MAGNETIC SENSOR

Abstract

A magnetic sensor comprises: an MR element including a magnetization-fixed layer, a free layer, and a gap layer; a protective layer arranged over the MR element; and a conductive layer electrically connected to the MR element. The protective layer includes a first part and a second part, such that the second part is positioned between the first part and the MR element. When viewed in a stacking direction of the magnetization-fixed layer, the gap layer, and the free layer, an outer edge of the second part lies on an inner surface of the outer edge of the first part. The conductive layer is in contact with the second part.

Description

BACKGROUND 1. Field of the invention

[0001] The disclosure relates to a magnetic sensor that includes a magnetoresistive element and a protective layer arranged over the magnetoresistive element. 2. Description of the related technology

[0002] In recent years, magnetic sensors have been used in a wide variety of applications. Examples of well-known magnetic sensors include those that use a magnetoresistive element with a spin valve on a substrate. The magnetoresistive element with a spin valve comprises a magnetization-fixed layer whose magnetization direction is fixed, a free layer whose magnetization direction is variable depending on the direction of a target magnetic field, and a gap layer located between the magnetization-fixed layer and the free layer.

[0003] US Patent 2023 / 0324477 A1 discloses a magnetic sensor device incorporating multiple tunnel-effect magnetoresistive (TMR) elements. Each TMR element encloses a free layer with a disk-like structure. A closed-flux magnetization pattern, also known as a vortex state, spontaneously forms within the free layer. In a magnetoresistive element enclosing the free layer with the magnetic vortex structure described in US Patent 2023 / 0324477 A1, the center of the magnetic vortex structure moves in response to a magnetic field to be detected, thereby changing the resistance of the magnetoresistive element.

[0004] In the TMR element, a lower electrode and an upper electrode are connected to a lower and an upper surface of the TMR element, respectively, to cause a measuring current for magnetic signal acquisition to flow in a direction substantially perpendicular to a surface of each layer constituting the TMR element. The upper electrode is formed, for example, as follows: First, an insulating layer is formed that covers the TMR element. Next, an opening is formed in the insulating layer that exposes the upper surface of the TMR element. Subsequently, a conductive layer, representing at least part of the upper electrode, is formed to fill the opening.

[0005] After the opening in the insulating layer has been created, a portion of the upper surface of the TMR element can be treated by ion beam etching or back sputtering. In this case, the exposed layer of the TMR element can be damaged, depending on the nature of the ion beam etching and back sputtering processes. The effect of this damage is particularly evident in the exposed layer with the magnetic vortex structure, as described in US 2023 / 0324477 A1. SUMMARY OF THE INVENTION

[0006] One objective of the disclosure is to provide a magnetic sensor capable of reducing the occurrence of a problem due to a conductive layer associated with a magnetoresistive element.

[0007] A magnetic sensor according to one embodiment of the disclosure includes: a magnetoresistive element comprising a magnetization-fixed layer with a magnetization in a fixed direction, a free layer with a magnetization that is variable according to an applied magnetic field, and a gap layer arranged between the magnetization-fixed layer and the free layer; a protective layer arranged above the magnetoresistive element; and a conductive layer electrically connected to the magnetoresistive element. The protective layer comprises a first part and a second part, such that the second part is arranged such that the first part lies between the second part and the magnetoresistive element. When viewed in a stacking direction of the magnetization-fixed layer, the gap layer, and the free layer, an outer edge of the second part is located on an inner side of the outer edge of the first part.The conductive layer comes into contact with the second part.

[0008] In the magnetic sensor of the disclosure, viewed in the stacking direction of the magnetization-fixed layer, the gap layer, and the free layer, the outer edge of the second part is located on the inside of the outer edge of the first part. The conductive layer comes into contact with the second part. Consequently, according to the disclosure, the occurrence of a problem due to the conductive layer can be reduced.

[0009] The objects, features, and benefits of the revelation will become more apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are included to provide a further understanding of the disclosure and are an integral part of this description. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the technology. Fig. Figure 1 is a top view showing a magnetic sensor according to a first embodiment of the disclosure. Fig. Figure 2 is a circuit diagram showing a circuit configuration of the magnetic sensor according to the first embodiment of the disclosure. Fig. Figure 3 is a top view showing part of the magnetic sensor according to the first embodiment of the disclosure. Fig. Figure 4 is a sectional view showing part of the magnetic sensor according to the first embodiment of the disclosure. Fig. 5 is an enlarged sectional view showing part of the Fig. The magnetic sensor shown in section 4 is shown. Fig. Figure 6 is a top view showing a protective layer according to the first embodiment of the disclosure. Fig. Figure 7 is a perspective view showing a magnetoresistive element in the first embodiment of the revelation. Fig. Figure 8 is a top view showing a free layer of the magnetoresistive element in the first embodiment of the disclosure. Fig. Figure 9 is a top view showing the free layer when a magnetic target field is applied to the magnetoresistive element in the first embodiment of the disclosure. Fig. Figure 10 is a top view showing the free layer when a magnetic target field is applied to the magnetoresistive element in the first embodiment of the disclosure. Fig. Figure 11 is a sectional view showing a step of a manufacturing process for the magnetic sensor according to the first embodiment of the disclosure. Fig. 12 is a sectional view showing a step that leads to the in Fig. The step shown in step 11 follows. Fig. 13 is a sectional view showing a step leading to the in Fig. Follow the step shown in step 12. Fig. 14 is a sectional view showing a step leading to the in Fig. Step 13 shown follows. Fig. 15 is a sectional view showing a step leading to the in Fig. The step shown in step 14 follows. Fig. Figure 16 is a sectional view showing part of the magnetic sensor of a modification example according to the first embodiment of the disclosure. Fig. Figure 17 is a sectional view showing a step of a manufacturing process for the magnetic sensor according to a second embodiment of the disclosure. Fig. 18 is a sectional view showing a step leading to the in Fig. The step shown in step 17 follows. Fig. 19 is a sectional view showing a step leading to the in Fig. The step shown in step 18 follows. Fig. Figure 20 is an enlarged sectional view showing part of the magnetic sensor according to a third embodiment of the disclosure. Fig. Figure 21 is an enlarged sectional view showing part of the magnetic sensor according to the fourth embodiment of the disclosure. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS

[0011] The following describes in detail some embodiments and modifications of the disclosure with reference to the accompanying drawings. It should be noted that the following description refers to illustrative examples of the disclosure and is not to be understood as a limitation of the technology. Factors such as numerical values, shapes, materials, components, component positions, and the way in which the components are coupled are for illustrative purposes only and are not to be understood as a limitation of the technology. Furthermore, elements in the following embodiments that are not included in a most general independent claim of the disclosure are optional and may be provided as required. The drawings are schematic and not to scale. Identical elements are designated with the same reference numbers to avoid redundant descriptions. [First embodiment]

[0012] First, a schematic configuration of a magnetic sensor according to a first embodiment of the disclosure is presented with reference to the Fig. 1 and Fig. 2 described. Fig. Figure 1 is a top view of a magnetic sensor 1 according to the embodiment. Fig. Figure 2 is a circuit diagram showing a circuit configuration of the magnetic sensor 1 according to the exemplary embodiment.

[0013] The magnetic sensor 1 according to the exemplary embodiment comprises a power supply terminal 11, a ground terminal 12, a first output terminal 13, a second output terminal 14, a first resistance range R1, a second resistance range R2, a third resistance range R3, a fourth resistance range R4, and a substrate 10. Each of the first to fourth resistance ranges R1 to R4 includes a plurality of magnetoresistive elements (hereinafter referred to as MR elements). The first to fourth resistance ranges R1 to R4, the power supply terminal 11, the ground terminal 12, and the first and second output terminals 13 and 14 are arranged on the substrate 10.

[0014] As in Fig. As shown in Figure 2, the first resistor R1 is located in the circuit configuration between the power supply terminal 11 and the first output terminal 13. The second resistor R2 is located in the circuit configuration between the ground terminal 12 and the first output terminal 13. The third resistor R3 is located in the circuit configuration between the ground terminal 12 and the second output terminal 14. The fourth resistor R4 is located in the circuit configuration between the power supply terminal 11 and the second output terminal 14. Note that the phrase "in the (a) circuit configuration" is used in the application to refer to a layout in a circuit diagram and not a layout in a physical configuration.

[0015] A voltage or current of a specific magnitude is applied to the power supply terminal 11. The ground terminal 12 is connected to earth.

[0016] As in Fig. As shown in Figure 1, an X-direction, a Y-direction, and a Z-direction are defined. The X-direction, the Y-direction, and the Z-direction are orthogonal to each other. The directions opposite to the X-, Y-, and Z-directions are designated as the -X-, -Y-, and -Z-directions, respectively. In this embodiment, a direction perpendicular to the surface of the substrate 10 is specifically designated as the Z-direction.

[0017] As used here, the term "top" refers to positions located in the Z-direction in front of a given reference position, and "bottom" refers to positions opposite the "top" positions with respect to the given reference position. For components of magnetic sensor 1, the term "top face" refers to a face of the component located at its end in the Z-direction, and "bottom face" refers to a face of the component located at its end in the Z-direction. The phrase "when viewed in a given direction (e.g., the Z-direction)" means that an object is viewed from a position located in the given direction or in a direction parallel to the given direction.

[0018] Fig. Figure 1 shows an example of the layout of the first to fourth resistor sections, R1 to R4. In this example, the first and second resistor sections, R1 and R2, are arranged in a direction parallel to the X-direction. The second resistor section, R2, is positioned before the first resistor section, R1, in the X-direction.

[0019] The third and fourth resistor sections, R3 and R4, are arranged in a direction parallel to the X-direction. The fourth resistor section, R4, is located upstream of the third resistor section, R3, in the -X-direction. The third resistor section, R3, is located upstream of the second resistor section, R2, in the -Y-direction. The fourth resistor section, R4, is located upstream of the first resistor section, R1, in the -Y-direction.

[0020] Note that the layout of the first to fourth resistor ranges R1 to R4 does not correspond to the one in Fig. The example shown is limited. For example, the first to fourth resistor ranges R1 to R4 can be arranged in a specific order parallel to the X direction or parallel to the Y direction.

[0021] The following describes a specific structure of the magnetic sensor 1 based on the Fig. 3 and Fig. 4 described in detail. Fig. Figure 3 is a top view showing part of the magnetic sensor 1. Fig. Figure 4 is a sectional view showing part of the magnetic sensor 1.

[0022] The magnetic sensor 1 in the exemplary embodiment comprises a plurality of MR elements 50, a plurality of lower electrodes 41, and a plurality of upper electrodes 42 for electrically connecting the plurality of MR elements 50. The plurality of lower electrodes 41 are arranged above the substrate 10 (see Fig. 1) The majority of MR elements 50 are arranged above the majority of lower electrodes 41. The majority of upper electrodes 42 are arranged above the majority of MR elements 50.

[0023] A method for connecting the majority of MR elements 50 to the majority of lower electrodes 41 and the majority of upper electrodes 42 is as follows. As in Fig. As shown in Figure 3, each individual lower electrode 41 has an elongated shape. A gap is formed between two lower electrodes 41 that are adjacent to each other longitudinally. On the upper surface of the lower electrode 41, the MR elements 50 are arranged longitudinally near both ends. Each individual upper electrode 42 has an elongated shape and is arranged over two lower electrodes 41 that are adjacent longitudinally, electrically connecting the two adjacent MR elements 50. In this way, the majority of the MR elements 50 are connected in series.

[0024] The upper electrode 42 can comprise a sublayer 421 and a conductive layer 422 arranged above the sublayer 421. The sublayer 421 comes into contact with the upper surfaces of the MR elements 50. For example, Ta, Ti, or similar materials are used for the sublayer 421. For example, Cu, Au, Al, or similar materials are used for the conductive layer 422.

[0025] The magnetic sensor 1 can further comprise a protective layer 70 arranged over the MR element 50, an inorganic material layer 80 arranged over the protective layer 70, and an insulating layer 30. The insulating layer 30 is arranged around the lower electrode 41, the MR element 50, the protective layer 70, the inorganic material layer 80, and the upper electrode 42. The insulating layer 30 can be a single-layer film or a multi-layer film. In the latter case, the multi-layer film can be formed from a single insulating material or from a plurality of insulating materials.

[0026] The inorganic layer 80 is made of materials such as carbon, Al2O3, or similar. The insulating layer 30 is made of materials such as SiO2, Al2O3, or similar.

[0027] The following are, with reference to the Fig. 5 and Fig. 6 the structures of the protective layer 70 and the inorganic material layer 80 are described in detail. Fig. 5 is an enlarged sectional view showing part of the Fig. 4 shows magnetic sensor 1. Fig. Figure 6 is a top view showing the protective layer 70 of the embodiment. The protective layer 70 comprises a first part 60, which is arranged above the MR element 50, and a second part 421A, which inserts the first part 60 between the second part 421A and the MR element 50.

[0028] In this embodiment, the second part 421A can, in particular, be part of the sublayer 421. In other words, the sublayer 421 can comprise the second part 421A and a different part 421B than the second part 421A. Fig. 5 is a boundary between the second part 421A and part 421B, represented by a dashed line. Note that this is also the case in the drawings used in the following description, which are similar to Fig. 5, the boundary between the second part 421A and part 421B is represented by a dashed line.

[0029] The first part 60 can enclose a first metal film formed from a first metal material. The first part 60 can be a single-layer film enclosing the first metal film, or a multi-layer film enclosing the first metal film. The second part 421A can enclose a second metal film formed from the first metal material. The second part 421A can be a single-layer film enclosing the second metal film, or a multi-layer film enclosing the second metal film. If at least one of the first part 60 and the second part 421A is a multi-layer film enclosing the first metal film, the protective layer 70 can also enclose a third metal film formed from a second metal material. The third metal film can be positioned between the first and second metal films.

[0030] The first metal material can be, for example, Ta. If the first part 60 is a multilayer film, then, in addition to the first metal film formed by Ta, the first part 60 can include at least one metal film formed by a metal material from the series Ru, Ta, Cu, or Cr, or a Ni-based non-magnetic alloy such as NiCr, as the third metal film. If the second part 421A is a multilayer film, then, in addition to the second metal film formed by Ta, the second part 421A can include at least one metal film formed by a metal material such as Ti as the third metal film. In an example, the first part 60 is a multilayer film in which a metal film formed by Ru and a metal film formed by Ta are stacked, and the second part 421A is a multilayer film in which a metal film formed by Ti and a metal film formed by Ta are stacked.

[0031] As in Fig. As shown in Figure 5, the first part 60 of the protective layer 70 comprises a first surface 60a and a second surface 60b, which are parallel to the Z-direction at both ends. The first surface 60a faces the MR element 50. The second surface 60b faces the second part 421A. The second surface 60b can be completely parallel to the first surface 60a or partially parallel to the first surface 60a.

[0032] As in Fig. As shown in Figure 6, the planar shape (shape seen in the Z direction) of the second part 421A is smaller than the planar shape of the first part 60. Fig. Reference numeral 60e denotes an outer edge of the first part 60 when viewed in the Z direction, and reference numeral 421Ae denotes an outer edge of the second part 421A when viewed in the Z direction. Viewed in the Z direction, the outer edge 421Ae of the second part 421A is located on the inside of the outer edge 60e of the first part 60.

[0033] Note that the in Fig. The outer edge 60e shown in Figure 6 can be an outer edge of the second surface 60b of the first part 60. In other words, viewed in the Z direction, the outer edge 421Ae of the second part 421A can be located on the inside of the outer edge of the second surface 60b of the first part 60.

[0034] Fig. Figure 6 shows an example of a case in which the planar shape of the first part 60 and the planar shape of the second part 421A each have a circular shape. In this case, the second part 421A is preferably arranged in the Z-direction such that it overlaps the center of the planar shape of the first part 60, and more preferably it is arranged such that the center of the planar shape of the first part 60 and the center of the planar shape of the second part 421A overlap.

[0035] The first part 60 further comprises a side surface 60d that connects the first surface 60a and the second surface 60b. At least part of the side surface 60d can be inclined relative to a direction (stacking direction) parallel to the Z-direction. The cross-sectional area of ​​the first part 60 parallel to the XY-plane can decrease with increasing approach to the second surface 60b. Viewed in the Z-direction, the outer edge of the second surface 60b can be located on the inside of the outer edge of the first surface 60a.

[0036] The inorganic material layer 80 is arranged around the second part 421A on the first part 60 of the protective layer 70. Viewed in the Z direction, the outer edge of the planar shape of the inorganic material layer 80 can coincide with the outer edge 60e of the first part 60 or with the outer edge of the second surface 60b.

[0037] Note that the outer diameter of the planar shape of the inorganic material layer 80 can be equal to or smaller than the outer diameter of the planar shape of the MR element 50. The cross-sectional area of ​​the inorganic material layer 80 parallel to the XY plane can be constant regardless of the distance to the second surface 60b, or it can decrease with increasing distance to the second surface 60b. In the latter case, the inorganic material layer 80 can have a side surface connecting the lower and upper surfaces of the inorganic material layer 80, and this side surface is inclined relative to the direction (stack direction) parallel to the Z-direction. In this case, the upper surface of the inorganic material layer 80 is located on the inside of the outer edge of the planar shape of the MR element 50 when viewed in the Z-direction.

[0038] The inorganic material layer 80 includes an opening 80a that exposes part of the second surface 60b of the first part 60 of the protective layer 70. The size of the opening 80a in the cross-section of the inorganic material layer 80 parallel to the XY plane can be constant regardless of the distance to the second surface 60b or increase with increasing distance to the second surface 60b.

[0039] The insulating layer 30 can cover the upper surface of the inorganic material layer 80. In this case, the insulating layer 30 can have an opening that exposes the opening 80a of the inorganic material layer 80.

[0040] The sublayer 421, which contains the second part 421A, is arranged along a wall surface of the opening 80a of the inorganic material layer 80 and a part of the second surface 60b. When the insulating layer 30 covers the upper surface of the inorganic material layer 80, the sublayer 421 is further arranged along a surface of the insulating layer 30, including a wall surface of the opening of the insulating layer 30.

[0041] The second part 421A comes into direct contact with the first part 60 and with the wall surface of the opening 80a of the inorganic material layer 80. Since the second part 421A is a component of the upper electrode 42, it can also be said that the upper electrode 42 comes into contact with the first part 60. Note that the part 421B of the lower layer 421 comes into contact with the wall surface of the opening 80a of the inorganic material layer 80, but does not come into contact with the first part 60.

[0042] The following is a configuration of the MR element 50 with reference to the Fig. 7 and Fig. 8 described. Fig. Figure 7 is a perspective view showing MR element 50. Fig. Figure 8 is a top view showing a free layer of the MR element 50.

[0043] The MR element 50 comprises a magnetization-fixed layer 51 with a fixed-direction magnetization 51m, a free layer 53, and a gap layer 52 located between the magnetization-fixed layer 51 and the free layer 53. The material and shape of the free layer 53 can be selected such that the free layer 53 exhibits a magnetic vortex structure (also referred to as a vortex structure). The gap layer 52 is a tunnel barrier layer or a non-magnetic conductive layer.

[0044] The free layer 53 has a cylindrical or substantially cylindrical shape. The free layer 53 exhibits a magnetization 53m, which displays a vortex pattern around a center 53c of the magnetic vortex structure. When no magnetic field is applied to the MR element 50, the center 53c of the magnetic vortex structure corresponds to, or substantially corresponds to, the axis of the cylinder. The free layer 53 is configured such that the center 53c of the magnetic vortex structure can move according to a target magnetic field MF. Note that in the examples of the Fig. 7 and Fig. 8 the entire MR element 50 has a cylindrical shape.

[0045] The center 53c of the magnetic vortex structure moves when a component of the target magnetic field MF, which lies in a direction orthogonal to the Z-direction, is applied to the free layer 53. The free layer 53 is preferably not saturated within a range of variation of the component's strength.

[0046] A dimension in the direction parallel to the Z-direction is referred to here as thickness. The thickness of the first part 60 of the protective layer 70 can be determined depending on the thickness of the free layer 53. In the exemplary embodiment, the thickness of the first part 60 can, in particular, be in a range of 40 to 100% of the thickness of the free layer 53. Alternatively, the thickness of the first part 60 can be in a range of 20 to 40% of the thickness of the free layer 53.

[0047] In the exemplary embodiment, the magnetization 51m of the magnetization-fixed layer 51 comprises a component in a direction parallel to the X-direction. Note that if the magnetization 51m of the magnetization-fixed layer 51 includes a component in a particular direction, the component in that particular direction may be the principal component of the magnetization 51m of the magnetization-fixed layer 51. In the exemplary embodiment, the direction of the magnetization 51m of the magnetization-fixed layer 51 is the specific direction, or substantially the specific direction, if the magnetization 51m of the magnetization-fixed layer 51 includes the component in that specific direction.

[0048] The MR element 50 can further include an antiferromagnetic layer. The antiferromagnetic layer is formed of an antiferromagnetic material and is in exchange coupling with the magnetization-fixed layer 51 in order to fix the direction of the magnetization 51m of the magnetization-fixed layer 51. Alternatively, the magnetization-fixed layer 51 can be a so-called self-fixed layer (synthetic ferri-pinned layer, SFP layer). The self-pinned layer has a stacked ferri structure in which a ferromagnetic layer, a non-magnetic interlayer, and a ferromagnetic layer are stacked, with the two ferromagnetic layers being antiferromagnetically coupled.

[0049] The resistance of the MR element 50 is described here using the example of a case in which the direction of the magnetization 51m of the magnetization-fixed layer 51 is the -X direction. Fig. 9 and Fig. Figure 10 shows the free layer 53 when a magnetic field component MFx of the target magnetic field MF, which runs in a direction parallel to the X-direction, is applied to the free layer 53.

[0050] Fig. Figure 9 shows the free layer 53 when the direction of the magnetic field component MFx is the X-direction. In this case, the center 53c of the magnetic vortex structure moves according to the magnetic field component MFx, and the magnitude of the magnetization 53m in the X-direction is greater than the magnitude of the magnetization 53m in the -X-direction. In this case, the resistance of the MR element 50 increases.

[0051] Fig. Figure 10 shows the free layer 53 when the direction of the magnetic field component MFx is the -X direction. In this case, the center 53c of the magnetic vortex structure moves according to the magnetic field component MFx, and the magnitude of the magnetization 53m in the -X direction is greater than the magnitude of the magnetization 53m in the X direction. In this case, the resistance of the MR element 50 decreases.

[0052] The magnitude of the resistance change of the MR element 50 depends on the strength of the magnetic field component MFx. If the direction of the magnetic field component MFx is the X-direction, the magnitude of the magnetization 53m in the X-direction increases as the strength of the magnetic field component MFx increases. The resistance of the MR element 50 increases as the magnitude of the magnetization 53m in the X-direction increases. If the direction of the magnetic field component MFx is the -X-direction, the magnitude of the magnetization 53m in the -X-direction increases as the strength of the magnetic field component MFx increases. The resistance of the MR element 50 decreases as the magnitude of the magnetization 53m in the -X-direction increases. As the strength of the magnetic field component MFx increases, the resistance of the MR element 50 changes such that the magnitude of the increase or the magnitude of the decrease increases.When the strength of the magnetic field component MFx decreases, the resistance of the MR element 50 changes, such that the magnitude of the increase or the magnitude of the decrease decreases. In the exemplary embodiment, the relationship between the strength of the magnetic field component MFx and the resistance of the MR element 50 is, in particular, a linear or substantially linear relationship, provided that the condition that the free layer 53 is not saturated is met.

[0053] Next, with reference to Fig. 2. The direction of the magnetization 51m of the magnetization-fixed layer 51 in each of the first to fourth resistance regions R1 to R4 is described. The magnetization 51m of the magnetization-fixed layer 51 of each of the plurality of MR elements 50 in the first resistance region R1 includes a component in a first magnetization direction. The magnetization 51m of the magnetization-fixed layer 51 of each of the plurality of MR elements 50 in the second resistance region R2 includes a component in a second magnetization direction, which is opposite to the first magnetization direction. The magnetization 51m of the magnetization-fixed layer 51 of each of the plurality of MR elements 50 in the third resistance region R3 includes a component in the first magnetization direction.The magnetization 51m of the magnetization-fixed layer 51 of each of the plurality of MR elements 50 in the fourth resistance region R4 includes a component in the second magnetization direction. In . Fig. 2. Each of the two arrows in the first and third resistance ranges, R1 and R3, indicates the first magnetization direction. Fig. Figure 2 shows the second magnetization direction for each of the two arrows in the second and fourth resistance sections R2 and R4. In this embodiment, the first magnetization direction is specifically the X-direction and the second magnetization direction is the -X-direction.

[0054] Next, with reference to Fig. 2. At least one detection signal generated by the magnetic sensor 1 is described. When the direction of the magnetic field component MFx is the X-direction, the resistance of each of the plurality of MR elements 50 of the first and third resistance ranges R1 and R3 decreases, and the resistance of each of the plurality of MR elements 50 of the second and fourth resistance ranges R2 and R4 increases, compared to the state in which the magnetic field component MFx is not present. Consequently, the resistance of each of the first and third resistance ranges R1 and R3 decreases, and the resistance of each of the second and fourth resistance ranges R2 and R4 increases.

[0055] If the direction of the magnetic field component MFx is the -X direction, the change in resistance of each of the first to fourth resistance ranges R1 to R4 is opposite to that in the previous case where the direction of the magnetic field component MFx is the X direction.

[0056] As described above, changes in the direction and strength of the magnetic field component MFx cause the resistances of the first to fourth resistance ranges R1 to R4 to change such that the resistances of the first and third resistance ranges R1 and R3 increase while the resistances of the second and fourth resistance ranges R2 and R4 decrease, or such that the resistances of the first and third resistance ranges R1 and R3 decrease while the resistances of the second and fourth resistance ranges R2 and R4 increase. This changes the potential of a connection point of the first and second resistance ranges R1 and R2, i.e., the potential of the first output terminal 13, and the potential of a connection point of the third and fourth resistance ranges R3 and R4, i.e., the potential of the second output terminal 14.The magnetic sensor 1 can generate two detection signals: one corresponding to the potential of the first output terminal 13 and another corresponding to the potential of the second output terminal 14. Alternatively, the magnetic sensor 1 can generate a detection signal corresponding to a potential difference between the first output terminal 13 and the second output terminal 14. In this case, the magnetic sensor 1 can also include a differential amplifier (difference detector) that outputs the signal corresponding to the potential difference between the first output terminal 13 and the second output terminal 14 as the detection signal.

[0057] Next, with reference to the Fig. Sections 11 to 15 describe a manufacturing process for the magnetic sensor 1 according to the exemplary embodiment. Fig. Figures 11 to 15 show cross-sections of a stacked body in a manufacturing process for the magnetic sensor 1. Here, the manufacturing process for the magnetic sensor 1 is described, with the focus on an MR element 50. In the manufacturing process for the magnetic sensor 1, an insulating layer (not shown) can first be deposited on the substrate 10 (see Figure 1). Fig. 1) be formed. Fig. Figure 11 shows the next step. In this step, the lower electrode 41 is first prepared. Next, an initial MR cell 50P, which later becomes the MR cell 50, is formed on the lower electrode 41. Note that prior to the formation of the initial MR cell 50P, a buffer layer (not shown), consisting of a non-magnetic metallic material, can be formed on the lower electrode 41.

[0058] Next, an initial protective layer 60P is formed on the initial MR element 50P, which later becomes the first part 60 of the protective layer 70. Then, the inorganic material layer 80 is formed on the initial protective layer 60P. The inorganic material layer 80 has a shape that corresponds to the planar shape of the MR element 50. Note that the manufacturing process for the magnetic sensor 1 according to the exemplary embodiment is described using the example of a case in which the inorganic material layer 80 is formed of carbon.

[0059] Fig. Figure 12 shows the next step. In this step, using the inorganic material layer 80 as an etching mask, a portion of the initial MR element 50P and the initial protective layer 60P are etched, for example, by ion beam etching. If both the initial MR element 50P and the initial protective layer 60P are etched, a redeposited film can form on the surface of the initial MR element 50P and the initial protective layer 60P due to etched and scattered substances. During ion beam etching, the redeposited film can be removed by tilting the ion beam progression direction relative to the stacking direction. A portion of the initial protective layer 60P that remains after etching becomes the first part 60 of the protective layer 70.

[0060] This section describes in detail a step for fixing the magnetization direction of the magnetization-fixed layer 51. The in Fig. 11 The initial MR element 50P shown comprises at least one initial magnetization-fixed layer, which later becomes the magnetization-fixed layer 51, the free layer 53 and the gap layer 52.

[0061] In the step of fixing the magnetization direction of the magnetization-fixed layer 51, the magnetization direction of the initial magnetization-fixed layer is fixed in the specific direction using laser light and external magnetic fields after the initial MR element 50P has been formed. For example, a plurality of initial MR elements 50P, which will later become the MR elements 50 of the first and third resistance regions R1 and R3, are irradiated with laser light while an external magnetic field is applied to them in the first magnetization direction (X-direction). In the case where the initial MR elements 50P enclose the antiferromagnetic layers, the laser irradiation is carried out such that the temperature of the plurality of initial MR elements 50P irradiated with the laser light becomes equal to or higher than a blocking temperature of the antiferromagnetic layers.The temperature of the majority of initial MR elements 50P can be adjusted, for example, by the intensity and pulse width of the laser light. After irradiation with laser light, when the temperature of the majority of initial MR elements 50P is lower than the lock-in temperature, the magnetization direction of the magnetization-fixed layer is fixed in the first magnetization direction. This transforms the initially magnetization-fixed layer into the magnetization-fixed layer 51.

[0062] In a plurality of other initial MR elements 50P, which later become a plurality of MR elements 50 of the second and fourth resistance ranges R2 and R4, the direction of magnetization of the initial magnetization-fixed layer of each of the plurality of other initial MR elements 50P can be fixed in the second magnetization direction by setting the direction of the external magnetic field to the second magnetization direction (-X direction).

[0063] The step described above, of fixing the direction of magnetization of the initially magnetization-fixed layer, can be performed after the etching step. Fig. The initial MR element 50P shown in Figure 12 can be used. In this case, if the direction of magnetization of the initial magnetization-fixed layer is fixed, the initial magnetization-fixed layer becomes the magnetization-fixed layer 51. Alternatively, the step of fixing the direction of magnetization of the initial magnetization-fixed layer described above can be performed before the step of etching the layer shown in Figure 12. Fig. The process is carried out on the initial MR element 50P shown in Figure 12. In this case, the initial magnetization-fixed layer is also etched when the initial MR element 50P is etched. This transforms the initially magnetization-fixed layer into the magnetization-fixed layer 51.

[0064] Note that in Fig. 12. The side surface of the MR element 50 is inclined relative to the direction parallel to the Z-direction. The side surface of the MR element 50 can comprise a plurality of parts whose respective angles, formed relative to the direction parallel to the Z-direction, are different. Alternatively, at least a part of the side surface of the MR element 50 can be parallel or substantially parallel to the Z-direction.

[0065] In Fig. 12. The side surface 60d of the first part 60 of the protective layer 70 is inclined relative to the direction parallel to the Z-direction. The angle formed by the side surface 60d of the first part 60 with respect to the direction parallel to the Z-direction can be identical to or different from the angle formed by the side surface of the MR element 50 with respect to the direction parallel to the Z-direction. The side surface 60d of the first part 60 can comprise a plurality of parts whose respective angles, formed relative to the direction parallel to the Z-direction, are different. Alternatively, at least a part of the side surface 60d of the first part 60 can be parallel or substantially parallel to the Z-direction.

[0066] Fig. Figure 13 shows the next step. In this step, the insulating layer 30 is formed so that it covers the lower electrode 41, the MR element 50, the first part 60, and the inorganic material layer 80. The insulating layer 30 is shaped so that its upper surface is positioned above the upper surface of the inorganic material layer 80.

[0067] Fig. Figure 14 shows the next step. In this step, a portion of the insulating layer 30 is polished, for example, by chemical-mechanical polishing (hereinafter referred to as CMP). The insulating layer 30 can be polished, for example, to a position where the upper surface of the inorganic material layer 80 is not exposed. Subsequently, a photoresist mask (not shown) is formed on the insulating layer 30. The photoresist mask (not shown) has an opening whose shape corresponds to the opening 80a of the inorganic material layer 80 to be formed later. Subsequently, using the photoresist mask (not shown), a portion of the insulating layer 30 is selectively etched, for example, by reactive ion etching (hereinafter referred to as RIE). The insulating layer 30 is etched until the upper surface of the inorganic material layer 80 is exposed.

[0068] Subsequently, at least a portion of the inorganic material layer 80 is selectively etched. In the exemplary embodiment, in particular, a portion of the inorganic material layer 80 is etched such that the opening 80a is formed in the inorganic material layer 80. If the inorganic material layer 80 is composed of carbon, it is etched by RIE using an O2-containing etching gas. The inorganic material layer 80 is etched until the second surface 60b of the first part 60 of the protective layer 70 is exposed.

[0069] Note that during the etching step of the inorganic material layer 80, part of the first part 60 can be etched along with the inorganic material layer 80. When the first part 60 is etched, a recess 60c can be formed in the first part 60, extending from the second surface 60b towards the first surface 60a, and having a depth such that it does not reach the first surface 60a. In the Fig. In the example shown in Figure 14, the first part 60 comprises the recess 60c. In this embodiment, the outer diameter of the planar shape of the recess 60c can be smaller than the outer diameter of the inorganic material layer 80. The area of ​​a contact surface between the upper electrode 42 to be formed later and the first part 60 of the protective layer 70 can be equal to the area of ​​the planar shape of the recess 60c.

[0070] When the inorganic material layer 80 is etched by RIE using an O2-containing etching gas as described above, an oxide film forms on the second surface 60b of the first part 60. Therefore, in this case, the oxide film is preferably removed by ion beam etching or reverse sputtering, e.g., after the inorganic material layer 80 has been etched.

[0071] A portion of the second surface 60b, other than the recess 60c, is covered by the inorganic material layer 80. Therefore, the surface of recess 60c and the surface of the portion not included in recess 60c are different. For example, the surface roughness of recess 60c and the surface roughness of the portion not included in recess 60c can differ. Note that any indicator can be used as an indicator of surface roughness.

[0072] Fig. Figure 15 shows the next step. In this step, the sublayer 421 is first formed along the second surface 60b of the first part 60 or the surface of the recess 60c, the wall surface of the opening 80a of the inorganic material layer 80, and the surface of the insulating layer 30. If the first part 60 encloses the recess 60c, at least part of the second part 421A of the sublayer 421 is located within the recess 60c. The sublayer 421 is produced, for example, by electroless coating or sputtering.

[0073] The conductive layer 422 is then formed on the sublayer 421. The conductive layer 422 is formed, for example, by electroplating. The sublayer 421 serves as the base for the conductive layer 422 and is used as the electrode and nucleation layer when the conductive layer 422 is formed by electroplating. Subsequently, the sublayer 421 and the conductive layer 422 are polished, for example, with CMP, until the insulating layer 30 is exposed. This completes the upper electrode 42.

[0074] Note that the conductive layer 422 can be configured to completely fill the opening 80a of the inorganic material layer 80, or it can be configured to not completely fill the opening 80a. In the latter case, a cavity may be formed in the conductive layer 422.

[0075] The manufacturing process for the magnetic sensor 1 has been described above, with a focus on an MR element 50. In the manufacturing process for the magnetic sensor 1, a plurality of MR elements 50, a plurality of lower electrodes 41, and a plurality of upper electrodes 42 are formed. After the plurality of upper electrodes 42 have been formed, a plurality of terminals are formed, corresponding to the power supply terminal 11, the ground terminal 12, and the first and second output terminals 13 and 14, and wiring is carried out to connect the plurality of terminals and the plurality of MR elements 50, thus completing the magnetic sensor 1.

[0076] The function and effect of the magnetic sensor 1 according to the exemplary embodiment will now be described. In this embodiment, the opening 80a in the inorganic material layer 80 must be formed to create the conductive layer 422, which forms part of the upper electrode 42. As described above, the second surface 60b of the first part 60 of the protective layer 70 is exposed when the opening 80a of the inorganic material layer 80 is formed. If the protective layer 70 is not present, the upper surface of the magnetic sensor element 50 is exposed during the etching of the inorganic material layer 80. Depending on the stage of etching of the inorganic material layer 80, the upper surface of the magnetic sensor element 50 must be etched, for example, by ion beam etching or reverse sputtering, after the inorganic material layer 80 has been etched. Depending on the state of the ion beam etching and reverse sputtering, the free layer 53 of the MR element 50 may be damaged.In the exemplary embodiment, in particular if the free layer 53 is damaged, the magnetic vortex structure may not be formed precisely, which can lead to a deterioration of the hysteresis characteristics of the MR element 50.

[0077] To address this, in the exemplary embodiment the protective layer 70 is arranged on the MR element 50. Consequently, according to the exemplary embodiment, the occurrence of a problem due to the formation of the conductive layer 422 can be reduced.

[0078] The conductive layer 422 has a relatively large volume. If the conductive layer 422 comes into direct contact with the MR element 50, the free layer 53 can be damaged due to the differing properties of the conductive layer 422 and other components. To address this, the conductive layer 422 does not come into contact with the MR element 50 in the exemplary embodiment. In this embodiment, the protective layer 70 specifically comprises the first part 60 and the second part 421A. The conductive layer 422 does come into contact with the second part 421A. Consequently, according to this embodiment, the conductive layer 422 can be positioned further away from the MR element 50 than in a case where the second part 421A is not provided. As a result, the occurrence of a problem due to the conductive layer 422 can be reduced according to this embodiment.

[0079] As a method for manufacturing the MR element 50 and the upper electrode 42, a manufacturing process using a photoresist mask without the use of the inorganic material layer 80 is considered. The manufacturing process using a photoresist mask is referred to below as the manufacturing process of a comparative example. In the manufacturing process of the comparative example, a photoresist mask is first formed on the initial MR element 50P. The photoresist mask has a shape that corresponds to the planar shape of the MR element 50.

[0080] A photoresist mask is a type of photoresist mask that comprises a base layer and an upper layer placed on top of the base layer. The upper layer is formed from a photoresist that is textured using photolithography. The base layer is formed from a material that is dissolved, for example, by a developer used in the texturing of the upper layer. Such a photoresist mask has an undercut that creates a space between the photoresist mask and its base layer.

[0081] In the manufacturing process of the comparative example, the initial MR element 50P is next etched by ion beam etching using the photoresist mask. This transforms the initial MR element 50P into the MR element 50. Next, the insulating layer 30 is formed on the entire upper surface of the stacked body using the remaining photoresist mask. The photoresist mask is then removed. Finally, the upper electrode 42 is formed on the MR element 50 and the insulating layer 30.

[0082] To form the magnetic vortex structure in the free layer 53, the thickness of the free layer 53 must be increased. When the initial MR element 50P, which encloses the free layer 53 with a large thickness, is etched, a re-deposited film increases due to substances dispersed during etching. Therefore, the width of the lower layer of the photoresist mask must be reduced. However, in this case, the photoresist mask can collapse during etching. If the insulating layer 30 is formed with the collapsing photoresist mask, the insulating layer 30 formed around the MR element 50 and the insulating layer 30 formed on the surface of the photoresist mask are bonded together, preventing removal of the photoresist mask.If the insulating layer 30 is formed with the collapsing photoresist mask, the insulating layer 30 may not be sufficiently formed around the MR element 50. In this case, the MR element 50 may be damaged when the photoresist mask is removed using a peeling solution.

[0083] To address this, in the exemplary embodiment, as described above, the MR element 50 and the upper electrode 42 are formed using the inorganic material layer 80. Consequently, according to the exemplary embodiment, the problem described above due to the photoresist mask can be avoided.

[0084] Next, further effects of the magnetic sensor 1 according to the exemplary embodiment are described. The thickness of the first part 60 of the protective layer 70 can be in a range of 40 to 100% of the thickness of the free layer 53 of the MR element 50. In this case, the damage to the free layer 53 during the etching step of the inorganic material layer 80 can be reduced.

[0085] Alternatively, the thickness of the first part 60 of the protective layer 70 can be within a range of 20 to 40% of the thickness of the free layer 53 of the MR element 50. In this case, the thickness of the entire magnetic sensor 1 can be reduced. [Modification example]

[0086] Next, with reference to Fig. 16 describes a modification example of the embodiment. Fig. Figure 16 is a sectional view showing part of the magnetic sensor 1 of a modification example. In the modification example, the angle formed by the side surface 60d of the first part 60 of the protective layer 70 relative to the direction parallel to the Z-direction is greater than the angle formed by the side surface of the MR element 50 relative to the direction parallel to the Z-direction. [Second embodiment]

[0087] Next, a second embodiment of the revelation will be described. First, with reference to the Fig. Sections 17 to 19 describe a manufacturing process for the magnetic sensor 1 according to the exemplary embodiment. Fig. Figures 17 to 19 show cross-sections of a stacked body in a manufacturing process for the magnetic sensor 1.

[0088] The manufacturing process for the magnetic sensor 1 according to the embodiment is the same as that of the first embodiment up to the step of forming the insulating layer 30. Fig. Figure 17 shows the next step. In this step, the insulating layer 30 is polished, for example, using CMP, until the inorganic material layer 80 is exposed.

[0089] Fig. Figure 18 shows the next step. In this step, the inorganic material layer 80 is removed. If the inorganic material layer 80 is composed of carbon, it is removed by ashing, for example, with an O2-containing ashing gas. In the exemplary embodiment, the inorganic material layer 80 is removed completely or substantially completely. During the removal of the inorganic material layer 80, a contact hole is formed in the insulating layer 30 for connecting the MR element 50 to the upper electrode 42. In this case, the entire inorganic material layer 80 can be removed from the second surface 60b of the first part 60. In other words, the second surface 60b of the first part 60 can be completely exposed.

[0090] Note that when etching the inorganic material layer 80, part of the first part 60 may be etched along with the inorganic material layer 80. When the first part 60 is etched, a recess may be formed in the first part 60, extending from the second surface 60b towards the first surface 60a, and having a depth such that it does not reach the first surface 60a.

[0091] If the inorganic material layer 80 is removed by ashing using an O2-containing ashing gas, as described above, an oxide film forms on the second surface 60b of the first part 60. Therefore, in this case, the oxide film is preferably removed after the removal of the inorganic material layer 80, e.g., by ion beam etching or reverse sputtering.

[0092] Fig. Figure 19 shows the next step. In this step, the sublayer 421 is formed along the second surface 60b of the first part 60 and the surface of the insulating layer 30. Subsequently, the conductive layer 422 is formed on the sublayer 421. The following steps are the same as in the first embodiment.

[0093] Next, with reference to Fig. 19 The differences between the configuration of the magnetic sensor 1 according to the exemplary embodiment and that of the first exemplary embodiment are described. In the exemplary embodiment, the outer edge 421Ae of the second part 421A coincides or substantially coincides with the outer edge of the second surface 60b of the first part 60 when viewed in the Z direction. The outer edge 421Ae of the second part 421A may be located, when viewed in the Z direction, on the inside of the outer edge of the first surface 60a of the first part 60.

[0094] In this embodiment, the planar shape of a portion of the upper electrode 42, located within the contact hole of the insulating layer 30, is the same or substantially the same as the planar shape of the first portion 60 of the protective layer 70. Consequently, according to this embodiment, the contact area between the first portion 60 and the upper electrode 42 (second portion 421A) can be increased. As a result, according to this embodiment, the resistance of the entire magnetic sensor 1 can be reduced.

[0095] The configuration, operation and effects of the embodiment are otherwise the same as those of the first embodiment. [Third embodiment]

[0096] Next, with reference to Fig. 20 a third embodiment of the revelation is described. Fig. Figure 20 is an enlarged sectional view showing part of the magnetic sensor 1 according to the embodiment. The configuration of the magnetic sensor 1 according to the embodiment differs from that of the first embodiment as follows. In the embodiment, an inorganic material layer 180 is provided instead of the inorganic material layer 80 of the first embodiment. The shape and layout of the inorganic material layer 180 are the same as the shape and layout of the inorganic material layer 80. The inorganic material layer 180 is, for example, formed of Al₂O₃.

[0097] If the inorganic material layer 180 is formed of Al2O3, the first part 60 of the protective layer 70 preferably includes a non-magnetic nickel-based alloy such as NiCr or a metal film formed of Ru. The non-magnetic nickel-based alloy or the metal film formed of Ru acts as an etch stopper in the etching step of the inorganic material layer 180. In the Fig. In the example shown in Figure 20, the first part 60 comprises a first layer 61, a second layer 62, and a third layer 63, which are stacked on the MR element 50 in the specified order. The inorganic material layer 180 is arranged on the third layer 63. In the Fig. In the example shown in Figure 20, the third layer 63 can be a metal film formed from NiCr.

[0098] In the Fig. In the example shown, the sublayer 421 comprises a first layer 4211 and a second layer 4212 stacked on top of the first layer 4211. In this case, the second layer 62 and the second layer 4212 can each be a first metal film formed from the first metal material. The first layer 61 and the first layer 4211 can be formed from the same metal material or from different metal materials. In one example, the first layer 61 is a metal film formed from Ru, the second layer 62 is a metal film formed from Ta, the third layer 63 is a metal film formed from NiCr, the first layer 4211 is a metal film formed from Ti, and the second layer 4212 is a metal film formed from Ta.

[0099] The configuration, operation and effects of the embodiment are otherwise the same as those of the first embodiment. [Fourth example]

[0100] Next, with reference to Fig. 21 a fourth embodiment of the revelation is described. Fig. Figure 21 is an enlarged sectional view showing part of the magnetic sensor 1 according to the exemplary embodiment. The configuration of the magnetic sensor 1 according to the exemplary embodiment differs from that of the third exemplary embodiment as follows. In the exemplary embodiment, the inorganic material layer 180 has an opening 180a that exposes part of the second surface 60b of the first part 60 of the protective layer 70. The size of the opening 180a in the cross-section of the inorganic material layer 180 parallel to the XY plane can be constant regardless of the distance to the second surface 60b or increase with increasing distance to the second surface 60b.

[0101] In the exemplary embodiment, the planar shape of the opening 180a of the inorganic material layer 180 is, in particular, larger than the planar shape of the second part 421A of the protective layer 70. The insulating layer 30 is arranged between the wall surface of the opening 180a of the inorganic material layer 180 and the second part 421A of the protective layer 70, as well as between the wall surface of the opening 180a of the inorganic material layer 180 and part 421B of the sublayer 421.

[0102] The insulating layer 30 encloses an opening 30a that exposes part of the second surface 60b of the first part 60 of the protective layer 70. The size of the opening 30a in the cross-section of the insulating layer 30 parallel to the XY plane can be constant regardless of the distance to the second surface 60b or increase with increasing distance to the second surface 60b.

[0103] The sublayer 421 including the second part 421A is arranged along the wall surface of the opening 30a of the insulation layer 30 and part of the second surface 60b.

[0104] The outer diameter of the planar shape of the recess 60c of the first part 60 is smaller than the inner diameter of the planar shape of the opening 180a of the inorganic material layer 180 and is the same or substantially the same as the outer diameter of the planar shape of the opening 30a of the insulating layer 30.

[0105] The configuration, operation, and effects of the embodiment are otherwise the same as those of the third embodiment.

[0106] Note that the disclosure is not limited to the foregoing embodiments and that various modifications may have been made thereto. For example, the shape of the side surface of the MR element 50 and the shape of the side surface 60d of the first part 60 are not limited to the examples described in the individual embodiments. Thus, the side surface of the MR element 50 may, for example, have a curved surface section. Likewise, the side surface 60d of the first part 60 may have a curved surface section.

[0107] As described above, a magnetic sensor according to one embodiment of the disclosure includes: a magnetoresistive element comprising a magnetization-fixed layer with a magnetization in a fixed direction, a free layer with a magnetization that is variable according to an applied magnetic field, and a gap layer arranged between the magnetization-fixed layer and the free layer; a protective layer arranged over the magnetoresistive element; and a conductive layer electrically connected to the magnetoresistive element. The protective layer comprises a first part and a second part, such that the second part is arranged such that the first part lies between the second part and the magnetoresistive element.Viewed in a stacking direction of the magnetization-fixed layer, the gap layer, and the free layer, an outer edge of the second part is located on an inner edge of the outer edge of the first part. The conductive layer comes into contact with the second part.

[0108] The magnetic sensor according to one embodiment of the disclosure can further include an electrode. The electrode can include the conductive layer and a sublayer that serves as a nucleation layer for the conductive layer. The sublayer can include the second part of the protective layer.

[0109] In the magnetic sensor according to one embodiment of the disclosure, the first part can include a first metal film formed from a first metal material. The second part can include a second metal film formed from the first metal material. The protective layer can further include a third metal film formed from a second metal material.

[0110] In the magnetic sensor according to one embodiment of the disclosure, the first part can have a first surface and a second surface located at both ends in the stacking direction. The first surface can face the magnetoresistive element. The second surface can face the second part. The first part can further have a recess that is set back from the second surface in the direction of the first surface. At least a portion of the second part can be arranged within the recess.

[0111] The magnetic sensor according to one embodiment of the disclosure can further comprise an inorganic material layer arranged around the second part on the first part of the protective layer. The outer diameter of a planar shape of the recess can be smaller, viewed in the stacking direction, than the outer diameter of the planar shape of the inorganic material layer, also viewed in the stacking direction. The outer diameter of the planar shape of the inorganic material layer can be equal to or smaller, viewed in the stacking direction, than the outer diameter of the planar shape of the magnetoresistive element.

[0112] The magnetic sensor according to one embodiment of the disclosure can further comprise an electrode. The electrode can enclose the conductive layer and a sublayer that serves as a nucleation layer for the conductive layer. The sublayer can enclose the second part of the protective layer. The electrode can come into contact with the first part of the protective layer. The area of ​​the contact surface between the electrode and the first part of the protective layer can be, viewed in the stacking direction, equal to the area of ​​the planar shape of the recess.

[0113] In the magnetic sensor according to one embodiment of the disclosure, the thickness of the first part of the protective layer in the stacking direction can be in a range of 40 to 100% of the thickness of the free layer in the stacking direction. The thickness of the first part of the protective layer in the stacking direction can be in a range of 20 to 40% of the thickness of the free layer in the stacking direction.

[0114] In the magnetic sensor according to an embodiment of the disclosure, the free layer can be configured such that the free layer can have a magnetic vortex structure and a center of the magnetic vortex structure can move according to a target magnetic field. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2023 / 0324477 A1 [0003, 0005]

Claims

[1] A magnetic sensor (1) comprising: a magnetoresistive element (50) comprising a magnetization-fixed layer (51) with a magnetization (51m) in a fixed direction, a free layer (53) with a magnetization (53m) that is variable according to an applied magnetic field, and a gap layer (52) arranged between the magnetization-fixed layer (51) and the free layer (53); a protective layer (70) arranged above the magnetoresistive element (50); and a conductive layer (422) which is electrically connected to the magnetoresistive element (50), wherein the protective layer (70) includes a first part (60) and a second part (421A) such that the second part (421A) is arranged in such a way that the first part (60) lies between the second part (421A) and the magnetoresistive element (50), seen in a stacking direction of the magnetization-fixed layer (51), the cleavage layer (52) and the free layer (53), an outer edge of the second part (421A) is arranged on an inner side of the outer edge of the first part (60), and the conductive layer (422) comes into contact with the second part (421A). [2] The magnetic sensor (1) according to claim 1, further comprising an electrode (42), wherein the electrode (42) includes the conductive layer (422) and a sublayer (421) which serves as a nucleation layer for the conductive layer (422), and the lower layer (421) includes the second part (421A) of the protective layer (70). [3] The magnetic sensor (1) according to claim 1, wherein the first part (60) includes a first metal film formed from a first metallic material, and the second part (421A) includes a second metal film formed from the first metal material. [4] The magnetic sensor (1) according to claim 3, wherein the protective layer (70) further encloses a third metal film formed from a second metal material. [5] The magnetic sensor (1) according to claim 1, wherein the first part (60) includes a first surface (60a) and a second surface (60b) which lie at both ends in the stacking direction, the first surface (60a) faces the magnetoresistive element (50), the second surface (60b) faces the second part (421A), the first part (60) further includes a recess (60c) which is deepened from the second surface (60b) in the direction of the first surface (60a), and at least part of the second part (421A) is provided within the recess (60c). [6] The magnetic sensor (1) according to claim 5, further comprising an inorganic material layer (80) arranged around the second part (421A) on the first part (60) of the protective layer (70). [7] The magnetic sensor (1) according to claim 6, wherein an outer diameter of a planar shape of the recess (60c) seen in the stacking direction is smaller than the outer diameter of the planar shape of the inorganic material layer (80) seen in the stacking direction. [8] The magnetic sensor (1) according to claim 7, wherein, when viewed in the stacking direction, the outer diameter of the planar shape of the inorganic material layer (80) is equal to or smaller than the outer diameter of the planar shape of the magnetoresistive element (50), [9] The magnetic sensor (1) according to claim 5, further comprising an electrode (42), wherein the electrode (42) includes the conductive layer (422) and a sublayer (421) which serves as a nucleation layer for the conductive layer (422), and the lower layer (421) includes the second part (421A) of the protective layer (70), the electrode (42) comes into contact with the first part (60) of the protective layer (70), and when, viewed in the stacking direction, an area of ​​a contact surface between the electrode (42) and the first part (60) of the protective layer (70) is equal to the area of ​​the planar shape of the recess (60c). [10] The magnetic sensor (1) according to claim 1, wherein the thickness of the first part (60) of the protective layer (70) in the stacking direction is in a range of 40 to 100% of the thickness of the free layer (53) in the stacking direction. [11] The magnetic sensor (1) according to claim 1, wherein the thickness of the first part (60) of the protective layer (70) in the stacking direction is in a range of 20 to 40% of the thickness of the free layer (53) in the stacking direction. [12] The magnetic sensor (1) according to any one of claims 1 to 11, wherein the free layer (53) is configured such that the free layer (53) can have a magnetic vortex structure and a center (53c) of the magnetic vortex structure can move according to a target magnetic field.

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