Magnetoresistive effect element manufacturing method and magnetoresistive effect element

Abstract

According to the present invention, a method for manufacturing a magnetized rotary element has a measurement step, a comparison step, and a determination step. In the measurement step, a laminate comprising a first detection layer and a second detection layer is etched, and a first measurement time period from when a first signal originating from a first material included in the first detection layer is detected until a second signal originating from a second material included in the second detection layer is detected, is measured. In the comparison step, a first reference time period from when the first signal is detected until the second signal is detected when etching a reference laminate having the same film formation as the laminate, and the first measurement time period are compared, and the deviation between the first reference time period and the first measurement time period is derived. In the determination step, a condition from when the second signal is detected until the etching is finished is determined from the deviation.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a magnetoresistive effect element and a magnetoresistive effect element.

Background Art

[0002] A giant magnetoresistive (GMR) element composed of a multilayer film of a ferromagnetic layer and a nonmagnetic layer, and a tunnel magnetoresistive (TMR) element using an insulating layer (tunnel barrier layer, barrier layer) in the nonmagnetic layer are known as magnetoresistive effect elements. Magnetoresistive effect elements can be applied to magnetic sensors, high-frequency components, magnetic heads, and nonvolatile random access memories (MRAMs).

[0003] MRAM is a memory element in which magnetoresistive effect elements are integrated. MRAM reads and writes data by utilizing the property that when the relative magnetization directions of two ferromagnetic layers sandwiching a nonmagnetic layer (barrier layer) in a magnetoresistive effect element change, the resistance of the magnetoresistive effect element changes. The magnetization direction of the ferromagnetic layer is controlled, for example, by using a magnetic field generated by an electric current. Also, for example, the magnetization direction of the ferromagnetic layer is controlled by utilizing spin-transfer torque (STT) generated by flowing an electric current in the stacking direction of the magnetoresistive effect element.

[0004] When rewriting the magnetization direction of the ferromagnetic layer by utilizing STT, an electric current is flowed in the stacking direction of the magnetoresistive effect element. The write current causes deterioration of the characteristics of the magnetoresistive effect element.

[0005] In recent years, attention has been focused on a method that does not require flowing an electric current in the stacking direction of the magnetoresistive effect element during writing. One such method is a writing method using spin-orbit torque (SOT) (for example, Patent Document 1). SOT is induced by a spin current generated by spin-orbit interaction or the Rashba effect at the interface of different materials. The current for inducing SOT in the magnetoresistive effect element flows in a direction intersecting the stacking direction of the magnetoresistive effect element. That is, it is not necessary to flow an electric current in the stacking direction of the magnetoresistive effect element, and a longer lifespan of the magnetoresistive effect element is expected. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-216286 Summary of the Invention [Problem to be solved by the invention]

[0007] A magnetoresistive element using SOT has a wiring layer that generates spin current and a stacked body that generates magnetoresistance changes. The stacked body is processed into a predetermined shape and is in contact with the wiring layer. The stacked body is processed into the predetermined shape by etching using an ion beam or the like. Etching conditions may vary due to various factors, such as reasons attributable to the output side, such as contamination adhering to the ion beam source, and reasons attributable to the irradiated object, such as the film quality of the films that make up the stacked body. If etching proceeds more than necessary, the performance of the magnetoresistive element may be affected.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a method for manufacturing a magnetoresistive effect element that can suppress the progress of excessive etching, and a magnetoresistive effect element manufactured by the manufacturing method. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides the following means.

[0010] (1) The manufacturing method of the magnetoresistive effect element according to the first aspect includes a measurement step, a comparison step, and a determination step. In the measurement step, a laminate including a first detection layer and a second detection layer is etched, and a first measurement time from when a first signal derived from a first material included in the first detection layer is detected until a second signal derived from a second material included in the second detection layer is detected is measured. In the comparison step, a first reference time from when the first signal is detected until the second signal is detected when a reference laminate having the same film configuration as the laminate is etched is compared with the first measurement time, and a deviation between the first reference time and the first measurement time is obtained. In the determination step, conditions from when the second signal is detected until the etching is completed are determined using the deviation.

[0011] (2) In the manufacturing method of the magnetoresistive effect element according to the above aspect, the first material and the second material may be different.

[0012] (3) In the manufacturing method of the magnetoresistive effect element according to the above aspect, the first material and the second material may be the same.

[0013] (4) In the manufacturing method of the magnetoresistive effect element according to the above aspect, the laminate may have, in the lamination direction, a wiring layer, a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, and a nonmagnetic layer in this order. Also, the nonmagnetic layer may be the first detection layer, and the barrier layer may be the second detection layer.

[0014] (5) In the manufacturing method of the magnetoresistive effect element according to the above aspect, the laminate may have, in the lamination direction, a wiring layer, a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, and a nonmagnetic layer in this order. Also, the nonmagnetic layer may have, from the second ferromagnetic layer side, a first layer, a second layer, and a third layer in this order. Also, the third layer of the nonmagnetic layer may be the first detection layer, and the first layer of the nonmagnetic layer may be the second detection layer.

[0015] (6) In the manufacturing method of the magnetoresistive effect element according to the above aspect, the distance between the first detection layer and the second detection layer may be 4 nm or more.

[0016] (7) In the method for manufacturing a magnetoresistive element according to the above aspect, the thickness of the first detection layer and the thickness of the second detection layer may be different.

[0017] (8) In the method for manufacturing a magnetoresistive element according to the above aspect, the thickness of the first detection layer and the thickness of the second detection layer may be the same.

[0018] (9) In the method for manufacturing a magnetoresistive element according to the above aspect, the thicknesses of both the first detection layer and the second detection layer may be 1 nm or more.

[0019] (10) In the method for manufacturing a magnetoresistive element according to the above aspect, the laminate and the reference laminate may further include a third detection layer. Further, the measurement step may further include a step of measuring a second measurement time from when the first signal is detected until a third signal derived from a third material included in the third detection layer is detected, or a step of measuring a third measurement time from when the second signal is detected until the third signal is detected. Further, the comparison step may further include a step of comparing the second reference time from when the first signal is detected until the third signal is detected when the reference laminate is etched with the second measurement time, or a step of comparing the third reference time from when the second signal is detected until the third signal is detected when the reference laminate is etched with the third measurement time.

[0020] (11) A magnetoresistive element according to a second aspect includes a wiring layer, a stack, and a sidewall layer. The stack is in contact with the wiring layer. The stack includes a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, and a nonmagnetic layer. The sidewall layer covers a sidewall of the stack. The first ferromagnetic layer is closer to the wiring layer than the second ferromagnetic layer. The barrier layer is sandwiched between the first ferromagnetic layer and the second ferromagnetic layer. The second ferromagnetic layer is sandwiched between the barrier layer and the nonmagnetic layer. The sidewall layer includes a first material contained in a first detection layer of the stack and a second material contained in a second detection layer of the stack. The first material and the second material may be any one selected from the group consisting of Ta, W, Mg, Ru, Si, Ir, Mn, Co, Fe, Ni, Al, O, and Ti.

[0021] (12) In the magnetoresistive element according to the above aspect, the sidewall layer may include a first sidewall layer and a second sidewall layer. The first sidewall layer is closer to the stack than the second sidewall layer. The first sidewall layer may be silicon oxynitride to which the first material and the second material are added, and the second sidewall layer may be silicon nitride.

[0022] (13) In the magnetoresistive effect element according to the above aspect, the second detection layer may be closer to the wiring layer than the first detection layer, and the concentration of the second material in the sidewall layer may be higher than the concentration of the first material.

[0023] (14) In the magnetoresistive effect element according to the above aspect, the wiring layer may have, when viewed from the stacking direction, an overlapping portion that overlaps with the laminate and a non-overlapping portion that does not overlap with the laminate, and the film thickness of the wiring layer in the non-overlapping portion may be 66% or more of the film thickness of the wiring layer in the overlapping portion.

[0024] (15) A magnetic array according to a third aspect includes a plurality of magnetoresistive effect elements, each of which is the magnetoresistive effect element according to the above aspect. [Effects of the Invention]

[0025] The method for manufacturing a magnetoresistive element according to the present disclosure can suppress excessive etching, and the magnetoresistive element manufactured by the method for manufacturing a magnetoresistive element according to the present disclosure is less likely to generate heat. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a flowchart of a method for manufacturing the magnetoresistive effect element according to the first embodiment. [Figure 2] 1 is an example of a cross-sectional view of a magnetoresistive element manufactured by a method for manufacturing a magnetoresistive element according to a first embodiment. [Figure 3] 1 is an example of a plan view of a magnetoresistive effect element manufactured by a method for manufacturing a magnetoresistive effect element according to a first embodiment. [Figure 4] 2A to 2C are schematic views for explaining a method for manufacturing the magnetoresistive effect element according to the first embodiment. [Figure 5] 2A to 2C are schematic views for explaining a method for manufacturing the magnetoresistive effect element according to the first embodiment. [Figure 6] 2A to 2C are schematic views for explaining a method for manufacturing the magnetoresistive effect element according to the first embodiment. [Figure 7] FIG. 2 is a circuit diagram of the magnetic array according to the first embodiment. [Figure 8] 1 is a cross-sectional view of the vicinity of a magnetoresistive effect element of a magnetic array according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present embodiment will be described in detail below with reference to the drawings as appropriate. The drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate changes can be made within the scope of the effects of the present invention.

[0028] "Method for manufacturing a magnetoresistive effect element" FIG. 1 is a flowchart of a method for manufacturing a magnetoresistive effect element according to the first embodiment. The method for manufacturing a magnetoresistive effect element according to the first embodiment includes, for example, a preparation step S0, a measurement step S1, a comparison step S2, and a determination step S3. The preparation step S0 is a separate step performed in advance and does not need to be always performed.

[0029] First, the magnetoresistive effect element manufactured by this manufacturing method will be described. FIG. 2 is a cross-sectional view of the magnetoresistive effect element 100 manufactured by the manufacturing method according to the first embodiment. FIG. 3 is a plan view of the magnetoresistive effect element 100 manufactured by the manufacturing method according to the first embodiment.

[0030] Hereinafter, the stacking direction of each layer of the magnetoresistive effect element 100 is defined as the z direction, and the plane orthogonal to the z direction is defined as the xy plane. One direction in the xy plane is the x direction, and the direction orthogonal to the x direction in the xy plane is the y direction. The x direction coincides with, for example, the direction in which the wiring layer 20 extends.

[0031] The magnetoresistive effect element 100 includes, for example, a stacked body 10, a wiring layer 20, a sidewall layer 30, a first via wiring 40, a second via wiring 50, and an insulating layer 60.

[0032] The magnetoresistive effect element 100 is a magnetic element that utilizes spin-orbit torque (SOT), and may be referred to as a spin-orbit torque type magnetoresistive effect element, a spin injection type magnetoresistive effect element, or a spin current magnetoresistive effect element.

[0033] The magnetoresistive effect element 100 is an element that records and stores data. The magnetoresistive effect element 100 records data with the resistance value in the z direction of the stacked body 10. The resistance value in the z direction of the stacked body 10 changes by applying a writing current along the wiring layer 20 and injecting spin from the wiring layer 20 into the stacked body 10. The writing current flows along the wiring layer 20 by applying a potential difference between the first via wiring 40 and the second via wiring 50. The resistance value in the z direction of the stacked body 10 can be read by applying a reading current in the z direction of the stacked body 10.

[0034] The laminate 10 is in contact with the wiring layer 20. The laminate 10 is, for example, laminated on the wiring layer 20.

[0035] The laminate 10 is a columnar body. The planar shape of the laminate 10 as viewed from the z-direction is, for example, circular, elliptical, or rectangular. The side wall of the laminate 10 is, for example, inclined with respect to the z-direction.

[0036] The laminate 10 includes, for example, a first ferromagnetic layer 1, a second ferromagnetic layer 2, a barrier layer 3, a base layer 4, a cap layer 5, and a non-magnetic layer 6. The laminate 10 may have layers other than the first ferromagnetic layer 1, the second ferromagnetic layer 2, the barrier layer 3, the base layer 4, the cap layer 5, and the non-magnetic layer 6. The resistance value of the laminate 10 changes according to the difference in the relative angle of magnetization between the first ferromagnetic layer 1 and the second ferromagnetic layer 2 sandwiching the barrier layer 3.

[0037] The first ferromagnetic layer 1 is, for example, closer to the wiring layer 20 than the second ferromagnetic layer 2. The first ferromagnetic layer 1 may be in direct contact with the wiring layer 20 or may be indirectly in contact via the base layer 4. The first ferromagnetic layer 1 is, for example, laminated on the wiring layer 20.

[0038] Spins are injected into the first ferromagnetic layer 1 from the wiring layer 20. The magnetization of the first ferromagnetic layer 1 receives a spin-orbit torque (SOT) from the injected spins, and the orientation direction changes. The first ferromagnetic layer 1 is called a magnetization free layer.

[0039] The first ferromagnetic layer 1 contains a ferromagnetic material. The ferromagnetic material is, for example, a metal selected from the group consisting of Cr, Mn, Co, Fe, and Ni, an alloy containing one or more of these metals, an alloy containing at least one of these metals and at least one element of B, C, and N, etc. The ferromagnetic material is, for example, Co-Fe, Co-Fe-B, Ni-Fe, Co-Ho alloy, Sm-Fe alloy, Fe-Pt alloy, Co-Pt alloy, CoCrPt alloy.

[0040] The first ferromagnetic layer 1 may contain a Heusler alloy. The Heusler alloy contains an intermetallic compound having a chemical composition of XYZ or X2YZ. X is a transition metal element or noble metal element of the Co, Fe, Ni, or Cu group in the periodic table, Y is a transition metal of the Mn, V, Cr, or Ti group or an element species of X, and Z is a typical element from Group III to Group V. The Heusler alloy is, for example, Co2FeSi, Co2FeGe, Co2FeGa, Co2MnSi, Co2Mn 1-a Fe a Al b Si 1-b , Co2FeGe 1-c Ga c and so on. The Heusler alloy has a high spin polarization rate.

[0041] The second ferromagnetic layer 2 is located at a position farther from the wiring layer 20 than the first ferromagnetic layer 1. The second ferromagnetic layer 2 is sandwiched between the barrier layer 3 and the nonmagnetic layer 6. The second ferromagnetic layer 2 contains a ferromagnetic material. The magnetization of the second ferromagnetic layer 2 is less likely to change in the orientation direction than the magnetization of the first ferromagnetic layer 1 when a predetermined external force is applied. The second ferromagnetic layer 2 is called a magnetization-fixed layer or a magnetization-reference layer. In the laminate 10 shown in FIG. 2, the magnetization-fixed layer is on the side away from the substrate Sub and is called a top-pin structure. The magnetoresistive effect element according to the present embodiment may have a bottom-pin structure in which the laminate 10 is closer to the substrate Sub than the wiring layer 20 and the magnetization-fixed layer is closer to the substrate Sub than the magnetization-free layer.

[0042] As the material constituting the second ferromagnetic layer 2, the same material as that constituting the first ferromagnetic layer 1 is used.

[0043] The second ferromagnetic layer 2 may have a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure consists of two magnetic layers sandwiching a nonmagnetic layer. The second ferromagnetic layer 2 may have two magnetic layers and a spacer layer sandwiched therebetween. By antiferromagnetic coupling of the two ferromagnetic layers, the coercive force of the second ferromagnetic layer 2 increases. The ferromagnetic layer is, for example, IrMn, PtMn, etc. The spacer layer contains at least one selected from the group consisting of Ru, Ir, and Rh.

[0044] The barrier layer 3 is sandwiched between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. The barrier layer 3 includes a nonmagnetic material. When the barrier layer 3 is an insulator (when it is a tunnel barrier layer), its material can be, for example, Al2O3, SiO2, MgO, or MgAl2O4. In addition to these, materials in which a portion of Al, Si, or Mg is substituted with Zn, Be, or the like can also be used. Among these, MgO and MgAl2O4 are materials that enable coherent tunneling, allowing efficient spin injection. When the barrier layer 3 is a metal, its material can be Cu, Au, Ag, or the like. Furthermore, when the barrier layer 3 is a semiconductor, its material can be Si, Ge, CuInSe2, CuGaSe2, Cu(In,Ga)Se2, or the like.

[0045] The underlayer 4 is, for example, between the first ferromagnetic layer 1 and the wiring layer 20. The underlayer 4 may be omitted.

[0046] The underlayer 4 includes, for example, a buffer layer and a seed layer. The buffer layer is a layer that alleviates lattice mismatch between different crystals. The seed layer improves the crystallinity of the layer stacked on the seed layer. The seed layer is formed, for example, on the buffer layer.

[0047] The buffer layer is, for example, Ta (element), TaN (tantalum nitride), CuN (copper nitride), TiN (titanium nitride), or NiAl (nickel aluminum).The seed layer is, for example, Pt, Ru, Zr, a NiCr alloy, or NiFeCr.

[0048] The cap layer 5 is on the second ferromagnetic layer 2. The cap layer 5, for example, strengthens the magnetic anisotropy of the second ferromagnetic layer 2. The cap layer 5, for example, strengthens the perpendicular magnetic anisotropy of the second ferromagnetic layer 2. The cap layer 5 is made of, for example, magnesium oxide, W, Ta, Mo, or the like. The thickness of the cap layer 5 is, for example, 0.5 nm or more and 5.0 nm or less.

[0049] The non-magnetic layer 6 is on the cap layer 5. The non-magnetic layer 6 is part of a hard mask used when processing the laminate 10 during manufacturing. The non-magnetic layer 6 also functions as an electrode. The non-magnetic layer 6 includes, for example, Al, Cu, Ta, Ti, Zr, NiCr, nitrides (e.g., TiN, TaN, SiN), and oxides (e.g., SiO2).

[0050] The wiring layer 20, for example, has a length in the x direction that is longer than the length in the y direction when viewed from the z direction. The write current flows in the x direction along the wiring layer 20 between the first via wiring 40 and the second via wiring 50.

[0051] The wiring layer 20 generates a spin current due to the spin Hall effect when a current flows, and injects spins into the first ferromagnetic layer 1. The wiring layer 20, for example, applies a spin-orbit torque (SOT) to the magnetization of the first ferromagnetic layer 1 that is sufficient to reverse the magnetization of the first ferromagnetic layer 1.

[0052] The spin Hall effect is a phenomenon in which a spin current is induced in a direction perpendicular to the direction of current flow based on the spin-orbit interaction when a current is passed. The spin Hall effect has something in common with the ordinary Hall effect in that the moving charge (electron) has its motion (movement) direction bent. In the ordinary Hall effect, the motion direction of charged particles moving in a magnetic field is bent by the Lorentz force. In contrast, in the spin Hall effect, even in the absence of a magnetic field, the moving direction of spins is bent just by the movement of electrons (just by the flow of current).

[0053] For example, when a current flows through the wiring layer 20, a first spin polarized in one direction and a second spin polarized in the direction opposite to the first spin are bent by the spin Hall effect in directions perpendicular to the direction of current flow, respectively. For example, the first spin polarized in the -y direction is bent from the x direction, which is the traveling direction, to the +z direction, and the second spin polarized in the +y direction is bent from the x direction, which is the traveling direction, to the -z direction.

[0054] A non-magnetic material (a material that is not a ferromagnetic material) has an equal number of electrons with a first spin and an equal number of electrons with a second spin generated by the spin Hall effect. That is, the number of electrons with a first spin in the +z direction is equal to the number of electrons with a second spin in the -z direction. The first spin and the second spin flow in a direction that eliminates the spin polarization. In the movement of the first spin and the second spin in the z direction, the charge flows cancel each other out, so the current amount becomes zero. A spin current without an accompanying current is particularly called a pure spin current.

[0055] Let the flow of electrons with the first spin be J ↑ and the flow of electrons with the second spin be J ↓ and the spin current be J S Then, if expressed as J S = J ↑ - J ↓ it is defined as such. The spin current J S is generated in the z direction. The first spin is injected from the wiring layer 20 into the first ferromagnetic layer 1.

[0056] The wiring layer 20 has a function of generating a spin current by the spin Hall effect when a writing current flows, and includes any one of a metal, an alloy, an intermetallic compound, a metal boride, a metal carbide, a metal silicide, a metal phosphide, and a metal nitride. The wiring layer 20 includes, for example, any one selected from the group consisting of heavy metals with an atomic number of ³9, metal oxides, metal nitrides, metal oxynitrides, and topological insulators.

[0057] The wiring layer 20 includes, for example, a non-magnetic heavy metal as a main component. A heavy metal means a metal having a specific gravity of yttrium (Y) or more. A non-magnetic heavy metal is, for example, a non-magnetic metal with a large atomic number of ³39 having d electrons or f electrons in the outermost shell. The wiring layer 20 consists of, for example, Hf, Ta, and W. A non-magnetic heavy metal has a stronger spin-orbit interaction than other metals. The spin Hall effect is caused by the spin-orbit interaction, and spins are likely to be unevenly distributed in the wiring layer 20, making it easier for the spin current J S to be generated.

[0058] In addition, the wiring layer 20 may contain a magnetic metal. The magnetic metal is a ferromagnetic metal or an antiferromagnetic metal. Trace amounts of magnetic metal contained in a non-magnetic material serve as spin scattering factors. Trace amounts mean, for example, 3% or less of the total molar ratio of the elements constituting the wiring layer 20. When the spin is scattered by the magnetic metal, the spin-orbit interaction is enhanced, and the generation efficiency of the spin current with respect to the current increases.

[0059] The wiring layer 20 may contain a topological insulator. A topological insulator is a substance in which the interior of the substance is an insulator or a high-resistance material, but a spin-polarized metallic state occurs on its surface. A topological insulator generates an internal magnetic field due to the spin-orbit interaction. A topological insulator exhibits a new topological phase due to the effect of the spin-orbit interaction even without an external magnetic field. A topological insulator can generate a pure spin current with high efficiency due to a strong spin-orbit interaction and the breaking of inversion symmetry at the edge.

[0060] Examples of topological insulators include SnTe, Bi 1.5 Sb 0.5 Te 1.7 Se 1.3 , TlBiSe2, Bi2Te3, Bi 1-x Sb x , (Bi 1-x Sb x )2Te3, and the like. A topological insulator can generate a spin current with high efficiency.

[0061] The wiring layer 20 has an overlapping portion 21 that overlaps with the laminate 10 when viewed in the z direction, and a non-overlapping portion 22 that does not overlap with the laminate 10 when viewed in the z direction. The film thickness t22 of the wiring layer 20 in the non-overlapping portion 22 is, for example, thinner than the film thickness t21 of the wiring layer 20 in the overlapping portion 21. The film thickness t22 of the wiring layer 20 in the non-overlapping portion 22 is, for example, 66% or more of the film thickness t21 of the wiring layer 20 in the overlapping portion 21. The thickness of the overlapping portion 21 is, for example, 3 nm or more. The thickness of the overlapping portion 21 may be, for example, 20 nm or less. The film thicknesses of the overlapping portion 21 and the non-overlapping portion 22 are average values of the film thicknesses measured at five different points in the x direction.

[0062] As will be described later, when the manufacturing method of the magnetoresistive element according to the present embodiment is used, it is possible to suppress the thickness t22 of the non-overlapping portion 22 from becoming too thin. The material constituting the wiring layer 20 has a higher resistance compared to a good conductor such as Al. If the non-overlapping portion 22 is too thin, heat is generated in that portion, causing breakage of the wiring layer 20 or the like.

[0063] The side wall layer 30 covers the side walls of the laminate 10. The side wall layer 30 is an insulator. The side wall layer 30 ensures electrical insulation between the laminate 10 and other components.

[0064] The side wall layer 30 contains the materials included in the layers set as the first detection layer and the second detection layer in the laminate 10. That is, the side wall layer 30 contains the first material included in the first detection layer and the second material included in the second detection layer. The first detection layer and the second detection layer can be arbitrarily set from the respective layers constituting the laminate 10. Note that the first detection layer is a layer located farther from the wiring layer 20 than the second detection layer.

[0065] For example, when the first detection layer is set as the non-magnetic layer 6 and the second detection layer is set as the barrier layer 3, the side wall layer 30 contains the first material derived from the non-magnetic layer 6 and the second material derived from the barrier layer 3. For example, when the non-magnetic layer 6 is TiN and the barrier layer 3 is Mg-Al-O, the side wall layer 30 contains Ti and Al.

[0066] The first material and the second material are each selected from the group consisting of Ta, W, Mg, Ru, Si, Ir, Mn, Co, Fe, Ni, Al, O, and Ti. The first material and the second material are, for example, a combination of any one selected from the group consisting of Mg and Co, Ru, Mn, Ta, Ti, Ni, a combination of any one selected from the group consisting of Ni and Co, Fe, Ru, a combination of any one selected from the group consisting of Ta and Co, Fe, Ru, and a combination of any one selected from the group consisting of Ti and Co, Fe, Ru. The first material and the second material may be the same or different.

[0067] When the side wall layer 30 includes the first material and the second material, the thermal conductivity of the side wall layer 30 is improved. When heat accumulates inside the magnetoresistive element 100, it may cause a decrease in magnetization stability, fluctuations in element performance, etc. By exhausting the heat in the magnetoresistive element 100 through the side wall layer 30, fluctuations in the resistance change range of the magnetoresistive element 100 can be suppressed.

[0068] When the first material and the second material are different, the concentration of the second material in the side wall layer 30 is preferably higher than the concentration of the first material. For example, when the first material is a heavy element such as Ta or Ru, if the concentration of the second material is high, oxidation of the side wall layer tends to progress, and shorts due to re-deposition are less likely to occur.

[0069] Also, the concentrations of the first material and the second material in the side wall layer 30 may be higher at a position closer to the wiring layer 20 than at a position farther from the wiring layer 20 in the z direction. When this configuration is satisfied, the heat generated in the magnetoresistive element 100 can be dissipated through the side wall layer 30 toward the first via wiring 40 and the second via wiring 50 having high thermal conductivity. By dissipating heat in a direction away from the first ferromagnetic layer 1 and the second ferromagnetic layer 2 having magnetization, the magnetization stability of the magnetoresistive element 100 can be enhanced.

[0070] The side wall layer 30 may have, for example, a first side wall layer 31 and a second side wall layer 32. The first side wall layer 31 is closer to the laminate 10 than the second side wall layer 32. The first side wall layer 31 covers the laminate 10, and the second side wall layer 32 covers the first side wall layer 31.

[0071] In this case, the first side wall layer 31 includes the first material and the second material. The first side wall layer 31 is, for example, silicon oxynitride to which the first material and the second material are added, and the second side wall layer is silicon nitride.

[0072] The first via wiring 40 is connected to the first end of the wiring layer 20. The first via wiring 40 is a columnar body. The first via wiring 40 may be a stack of a plurality of columnar bodies. The columnar body is, for example, a cylinder, an elliptical cylinder, or a prism. The first via wiring 40 includes a material having conductivity.

[0073] The second via wiring 50 is in contact with the wiring layer 20 at a position sandwiching the first ferromagnetic layer 1 together with the first via wiring 40 when viewed from the z direction. The second via wiring 50 may be connected to the same surface as the surface to which the first via wiring 40 of the wiring layer 20 is connected, or may be connected to a different surface. The second via wiring 50 is made of the same material as the first via wiring 40.

[0074] The insulating layer 60 is an insulating layer that insulates between wirings and between elements in the multilayer wiring. The insulating layer 60 is, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO x ), magnesium oxide (MgO), aluminum nitride (AlN), or the like.

[0075] Next, based on the flowchart of FIG. 1, the manufacturing method of the magnetoresistive element 100 described above will be explained.

[0076] First, before actually manufacturing the magnetoresistive element 100, a reference magnetoresistive element is created, and a preparation process S0 is performed to determine the reference processing time. The preparation process S0 does not need to be performed every time the magnetoresistive element 100 is manufactured, and it may be performed first as a conditioning step.

[0077] The preparation process S0 includes a film formation process S01, an etching process S02, a first signal detection process S03, a second signal detection process S04, a first reference time calculation process S05, and a reference processing time determination process S06.

[0078] FIGS. 4 to 6 are schematic diagrams for explaining the manufacturing method of the magnetoresistive element according to the first embodiment.

[0079] In the film formation step S01, a reference stacked body 80 is fabricated. The reference stacked body 80 is fabricated, for example, on the first via wiring 40, the second via wiring 50, and the insulating layer 60. The first via wiring 40 and the second via wiring 50 are fabricated by forming openings in the insulating layer 60 and filling the openings with a conductor.

[0080] First, the wiring layer 81, the underlayer 82, the first ferromagnetic layer 83, the barrier layer 84, the second ferromagnetic layer 85, and the cap layer 86 are deposited in this order. Each layer is deposited by, for example, sputtering. The wiring layer 81, the underlayer 82, the first ferromagnetic layer 83, the barrier layer 84, the second ferromagnetic layer 85, and the cap layer 86 correspond to the wiring layer 20, the underlayer 4, the first ferromagnetic layer 1, the barrier layer 3, the second ferromagnetic layer 2, and the cap layer 5, respectively, and are made of the same materials.

[0081] Next, a nonmagnetic layer 87 is formed on a portion of the cap layer 86. The nonmagnetic layer 87 is formed at a position where the stack 10 is to be fabricated. The nonmagnetic layer 87 may have a three-layer structure of a first layer 87A, a second layer 87B, and a third layer 87C. The first layer 87A is closer to the second ferromagnetic layer 85 than the third layer 87C. The second layer 87B is sandwiched between the first layer 87A and the third layer 87C. The nonmagnetic layer 87 is formed by stacking the first layer 87A, the second layer 87B, and the third layer 87C in this order from the second ferromagnetic layer 85 side.

[0082] The nonmagnetic layer 87 corresponds to the nonmagnetic layer 6 and is made of the same material. When the nonmagnetic layer 87 has a three-layer structure, for example, the first layer 87A is made of Ta, the second layer 87B is made of Ru, and the third layer 87C is made of TiN.

[0083] Next, an etching step S02 is performed. The etching is performed by, for example, ion beam milling (IBE), reactive ion etching (RIE), or the like.

[0084] When performing the etching process S02, it is determined which layer of the reference laminate 80 is to be the first detection layer and the second detection layer. For example, the non-magnetic layer 87 may be the first detection layer and the barrier layer 84 may be the second detection layer. For example, as shown in FIG. 4, when the non-magnetic layer 87 has a three-layer structure, any layer of the non-magnetic layer 87 may be the first detection layer. For example, the third layer 87C may be the first detection layer and the first layer 87A may be the second detection layer. Also, as the third detection layer, any layer of the reference laminate 80 may be further set.

[0085] The first detection layer and the second detection layer may be selected from the reference laminate 80 such that the distance between the first detection layer and the second detection layer is 4 nm or more. Also, when selecting the third detection layer, the third detection layer may be selected from the reference laminate 80 such that the distances between the first detection layer and the third detection layer and between the second detection layer and the third detection layer are 4 nm or less. When the distances between the detection layers are far apart, the signals at the time of detection are less likely to be mixed. By selecting the detection layers in this way, the detection accuracy of the detection device is improved.

[0086] Also, a layer having a thickness of 1 nm or more may be selected as the first detection layer and the second detection layer. Also, when selecting the third detection layer, a layer having a thickness of 1 nm or more may be selected as the third detection layer. When the thickness of the detection layer is sufficiently thick, the time for detecting the signal becomes longer. By selecting the detection layers in this way, detection leakage of the detection device can be avoided.

[0087] Also, the first detection layer and the second detection layer may be selected from the reference laminate 80 such that the first detection layer and the second detection layer are layers containing the same material. In this case, the first material derived from the first detection layer and the second material derived from the second detection layer are the same. Since the detection sensitivity of the detection device varies for each material, when the first material and the second material are the same material, signals can be detected well without sensitivity adjustment. Also, when selecting the third detection layer, as the third detection layer, a layer containing the same material as the first detection layer and the second detection layer may be selected.

[0088] Also, the first detection layer and the second detection layer may be selected from the reference laminate 80 so as to be layers including different materials. In this case, the first material derived from the first detection layer is different from the second material derived from the second detection layer. By having different materials to be detected, it becomes easier to determine which layer is being processed from the signal. Also, when selecting the third detection layer, as the third detection layer, a layer including a material different from the first detection layer and the second detection layer may be selected.

[0089] Also, layers having the same thickness may be selected as the first detection layer and the second detection layer. For example, when the first material and the second material are the same material, if the thicknesses of the first detection layer and the second detection layer are the same, the intensity of the first signal detected during processing of the first detection layer and the intensity of the second signal detected during processing of the second detection layer are substantially the same. When the intensities of the detected signals are substantially the same, it is difficult to overlook the signals. Also, when selecting the third detection layer, as the third detection layer, a layer having the same thickness as the first detection layer and the second detection layer may be selected.

[0090] Also, layers having different thicknesses may be selected as the first detection layer and the second detection layer. For example, when the first material and the second material are different materials, the detection sensitivities of the detection device may be different. If the first detection layer and the second detection layer are selected such that the layer including the material with a low detection sensitivity has a greater thickness and the layer including the material with a high detection sensitivity has a smaller thickness, the signal intensities generated when processing each layer will be close. Also, when selecting the third detection layer, as the third detection layer, a layer having a thickness different from the first detection layer and the second detection layer may be selected.

[0091] Hereinafter, an example in which the first detection layer is the third layer 87C of the non-magnetic layer 87 and the second detection layer is the barrier layer 84 will be described.

[0092] Next, in the first signal detection step S03, a first signal derived from the first material included in the first detection layer is detected. The first signal can be detected by performing secondary ion mass spectrometry (SIMS) or optical emission spectrometry (OES) while performing etching. For example, when etching the reference laminate 80, first, a part of the third layer 87C and the cap layer 86 is etched. At this time, the atoms constituting the third layer 87C are scattered and detected by the detection device. The detection device detects, for example, a first signal derived from the first material included in the third layer 87C.

[0093] Next, in the second signal detection step S04, a second signal derived from the second material included in the second detection layer is detected. The second signal can be detected by performing secondary ion mass spectrometry (SIMS) or optical emission spectrometry (OES) while performing etching. For example, as shown in FIG. 5, when the etching reaches the barrier layer 84, the atoms constituting the barrier layer 84 are scattered and detected by the detection device. The detection device detects, for example, a second signal derived from the second material included in the barrier layer 84.

[0094] There is a time lag between when the first signal is detected and when the second signal is detected. In the first reference time calculation step S05, this time lag is calculated. The time when the first signal is detected is set as the start time when the first signal reaches a predetermined intensity or more. Similarly, the time when the second signal is detected is set as the start time when the second signal reaches a predetermined intensity or more. The time lag is calculated by obtaining the time difference between the detection start time of the first signal and the detection start time of the second signal. This time lag is taken as the first reference time.

[0095] When setting the third detection layer, a second reference time from when the first signal is detected to when the third signal is detected, and a third reference time from when the second signal is detected to when the third signal is detected may be obtained.

[0096] Next, a reference processing time determination step S06 is performed. The reference processing time is the time from the detection start time of the second signal to the end of the etching. For example, an experiment is conducted by changing the time from the detection start time of the second signal to the end of the etching, and a condition is obtained such that the film thickness t22 of the non-overlapping portion 22 is 66% or more of the film thickness t21 of the overlapping portion 21. The time satisfying this condition is set as the reference processing time. The reference processing time may be set as a predetermined time as an absolute value, or may be set as a time that is a predetermined ratio with respect to the first reference time.

[0097] Next, a measurement step S1 is performed. The measurement step S1 includes a film formation step S11, an etching step S12, a first signal detection step S13, a second signal detection step S14, and a first measurement time calculation step S15.

[0098] In the film formation step S11, a laminate is produced under the same conditions and with the same film configuration as the reference laminate 80 produced in the film formation step S01.

[0099] Next, the etching step S12 is performed. The etching conditions of the etching step S12 are also the same as those of the etching step S02. Also, the same layer as the layer selected in the preparation step S0 is used as the first detection layer and the second detection layer. Also, if necessary, the same layer as the layer selected in the preparation step S0 is used as the third detection layer.

[0100] Next, in the first signal detection step S13, a first signal derived from the first material included in the first detection layer is detected. For example, when the laminate is etched, first, a part of the third layer and the cap layer is etched. At this time, the atoms constituting the third layer are scattered and detected by the detection device. The detection device detects, for example, a first signal derived from the first material included in the third layer.

[0101] Next, in the second signal detection step S14, a second signal derived from the second material included in the second detection layer is detected. For example, when the etching reaches the barrier layer, the atoms constituting the barrier layer are scattered and detected by the detection device. The detection device detects, for example, a second signal derived from the second material included in the barrier layer.

[0102] There is a time lag between when the first signal is detected and when the second signal is detected. In the first measurement time calculation step S15, this time lag is calculated in the same way as in the first reference time calculation step S05. This time lag is called the first measurement time.

[0103] Furthermore, when a third detection layer is set up, a second measurement time from the detection of the first signal to the detection of the third signal, and a third measurement time from the detection of the second signal to the detection of the third signal may be determined in the measurement step S1.

[0104] Next, a comparison step S2 is performed, which includes a first step S21 of comparing the first reference time with the first measured time, and a second step S22 of determining the difference between the first reference time and the first measured time.

[0105] In the first step S21, the first reference time is compared with the first measured time to determine whether they match. Because a stacked body formed under the same conditions as the reference stacked body 80 is etched under the same conditions, the first reference time and the first measured time may match. On the other hand, even if a stacked body formed under the same conditions as the reference stacked body 80 is etched under the same conditions, the first measured time and the first reference time may not match. This is because the etching time may vary due to various factors.

[0106] In the first step S21, if the first reference time and the first measured time are the same, there is no difference between the first reference time and the first measured time, which means that the etching rate in the reference stack 80 and the etching rate in the stack are substantially the same.

[0107] In the first step S21, if the first reference time and the first measured time do not match, a second step S22 is performed to determine the deviation between the first reference time and the first measured time. The deviation between the first reference time and the first measured time can be obtained by calculating the difference between the first reference time and the first measured time.

[0108] When using the third detection layer, the second reference time and the second measurement time may be compared, or the third reference time and the third measurement time may be compared. That is, the deviation between the second reference time and the second measurement time, or the deviation between the third reference time and the third measurement time may be obtained.

[0109] Next, the determination step S3 is performed. When the first reference time and the first measurement time do not match, the first determination step S31 of the determination step S3 is performed. When the first reference time and the first measurement time match, the second determination step S32 of the determination step S3 is performed.

[0110] In the first determination step S31, the actual processing conditions from when the second signal is detected from the deviation between the first reference time and the first measurement time until the etching ends are determined. For example, when the first measurement time is shorter than the first reference time, the actual processing conditions are made shorter than the reference processing time. For example, when the first measurement time is longer than the first reference time, the actual processing conditions are made longer than the reference processing time. For example, (the first reference time)+{「(the first reference time)-(the first measurement time)」 / (the first reference time)×(the reference processing time)} may be used as the actual processing time.

[0111] In the second determination step S32, the actual processing time from when the second signal is detected until the etching ends is set as the reference processing time.

[0112] When using the third detection layer, the deviation between the second reference time and the second measurement time, or the deviation between the third reference time and the third measurement time may be considered in determining the actual processing time in the determination step S3. By adding this deviation information to the deviation information between the first reference time and the first measurement time and determining the actual processing time, the actual processing time can be made a more appropriate value.

[0113] As described above, according to the method for manufacturing a magnetoresistive effect element according to the present embodiment, excessive etching of the wiring layer 20 due to variations in etching conditions can be suppressed. Since the wiring layer 20 has a high resistance and easily generates heat, by preventing the wiring layer 20 from becoming too thin, heat generation of the magnetoresistive effect element 100 can be suppressed.

[0114] "Magnetic Array, Magnetoresistive Element" FIG. 7 is a circuit diagram of the magnetic array according to the present embodiment. The magnetic array 200 includes a plurality of magnetoresistive elements 100, a plurality of write wirings WL, a plurality of common wirings CL, a plurality of read wirings RL, a plurality of first switching elements Sw1, a plurality of second switching elements Sw2, and a plurality of third switching elements Sw3. In the magnetic array 200, for example, the magnetoresistive elements 100 are arranged in a matrix. Each of the magnetoresistive elements 100 is the above-described magnetic low-resistance element shown in FIGS. 3 and 4.

[0115] Each write wiring WL electrically connects the power supply and one or more magnetoresistive elements 100. Each common wiring CL is a wiring used both during data writing and reading. Each common wiring CL electrically connects the reference potential and one or more magnetoresistive elements 100. The reference potential is, for example, ground. The common wiring CL may be provided for each of the plurality of magnetoresistive elements 100 or may be provided across the plurality of magnetoresistive elements 100. Each read wiring RL electrically connects the power supply and one or more magnetoresistive elements 100. The power supply is connected to the magnetic array 200 during use.

[0116] Each magnetoresistive element 100 is electrically connected to each of the first switching element Sw1, the second switching element Sw2, and the third switching element Sw3. The first switching element Sw1 is connected between the magnetoresistive element 100 and the write wiring WL. The second switching element Sw2 is connected between the magnetoresistive element 100 and the common wiring CL. The third switching element Sw3 is connected to the read wiring RL extending across the plurality of magnetoresistive elements 100.

[0117] When the predetermined first switching element Sw1 and second switching element Sw2 are turned ON, a write current flows between the write wiring WL and the common wiring CL connected to the predetermined magnetoresistive element 100. When the write current flows, data is written into the predetermined magnetoresistive element 100. When the predetermined second switching element Sw2 and third switching element Sw3 are turned ON, a read current flows between the common wiring CL and the read wiring RL connected to the predetermined magnetoresistive element 100. When the read current flows, data is read from the predetermined magnetoresistive element 100.

[0118] The first switching element Sw1, the second switching element Sw2, and the third switching element Sw3 are elements that control the flow of current. The first switching element Sw1, the second switching element Sw2, and the third switching element Sw3 are, for example, a transistor, an element that utilizes a phase change of a crystal layer such as an ovonic threshold switch (OTS), an element that utilizes a change in a band structure such as a metal insulator transition (MIT) switch, an element that utilizes a breakdown voltage such as a Zener diode and an avalanche diode, and an element whose conductivity changes with a change in atomic position.

[0119] In the magnetic array 200 shown in FIG. 7, the magnetoresistive elements 100 connected to the same read wiring RL share the third switching element Sw3. The third switching element Sw3 may be provided for each magnetoresistive element 100. Further, the third switching element Sw3 may be provided for each magnetoresistive element 100, and the first switching element Sw1 or the second switching element Sw2 may be shared by the magnetoresistive elements 100 connected to the same wiring.

[0120] FIG. 8 is a cross-sectional view of a characteristic portion of the magnetic array 200 according to the first embodiment. FIG. 8 is a cross-section taken along the xz plane passing through the center of the width of the wiring layer 20, which will be described later, in the y direction of the magnetoresistive element 100.

[0121] The first switching element Sw1 and the second switching element Sw2 shown in FIG. 8 are transistors Tr. The third switching element Sw3 is electrically connected to the readout wiring RL and is located, for example, at different positions in the y direction in FIG. 8. The transistor Tr is, for example, a field effect transistor and has a gate electrode G, a gate insulating film GI, and a source S and a drain D formed on a substrate Sub. The source S and the drain D are defined by the direction of current flow, and they are in the same region. The positional relationship between the source S and the drain D may be reversed. The substrate Sub is, for example, a semiconductor substrate.

[0122] The transistor Tr and the magnetoresistive element 100 are electrically connected via a first via wiring 40 and a second via wiring 50. Also, the transistor Tr and the write wiring WL or the common wiring CL are each connected by a via wiring W1. The first via wiring 40, the second via wiring 50, and the via wiring W1 each extend, for example, in the z direction. The first via wiring 40, the second via wiring 50, and the via wiring W1 may each be formed by laminating a plurality of columnar bodies.

[0123] The periphery of the magnetoresistive element 100 and the transistor Tr is covered with an insulating layer 90. The above-mentioned insulating layer 60 is a part of the insulating layer 90. The insulating layer 90 is an insulating layer that insulates between wirings and between elements in a multilayer wiring. The insulating layer 90 is, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO x ), magnesium oxide (MgO), aluminum nitride (AlN), etc.

[0124] For each magnetoresistive element 100 belonging to the magnetic array 200, the film thickness t22 of the non-overlapping portion 22 of the wiring layer 20 is 66% or more of the film thickness t21 of the overlapping portion 21.

[0125] By using the manufacturing method of the magnetoresistive effect element 100 according to this embodiment, the etching conditions can be adjusted each time each magnetoresistive effect element 100 belonging to the magnetic array 200 is manufactured. Therefore, even when a plurality of magnetoresistive effect elements 100 are integrated, it is possible to prevent the film thickness t22 of the non-overlapping portion 22 of the wiring layer 20 from becoming extremely thin in any of the magnetoresistive effect elements 100.

[0126] Although the first embodiment has been described above as an example of a preferred embodiment of the present invention, the present invention is not limited to these embodiments. For example, the characteristic configurations of each embodiment may be applied to other embodiments and modified examples. [Explanation of symbols]

[0127] 1,83...first ferromagnetic layer, 2,85...second ferromagnetic layer, 3,84...barrier layer, 4,82...underlayer, 5,86...cap layer, 6,87...non-magnetic layer, 10...laminated body, 20,81...wiring layer, 21...overlapping portion, 22...non-overlapping portion, 30...sidewall layer, 31...first sidewall layer, 32...second sidewall layer, 40...first via wiring, 50...second via wiring, 60,90...insulating layer, 80...reference laminate, 87A...first layer, 87B...second layer, 87C...third layer, 100...magnetoresistive element Child, 200...magnetic array, S0...preparation step, S01, S11...film formation step, S02, S12...etching step, S03, S13...first signal detection step, S04, S14...second signal detection step, S05...first reference time calculation step, S15...first measurement time calculation step, S06...reference processing time determination step, S1...measurement step, S2...comparison step, S21...first step, S22...second step, S3...determination step, S31...first determination step, S32...second determination step

Claims

1. Etching a laminate including a first detection layer and a second detection layer, and measuring a first measurement time from when a first signal derived from a first material included in the first detection layer is detected until a second signal derived from a second material included in the second detection layer is detected; Comparing a first reference time from when the first signal is detected until the second signal is detected when etching a reference laminate having the same film configuration as the laminate, and obtaining a deviation between the first reference time and the first measurement time; A method for manufacturing a magnetoresistive element, comprising: a determination step of determining a reference processing time as a time of actual processing from when the second signal is detected until the etching is completed when there is no deviation, and determining conditions from when the second signal is detected until the etching is completed using the deviation when there is a deviation.

2. The method for manufacturing a magnetoresistive element according to claim 1, wherein the first material and the second material are different.

3. The method for manufacturing a magnetoresistive element according to claim 1, wherein the first material and the second material are the same.

4. The laminate has, in a stacking direction, a wiring layer, a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, and a nonmagnetic layer in this order, The nonmagnetic layer is the first detection layer, The method for manufacturing a magnetoresistive element according to claim 1, wherein the barrier layer is the second detection layer.

5. The laminate has, in a stacking direction, a wiring layer, a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, and a nonmagnetic layer in this order, The nonmagnetic layer has, from the second ferromagnetic layer side, a first layer, a second layer, and a third layer in this order, The third layer of the nonmagnetic layer is the first detection layer, The method for manufacturing a magnetoresistive element according to claim 1, wherein the first layer of the nonmagnetic layer is the second detection layer.

6. The method for manufacturing a magnetoresistive element according to claim 1, wherein a distance between the first detection layer and the second detection layer is 4 nm or more.

7. The method for manufacturing a magnetoresistive element according to claim 1, wherein a thickness of the first detection layer and a thickness of the second detection layer are different.

8. The method for manufacturing a magnetoresistive element according to claim 1, wherein a thickness of the first detection layer and a thickness of the second detection layer are the same.

9. The method for manufacturing a magnetoresistive element according to claim 1, wherein both the thickness of the first detection layer and the thickness of the second detection layer are 1 nm or more.

10. The laminate and the reference laminate further include a third detection layer, The measurement step is a second measurement time from when the first signal is detected until a third signal derived from a third material included in the third detection layer is detected, or The method further includes a step of measuring a third measurement time from when the second signal is detected until the third signal is detected. The comparison step is a step of comparing a second reference time from when the first signal is detected until the third signal is detected when the reference laminate is etched with the second measurement time, or The method for manufacturing a magnetoresistive element according to claim 1, further comprising a step of comparing a third reference time from when the second signal is detected until the third signal is detected when the reference laminate is etched with the third measurement time.

11. having a wiring layer, a laminate, and a sidewall layer, The laminate is in contact with the wiring layer, The laminate has a first ferromagnetic layer, a barrier layer, a second ferromagnetic layer, and a nonmagnetic layer, The sidewall layer covers the sidewall of the laminate, The first ferromagnetic layer is closer to the wiring layer than the second ferromagnetic layer, The barrier layer is sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, The second ferromagnetic layer is sandwiched between the barrier layer and the nonmagnetic layer, The sidewall layer includes a first material included in the first detection layer of the laminate and a second material included in the second detection layer of the laminate, The magnetoresistive element, wherein the first material and the second material are each selected from the group consisting of Ta, W, Mg, Ru, Si, Ir, Mn, Co, Fe, Ni, Al, O, and Ti.

12. The sidewall layer has a first sidewall layer and a second sidewall layer, The first sidewall layer is closer to the laminate than the second sidewall layer, The first sidewall layer is obtained by adding the first material and the second material to silicon oxynitride, The magnetoresistive element according to claim 11, wherein the second sidewall layer is silicon nitride.

13. The second detection layer is closer to the wiring layer than the first detection layer, In the sidewall layer, the concentration of the second material is higher than the concentration of the first material. The magnetoresistive element according to claim 11.

14. The wiring layer has a superimposed portion that overlaps the laminate and a non-superimposed portion that does not overlap the laminate when viewed in the stacking direction. The magnetic resistance effect element according to claim 11, wherein the film thickness of the wiring layer in the non-overlapping portion is 66% or more of the film thickness of the wiring layer in the overlapping portion.

15. The magnetic resistance effect element according to claim 11, wherein a first portion covering the periphery of a layer on the wiring layer side of the first detection layer among the side wall layers contains the first material and the second material.

16. Having a plurality of magnetic resistance effect elements, A magnetic array, wherein each of the plurality of magnetic resistance effect elements is a magnetic resistance effect element according to claim 11.

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