper first magnetization layer 67. The structure is the same as that of the GMR film of the fourth example except that the second pinned magnetization layer 46 has the second ferromagnetic junction layer 69 on the upper nonmagnetic coupling layer 45 side.

  The first ferromagnetic junction layer 68 and the second ferromagnetic junction layer 69 have a thickness set in the range of, for example, 0.2 nm to 2.5 nm and include at least one of Co, Ni, and Fe. For example, it is made of a CoFe alloy, a CoFeB alloy, a CoNiFe alloy, or the like. The first ferromagnetic junction layer 68 and the second ferromagnetic junction layer 69 are made of a ferromagnetic material whose saturation magnetization is larger than that of the lower second fixed magnetization layer 36 and the upper second fixed magnetization layer 46, respectively. Thus, the exchange coupling with the lower first pinned magnetic layer 34 and the upper first pinned magnetic layer 44 can be enhanced, and the magnetization directions of the lower second pinned magnetic layer 36 and the upper second pinned magnetic layer 46 can be further stabilized. As a result, the magnetoresistance change ΔRA can be stabilized.

  As described above, the GMR film 65 of the fifth example has the same effect as the GMR film of the second example, and further, by providing the first ferromagnetic junction layer 68 and the second ferromagnetic junction layer 69, The magnetoresistance change ΔRA can be stabilized.

  In the first embodiment, the GMR films of the third to fifth examples are modified examples of the GMR film having the dual spin valve structure of the second example, but the GMR films of the third to fifth examples. A modification similar to the above may be applied to the free magnetic layer and the second pinned magnetic layer of the GMR film having the single spin valve structure of FIG. Further, the GMR film of the third example and the GMR film of the fourth example or the fifth example may be combined with each other.

  Example 1 is a magnetoresistive effect element having the configuration of the GMR film of the second example of the first embodiment shown in FIG.

  FIG. 7 is a graph showing the relationship between the composition of the free magnetic layer and ΔRA according to the first embodiment. However, in FIG. 1-No. 11 samples have different compositions of the CoFeMg alloys used for the free magnetic layer.

  Each sample of Example 1 was produced as follows.

First, a Cu (250 nm) / NiFe (50 nm) laminated film is formed from the silicon substrate side as a lower electrode on a silicon substrate on which a thermal oxide film is formed, and then an underlayer having the following composition and thickness Each layer of the laminate up to the protective layer is formed in a super high vacuum atmosphere (vacuum degree: 2 × 10 ⁻⁶ Pa or less) using a sputtering apparatus without heating the substrate, and then the antiferromagnetic layer Heat treatment was performed to make antiferromagnetism appear. The heat treatment conditions were a heating temperature of 300 ° C., a treatment time of 3 hours, and an applied magnetic field of 1952 kA / m.

Then, the thus obtained laminate was ground by ion milling, to produce a laminate, having six junction area in the range of 0.1μm ² ~0.6μm ^2. In Example 1, 40 laminated bodies were produced for each bonding area. Next, the laminated body thus obtained was covered with a silicon oxide film, then the protective layer was exposed by dry etching, and an upper electrode made of an Au film was formed so as to be in contact with the protective layer. In the following, sample No. 1-No. 11 shows a specific configuration of 11 GMR films. In addition, the numerical value in parenthesis represents a film thickness and is the same in the following examples.

Underlayer: Ru (4 nm)
Antiferromagnetic layer: IrMn (7 nm)
First pinned magnetic layer: Co ₆₀ Fe ₄₀ (3 nm)
Nonmagnetic coupling layer: Ru (0.72 nm)
Second pinned magnetic layer: Co ₄₀ Fe ₆₀ (4 nm)
Nonmagnetic metal layer: Cu (3.5 nm)
Free magnetic layer: CoFeMg (4.7 nm)
Nonmagnetic metal layer: Cu (3.5 nm)
Protective layer: Ru (5 nm)
Sample No. obtained in this way. 1-No. 11, the current value of the sense current is set to 2 mA, the external magnetic field is swept in the range of −79 kA / m to 79 kA / m parallel to the magnetization direction of the lower and upper second fixed magnetization layers, The voltage between the upper electrode was measured with a digital voltmeter to obtain a magnetoresistance curve. Further, the magnetoresistance change ΔRA was obtained from the difference between the maximum value and the minimum value of the magnetoresistance curve. The coercive force of the free magnetic layer was determined from the hysteresis of the magnetoresistive curve obtained by sweeping the external magnetic field in the same direction as described above in the range of −7.9 kA / m to 7.9 kA / m.

Referring to FIG. 1 to 11, the MR ratio is approximately 2.88 mΩμm ² or more, and the dependency on the composition is low, and a high ΔRA can be obtained in a wide range.

FIG. 8 is a graph comparing the case where a conventional Co ₄₀ Fe ₆₀ alloy film is used for the conventional free magnetic layer and the case where the CoFeMg alloy film of the present invention is used.

Referring to FIG. 8, in the CoFeMg alloy film of the present invention, ΔRA greatly increases by adding Mg at 10 at%, and the maximum composition of Co ₆₈ Fe ₂₂ Mg ₁₀ is 4.4 mΩμm ^{2, which} is the case of the CoFe alloy film. The value is 1.5 times. In the illustrated experiment, the CoFeMg alloy film is used only for the free magnetic layer. However, by using this material for the second pinned magnetic layer, ΔRA can be further increased.

  On the other hand, when Mg is introduced at 30 at%, the value of ΔRA decreases to almost the same level as that of the conventional CoFe film. This phenomenon is caused by adding 30 at% of nonmagnetic Mg atoms to the CoFeMg alloy. It is considered that the value of ΔRA decreased due to the decrease in the magnetic moment and the cancellation of the effect of increasing the specific resistance accompanying the increase in Mg composition. From this, it is concluded that the composition range of Mg is limited to 30 atomic% or less (Mg ≦ 30 at%).

Further, from FIG. 8, Hcf indicating the ease of rotation of the free layer magnetization is also lower than in the case of the CoFe alloy. In this respect, the CoFeMg alloy is more effective than the conventional material.
(Second Embodiment)
In the magnetic head according to the second embodiment of the present invention, the magnetoresistive element has a tunnel magnetoresistive (hereinafter referred to as “TMR”) film. The configuration of the magnetic head according to the second embodiment is the same except that a TMR film is provided instead of the GMR film 30 of the magnetic head shown in FIG.

  9 to 13 are cross-sectional views of the TMR films of the first to fifth examples constituting the magnetoresistance effect element according to the second embodiment of the present invention.

  Referring to FIGS. 9 to 13, the TMR films 70 to 74 of the first to fifth examples are nonmagnetic in the GMR films 30, 40, 50, 60 and 65 shown in FIGS. The metal layer (lower nonmagnetic metal layer) 37 and the upper nonmagnetic metal layer 47 are respectively divided into a nonmagnetic insulating layer (lower nonmagnetic insulating layer 37a) and an upper nonmagnetic insulating layer 47a (hereinafter referred to as “nonmagnetic”) made of an insulating material. The structure is the same except that the layers are abbreviated as “insulating layers 37a and 47a”.

  The nonmagnetic insulating layers 37a and 47a have a thickness of 0.2 nm to 2.0 nm, for example, and are made of any one of oxides selected from the group consisting of Mg, Al, Ti, and Zr. Examples of such oxides include MgO, AlOx, TiOx, and ZrOx. Here, x indicates that the composition may deviate from the stoichiometric composition of the compound of each material. In particular, the nonmagnetic insulating layers 37a and 47a are preferably made of crystalline MgO. In particular, the (001) plane of MgO is preferably substantially parallel to the film plane in terms of increasing the tunnel resistance change rate. . Further, the nonmagnetic insulating layers 37a and 47a may be made of any one nitride or oxynitride selected from the group consisting of Al, Ti, and Zr. Examples of such nitride include AlN, TiN, and ZrN. As a method for forming the nonmagnetic insulating layers 37a and 47a, the above materials may be directly formed using a sputtering method, a CVD method, or a vapor deposition method, and after forming a metal film using a sputtering method, a CVD method, or a vapor deposition method. Alternatively, the oxide film or the nitride film may be converted by performing an oxidation process or a nitridation process.

  The amount of change in tunnel resistance of the unit area is obtained in the same manner as the measurement of the amount of change in magnetoresistance ΔRA of the unit area in the first embodiment. The amount of change in tunnel resistance of the unit area is expected to increase by using CoFeMg for the free magnetic layer 38 for the same reason as in the first embodiment. Further, by using the CoFeMg alloy or CoFeAl alloy for the second pinned magnetic layers 36 and 46, a further increase in the amount of change in tunnel resistance of the unit area is also expected.

  The composition range of CoFeMg of the free magnetic layer 38 is set to the same range as the composition range of CoFeMg of the free magnetic layer described in the first embodiment. Thereby, a magnetoresistive effect element having a high output TMR film can be realized.

In the second embodiment, the TMR films of the third to fifth examples are modifications of the TMR film of the second example. However, modifications similar to the TMR films of the third to fifth examples are used. May be applied to the free magnetic layer and the second pinned magnetic layer of the TMR film of FIG. Further, the TMR film of the third example and the TMR film of the fourth example or the fifth example may be combined with each other.
(Third embodiment)
FIG. 14 is a plan view showing the main part of a magnetic memory device according to the third embodiment of the present invention.

Referring to FIG. 14, the magnetic storage device 90 generally comprises a housing 91. In the housing 91, a hub 92 driven by a spindle (not shown), a magnetic recording medium 93 fixed to the hub 92 and rotated by the spindle, an actuator unit 94, and supported by the actuator unit 94, the magnetic recording medium 93 An arm 95 and a suspension 96 that are driven in the radial direction, and a magnetic head 98 supported by the suspension 96 are provided. The magnetic recording medium 93 may be either a longitudinal magnetic recording system or a perpendicular magnetic recording system, or a recording medium having oblique anisotropy. The magnetic recording medium 93 is not limited to a magnetic disk but may be a magnetic tape.
As shown in FIG. 1, the magnetic head 98 includes a magnetoresistive effect element 20 formed on the ceramic substrate 11 and an inductive recording element 13 formed thereon. The inductive recording element 13 may be a ring-type recording element for in-plane recording, a single-pole recording element for perpendicular magnetic recording, or another known recording element. The magnetoresistive element includes the GMR film of any one of the first to fifth examples of the first embodiment, or the TMR film of any of the first to fifth examples of the second embodiment. . Therefore, the magnetoresistive effect element has a large magnetoresistance change amount ΔRA per unit area or a tunnel resistance change amount per unit area and a high output. Therefore, the magnetic storage device 90 is suitable for high recording density recording. The basic configuration of the magnetic storage device 90 according to the third embodiment is not limited to that shown in FIG.
(Fourth embodiment)
FIG. 15A is a cross-sectional view of a first example magnetic memory device according to the fourth embodiment of the present invention, and FIG. 15B is a configuration diagram of the GMR film shown in FIG. 15A. FIG. 16 is an equivalent circuit diagram of one memory cell of the magnetic memory device of the first example. In FIG. 15A, the orthogonal coordinate axes are shown together to indicate the direction. Of these, the Y1 and Y2 directions are directions perpendicular to the paper surface, the Y1 direction is the direction toward the back of the paper surface, and the Y2 direction is the direction toward the front of the paper surface. In the following description, for example, simply referring to the X direction indicates that either the X1 direction or the X2 direction may be used, and the same applies to the Y direction and the Z direction.
In the figure, the same reference numerals are assigned to the parts corresponding to the parts described above, and the description thereof is omitted.

  Referring to FIGS. 15A, 15B, and 16, the magnetic memory device 100 includes a plurality of memory cells 101 arranged in a matrix, for example. The memory cell 101 is roughly composed of a magnetoresistive effect (GMR) film 30 and a MOS field effect transistor (FET) 102. Note that a p-channel MOS type FET or an n-channel MOS type FET can be used as the MOS type FET. Here, an n-channel MOS type FET in which electrons are carriers will be described as an example. The MOS FET 102 is an impurity in which an n-type impurity is introduced in the vicinity of the surface of the silicon substrate 103 in the p-well region 104 and the p-well region 104 containing the p-type impurity formed in the silicon substrate 103. Diffusion regions 105a and 105b are provided. Here, one impurity diffusion region 105a is a source S, and the other impurity diffusion region 105b is a drain D. In the MOS type FET 102, a gate electrode G is provided on the surface of the silicon substrate 103 between the two impurity diffusion regions 105a and 105b via a gate insulating film 106.

  The source S of the MOS type FET 102 is electrically connected to one side of the GMR film 30, for example, the base layer 31 through the vertical wiring 114 and the intralayer wiring 115. Further, the plate line 108 is electrically connected to the drain D through the vertical wiring 114. The gate electrode G is electrically connected to the read word line 109. Note that the gate electrode G may also serve as the read word line 109. The bit line 101 is electrically connected to the other side of the GMR film 30, for example, the protective film 39. A write word line 111 is provided below the GMR film 30 at a distance. The GMR film 30 has the same configuration as that of the GMR film 30 shown in FIG. 2. In the GMR film 30, the direction of the easy axis of the free magnetic layer 38 is along the X-axis direction shown in FIG. And the direction of the hard axis is set along the Y direction. The direction of the easy axis of magnetization may be formed by heat treatment or by shape anisotropy. When the easy magnetization axis is formed in the X-axis direction due to the shape anisotropy, the cross-sectional shape parallel to the film surface of the GMR film 30 (the cross-sectional shape parallel to the XY plane) is set in the X direction rather than the side in the Y direction. A rectangle with a long side.

    In the magnetic memory device 100, the surface of the silicon substrate 103 and the gate electrode G are covered with an interlayer insulating film 113 such as a silicon nitride film or a silicon oxide film. In addition, the GMR film 30, the plate line 108, the read word line 109, the bit line 110, the write word line 111, the vertical wiring 114, and the intra-layer wiring 115 are interlayer insulating except for the electrical connection described above. The film 113 is electrically insulated from each other.

  The magnetic memory device 100 holds information in the GMR film 30. Information is held depending on whether the magnetization direction of the free magnetic layer 38 is parallel or antiparallel to the magnetization direction of the second pinned magnetic layer 36.

Next, write and read operations of the magnetic memory device 100 will be described.
The information write operation to the GMR film 30 of the magnetic memory device 100 is performed by the bit line 110 and the write word line 111 arranged above and below the GMR film 30. The bit line 110 extends in the X direction above the GMR film 30, and is applied to the GMR film 30 in the Y direction by passing a current through the bit line 110. The write word line 111 extends below the GMR film 30 in the Y direction, and a magnetic field is applied to the GMR film 30 in the X direction by passing a current through the write word line 111. The magnetization of the free magnetic layer 38 of the GMR film 30 is in the X direction (for example, the X2 direction) when a magnetic field is not substantially applied, and the magnetization direction is stable.

  When writing information to the GMR film 30, a current is simultaneously applied to the bit line 110 and the write word line 111. For example, when the magnetization of the free magnetic layer 38 is directed in the X1 direction, a current flowing through the write word line 111 is passed in the Y1 direction. As a result, the magnetic field in the GMR film 30 is in the X1 direction. At this time, the direction of the current flowing through the bit line 110 may be either the X1 direction or the X2 direction. The magnetic field generated by the current flowing through the bit line 110 is in the Y1 direction or the Y2 direction in the GMR film 30, and functions as part of the magnetic field for the magnetization of the free magnetic layer 38 to cross the barrier of the hard axis. That is, when the magnetic field in the X1 direction and the Y1 direction or the Y2 direction are simultaneously applied to the magnetization of the free magnetic layer 38, the magnetization of the free magnetic layer 38 facing the X2 direction is reversed in the X1 direction. Even after the magnetic field is removed, the magnetization of the free magnetic layer 38 is oriented in the X1 direction, and is stable unless a magnetic field for the next write operation or a magnetic field for erasure is applied.

  In this way, “1” or “0” can be recorded in the GMR film 30 depending on the magnetization direction of the free magnetic layer 38.

  For example, when the magnetization direction of the second pinned magnetic layer 36 is the X1 direction and the magnetization direction of the free magnetic layer 38 is the X1 direction (the tunnel resistance value is low), “1”, the X2 direction (tunnel resistance value) Is set to “0”. Note that the magnitude of the current supplied to the bit line 110 and the write word line 111 during the write operation is such that the free magnetization is applied even if the current flows only in either the bit line 110 or the write word line 111. It is set to such an extent that the magnetization reversal of the layer 38 does not occur. As a result, recording is performed only on the magnetization of the free magnetic layer 38 of the GMR film 30 at the intersection of the bit line 110 supplied with current and the write word line 111 supplied with current. Note that the source S side is set to high impedance so that no current flows through the GMR film 30 when a current is passed through the bit line 110 during the write operation.

  Next, in the information read operation to the GMR film 30 of the magnetic memory device 100, a negative voltage is applied to the bit line 110 with respect to the source S, and the threshold value of the MOS FET 102 is applied to the read word line 109, that is, the gate electrode G. This is performed by applying a voltage (positive voltage) larger than the voltage. As a result, the MOS FET 102 is turned on, and electrons flow from the bit line 110 to the plate line 108 via the GMR film 30, the source S, and the drain D. By electrically connecting a current value detector 118 such as an ammeter to the plate line 108, a magnetoresistance value corresponding to the magnetization direction of the free magnetic layer 38 relative to the magnetization direction of the second pinned magnetic layer 36 is detected. . Thereby, “1” or “0” information held by the GMR film 30 can be read.

  In the magnetic memory device 100 of the first example according to the fourth embodiment, since the free magnetic layer 38 of the GMR film 30 is made of the CoFeMg alloy film, the magnetoresistance change ΔRA is large. Therefore, the magnetic memory device 100 can read data accurately because there is a large difference in magnetoresistive values corresponding to the stored “0” and “1” when reading information. The GMR film 30 constituting the magnetic memory device 100 may be replaced with any of the GMR films 40, 50, 60, and 65 of the second to fifth examples shown in FIGS.

  FIG. 17 is a configuration diagram of a TMR film constituting a modification of the magnetic memory device of the first example.

  Referring to FIG. 17 together with FIG. 15A, a TMR film 70 may be used instead of the GMR film 30 constituting the magnetic memory device 100. The TMR film 70 has the same configuration as the TMR film of the first example that constitutes the magnetoresistive element according to the second embodiment. In the TMR film 70, for example, the base layer 31 is in contact with the in-layer wiring 115 and the protective film 39 is in contact with the bit line 110. Further, the easy axis of the free magnetic layer 38 is arranged in the same manner as the GMR film 30 described above. Since the write operation and read operation of the magnetic memory device 100 using the TMR film 70 are the same as those of the GMR film, the description thereof is omitted.

  The TMR film 70 exhibits a tunnel resistance effect as described in the second embodiment. The TMR film 70 has a large amount of tunnel resistance change because the free magnetic layer 38 is made of CoFeMg. Therefore, the magnetic memory device 100 can read data accurately because the amount of change in tunnel resistance corresponding to the stored “0” and “1” is large when reading information. Note that the TMR films of the second to fourth examples shown in FIGS. 11 to 13 may be used as the TMR films constituting the magnetic memory device.

  FIG. 18 is a cross-sectional view of the magnetic memory device of the second example according to the fourth embodiment. In the figure, portions corresponding to the portions described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 18, the magnetic memory device 120 is different from the magnetic memory device of the first example in the mechanism for writing information to the GMR film 30.

  The memory cell of the magnetic memory device 120 has the same configuration as the memory cell 101 shown in FIGS. 15A and 15B, except that the write word line 111 is not provided. Hereinafter, description will be made with reference to FIG.

The magnetic memory device 120 is different from the magnetic memory device of the first example in writing operation. The magnetic memory device 120 injects a polarized spin current Iw into the GMR film 30, and the magnetization direction of the free magnetic layer 38 is parallel to the magnetization direction of the second pinned magnetic layer 36 depending on the direction of the current. From anti-parallel to anti-parallel or from anti-parallel to parallel. The polarized spin current Iw is an electron flow composed of electrons in one of two spin directions that can be taken by electrons. By causing the direction of the polarized spin current Iw to flow in the Z1 direction or the Z2 direction of the GMR film 30, torque is generated in the magnetization of the free magnetic layer, and so-called spin injection magnetization reversal is caused. The amount of the polarized spin current Iw is appropriately selected according to the film thickness of the free magnetic layer 38, but is about several mA to 20 mA. The amount of current of the polarized spin current Iw is smaller than the amount of current flowing through the bit line 110 and the write word line 111 during the write operation of the magnetic memory device of the first example of FIG. Can be reduced.

  The polarized spin current can be generated by passing a current vertically through a stacked body in which a Cu film having a configuration substantially similar to that of the GMR film 30 is sandwiched between two ferromagnetic layers. The direction of electron spin can be controlled by setting the magnetization directions of the two ferromagnetic layers to be parallel or antiparallel. The reading operation of the magnetic memory device 120 is the same as that of the magnetic memory device 100 of the first example in FIG.

The magnetic memory device 120 of the second example has the same effect as the magnetic memory device of the first example. Furthermore, the magnetic memory device 120 of the second example can reduce power consumption compared with the magnetic memory device of the first example. The magnetic memory device 120 may be replaced with any of the GMR films 40, 50, 60, 65 of the second to fifth examples shown in FIGS. 3 to 6 instead of the GMR film 30, or The TMR films of the first to fourth examples shown in FIGS. 9 to 13 may be substituted. In the magnetic memory devices of the first example and the second example of the fourth embodiment, the current direction during the write operation and the read operation is controlled by the MOS type FET. Direction control may be performed.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the present invention described in the claims. It can be changed. For example, in the third embodiment, the case where the magnetic recording medium is disk-shaped has been described as an example. However, it is needless to say that the present invention can also be applied to a magnetic tape device in which the magnetic recording medium is tape-shaped. Further, the magnetic head including the magnetoresistive effect element and the recording element has been described as an example, but a magnetic head including only the magnetoresistive effect element may be used. Furthermore, a magnetic head in which a plurality of magnetoresistive elements are arranged may be used.

As mentioned above, although this invention was described about preferable embodiment, this invention is not limited to this specific embodiment, A various deformation | transformation and change are possible within the summary described in the claim.
(Appendix 1)
A CPP-type magnetoresistive effect element comprising a fixed magnetic layer, a free magnetic layer, and a nonmagnetic layer inserted between the fixed magnetic layer and the free magnetic layer, wherein the free magnetic layer and the fixed magnetic layer At least one of them is composed of a CoFeMg alloy film containing Co and / or Fe as a constituent component and further containing Mg, and the CoFeMg alloy film is (Co _x Fe _100-x ) M g _y (where 0 ≦ x ≦ 100 , 0 <y <30 at%).
(Appendix 2)
A symmetric arrangement of the fixed magnetization layer disposed on the opposite side of the fixed magnetization layer with the free magnetization layer interposed therebetween, and a second non-magnetism inserted between the free magnetization layer and the symmetric arrangement of the fixed magnetization layer Supplementary note 1 wherein at least one of the free magnetic layer, the fixed magnetic layer, and the symmetrical fixed magnetic layer is formed of a CoFeMg alloy film having a composition within the composition range. Magnetoresistive effect element.
(Appendix 3)
The magnetic field according to claim 1 or 2, wherein a CoFe alloy film, a NiFe alloy film, or a CoFeAl alloy film, which is a soft magnetic material, is laminated as an anti-diffusion layer at the interface between the free layer and / or the fixed magnetic layer and the nonmagnetic layer. Resistive effect element.
(Appendix 4)
A CPP magnetoresistive element including a fixed magnetic layer, a free magnetic layer, and an insulating layer inserted between the fixed magnetic layer and the free magnetic layer, wherein the free magnetic layer, the fixed magnetic layer, At least one is composed of a CoFeMg alloy film containing Co and / or Fe as a constituent component and further containing Mg, and the CoFeMg alloy film is (Co _x Fe _(100−x) ) M _y (where 0 ≦ x ≦ A magnetoresistive element having a composition of 100, 0 <y <30 at%).
(Appendix 5)
The magnetoresistive element according to claim 4, wherein a CoFe alloy film, a NiFe alloy film, or a CoFeAl alloy film, which is a soft magnetic material, is laminated as an anti-diffusion layer at an interface between the free layer and / or the fixed magnetization layer and the insulating layer. .
(Appendix 6)
The magnetoresistive effect element according to appendix 3 or 5, wherein the interface diffusion preventing layer has a thickness of 0.2 to 3 nm.
(Appendix 7)
The magnetoresistive effect element according to any one of appendices 1 to 6, wherein the CoFeMg alloy film further includes at least one of Al, Ge, Sb, and Cu.
(Appendix 8)
The magnetoresistive effect element according to any one of appendices 1 to 7, wherein the CoFeMg alloy film is made of an alloy of Co, Fe, and Mg.
(Appendix 9)
The said CoFeMg alloy film is a magnetoresistive effect element as described in any one of the additional remarks 1-7 which have a laminated structure of Co layer, Fe layer, and Mg layer.
(Appendix 10)
A magnetic storage device comprising: a magnetic head having the magnetoresistive effect element according to any one of appendices 1 to 9; and a magnetic recording medium.
(Appendix 11)
A storage element including a pinned magnetic layer, a free magnetic layer, and a non-magnetic layer inserted between the fixed magnetic layer and the free magnetic layer, a bit line and a word line Current is applied to the magnetoresistive film, or a spin-polarized current is applied to the magnetoresistive film to align the magnetization of the free magnetic layer in a predetermined direction; and Reading means for detecting a resistance value by supplying a sense current, wherein at least one of the free magnetic layer and the fixed magnetic layer further includes Co and / or Fe as a constituent component, and further includes Mg (Co _x Fe _{(100 -x))} Mg _y (magnetic memory device characterized by consisting CoFeMg alloy film having a composition of wherein 0 ≦ x ≦ 100,0 <y < 30at%).

FIG. 3 is a diagram illustrating a main part of a medium facing surface of the magnetic head according to the first embodiment of the invention. It is sectional drawing of the GMR film | membrane of the 1st example which comprises the magnetoresistive effect element based on 1st Embodiment. It is sectional drawing of the GMR film | membrane of the 2nd example which comprises the magnetoresistive effect element based on 1st Embodiment. It is sectional drawing of the GMR film | membrane of the 3rd example which comprises the magnetoresistive effect element based on 1st Embodiment. It is sectional drawing of the GMR film | membrane of the 4th example which comprises the magnetoresistive effect element based on 1st Embodiment. It is sectional drawing of the GMR film | membrane of the 5th example which comprises the magnetoresistive effect element which concerns on 1st Embodiment. It is a figure which shows the composition of the free magnetic layer of Example 1, and (DELTA) RA. The figure showing the relationship between CoFeMg alloy composition of a free magnetic layer, (DELTA) RA, and Hcf. It is sectional drawing of the TMR film | membrane of the 1st example which comprises the magnetoresistive effect element which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the TMR film | membrane of the 2nd example which comprises the magnetoresistive effect element which concerns on 2nd Embodiment. It is sectional drawing of the TMR film | membrane of the 3rd example which comprises the magnetoresistive effect element which concerns on 2nd Embodiment. It is sectional drawing of the TMR film | membrane of the 4th example which comprises the magnetoresistive effect element which concerns on 2nd Embodiment. It is sectional drawing of the TMR film | membrane of the 5th example which comprises the magnetoresistive effect element which concerns on 2nd Embodiment. It is a top view which shows the principal part of the magnetic memory device based on the 3rd Embodiment of this invention. (A) is sectional drawing of the magnetic memory device of the 1st example which concerns on the 4th Embodiment of this invention, (B) is a block diagram of the GMR film | membrane shown to (A). It is an equivalent circuit diagram of one memory cell of the magnetic memory device of the first example. It is a block diagram of the TMR film | membrane which comprises the modification of the magnetic memory device of a 1st example. It is sectional drawing of the magnetic memory device of the 2nd example which concerns on 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,98 Magnetic head 11 Ceramic substrate 12, 25 Alumina film 13 Inductive recording element 14 Upper magnetic pole 15 Recording gap layer 16 Lower magnetic pole 20 Magnetoresistive element 21 Lower electrode 22 Upper electrode 23 Insulating film 24 Magnetic domain control film 30, 40, 50, 60, 65 Magnetoresistive (GMR) film 31 Underlayer 32 Antiferromagnetic layer (lower antiferromagnetic layer)
33 Fixed magnetization stack (lower fixed magnetization stack)
34. First fixed magnetic layer (lower first fixed magnetic layer)
35 Nonmagnetic coupling layer (lower nonmagnetic coupling layer)
36 Second pinned magnetic layer (lower second pinned magnetic layer)
37 Nonmagnetic metal layer (lower nonmagnetic metal layer)
37a Nonmagnetic insulating layer (lower nonmagnetic insulating layer)
38 free magnetic layer 39 protective layer 42 upper antiferromagnetic layer 43, 62, 67 upper fixed magnetization stack 44 upper first fixed magnetic layer 45 upper nonmagnetic coupling layer 46 upper second fixed magnetic layer 47 upper nonmagnetic metal layer 47a Upper nonmagnetic insulating layer 51 Free magnetization stack 52 First interface magnetic layer 53 Second interface magnetic layer 61, 66 Lower fixed magnetization stack 63 Third interface magnetic layer 64 Fourth interface magnetic layer 68 First ferromagnetic junction layer 69 Second ferromagnetic junction layer 70 to 74 Tunnel magnetoresistive effect (TMR) film 90 Magnetic storage device 100, 120 Magnetic memory device

Claims (7)

A CPP-type magnetoresistive effect element comprising a fixed magnetic layer, a free magnetic layer, and a nonmagnetic layer inserted between the fixed magnetic layer and the free magnetic layer, wherein the free magnetic layer and the fixed magnetic layer At least one of them is composed of a CoFeMg alloy film containing Co and / or Fe as a constituent component and further containing Mg, and the CoFeMg alloy film is (Co _x Fe _100-x ) M g _y (where 0 ≦ x ≦ 100 , 0 <y <30 at%).   A symmetric arrangement of the fixed magnetization layer disposed on the opposite side of the fixed magnetization layer with the free magnetization layer interposed therebetween, and a second non-magnetism inserted between the free magnetization layer and the symmetric arrangement of the fixed magnetization layer The at least one of the free magnetic layer, the fixed magnetic layer, and the symmetrically arranged fixed magnetic layer is formed of a CoFeMg alloy film having a composition within the composition range. 2. A magnetoresistive element described in 1.   The magnetoresistive film according to claim 2, wherein a CoFe alloy film, a NiFe alloy film, or a CoFeAl alloy film, which is a soft magnetic material, is laminated as a diffusion prevention layer at an interface between the free layer and / or the fixed magnetic layer and the nonmagnetic layer. Effect element. A CPP magnetoresistive element including a fixed magnetic layer, a free magnetic layer, and an insulating layer inserted between the fixed magnetic layer and the free magnetic layer, wherein the free magnetic layer, the fixed magnetic layer, At least one is composed of a CoFeMg alloy film containing Co and / or Fe as a constituent component and further containing Mg, and the CoFeMg alloy film is (Co _x Fe _(100−x) ) M _y (where 0 ≦ x ≦ A magnetoresistive element having a composition of 100, 0 <y <30 at%).   5. The magnetoresistance according to claim 4, wherein a CoFe alloy film, a NiFe alloy film, or a CoFeAl alloy film, which is a soft magnetic material, is laminated as an anti-diffusion layer at an interface between the free layer and / or the fixed magnetization layer and the insulating layer. Effect element.   A magnetic storage device comprising: a magnetic head having the magnetoresistive effect element according to claim 1; and a magnetic recording medium. A storage element including a pinned magnetic layer, a free magnetic layer, and a non-magnetic layer inserted between the fixed magnetic layer and the free magnetic layer, a bit line and a word line Current is applied to the magnetoresistive film, or a spin-polarized current is applied to the magnetoresistive film to align the magnetization of the free magnetic layer in a predetermined direction; and Reading means for detecting a resistance value by supplying a sense current, wherein at least one of the free magnetic layer and the fixed magnetic layer further includes Co and / or Fe as a constituent component, and further includes Mg (Co _x Fe _{(100 -x))} Mg _y (magnetic memory device characterized by consisting CoFeMg alloy film having a composition of wherein 0 ≦ x ≦ 100,0 <y < 30at%).

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