Tunnel magnetoresistance effect element and magnetic detection device provided with same

Abstract

A tunnel magnetoresistance effect element (TMR film (10)) of a top pinning type according to the present application sequentially stacks a free magnetic layer (12), an insulating barrier layer (13), and a fixed magnetic layer (19) having a second magnetic layer (14), a non-magnetic intermediate layer (15), and a first magnetic layer (16) sequentially stacked from the side of the insulating barrier layer (13) and a self-pinning configuration in which the fixed magnetization directions of the second magnetic layer (14) and the first magnetic layer (16) are anti-parallel. The second magnetic layer (14) sequentially stacks a first CoFe layer (141), a CoFeB layer (crystalline orientation resetting layer (142)), a NiFe layer (crystalline orientation promoting layer (143)), and a second CoFe layer (144) from the side of the insulating barrier layer (13). The first magnetic layer is an FeCo layer (16), the composition ratio of Fe of the FeCo layer (16) is 40 to 80 at.%, and the film thickness is 1.6 to 4.5 nm. Thus, the tunnel magnetoresistance effect element according to the present application is excellent in the resistance to a strong magnetic field and has a small hysteresis.

Description

Technical Field

[0001] This invention relates to a tunneling magnetoresistive element and a magnetic detection device having the same. Background Technology

[0002] Magnetoresistive elements, whose resistance varies with an external magnetic field, are used in magnetic detection devices and the like. Types of magnetoresistive elements include giant magnetoresistive elements (GMR films, GMR elements) and tunneling magnetoresistive elements (TMR films, TMR elements).

[0003] Patent Document 1 describes a TMR sensor with a bottom-pinned (bottom spin valve) structure comprising a free magnetic layer, a tunnel barrier layer (Mg / MgO / Mg), and pinned layers (AP1 / coupling layer (Ru) / AP2). Furthermore, it describes that in this TMR sensor, the AP1 layer, which is connected to the tunnel barrier layer, is formed using Co or CoFe, and that the TMR sensor can also have a top-pinned (top spin valve) structure.

[0004] Patent document 2 describes a top-pinned TMR element consisting of a free magnetic layer, a bonding layer (tunnel barrier layer, MgO), a reference layer, and an exchange pinning layer, wherein the reference layer connected to the bonding layer is formed by a stacked structure of CoFe, CoFeB, or CoFeB / CoFe.

[0005] In top-pinned TMR devices, the following problem exists: the crystallinity of the fixed magnetic layer stacked on the insulating barrier layer (tunnel barrier layer) decreases, becoming almost amorphous, thus reducing the layer separation of the fixed magnetic layer that constitutes the self-pinned structure. Neither Patent Document 1 nor Patent Document 2 addresses the problem of reduced crystallinity of the fixed magnetic layer due to the insulating barrier layer in top-pinned TMR devices. Conventionally, in top-pinned TMR devices, the reduced crystallinity of the fixed magnetic layer stacked on the insulating barrier layer prevents improvement in magnetic field tolerance and resistivity change rate ΔMR.

[0006] Patent document 3 describes a pinned tunnel magnetoresistive effect element, which, in order to improve the strong magnetic field tolerance and the resistance change rate, sequentially stacks a free magnetic layer, an insulating barrier layer, and a fixed magnetic layer. The fixed magnetic layer has a second magnetic layer, a non-magnetic intermediate layer, and a first magnetic layer stacked sequentially from the insulating barrier layer side. It has a self-pinning structure in which the fixed magnetization directions of the second magnetic layer and the first magnetic layer are antiparallel. The second magnetic layer has a crystal orientation promoting layer.

[0007] Prior art literature

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2008-300840

[0010] Patent Document 2: Japanese Patent Application Publication No. 2011-238342

[0011] Patent Document 3: Japanese Patent Application Publication No. 2020-136471 Summary of the Invention

[0012] -The problem the invention aims to solve-

[0013] Patent document 3 describes a top-pinned tunneling magnetoresistive element with improved strong magnetic field tolerance and resistance change rate by incorporating a crystal orientation promoting layer in the second magnetic layer. However, it does not describe a structure for reducing hysteresis. If the hysteresis of the fixed magnetic layer is large, magnetization will disperse after a large magnetic field is applied, and the resistance change rate ΔMR will easily deteriorate. Therefore, the object of the present invention is to provide a top-pinned tunneling magnetoresistive element with excellent strong magnetic field tolerance and low hysteresis, and a magnetic detection device using the element.

[0014] -Methods for solving problems-

[0015] Regarding the present invention provided to solve the above-mentioned problems, one aspect is a tunneling magnetoresistive effect element. In a top-pinned tunneling magnetoresistive effect element in which a free magnetic layer, an insulating barrier layer, and a fixed magnetic layer are stacked sequentially, the fixed magnetic layer has a second magnetic layer, a non-magnetic intermediate layer, and a first magnetic layer stacked sequentially from the insulating barrier layer side. It has a self-pinning structure in which the fixed magnetization directions of the second magnetic layer and the first magnetic layer are antiparallel. The second magnetic layer has a first CoFe layer, a CoFeB layer, a NiFe layer, and a second CoFe layer stacked sequentially from the insulating barrier layer side. The first magnetic layer is an FeCo layer, the Fe composition ratio of the FeCo layer is 40 to 80 at.%, and the film thickness is 1.6 to 4.5 nm.

[0016] The second magnetic layer consists of a first CoFe layer, a CoFeB layer, a NiFe layer, and a second CoFe layer, stacked sequentially from the insulating barrier layer side. The first magnetic layer is an FeCo layer with an Fe composition of 40–80 at.% and a film thickness of 1.6–4.5 nm, which reduces hysteresis. Furthermore, it increases the Hex / Hc ratio, improving strong magnetic field tolerance.

[0017] Alternatively, the thickness of the first CoFe layer can be 0.3–3.6 nm, the thickness of the CoFeB layer can be 0.5–4.1 nm, the thickness of the NiFe layer can be 0.5–8.1 nm, and the thickness of the second CoFe layer can be 0.3–3.9 nm.

[0018] Alternatively, the Co composition of the first CoFe layer can be 20–80 at.%, and the composition of the CoFeB layer can be within (Co) 100-X FeX) 100-Y B Y In this context, X is 25–100 at.%, Y is 10–30 at.%, the Ni composition of the NiFe layer is 40–100 at.%, and the Co composition of the second CoFe layer is 60–100 at.%.

[0019] With the above structure, the hysteresis is reduced, making it a tunnel-type magnetoresistive effect element with good resistance to strong magnetic fields.

[0020] Alternatively, in the first magnetic layer, the ratio of ΔM0 to 2Ms is less than 1%, where 2Ms is the saturation magnetization Ms on the positive side and the saturation magnetization Ms on the negative side. - The difference (Ms-Ms) - The ΔM0 is the magnetization M0 in the zero magnetic field when the saturation state changes from the negative side to the positive side, and the magnetization M0 in the zero magnetic field when the saturation state changes from the positive side to the positive side. - The difference (M0-M0) - ).

[0021] By setting the ratio of ΔM0 to 2Ms to less than 1%, the magnetization dispersion of the first magnetic layer is suppressed. Therefore, the hysteresis of the first magnetic layer is reduced, making it a tunneling magnetoresistive effect element with good resistance to strong magnetic fields.

[0022] Alternatively, in a tunnel-type magnetoresistive effect element, when the resistance change rate before applying a magnetic field of 1T is set as ΔMRa and the resistance change rate after applying a magnetic field of 1T is set as ΔMRb, the ΔMR change rate expressed by the following formula (1) is less than 2%.

[0023] △MR change rate (%) = [(△MRa-△MRb) / △MRa]×100 …(1)

[0024] In another aspect, the present invention provided to solve the aforementioned problems is a magnetic detection device in which a plurality of tunneling magnetoresistive elements of the present invention are formed on the same substrate, wherein the plurality of tunneling magnetoresistive elements include tunneling magnetoresistive elements with different fixed magnetization directions of the fixed magnetic layer.

[0025] By using the tunnel-type magnetoresistive effect element of the present invention, a magnetic detection device with excellent resistance to strong magnetic fields and a high rate of resistance change can be configured.

[0026] -Invention Effects-

[0027] In the tunneling magnetoresistive element of the present invention, the first magnetic layer is an FeCo layer with an Fe composition ratio of 40–80 at.% and a film thickness of 1.6–4.5 nm. Therefore, the antiferromagnetic magnetic interaction with the second magnetic layer, which is sequentially stacked from the insulating barrier layer side, consisting of a first CoFe layer, a CoFeB layer, a NiFe layer, and a CoFe layer, is strengthened, stabilizing the self-pinning structure. Thus, a top-pinned tunneling magnetoresistive element with low hysteresis, excellent strong magnetic field tolerance, and a high rate of resistance change can be provided. Attached Figure Description

[0028] Figure 1 This is a schematic diagram illustrating the membrane structure of a top-studded TMR membrane.

[0029] Figure 2 This is an illustrative diagram related to the reason why the magnetic field resistance of top-pinned TMR membranes is weakened.

[0030] Figure 3 This is a graph that schematically illustrates the differences in magnetization curves caused by differences in the orientation of the crystalline structure of the fixed magnetic layer.

[0031] Figure 4 This is a circuit block diagram of the magnetic detection device of the present invention.

[0032] Figure 5 This diagram schematically illustrates the process of forming a fixed magnetic layer in the manufacturing method of the magnetic detection device of the present invention.

[0033] Figure 6A This is a schematic diagram showing the structure of the TMR membrane of Example 1.

[0034] Figure 6B This is a graph showing the film thickness dependence of the crystal orientation reset layer in the TMR film of Example 1.

[0035] Figure 7A This is a schematic diagram showing the structure of the TMR membrane in Example 2.

[0036] Figure 7B This is a graph showing the film thickness dependence of the crystal orientation promoting layer in the TMR film of Example 2.

[0037] Figure 8A This is a schematic diagram showing the structure of the TMR membrane in Example 3.

[0038] Figure 8B This is a graph showing the thickness dependence of the second CoFe layer in the TMR membrane of Example 3.

[0039] Figure 9A This is a schematic diagram showing the structure of the TMR membrane in Example 4.

[0040] Figure 9B This is a graph showing the thickness dependence of the first CoFe layer in the TMR membrane of Example 4.

[0041] Figure 10A This is a schematic diagram showing the structure of the TMR membrane in Example 5.

[0042] Figure 10B This is a graph showing the film thickness dependence of the crystal orientation reset layer in the TMR film of Example 5.

[0043] Figure 11A This is a schematic diagram showing the structure of the TMR membrane in Example 6.

[0044] Figure 11B This is a graph showing the film thickness dependence of the crystal orientation promoting layer in the TMR film of Example 6.

[0045] Figure 12A This is a schematic diagram showing the structure of the TMR membrane in Example 7.

[0046] Figure 12B This is a graph showing the thickness dependence of the second CoFe layer in the TMR membrane of Example 7.

[0047] Figure 13 This is a graph illustrating the parameters used to evaluate the compositional dependence of the second CoFe layer at the Ru interface.

[0048] Figure 14A This is a schematic diagram showing the structure of the membrane in Example 8.

[0049] Figure 14B This is a graph showing the composition dependence of the second CoFe layer in the membrane of Example 8.

[0050] Figure 15A This is a graph illustrating the parameters used in the evaluation of the film thickness dependence of the first magnetic layer constituting the film in Examples 9 and 10.

[0051] Figure 15B This is a schematic diagram showing the structure of the membrane in Example 9.

[0052] Figure 15C This is a graph showing the relationship between the applied magnetic field and the magnetization of the first magnetic layer when the thickness of the first magnetic layer in the film of Example 9 is 1.5 nm, 2.4 nm, and 4.5 nm.

[0053] Figure 15D This is a graph showing the film thickness dependence of the first magnetic layer in M0 / Ms.

[0054] Figure 15EThis is a graph showing the film thickness dependence of the first magnetic layer of Hex.

[0055] Figure 15F This is a graph showing the film thickness dependence of the first magnetic layer of Hc.

[0056] Figure 15G This is a graph showing the film thickness dependence of the first magnetic layer, including Hex / Hc and ΔM0 / 2Ms.

[0057] Figure 15H This is a graph showing the film thickness dependence of the first magnetic layer on the change rate of ΔM0 / 2Ms and ΔMR.

[0058] Figure 16A This is a schematic diagram of the structure of the TMR membrane in Example 10.

[0059] Figure 16B This is a graph showing the relationship between the thickness of the first magnetic layer and the second CoFe layer in Example 10 and the normalized bridge output.

[0060] Figure 17A This is a schematic diagram of the structure of the membrane in Example 11.

[0061] Figure 17B This is a graph showing the relationship between the composition of the first magnetic layer and Hc in Example 11. Detailed Implementation

[0062] When a strong magnetic field is applied to a magnetoresistive element, the magnetization state of the fixed magnetic layer disperses, and the rate of change of resistance of the magnetoresistive element irreversibly deteriorates. Therefore, a self-pinned magnetoresistive element with excellent magnetic field tolerance of the fixed magnetic layer is proposed. In the self-pinned magnetoresistive element, the first and second magnetic layers of the fixed magnetic layer are coupled through antiferromagnetic magnetic interaction (hereinafter, appropriately referred to as antiferromagnetic coupling or RKKY interaction) via the nonmagnetic intermediate layer. The magnetization fixation force of the fixed magnetic layer is based on the high coercivity of the first magnetic layer on the side away from the free magnetic layer. Therefore, by stacking an antiferromagnetic layer on the first magnetic layer (on the side opposite to the nonmagnetic intermediate layer) and applying an exchange-coupled magnetic field Hex to the first magnetic layer, the degradation of the rate of change of resistance of the magnetoresistive element due to the strong magnetic field is suppressed.

[0063] In so-called bottom-pinned (bottom-spin valve) type magnetoresistive elements, a free magnetic layer is formed after the fixed magnetic layer. An antiferromagnetic layer is formed before the fixed magnetic layer, and a first magnetic layer with the fixed magnetic layer is stacked on top of the antiferromagnetic layer. When a highly coercive FeCo layer is stacked on top of the antiferromagnetic layer as the first magnetic layer, there is a problem of deterioration in the rectangularity (rectangularity) of the FeCo layer's magnetization curve. If the rectangularity of the FeCo layer deteriorates and the first magnetic layer cannot generate sufficient remanent magnetization, antiferromagnetic coupling will not occur between the two ferromagnetic layers (first magnetic layer, second magnetic layer), and it will no longer function as a fixed magnetic layer.

[0064] In a top-pinned (top-spin valve) type magnetoresistive element, an antiferromagnetic layer is formed after the formation of a free magnetic layer, followed by the formation of a fixed magnetic layer. An antiferromagnetic layer is then stacked on top of this first magnetic layer. In a giant magnetoresistive element (suitably referred to as a "GMR film"), a first magnetic layer is formed of a rectangular FeCo layer with a well-defined magnetization curve. An antiferromagnetic layer is then stacked on top of this first magnetic layer, thereby suppressing the dispersion of magnetic anisotropy in the FeCo layer.

[0065] However, unlike GMR films, tunneling magnetoresistive elements (TMR films), even when pinned, cannot form a fixed magnetic layer with good magnetic field tolerance. This is believed to be due to the presence of a layer different from that in GMR films between the free magnetic layer and the fixed magnetic layer. Specifically, it is speculated that the difference in crystal structure between oxides such as Al₂O₃ and MgO used as insulating barrier layers in TMR films and Cu used as a non-magnetic material layer in GMR films alters the crystallinity of the fixed magnetic layer, thereby affecting magnetic field tolerance.

[0066] Figure 2 This is an explanatory diagram related to the reason for the weakened magnetic field tolerance of top-pinned TMR films. For an example of GMR and TMR films, it shows the presumption of the crystal orientation of the layers constituting each film before annealing (As-depo).

[0067] As shown in the figure, in the top-pinned GMR film, the crystal orientation of Cu used as the non-magnetic material layer differs from that of Co used in the fixed magnetic layer. 90at.% Fe 10at.% (In this specification and the accompanying drawings, at.%, is appropriately omitted; only the proportion of the element described first is shown, also referred to as 90CoFe.) Similarly, it is a face-centered cubic lattice structure fcc

[111] . Therefore, the 90CoFe of the fixed magnetic layer is stacked on the Cu layer with a homogeneous crystal structure, resulting in a structure with sufficient crystal orientation and high atomic density. Therefore, the fixed magnetic layer has strong antiferromagnetic coupling through the Ru layer and good magnetic field resistance.

[0068] In contrast, in the top-pinned TMR film, the MgO used as the insulating barrier layer has a NaCl-type crystalline structure. Therefore, 90CoFe, which forms the fixed magnetic layer, is stacked on top of the MgO layer, which has a significantly different crystalline structure and interatomic distances. 90CoFe is difficult to spontaneously oriented, so when stacked on MgO, it cannot achieve sufficient crystalline orientation and is presumed to be non-oriented or amorphous. Ru and 60FeCo, stacked on 90CoFe, also become non-oriented or amorphous, similar to 90CoFe. Therefore, the decreased crystallinity and poor layer separation of the layers constituting the fixed magnetic layer are considered to result in weaker antiferromagnetic coupling via Ru, with ferromagnetic coupling becoming dominant, and lower magnetic field tolerance.

[0069] That is, in the top-pinned TMR film, the insulating barrier layer between the free magnetic layer and the fixed magnetic layer is a crystalline structure that is different from the adjacent layers. Therefore, the crystal orientation is broken, and each layer constituting the fixed magnetic layer becomes unoriented or amorphous. The antiferromagnetic coupling is weakened, which is presumably due to the reduced magnetic field tolerance.

[0070] Figure 3 This is a graph schematically illustrating the effect of differences in crystallinity among the layers constituting the fixed magnetic layer on the magnetization curve of a TMR element. In the same graph, solid lines represent the magnetization curves of TMR films with fixed magnetic layers having high crystallinity and atomic density, while dashed lines represent the magnetization curves of TMR films with fixed magnetic layers having low crystallinity and atomic density.

[0071] In TMR films with highly crystalline, i.e., strongly oriented fixed magnetic layers, the regions where the free magnetic layer undergoes magnetization reversal and the regions where the fixed magnetic layer (first or second magnetic layer) undergoes magnetization reversal are clearly distinguished on the magnetization curve. This indicates that the fixed magnetic layer constituting the TMR film has good layer separation. The degree of layer separation of the fixed magnetic layer can be evaluated using plateau magnetic fields (Hp(+), Hp(-)). Here, the "plateau magnetic field" is the magnitude of the magnetic field at the beginning of the magnetization reversal of the fixed layer, defined as the magnitude of the magnetic field that changes by 2% from Ms·t (saturation magnetization per unit area, at the end of the magnetization reversal of the free magnetic layer).

[0072] In contrast, in TMR films with fixed magnetic layers exhibiting low crystallinity (i.e., weak crystal orientation), the regions of magnetization reversal in the free magnetic layer and the regions of magnetization reversal in the fixed magnetic layer (first or second magnetic layer) are not clearly distinguished in the magnetization curve. This indicates poor layer separation of the fixed magnetic layer constituting the TMR film, with continuous magnetization reversals occurring in both the free and fixed magnetic layers. In cases of poor layer separation in the fixed magnetic layer, no plateau magnetic field appears in the magnetization curve.

[0073] In the face of Figure 2 In the top-pinned TMR film shown on the right, due to the weak crystalline orientation of the insulating barrier layer and the fixed magnetic layer stacked thereon, the antiferromagnetic coupling (RKKY interaction) of the fixed magnetic layer via Ru is weak. Therefore, magnetization reversals occur continuously in the free magnetic layer and the first and second magnetic layers of the fixed magnetic layer. In this case, as... Figure 3 As shown by the dashed line, the antiparallel magnetization state of the fixed magnetic layer and the free magnetic layer was almost not formed, making it impossible to become a TMR film with a high resistivity change rate (ΔMR).

[0074] (Tunneling magnetoresistive element)

[0075] Figure 1 This is an illustrative diagram schematically illustrating the film structure of the top-pinned TMR film 10 of the present invention. As shown in the figure, the TMR film 10 is a top-pinned tunnel magnetoresistive element stacked in the following order: a substrate layer (seed layer) 11, a free magnetic layer 12, an insulating barrier layer 13, a second magnetic layer 14, a non-magnetic intermediate layer 15, a first magnetic layer 16, an antiferromagnetic layer 17, and a protective layer 18. The fixed magnetic layer 19 is formed by the second magnetic layer 14, the non-magnetic intermediate layer 15, and the first magnetic layer 16.

[0076] The substrate layer 11 is the layer initially formed on the substrate (not shown) and the lower electrode layer. The material is not particularly limited, but for example, NiFeCr, Ru, etc., can be used.

[0077] The free magnetic layer 12 is stacked on the base layer 11, and its material and structure are not limited. For example, CoFe alloy (cobalt-iron alloy) or NiFe alloy (nickel-iron alloy) can be used as materials, and it can be formed into a single-layer structure, a stacked structure, a stacked ferristructure, etc.

[0078] An insulating barrier layer 13 is stacked on the free magnetic layer 12. Materials used include, for example, Al₂O₃, TiO₂, and MgO. From the viewpoint of improving the resistivity change rate of the TMR film 10, MgO is preferred.

[0079] The fixed magnetic layer 19 comprises, sequentially stacked from the insulating barrier layer 13 side, a second magnetic layer 14, a non-magnetic intermediate layer 15, and a first magnetic layer 16. The second magnetic layer 14 and the first magnetic layer 16 are ferromagnetic layers with a self-pinning structure where the magnetization direction is fixed antiparallel through antiferromagnetic coupling via the non-magnetic intermediate layer 15. The sensitivity axis of the TMR film 10 is aligned with the fixed magnetization direction of the second magnetic layer 14.

[0080] In the second magnetic layer 14, the first CoFe layer 141, the crystal orientation reset layer 142, the crystal orientation promotion layer 143, and the second CoFe layer 144 are stacked in this order starting from the insulating barrier layer 13 side.

[0081] By stacking the first CoFe layer 141, which is a bcc crystal structure, on the insulating barrier layer 13, it is possible to set it as a TMR film 10 with a large resistance change rate.

[0082] The first CoFe layer 141 is preferably CoxFe. 100-X The CoFe layer has a Co composition ratio X of 20 to 80 at.%. This CoFe layer can form a body-centered cubic (bcc) structure under conditions that allow for the formation of a highly crystalline layer. From the viewpoint of designing a TMR film 10 with a large resistivity change rate, its thickness is preferably 0.3 nm or more, more preferably 0.5 nm or more.

[0083] The crystal orientation reset layer 142 can be formed from an amorphous state. An amorphous state can be formed, for example, from a CoFeB layer and / or a Ta layer. "Amorphous state" refers to a state whose crystalline structure cannot be identified by transmission electron microscopy (TEM).

[0084] The composition of CoFeB forming the crystal orientation reset layer 142 is not particularly limited, but in (Co 100-X Fe X ) 100-Y B Y In this process, the preferred composition ratio X is 25–100 at.%, and the composition ratio Y is 10–30 at.%.

[0085] When the crystal orientation reset layer 142 is formed using amorphous CoFeB, from the viewpoint of interrupting the effect of the insulating barrier layer 13, its thickness is preferably 0.5 nm or more, more preferably 0.8 nm or more, and even more preferably 1.0 nm or more. From the viewpoint of enhancing the magnetization fixing force of the fixed magnetic layer 19 based on antiferromagnetic coupling, it is preferably 3.0 nm or less, more preferably 2.5 nm or less, and even more preferably 2.0 nm or less.

[0086] When a Ta layer is used as the crystal orientation reset layer 142, it is preferable to use a β-Ta layer with a thickness of 0.1 to 0.4 nm. This can interrupt the influence of the insulating barrier layer 13 and enable the layer magnetic coupling between the layers stacked above and below the Ta layer, thereby enhancing the magnetization fixing force of the fixed magnetic layer 19 based on antiferromagnetic coupling.

[0087] The crystal orientation reset layer 142 can be either a single layer or multiple layers. For example, if it is a stacked structure of CoFeB and Ta layers, the influence of the insulating barrier layer 13 can be further reduced. As a result, the layers stacked on the crystal orientation reset layer 142 are clearly distinguished, resulting in excellent layer separation.

[0088] By setting the crystal orientation reset layer 142, the influence of the insulating barrier layer 13 is reset, and the influence of the crystal structure of the insulating barrier layer 13 on the layers stacked thereafter can be further suppressed. As a result, the layers stacked on the crystal orientation promoting layer 143 achieve a state of good crystal structure and high atomic density, resulting in a fixed magnetic layer 19 with excellent layer separation. Therefore, the self-pinning structure of the fixed magnetic layer can be stabilized.

[0089] The crystal orientation promoting layer 143 is formed, for example, of a metal having an fcc

[111] lattice structure, to promote the crystal orientation of the second CoFe layer 144, the non-magnetic intermediate layer 15, and the first magnetic layer 16 formed thereon, and is designed to be a layer with high crystallinity. Examples of metals having an fcc

[111] lattice structure include ferromagnetic materials such as NiFe, which are mainly composed of nickel. Examples of components other than Ni include Co, Nb, and Ta, in addition to Fe. The composition of the NiFe layer constituting the crystal orientation promoting layer 143 is not particularly limited, but the composition of NiFe is... X Fe 100-X In this composition, a Ni composition ratio of 40 to 100 at.% is preferred. Due to its high tendency to spontaneously orient towards fcc

[111] and excellent soft magnetic properties, 81.5NiFe (Pc Permalloy) is preferred.

[0090] From the viewpoint of promoting crystal orientation, the thickness of the crystal orientation promoting layer 143 is preferably 0.5 nm or more, more preferably 1.0 nm or more, and even more preferably 1.5 nm or more. From the viewpoint of enhancing the magnetization fixing force of the fixed magnetic layer 19 based on antiferromagnetic coupling, it is preferably 5.0 nm or less, more preferably 4.0 nm or less, and even more preferably 3.0 nm or less.

[0091] The second CoFe layer 144 functions as an RKKY reinforcing layer. It is stacked adjacent to the crystal orientation promoting layer 143, rather than the insulating barrier layer 13, thus becoming a layer with excellent crystallinity and high atomic density. For example, by stacking it on the crystal orientation promoting layer 143 with an fcc

[111] lattice structure, a second CoFe layer 144 with excellent crystallinity and high atomic density with an fcc

[111] lattice structure can be formed. Therefore, the non-magnetic intermediate layer 15 and the first magnetic layer 16 stacked on the second CoFe layer 144 also become highly crystalline layers. Consequently, the antiferromagnetic coupling of the fixed magnetic layer 19 is strengthened, and the self-pinning structure is stabilized.

[0092] The composition of the second CoFe layer 144 is not particularly limited, but from the perspective of excellent soft magnetic properties, suppressing the dispersion of the magnetic field direction during film formation in a magnetic field and facilitating magnetization, or increasing RKKY interactions via Ru, the composition of the CoFe layer 144 is considered. X Fe 100-X In this case, the preferred composition ratio X is 60 to 100 at.%.

[0093] From the viewpoint of improving the above-mentioned effects, the thickness of the second CoFe layer 144 is preferably 0.3 to 3.9 nm, more preferably 0.3 to 2.3 nm.

[0094] The non-magnetic interlayer 15 is formed of Ru. If the thickness of the non-magnetic interlayer 15 formed of Ru is set to 0.3-0.45 nm or 0.75-0.95 nm, the second magnetic layer 14 and the first magnetic layer 16 can be antiferromagnetically coupled.

[0095] The first magnetic layer 16 uses Co X Fe 100-X Materials with high coercivity Hc, such as (X = 40~80). After the formation (film making) of the first magnetic layer 16, the first magnetic layer 16 and the second magnetic layer 14 are antiparallel coupled via the non-magnetic intermediate layer 15, functioning as the fixed magnetic layer 19. From the viewpoint of enhancing the magnetic field tolerance of the fixed magnetic layer 19, it is preferable to adjust the first magnetic layer 16 and the second magnetic layer 14 so that the difference in magnetization (saturation magnetization Ms·layer thickness t) is approximately equal (essentially zero).

[0096] In the first magnetic layer 16, the ratio of ΔM0 to 2Ms can be less than 1%.

[0097] The term 2Ms refers to the saturation magnetization Ms on the positive side and the saturation magnetization Ms on the negative side of the first magnetic layer 16. - The difference. Furthermore, ΔM0 refers to the magnetization M0 of the first magnetic layer 16 in a zero magnetic field when the first magnetic layer 16 changes from a negative saturation state to a positive saturation state, and the magnetization M0 of the first magnetic layer 16 in a zero magnetic field when the first magnetic layer 16 changes from a positive saturation state to a positive saturation state. - The difference (M0-[M0]) - ]).

[0098] By setting the ratio of ΔM0 to 2Ms of the first magnetic layer to less than 1%, that is, setting ΔM0 / 2Ms to less than 0.01, the magnetization dispersion of the first magnetic layer can be suppressed, thus reducing the hysteresis and resulting in a TMR film 10 with good resistance to strong magnetic fields.

[0099] By setting the ratio of ΔM0 to 2Ms of the first magnetic layer to less than 1%, it is possible to provide, for example, a TMR film 10 with a ΔMR change rate of less than 2% and excellent resistance to strong magnetic fields, as expressed by the following formula (1).

[0100] △MR change rate (%) = [(△MRa-△MRb) / △MRa]×100 …(1)

[0101] (In equation (1), ΔMRa is the rate of change of resistance of the TMR film 10 before a magnetic field of 1T is applied, and ΔMRb is the rate of change of resistance after a magnetic field of 1T is applied.)

[0102] The antiferromagnetic layer 17 fixes (pins) the magnetization direction of the first magnetic layer 16 using exchange coupling. The material is not particularly limited, and antiferromagnetic materials containing element X (where X is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and one or two of Mn and Cr can be used.

[0103] The material of the protective layer 18 is not limited; Ru, Ta, etc. can be used.

[0104] Figure 1 The top-pinned TMR film 10 of this embodiment, by having the above-described structure, achieves excellent layer separation for fixing the magnetic layer. Therefore, as shown... Figure 3 As shown by the solid line, a plateau magnetic field (Hp(-)) is generated in the magnetization curve, which significantly increases the rate of change of resistance.

[0105] (Magnetic detection device)

[0106] Figure 4 This is a circuit block diagram of the magnetic detection device 50 according to this embodiment. The magnetic detection device 50 is composed of a full-bridge circuit 40. In the same figure, the arrows indicate the magnetization direction of the second magnetic layer 14 with fixed magnetic layer 19. The full-bridge circuit 40 has the following structure: two series circuits 42a and 42b, which are connected in parallel between the power supply voltage Vdd 41 and the ground potential GND 44, and have swapped the order of the TMR films 10 with different fixed magnetization directions of the second magnetic layer 14.

[0107] The differential output of the output potential of the midpoint terminal 43a of the series circuit 42a constituting the full-bridge circuit 40 and the output potential of the midpoint terminal 43b of the series circuit 42b is obtained as the magnetic field detection output voltage.

[0108] In the magnetic detection device 50, the free magnetic layer 12 of the TMR film 10 (refer to...) Figure 1 The orientation of the TMR film 10 changes in accordance with the direction of the external magnetic field. At this time, the resistance value of the TMR film 10 changes according to the relative angle between the fixed magnetization direction of the second magnetic layer 14 and the magnetization direction of the free magnetic layer 12.

[0109] When the direction and intensity of the external magnetic field change, the detection output voltage of the full-bridge circuit 40 also changes accordingly. Therefore, the external magnetic field can be detected based on the detection output voltage obtained from the full-bridge circuit 40. Figure 4 The diagram shows a magnetic detection device 50 configured to detect magnetic fields in the left-right direction facing the paper of the diagram. However, if combined with a magnetic detection device configured to detect magnetic fields in the up-down direction facing the paper of the diagram, magnetic fields in both the up-down and left-right directions can be detected simultaneously.

[0110] (Manufacturing method of magnetic detection device)

[0111] Figure 5 It is shown schematically. Figure 4 The diagram illustrates the manufacturing method of the magnetic detection device 50, showing the relationship between the substrate and the direction of application of the magnetic field during the film formation process. The same diagram also explains the formation of the TMR film 10 as a magnetoresistive effect element.

[0112] exist Figure 5 In the process shown in (a), two TMR films 10 are formed on the substrate. The first magnetic layer 16 (refer to) is used to fix the magnetic layer 19 in the TMR film 10. Figure 1 In the film formation process, a first magnetic layer 16 is formed while a magnetic field in the direction indicated by the hollow arrow at 180° is applied to the substrate. Through the RKKY interaction generated between the first magnetic layer 16 and the second magnetic layer 14, a TMR film 10 with the fixed magnetization direction of the second magnetic layer 14 at 0° as indicated by the black arrow can be formed.

[0113] exist Figure 5 In the process shown in (b), the direction of the magnetic field, indicated by the hollow arrow, applied in the process of forming the first magnetic layer 16 is changed to the 0° direction, and a TMR film 10 with a magnetization direction different from that formed in the process of (a) is formed on the same substrate. The fixed magnetization direction of the second magnetic layer 14 in the TMR film 10 formed by this process is the 180° direction indicated by the black arrow. The direction of application of the magnetic field is determined according to the relative relationship between the substrate and the magnetic field, so when the direction of the applied magnetic field is changed, either the substrate or the magnetic field application unit can be moved.

[0114] In this way, by repeatedly performing the formation process of the fixed magnetic layer 19 by changing the direction of the applied magnetic field, TMR films 10 with different fixed magnetization directions of the fixed magnetic layer 19 can be formed on the same substrate.

[0115] After the deposition of multiple TMR films 10 with different magnetization directions, which are fixed magnetic layers 19 on the substrate, is completed, annealing is performed in a magnetic field-free environment without an applied magnetic field in order to generate an exchange-coupled magnetic field Hex between the first magnetic layer 16 and the antiferromagnetic layer 17 of the fixed magnetic layer 19. This allows the TMR films 10 to undergo aging treatment, enabling the creation of a stable magnetic detection device 50.

[0116] Subsequently, by connecting multiple TMR films 10 formed on a single substrate, a process is formed. Figure 4 The full-bridge circuit 40 shown completes the manufacturing of the magnetic detection device 50.

[0117] Example

[0118] The present invention will be further described in detail below through examples, etc., but the scope of the present invention is not limited to these examples, etc.

[0119] (Example 1: Effect of film thickness on crystal orientation resetting layer)

[0120] A TMR film is fabricated by stacking layers on the lower electrode layer [Ta(10)] in the following order: substrate layer: NiFeCr(4.2) / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.5) / crystal orientation reset layer: CoFeB(X) / crystal orientation promoting layer: NiFe(1.5) / second CoFe layer: 70CoFe(0.8)] / non-magnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8) / protective layer: [Ru(5) / Ta(15) / Ru(5)]. In this embodiment and subsequent embodiments, the numbers in parentheses indicate the thickness (nm) of each layer.

[0121] Figure 6A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0122] In this embodiment, a TMR film is manufactured with the thickness X of the crystal orientation reset layer: CoFeB film set to 0.0, 0.3, 0.5, 0.6 and 0.7 nm, and the thickness Y of the first magnetic layer: 60FeCo film set to a thickness (Y = 1.8~2.5 nm) such that the magnetization (saturation magnetization Ms·layer thickness t) of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer.

[0123] exist Figure 6BThe figure shows the MH curve of the TMR film in this embodiment. The thickness X (nm) of the CoFeB film in the MH curve is compared with the slope (mem / cm) of the applied magnetic field ±1kOe. 2 The relationship between / kOe) is shown in the following table.

[0124] [Table 1]

[0125]

[0126] according to Figure 6B As shown in Table 1, when the CoFeB film thickness is 0.0 nm, the first and second magnetic layers exhibit ferromagnetic coupling. Furthermore, by setting the CoFeB layer thickness to 0.5 nm or more, a tendency for stabilization of the antiferromagnetic coupling between the first and second magnetic layers was identified.

[0127] (Example 2: Effect of film thickness on crystal orientation promoting layer)

[0128] A TMR film is fabricated on the lower electrode layer [Ta(10)] by stacking the following layers in the order of substrate layer: NiFeCr(4.2) / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.5) / crystal orientation reset layer: CoFeB(0.7) / crystal orientation promotion layer: NiFe(X) / second CoFe layer: 70CoFe(0.8)] / non-magnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8) / protective layer: [Ru(5)Ta(15) / Ru(5)].

[0129] Figure 7A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0130] In this embodiment, a TMR film is manufactured in which the thickness X of the crystal orientation promoting layer (NiFe) is set to 0.0, 0.3, 0.5, 0.8 and 1.0 nm, and the thickness Y of the first magnetic layer (60FeCo) is set to such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer (Y = 1.8 to 2.3 nm).

[0131] exist Figure 7B The figure shows the MH curve of the TMR film in this embodiment. The thickness X (nm) of the CoFeB film in the MH curve is compared with the slope (mem / cm) of the applied magnetic field ±1kOe. 2 The relationship between / kOe) is shown in the following table.

[0132] [Table 2]

[0133]

[0134] according to Figure 7B As shown in Table 2, when the NiFe film thickness is 0.0 nm, the first and second magnetic layers exhibit ferromagnetic coupling. Furthermore, by setting the NiFe film thickness to 0.5 nm or greater, a tendency for stabilization of the antiferromagnetic coupling between the first and second magnetic layers was identified.

[0135] (Example 3: The effect of the thickness of the second CoFe layer)

[0136] A TMR film is fabricated on the lower electrode layer [Ta(10)] by stacking the following layers in the order of substrate layer: NiFeCr(4.2) / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.5) / crystal orientation reset layer: CoFeB(0.7) / crystal orientation promotion layer: NiFe(1.5) / second CoFe layer: 70CoFe(X)] / non-magnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8) / protective layer: [Ru(5) / Ta(15) / Ru(5)].

[0137] Figure 8A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0138] In this embodiment, a TMR film is manufactured in which the thickness X of the second CoFe layer (70CoFe) is set to 0.0, 0.15, 0.30 and 0.5 nm, and the thickness Y of the first magnetic layer (60FeCo) is set to such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer (Y = 1.8 to 2.2 nm).

[0139] exist Figure 8B The figure shows the MH curve of the TMR film in this embodiment. The thickness X (nm) of the CoFeB film in the MH curve is compared with the slope (mem / cm) of the applied magnetic field ±1kOe. 2 The relationship between / kOe) is shown in the following table.

[0140] [Table 3]

[0141]

[0142] according to Figure 8B As shown in Table 3, when the thickness of the second CoFe layer is 0.0 nm, the first and second magnetic layers exhibit antiferromagnetic coupling, but the saturation magnetic field is relatively small. By setting the thickness of the second CoFe layer to 0.30 nm or more, a tendency to stabilize the antiferromagnetic coupling between the first and second magnetic layers was identified.

[0143] (Example 4: Effect of the thickness of the first CoFe layer)

[0144] A TMR film is fabricated on the lower electrode layer [Ta(3) / Cu(20) / Ta(3) / Cu(20) / Ta(35)] in the following order: substrate layer: NiFeCr(4.2) / free magnetic layer: [86NiFe(9.0) / CoFeB(1.0) / 50CoFe(0.6)] / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(X) / crystallization orientation reset layer: CoFeB(0.7) / crystallization orientation promoting layer: 81.5NiFe(1.5) / second CoFe layer: 70CoFe(0.5)] / nonmagnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8.0) / protective layer: [Ru(5.0) / Ta(15.0) / Ru(5.0)].

[0145] Figure 9A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0146] In this embodiment, a TMR film is manufactured in which the thickness X of the first CoFe layer (50CoFe) is set to 0.0, 0.15, 0.3, 0.5, 1.0, 1.5 and 2.0 nm, and the thickness Y of the first magnetic layer (60FeCo) is set to such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer (Y = 1.7 to 3.7 nm).

[0147] Figure 9B The figure illustrates the relationship between the thickness X (nm) of the 50CoFeB film in the TMR film of this embodiment and the change in resistance (ΔR / Rmin (%)). As shown in the figure, 50CoFeB saturates at a film thickness of 0.3 nm with ΔR / Rmin. Based on this result, it can be said that the film thickness of the first CoFe layer in the second magnetic layer is preferably 0.3 nm or more.

[0148] (Example 5: Effect of film thickness on crystal orientation reset layer)

[0149] A TMR film is fabricated on the lower electrode layer [Ta(3) / Cu(20) / Ta(3) / Cu(20) / Ta(35)] in the following order: substrate layer: NiFeCr(4.2) / free magnetic layer: [86NiFe(9.0) / CoFeB(1.0) / 50CoFe(0.6)] / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.3) / crystallization orientation reset layer: CoFeB(X) / crystallization orientation promoting layer: 81.5NiFe(1.5) / second CoFe layer: 70CoFe(0.5)] / nonmagnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8.0) / protective layer: [Ru(5.0) / Ta(15.0) / Ru(5.0)].

[0150] Figure 10A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0151] In this embodiment, a TMR film is manufactured in which the thickness X of the crystal orientation reset layer: CoFeB is set to 0.0, 0.3, 0.5, 1.0, 1.5 and 2.0 nm, and the thickness Y of the first magnetic layer: 60FeCo is set to a thickness (Y = 1.6 to 3.2 nm) such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer.

[0152] exist Figure 10B The figure shows the relationship between the thickness X (nm) of the CoFeB film in the TMR film of this embodiment and the change in resistance (ΔR / Rmin (%)). As shown in the figure, the 50CoFeB layer tends to saturate at a film thickness of 0.5 nm and ΔR / Rmin increases gradually as the film thickness increases beyond that. Based on this result, it can be said that the film thickness of the crystal orientation reset layer in the second magnetic layer is preferably 0.5 nm or more.

[0153] (Example 6: Effect of film thickness on crystal orientation promoting layer)

[0154] A TMR film is fabricated on the lower electrode layer [Ta(3) / Cu(20) / Ta(3) / Cu(20) / Ta(35)] in the following order: substrate layer: NiFeCr(4.2) / free magnetic layer: [86NiFe(9.0) / CoFeB(1.0) / 50CoFe(0.6)] / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.3) / crystallization orientation reset layer: CoFeB(0.7) / crystallization orientation promoting layer: 81.5NiFe(X) / second CoFe layer: 70CoFe(0.5)] / nonmagnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8.0) / protective layer: [Ru(5.0) / Ta(15.0) / Ru(5.0)].

[0155] Figure 11A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0156] In this embodiment, a TMR film is manufactured in which the thickness X of the crystal orientation promoting layer (81.5NiFe) is set to 0.0, 0.3, 0.5, 1.0, 1.5, 2.0, 3.0 and 4.0 nm, and the thickness Y of the first magnetic layer (60FeCo) is set to such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer (Y = 1.6 to 3.1 nm).

[0157] exist Figure 11B The figure shows the relationship between the thickness X (nm) of the 81.5NiFe film in this embodiment and ΔR / Rmin (%). As shown in the figure, the thickness of the 81.5NiFe film tends to saturate at 0.5nm with ΔR / Rmin, and then decreases gradually. Based on this result, it can be said that the thickness of the crystal orientation promoting layer in the second magnetic layer is preferably 0.5nm or more.

[0158] (Example 7: Effect of the film thickness of the second CoFe layer)

[0159] A TMR film is fabricated on the lower electrode layer [Ta(3) / Cu(20) / Ta(3) / Cu(20) / Ta(35)] in the following order: substrate layer: NiFeCr(4.2) / free magnetic layer: [86NiFe(9.0) / CoFeB(1.0) / 50CoFe(0.6)] / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.3) / crystallization orientation reset layer: CoFeB(0.7) / crystallization orientation promoting layer: 81.5NiFe(1.5) / second CoFe layer: 70CoFe(X)] / nonmagnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8.0) / protective layer: [Ru(5.0) / Ta(15.0) / Ru(5.0)].

[0160] Figure 12A This is a schematic diagram of the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0161] In this embodiment, a TMR film is manufactured with the thickness X of the second CoFe layer (70CoFe) film set to 0.0, 0.15, 0.3, 0.5, 1.0, 1.5, and 2.0 nm, and the thickness Y of the first magnetic layer (60FeCo) film set to a thickness (1.6 to 3.4 nm) such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer.

[0162] exist Figure 12B The relationship between the thickness X (nm) and ΔR / Rmin (%) of the second CoFe layer in the TMR film of this embodiment is shown in the following table. As shown in the figure, the second CoFe layer saturates at a film thickness of 0.3 nm with ΔR / Rmin. Based on this result, it can be said that the film thickness of the second CoFe layer in the second magnetic layer is preferably 0.3 nm or more.

[0163] (Example 8: Composition dependence of the second CoFe layer at the Ru interface)

[0164] Figure 13This is a graph showing the relationship between the applied magnetic field and ΔR / R (MR ratio). The parameters used in evaluating the composition dependence of the second CoFe layer at the Ru interface are explained using the same graph. As shown in the figure, the maximum value of ΔR / R in the graph of the magnetoresistive film, which varies according to the orientation of the applied magnetic field, is defined as ΔMR. The value of ΔR / R when a magnetic field of +5 kOe is applied is defined as ΔMR(+5 k), and the value of ΔR / R when a magnetic field of -5 kOe is applied is defined as ΔMR(-5 k). The ideal magnetoresistive film is [ΔMR(+5 k) - ΔMR(-5 k)] / ΔMR = 1.0.

[0165] In this embodiment, a GMR film is fabricated by stacking the following layers in the order of substrate layer: NiFeCr (4.2) / free magnetic layer: [NiFe (7.0) / 90CoFe (0.5)] / non-magnetic material layer: Cu (2.0) / second magnetic layer: [first CoFe layer: 90CoFe (1.9) / second CoFe layer: xCoFe (0.5)] / non-magnetic intermediate layer: Ru (0.4) / first magnetic layer: 60FeCo (Y) / antiferromagnetic layer: IrMn (8) / protective layer: Ta (12).

[0166] Figure 14A This is a schematic diagram of the structure of the GMR film in this embodiment. In the same figure, ● represents a layer whose composition ratio is varied in order to investigate the effect of composition, and 〇 represents a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the composition of the layer.

[0167] In this embodiment, a GMR film is manufactured in which the composition ratio x of Co in the second magnetic layer [first CoFe layer: 90CoFe (1.9) / second CoFe layer: xCoFe (0.5)] is set to 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 at.%, and the thickness Y of the first magnetic layer: 60FeCo is set to a thickness (1.9 to 2.05 nm) such that the magnetization of the first magnetic layer and the second magnetic layer is equal to that of the second magnetic layer.

[0168] Figure 14B This is a graph showing the composition dependence of the second CoFe layer. According to the results shown in the graph, the preferred Co composition ratio at the FeCo interface with Ru in the second magnetic layer is 60–100 at.%.

[0169] (Example 9)

[0170] Figure 15AThis is a graph illustrating the parameters used in evaluating the film thickness dependence of the first magnetic layer constituting the film in Examples 9 and 10. The same graph shows the relationship between the applied magnetic field and the magnetization of the film (saturation magnetization Ms·layer thickness t). The meanings of the parameters shown in the same graph are described below.

[0171] 2Ms: The saturation magnetization Ms on the positive side and the saturation magnetization Ms on the negative side - The difference (Ms―Ms) - ).

[0172] △M0: Magnetization M0 in zero magnetic field when changing from saturation state on the negative side to saturation state on the positive side, and magnetization M0 in zero magnetic field when changing from saturation state on the positive side to saturation state on the positive side. - The difference (M0-M0) - ).

[0173] Hex = 0.5 multiplied by the sum of H0 and H0 - (H0 + H0) - The value obtained by taking the absolute value of ).

[0174] 2Hc: The magnetic field H0 that becomes magnetized to 0 when changing from a saturation state on the negative side to a saturation state on the positive side, and the magnetic field H0 that becomes magnetized to 0 when changing from a saturation state on the positive side to a saturation state on the negative side. - The difference (H0-H0) - The absolute value of ).

[0175] Figure 15B This is a schematic diagram illustrating the structure of the membrane in this embodiment. In the same figure, ● indicates a layer whose thickness is varied in order to investigate the effect of membrane thickness.

[0176] Figure 15C This is a graph showing the relationship between the applied magnetic field and the magnetization of the film when the thickness of the first magnetic layer, 60FeCo, is set to 1.5 nm, 2.4 nm, and 4.5 nm. As shown in the figure, the magnetization (Ms·t) of the film varies depending on the thickness of the first magnetic layer, 60FeCo.

[0177] In this embodiment, films with a first magnetic layer (60FeCo) thickness of 1.4, 1.5, 1.6, 1.8, 2.0, 2.4, 2.8, 3.2, 3.6, 4.0, 4.5, 5.0, 6.0, and 7.0 nm were fabricated. Furthermore, for films with different 60FeCo thicknesses, the relationship between the applied magnetic field and the magnetization of the first magnetic layer was measured, and the parameters M0, ΔM0, Ms, Hex, and Hc for each film were determined.

[0178] Figure 15DThis is a graph showing the thickness dependence of the first magnetic layer, 60FeCo, for M0 / Ms. Ideally, M0 / Ms is 1.0. A smaller M0 / Ms means a less rectangular graph showing the relationship between the applied magnetic field and the magnetization of the first magnetic layer, indicating a greater magnetization dispersion (see reference). Figure 15C Therefore, when M0 / Ms is small, it is difficult to increase ΔMR.

[0179] like Figure 15D As shown, by setting the film thickness of 60FeCo to 1.6 mm or more, M0 / Ms becomes 0.8 or more, resulting in a film with a larger ΔMR.

[0180] Figure 15E This is a graph showing the film thickness dependence of the first magnetic layer of Hex.

[0181] Figure 15F This is a graph showing the film thickness dependence of the first magnetic layer of Hc.

[0182] As shown in these figures, it can be seen that the Hex and Hc of the membrane vary depending on the thickness of the 60FeCo membrane.

[0183] Figure 15G This is a graph showing the film thickness dependence of the first magnetic layer, including the Hex / Hc ratio and the ΔM0 ratio relative to 2Ms. The values ​​are shown in Table 4. Furthermore, in both the graph and Table 4, the percentage (%) represents the ΔM0 ratio relative to 2Ms; therefore, the ΔM0 / 2Ms (%) shown in these graphs and tables is a value of 100 × (ΔM0 / 2Ms). Hereinafter, the ratio of ΔM0 to 2Ms will be referred to as ΔM0 / 2Ms.

[0184] [Table 4]

[0185]

[0186] When the Hex / Hc ratio of the film is small, hysteresis is easily generated in zero magnetic field, and the tolerance to strong magnetic fields deteriorates. Therefore, from the viewpoint of strong magnetic field tolerance, a larger Hex / Hc ratio is preferred. The Hex / Hc ratio increases for 60FeCo films with a thickness of 1.5 nm or less, but this is because the rectangularity of the graph representing the relationship between the applied magnetic field and the magnetization of the first magnetic layer deteriorates, resulting in a smaller Hc ratio, which is not practical. The Hex / Hc ratio of the film shows a tendency to increase above 1.8 nm for 60FeCo films, saturate around 3.2 nm, and decrease above 4.5 nm.

[0187] When the ΔM0 / 2Ms of the film is large, hysteresis is easily generated in a zero magnetic field, and the tolerance to strong magnetic fields deteriorates. Therefore, it is preferable that ΔM0 / 2Ms is close to zero. ΔM0 / 2Ms was found to be a relatively low value of less than 1% in the range of 1.6 to 4.5 nm for 60FeCo films, and tends to increase when the thickness exceeds 4.5 nm.

[0188] In addition, for Figure 15B The membrane of this embodiment is subjected to a magnetic field of 1T, and the resistance change rate ΔMR after the strong magnetic field is applied is measured. The ΔMR change rate is calculated by the following formula (1) using ΔMRa before the magnetic field of 1T is applied and ΔMRb after the magnetic field of 1T is applied.

[0189] △MR change rate (%) = [(△MRa-△MRb) / △MRa]×100 …(1)

[0190] Figure 15H This is a graph showing the film thickness dependence of the first magnetic layer 60FeCo with respect to the changes in ΔM0 / 2Ms and ΔMR. As shown in the figure and Table 4, ΔM0 / 2Ms and ΔMR change rates vary approximately the same with respect to the film thickness of the first magnetic layer 60FeCo. Therefore, it can be concluded that the ΔMR change rate can be used instead of ΔM0 / 2Ms for evaluating the magnetization dispersion of the first magnetic layer 60FeCo. The ΔMR change rate was identified as a relatively low value, consistently below 2% in the range of 1.6–4.5 nm for 60FeCo film thickness, with a tendency to increase beyond 4.5 nm.

[0191] (Example 10: Magnetic Detection Device)

[0192] A TMR film is fabricated on the lower electrode layer [Ta(3) / Cu(20) / Ta(3) / Cu(20) / Ta(35)] in the following order: substrate layer: NiFeCr(4.2) / free magnetic layer: [86NiFe(9.0) / CoFeB(1.0) / 50CoFe(0.6)] / insulating barrier layer: MgO(2.0) / second magnetic layer: [first CoFe layer: 50CoFe(0.3) / crystallization orientation reset layer: CoFeB(0.7) / crystallization orientation promoting layer: 81.5NiFe(1.5) / second CoFe layer: 70CoFe(X)] / nonmagnetic intermediate layer: Ru(0.4) / first magnetic layer: 60FeCo(Y) / antiferromagnetic layer: IrMn(8.0) / protective layer: [Ru(5.0) / Ta(15.0) / Ru(5.0)].

[0193] Figure 16AThis is a schematic diagram illustrating the structure of the TMR film in this embodiment. In the same figure, ● indicates a layer whose film thickness is varied in order to investigate the effect of film thickness, and 〇 indicates a layer whose film thickness is varied in order to be equal to the magnetization of the second magnetic layer that varies with the film thickness of the layer that is varied.

[0194] In this embodiment, a TMR film with thickness X of the second CoFe layer (70CoFe film) and thickness Y of the first magnetic layer (60FeCo film) is fabricated as a combination of these two thicknesses. The resulting films have thicknesses (X, Y) of (0.5, 2.0), (1.6, 3.0), and (2.7, 4.0). A magnetic detection device is then fabricated using this TMR film (see reference). Figure 4 ).

[0195] Figure 16B This is a graph showing the relationship between the normalized bridge output of the magnetic detection device and variations in the thickness X of the first magnetic layer and the thickness Y of the second CoFe layer. As shown in the graph, the larger the magnetization (Ms·t) of the first and second magnetic layers, the smaller the plateau regions of the RH and VH waveforms, and the lower the tolerance to strong magnetic fields. Based on this result, it can be said that it is preferable to have smaller film thicknesses for the first and second magnetic layers.

[0196] according to Figure 15H as well as Figure 16B From the viewpoint of designing a tunneling magnetoresistive element with excellent resistance to strong magnetic fields and a magnetic detection device, the thickness of the first magnetic layer, the 60FeCo film, is preferably 1.6–4.5 nm, based on the embodiments shown. This improves the performance of the device. Figure 15H From the viewpoint of the strong magnetic field tolerance of the magnetoresistive effect element shown, a wavelength of 3.0–4.5 nm is arguably more preferable. Furthermore, from the perspective of improving… Figure 16B From the perspective of strong magnetic field tolerance in the normalized bridge output shown, it can be said that the thickness of the first magnetic layer, 60FeCo film, is more preferably 1.6 to 3.2 nm.

[0197] Based on the results of the above embodiments, from the viewpoint of providing a tunneling magnetoresistive film with excellent resistance to strong magnetic fields and a magnetic detection device, the thickness of the first magnetic layer, 60FeCo, is preferably 1.6 to 4.5 nm. When the thickness of the first magnetic layer is set to 1.6 to 4.5 nm, and the second magnetic layer is composed of [first CoFe layer / CoFeB / NiFe / second CoFe layer], and the thickness of the three layers constituting the second magnetic layer is set as the functional lower limit, the upper limit of the acceptable thickness of the remaining layer is determined based on the condition that the magnetization (saturation magnetization Ms·layer thickness t) of the first and second magnetic layers is equal.

[0198] The upper limit film thickness and the range of optimal film thickness for each layer constituting the second magnetic layer are shown in the table below, with the first magnetic layer (60FeCo) set to an upper limit of 4.5 nm.

[0199] [Table 5]

[0200]

[0201] The upper limit film thickness of each layer constituting the second magnetic layer is shown in the table below, with the first magnetic layer (60FeCo) set to a lower limit of 1.6 nm.

[0202] [Table 6]

[0203]

[0204] With the first magnetic layer, 60FeCo, set to the optimal value of 3.0 nm, the upper limit film thickness of each layer constituting the second magnetic layer is shown in the following table.

[0205] [Table 7]

[0206]

[0207] (Composition dependence of the first magnetic layer CoFe of Hc in Example 11)

[0208] Figure 17A This is a schematic diagram showing a structure in which a fixed magnetic layer is formed into a film on a substrate. In the same figure, ● indicates a layer in which the Fe composition ratio is varied in order to investigate the effect of the coercivity Hc on the Fe composition ratio of FeCo in the first magnetic layer that fixes the magnetic layer. Therefore, the optimal composition range of Fe in the FeCo alloy of the first magnetic layer of the TMR film can be defined.

[0209] The film was fabricated by stacking the following layers in the order of substrate: NiFeCr (4.2) / non-magnetic material layer: Cu (4.0) / non-magnetic intermediate layer: Ru (0.4) / first magnetic layer: xFeCo (2.0) / antiferromagnetic layer: IrMn (8.0) / protective layer: Ta (12.0).

[0210] In this embodiment, films were fabricated by setting the x (at.%) of Fe in the first magnetic layer, xFeCo, to 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100. For each film, the relationship between the applied magnetic field and the coercivity (Ms·t) was measured, and Hc (refer to...) was determined. Figure 15A ).

[0211] Figure 17A This is a schematic diagram illustrating the structure of the membrane in this embodiment. In the same figure, ● indicates a layer whose composition ratio is varied in order to investigate the effect of membrane thickness.

[0212] Figure 17B This is a graph showing the relationship between the composition of the first magnetic layer and Hc. As shown in the graph, when the Fe composition ratio in FeCo is in the range of 40 to 80 at.%, Hc becomes 350 Oe or more, and the graph showing the relationship between the applied magnetic field and the magnetization of the first magnetic layer exhibits excellent rectangularity. Therefore, the Fe composition ratio in FeCo constituting the first magnetic layer is preferably 40 to 80 at.%.

[0213] Industrial availability

[0214] The tunnel-type magnetoresistive effect element of the present invention can be used in magnetic detection devices and the like, which have multiple magnetization directions of magnetoresistive effect elements having multiple fixed magnetic layers on the same substrate.

[0215] -Explanation of Figure Markers-

[0216] 10: TMR film (tunneling magnetoresistive element)

[0217] 11: Basal layer

[0218] 12: Free magnetic layer

[0219] 13: Insulating barrier layer

[0220] 14: Second magnetic layer

[0221] 141: First CoFe layer

[0222] 142: Crystal orientation reset layer

[0223] 143: Crystallization Orientation Promoting Layer

[0224] 144: Second CoFe layer

[0225] 15: Non-magnetic intermediate layer

[0226] 16: First magnetic layer

[0227] 17: Antiferromagnetic layer

[0228] 18: Protective layer

[0229] 19: Fixed magnetic layer

[0230] 40: Full-bridge circuit

[0231] 41: Power supply voltage Vdd

[0232] 42a, 42b: Series circuit

[0233] 43a, 43b: Midpoint terminals

[0234] 44: Grounding potential GND

[0235] 50: Magnetic detection device.

Claims

1. A tunnel-type magnetoresistive effect element, which is a top-pinned tunnel-type magnetoresistive effect element consisting of a free magnetic layer, an insulating barrier layer, and a fixed magnetic layer stacked sequentially. The tunneling magnetoresistive effect element is characterized in that... The fixed magnetic layer has a self-pinning structure in which a second magnetic layer, a non-magnetic intermediate layer, and a first magnetic layer are sequentially stacked from the insulating barrier layer side, and the fixed magnetization directions of the second magnetic layer and the first magnetic layer are antiparallel. The second magnetic layer consists of a first CoFe layer, a CoFeB layer, a NiFe layer, and a second CoFe layer, stacked sequentially from the insulating barrier layer side. The first magnetic layer is an FeCo layer, wherein the Fe composition of the FeCo layer is 40-80 at.%, and the film thickness is 1.6-4.5 nm.

2. The tunneling magnetoresistive effect element according to claim 1, wherein, The thickness of the first CoFe layer is 0.3–3.6 nm. The CoFeB layer has a thickness of 0.5–4.1 nm. The NiFe layer has a film thickness of 0.5–8.1 nm. The thickness of the second CoFe layer is 0.3–3.9 nm.

3. The tunneling magnetoresistive effect element according to claim 2, wherein, The Co composition of the first CoFe layer is 20–80 at.%. The composition ratio of the CoFeB layer is in (Co 100-X Fe X ) 100-Y B Y In this context, X ranges from 25 to 100 at.%, and Y ranges from 10 to 30 at.%. The Ni composition of the NiFe layer is 40–100 at.%. The Co composition of the second CoFe layer is 60–100 at.%.

4. The tunneling magnetoresistive effect element according to claim 1, wherein, In the first magnetic layer, the ratio of ΔM0 to 2Ms is less than 1%, where 2Ms is the saturation magnetization Ms on the positive side and the saturation magnetization Ms on the negative side. - The difference (Ms-Ms) - The ΔM0 is the magnetization M0 in the zero magnetic field when the saturation state changes from the negative side to the positive side, and the magnetization M0 in the zero magnetic field when the saturation state changes from the positive side to the positive side. - The difference (M0-M0) - ).

5. The tunneling magnetoresistive effect element according to claim 1, wherein, When the rate of change of resistance before applying a magnetic field of 1T is defined as ΔMRa and the rate of change of resistance after applying a magnetic field of 1T is defined as ΔMRb, the rate of change of ΔMR, expressed by the following formula (1), is less than 2%. △MR change rate (%) = [(△MRa-△MRb) / △MRa]×100 … (1).

6. A magnetic detection device, wherein multiple tunneling magnetoresistive elements as described in claim 1 are formed on the same substrate, characterized in that, Among the plurality of tunnel-type magnetoresistive effect elements, there are tunnel-type magnetoresistive effect elements with different fixed magnetization directions of the fixed magnetic layer.

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