Magnetic sensor device and manufacturing process for a magnetic sensor device

Abstract

The invention relates to a magnetic sensor device comprising a substrate (10) and at least one sensor structure (A) with at least one sensing element (16a), which is arranged in a first sensing area (14a) located directly on or adjacent to a substrate surface (12), and by means of which a magnetic field component present in the first sensing area (14a) can be detected along a sensing axis (18a) assigned to each sensing axis and aligned parallel to the substrate surface (12), and a first layer (20a) comprising at least one soft magnetic material, which is located between the substrate (10) and the first sensing area (14a) located directly on or adjacent to the substrate surface (12) or on a side of the first sensing area (14a) facing away from the substrate (10).wherein a first outer surface (22a) of the first layer (20a) oriented towards the first sensing area (14a) has at least one partial surface (24a) which is oriented at a local angle of inclination greater than or equal to 2° and less than or equal to 70° to the substrate surface (12).

Description

[0001] The invention relates to a magnetic sensor device. The invention also relates to a manufacturing method for a magnetic sensor device. State of the art

[0002] US Pat. No. 11,209,503 B2 describes a magnetic sensor comprising at least one magnetoresistive sensing element and a shielding layer made of at least one soft magnetic material. The shielding layer is arranged either between a substrate surface of a substrate of the magnetic sensor and the at least one magnetoresistive sensing element or on a side of the at least one magnetoresistive sensing element facing away from the substrate. Disclosure of the invention

[0003] The present invention provides a magnetic sensor device having the features of claim 1 and manufacturing methods for a magnetic sensor device having the features of claim 13. Advantages of the invention

[0004] The present invention provides magnetic sensor devices in which a layer, hereinafter referred to as the first layer, which comprises at least one soft magnetic material, can be used not only as a shielding element / shielding layer, but also as a flux diverter / deflecting element (flux guide), in contrast to the prior art. The functionality of the first layer of at least one sensor structure of the magnetic sensor device according to the invention is thus increased compared to the prior art. Firstly, the first layer shields a first sensing region of the sensor structure formed thereby from a magnetic field component of an external magnetic field, which is aligned parallel to a substrate surface of a substrate of the magnetic sensor device.In addition, the first layer directs a magnetic field component of the external magnetic field, oriented perpendicular to the substrate surface, into the associated first sensing region along a sensing axis of at least one sensing element of the respective sensor structure. The respective first layer of a magnetic sensor device according to the invention can therefore also be referred to as a (first) shielding and flux deflection layer.

[0005] By means of the (first) shielding and flux deflector layer realized by utilizing the present invention, there is no need to equip the at least one sensor structure of the magnetic sensor device according to the invention with a conventional flux deflector. The present invention thus facilitates the miniaturization of magnetic sensor devices. By means of the possibility created by the invention for reducing the volume and / or weight of magnetic sensor devices, the usability of magnetic sensor devices can also be increased. Furthermore, the present invention contributes to reducing the costs of magnetic sensor devices by eliminating the need for conventional flux deflectors.

[0006] In one embodiment of the magnetic sensor device, the first layer is designed such that, by means of the first layer, the first sensing region can be shielded from a magnetic field component of an external magnetic field aligned along a first spatial axis, and by means of the first layer, a magnetic field component of the external magnetic field aligned along a vertical axis can be deflected into the first sensing region along the first sensing axis, wherein the first spatial axis is aligned parallel to the substrate surface and the vertical axis is aligned perpendicular to the substrate surface, and wherein the first sensing axis is aligned along a second spatial axis aligned parallel to the substrate surface and perpendicular to the first spatial axis.In the embodiment of the magnetic sensor device described here, the first layer thus advantageously fulfills the functions of a shielding element / shielding layer according to the prior art and a conventional flux diverter. In the embodiment described here, the multifunctionality of the first layer is thus increased compared to the prior art.

[0007] The multifunctionality of the first layer is also increased if the first layer is designed such that by means of the first layer the first sensing region can be shielded from a magnetic field component of an external magnetic field aligned along a first spatial axis and by means of the first layer a magnetic field component of the external magnetic field aligned along a vertical axis can be deflected into the first sensing region along the first sensing axis, wherein the first spatial axis is aligned parallel to the substrate surface and the vertical axis is aligned perpendicular to the substrate surface, and wherein the first sensing axis is aligned along the first spatial axis.

[0008] Likewise, the first layer can be designed such that, by means of the first layer, the first sensing region can be shielded from a magnetic field component of an external magnetic field aligned along a first spatial axis and a magnetic field component of the external magnetic field aligned along a second spatial axis, and by means of the first layer, a magnetic field component of the external magnetic field aligned along a vertical axis can be deflected into the first sensing region along the first sensing axis, wherein the first spatial axis and the second spatial axis are aligned parallel to the substrate surface, the first spatial axis is aligned perpendicular to the second spatial axis, and the vertical axis is aligned perpendicular to the substrate surface.

[0009] Preferably, the at least one first sensor structure additionally has a second layer which comprises the at least one and / or at least one further soft magnetic material, wherein, if the first layer lies between the substrate and the first sensing region lying directly on or adjacent to the substrate surface, the second layer lies on the side of the first sensing region facing away from the substrate, or, if the first layer lies on the side of the first sensing region facing away from the substrate, the second layer lies between the substrate and the first sensing region lying directly on or adjacent to the substrate surface. In addition to the first layer, the second layer can thus also be used at least as a shielding element / shielding layer in order to improve shielding of the first sensing region.

[0010] As an advantageous development, a second outer surface of the second layer aligned with the first sensing region can have at least one partial surface that is aligned with the substrate surface at a local inclination angle of greater than or equal to 2° and less than or equal to 70°. The second layer can thus also be used as a flux diverter in addition to a shielding function. In the embodiment of the magnetic sensor device described here, the multifunctionality of the second layer is therefore also increased.

[0011] For example, the first outer surface and / or the second outer surface can be corrugated and / or angled at least partially. As will become clear from the following description, such a design for the first layer and / or for the second layer can be realized using a simple manufacturing process.

[0012] As a further advantageous development, the magnetic sensor device can additionally be designed with at least one second sensor structure with at least one further sensing element, which is arranged in a second sensing region lying directly on or adjacent to the substrate surface, and by means of which a magnetic field component present in the second sensing region can be detected along a respectively assigned second sensing axis aligned parallel to the substrate surface, and a third layer which comprises the at least one and / or at least one further soft magnetic material, and which lies between the substrate and the second sensing region lying directly on or adjacent to the substrate surface or on a side of the second sensing region directed away from the substrate,and which has a third outer surface aligned with the second sensing region, with at least one partial surface aligned with the substrate surface at a local inclination angle of greater than or equal to 2° and less than or equal to 70°. The embodiment of the magnetic sensor device described here thus has, in addition to a first sensor structure comprising at least the first sensing region and the first layer, a second sensor structure formed with at least the second sensing region and the third layer. By equipping the embodiment of the magnetic sensor device described here with the (at least) two sensor structures, its measurement accuracy and reliability can be increased.

[0013] Advantageously, a first average distance of the at least one sensing element in the first sensing region from the first outer surface of the first layer can be unequal to a second average distance of the at least one sensing element in the second sensing region from the third outer surface of the third layer, and / or a first maximum local angle of inclination of the at least one inner partial surface of the first outer surface of the first layer to the substrate surface can be unequal to a second maximum local angle of inclination of the at least one inner partial surface of the third outer surface of the third layer to the substrate surface. In all cases described here, the first sensor structure can be designed with a first sensitivity that differs from a second sensitivity of the second sensor structure.This can be used to extend the measuring range of the magnetic sensor device equipped with (at least) two sensor structures.

[0014] The advantage described above can also be realized by a first layer thickness of the first layer oriented perpendicular to the substrate surface being unequal to a second layer thickness of the third layer oriented perpendicular to the substrate surface, a first length of the first layer oriented along the first sensing axis being unequal to a second length of the third layer oriented along the second sensing axis, a first width of the first layer oriented perpendicular to the substrate surface and perpendicular to the first sensing axis being unequal to a second width of the third layer oriented perpendicular to the substrate surface and perpendicular to the second sensing axis, a first interlayer distance of the first layer to the second layer being unequal to a second interlayer distance of the third layer to a fourth layer of the same second sensor structure,which comprises the at least one and / or at least one further soft magnetic material and, if the third layer lies between the substrate and the second sensing region lying directly on or adjacent to the substrate surface, lies on the side of the second sensing region facing away from the substrate, or, if the third layer lies on the side of the second sensing region facing away from the substrate, lies between the substrate and the second sensing region lying directly on or adjacent to the substrate surface, and / or an arrangement or distribution of the at least one sensing element in the first sensing region with respect to a first volume center of the first sensing region deviates from an arrangement or distribution of the at least one sensing element in the second sensing region with respect to a second volume center of the second sensing region.

[0015] Advantageously, a first orientation of the first sensing axis can also differ from a second orientation of the second sensing axis. This allows different directional sensitivities to be implemented on the magnetic sensor device.

[0016] As an advantageous development, the magnetic sensor device can have at least two first sensor structures and at least two second sensor structures, wherein a first intermediate distance between two adjacent first sensor structures is not equal to a second intermediate distance between two adjacent second sensor structures.

[0017] The advantages explained above are also achieved by implementing a corresponding manufacturing method for a magnetic sensor device. In an advantageous embodiment of the manufacturing method, the second layer is formed between the substrate and the first sensing region located directly on or adjacent to the substrate surface. Before forming the first layer, a dielectric, non-magnetic layer is formed on the side of the first sensing region facing away from the substrate, which dielectric, non-magnetic layer is formed at least partially with a wave shape and / or a truncated pyramid shape. The first layer is then formed on the dielectric, non-magnetic layer. This is easy to implement and results in an at least partially waved and / or angled outer surface of the first layer. Short description of the drawings

[0018] Further features and advantages of the present invention are explained below with reference to the figures. They show: Fig. 1a to 1h are schematic representations of a first embodiment of the magnetic sensor device together with a coordinate system and magnetic field line images for explaining its operation; Fig. 2 a schematic representation of a second embodiment of the magnetic sensor device; Fig. 3 is a schematic representation of a third embodiment of the magnetic sensor device; Fig. 4 is a flowchart for explaining a first embodiment of the manufacturing method for a magnetic sensor device; Fig. 5A to 5D are cross-sectional views of intermediate products for explaining a second embodiment of the manufacturing method for a magnetic sensor device; and Fig. 6A to 6D are cross-sectional views of intermediate products for explaining a third embodiment of the manufacturing method for a magnetic sensor device. Embodiments of the invention

[0019] Fig. 1a to 1h show schematic representations of a first embodiment of the magnetic sensor device together with a coordinate system and magnetic field line images for explaining its operation.

[0020] The Fig. 1a and Fig. The magnetic sensor device schematically illustrated in Figure 1b comprises a substrate 10 with a substrate surface 12. The substrate 10 can be, for example, a semiconductor substrate, such as specifically a silicon substrate. The magnetic sensor device is also formed with at least one sensor structure A. The respective sensor structure A comprises a sensing region 14a, in which at least one sensing element 16a is arranged / formed. The sensing region 14a lies optionally directly on or adjacent to the substrate surface 12 of the substrate 10. The at least one sensing element 16a, which is arranged / formed in the sensing region 14a, is implemented such that, by means of the at least one sensing element 16a, a magnetic field component present in the sensing region 14a along a respectively assigned sensing axis 18a can be detected / is detected. The sensing axis 18a is also aligned parallel to the substrate surface 12 of the substrate 10.Detection of the magnetic field component present in the sensing region 14a and aligned along the sensing axis 18a can be understood as detecting at least a minimum magnetic field strength and / or measuring a magnetic field strength / magnetic flux density of the respective magnetic field component.

[0021] The at least one sensing element 16a in the sensing region 14a can, for example, be a Hall element and / or a magnetoresistive element, such as in particular a TMR element (Tunnel Magnetoresistance), an AMR element (Anisotropic Magnetoresistance), and / or a GMR element (Giant Magnetoresistance). The detection of the magnetic field component present in the sensing region 14a and aligned along the sensing axis 18a, which can be carried out / is carried out by means of the at least one sensing element 16a, can thus be based on the Hall, GMR, AMR, and / or TMR functional principle. However, it should be noted that the designability of the magnetic sensor device described here is not limited to any specific sensing element type of its at least one sensing element 16a. Several sensing elements 16a can be placed in pairs such that they each measure identical magnetic field strengths but opposite field directions.Preferably, a plurality of sensing elements 16a can be arranged in a plane parallel to the substrate surface 12 of the substrate 10. However, other arrangements for the at least one sensing element 16a arranged / formed in the sensing region 14a are also possible. In particular, a plurality of sensing elements 16a can be interconnected to form a Wheatstone bridge, wherein the individual bridge resistors can be composed of a plurality of sensing elements 16a connected in parallel and / or series.

[0022] The magnetic sensor device also has a first layer 20a, which comprises at least one soft magnetic material. Preferably, the first layer 20a is formed (completely) from the at least one soft magnetic material. For example, the first layer 20a can be formed at least partially (preferably completely) from a nickel-iron alloy (NiFe). Preferably, the first layer 20a consists of 81% nickel and 19% iron.

[0023] In the design of the Fig. 1a to 1h, the first layer 20a lies on a side of the sensing region 14a facing away from the substrate 10. Alternatively, however, the first layer 20a can also be arranged between the substrate 10 and the sensing region 14a located directly on or adjacent to the substrate surface 12. If the first layer 20a lies between the substrate 10 and the sensing region 14a, the first layer 20a can optionally be arranged between the substrate surface 12 and the sensing region 14a located adjacent to the substrate surface 12, or in a recess of the substrate 10 structured into the substrate surface 12.

[0024] Due to its advantageous arrangement relative to the sensing region 14a, the first layer 20a can be used as a shielding element / shielding layer for the sensing region 14a, in particular for the at least one sensing element 16a arranged in the sensing region 14a. In particular, the first layer 20a can be designed such that the sensing region 14a / its at least one sensing element 16a can be shielded / shielded by the first layer 20a (primarily) from a magnetic field component Bx_ext of an external magnetic field B_ext oriented along a first spatial axis x, wherein the first spatial axis x is oriented parallel to the substrate surface 12 of the substrate 10. This is easily achieved by providing the first layer 20a with a sufficient extension along a second spatial axis y oriented perpendicular to the first spatial axis x and parallel to the substrate surface 12.

[0025] By way of example only, the Fig. 1a and Fig. 1b, the first layer 20a has its longest axis along the second spatial axis y, so that the strongest shielding effect of the first layer 20a is achieved along the first spatial axis x. The first spatial axis x can therefore also be defined as a shielding axis of the first layer 20a. Alternatively, the first layer 20a can have its longest axis along the first spatial axis x, so that the strongest shielding effect of the first layer 20a is achieved along the second spatial axis y. In this case, the second spatial axis y can also be defined as a shielding axis of the first layer 20a. Likewise, the first layer 20a can have the same dimensions along the first spatial axis x and along the second spatial axis y, so that its shielding effect for the sensing region 14a / its at least one sensing element 16a is achieved to the same extent in both spatial axes x and y aligned parallel to the substrate surface 12.Preferably, the dimensions of the first layer 20a in the spatial axes x and y aligned parallel to the substrate surface 12 are greater than its maximum extent along a third spatial axis z aligned perpendicular to the substrate surface 12.

[0026] The Fig. The orientation of the sensing axis 18a along the second spatial axis y and perpendicular to the first spatial axis x, illustrated in Figure 1a, is to be interpreted only as an example. Alternatively, the sensing axis 18a can also run parallel to the first spatial axis x and perpendicular to the second spatial axis y. Likewise, the sensing axis 18a can be inclined relative to the spatial axes x and y, which are aligned parallel to the substrate surface 12.

[0027] As in Fig. 1a and Fig. 1b, a first outer surface 22a of the first layer 20a, which is aligned with the sensing region 14a, has at least one partial surface 24a, which is aligned with the substrate surface 12 at a local inclination angle of greater than or equal to 2° and less than or equal to 70°. The first outer surface 22a of the first layer 20a, which is aligned with the sensing region 14a, is thus to be understood as a "non-planar surface." Preferably, the respective local inclination angle of the at least one partial surface 24a lies between 2° and 70° in a cross-sectional plane that is aligned perpendicular to the substrate surface 12 and extends along the sensing axis 18a.This can also be described by the fact that each section line of each partial surface 24a in the cross-sectional plane aligned perpendicular to the substrate surface 12 and extending along the sensing axis 18a is inclined by the local inclination angle between 2° and 70° to a section line of the substrate surface 12 in the cross-sectional plane.

[0028] The first layer 20a formed with the first outer surface 22a therefore acts not only as a shielding element / shielding layer, but also as a flux guide / deflector element (flux guide). In particular, by means of the first layer 20a, a magnetic field component Bz_ext of the external magnetic field B_ext, aligned along the third spatial axis z, can be deflected / deflected into the sensing region 14a and along the sensing axis 18a. The functionality of the first layer 20a is therefore enhanced compared to the previously described prior art.

[0029] The first outer surface 22a of the first layer 20a can be at least partially corrugated and / or angled. A section line of the first outer surface 22 in the cross-sectional plane oriented perpendicular to the substrate surface 12 and extending along the sensing axis 18a can thus at least partially be a wavy line and / or a zigzag line. In the example of Fig. 1a and Fig. 1b, a plurality of partial surfaces 24a of the first outer surface 22a, each inclined by a local angle of inclination greater than or equal to 2° and less than or equal to 70° relative to the substrate surface 12, lie as inner partial surfaces 24a between intermediate partial surfaces 26a of the first outer surface 22a aligned parallel to the substrate surface 12. Alternatively, however, the formation of the intermediate partial surfaces 26a on the first outer surface 22a can be omitted. A rear surface 28a of the first layer 20a directed away from the sensing region 14a can optionally be planar or at least partially corrugated and / or angled.

[0030] As an advantageous development, the magnetic sensor device of the embodiment described here also has a second layer 30a, which comprises the at least one and / or at least one further soft magnetic material. Preferably, the second layer 30a is formed (completely) from the at least one soft magnetic material. In particular, the second layer 30a can be formed at least partially (preferably completely) from a nickel-iron alloy (NiFe), specifically 81% nickel and 19% iron.

[0031] Because in the example of Fig. 1a to 1h, the first layer 20a is located on the side of the sensing region 14a facing away from the substrate 10, the second layer 30a is located between the substrate 10 and the sensing region 14a located directly on or adjacent to the substrate surface 12. In particular, the second layer 30a is located between the substrate surface 12 and the sensing region 14a located adjacent to the substrate surface 12. Alternatively, the second layer 30a can also be arranged in a recess of the substrate 10 structured into the substrate surface 12. It is also pointed out that the Fig. The arrangement of the second layer 30a in (direct) contact with the substrate 10, illustrated in Figure 1a, is to be interpreted only as an example. Optionally, at least one (not sketched) intermediate layer can be formed between the substrate 10 and the second layer 30a.

[0032] If the first layer 20a is arranged between the substrate 10 and the sensing region 14a lying directly on or adjacent to the substrate surface 12, with at least one intermediate layer possibly also being arranged between the substrate 10 and the first layer 20a, the second layer 30a lies on the side of the sensing region 14a facing away from the substrate 10. Preferably, the layers 20a and 30a are arranged relative to one another such that they are (essentially) congruent in the cross-section of the third spatial axis z. The distance between the layers 20a and 30a is preferably between 0.5 µm (micrometers) and 10 µm (micrometers). The at least one material surrounding at least the first layer 20a and possibly also the second layer 30a is preferably non-magnetic.

[0033] Regardless of whether the second layer 30a is located between the substrate 10 and the sensing region 14a or on the side of the sensing region 14a facing away from the substrate 10, the second layer 30a can also be used as a shielding element / shielding layer. This is possible by means of the magnetic field line images of the Fig. 1c and Fig. 1d shown pictorially: The magnetic field line pattern of the Fig. 1c indicates a local quotient Qx of a local magnetic flux density value of a local magnetic field B divided by a magnetic flux density value of the magnetic field component Bx_ext of the external magnetic field B_ext aligned along the first spatial axis x. Accordingly, the magnetic field line image of the Fig. 1d shows a local quotient Qz of the local magnetic flux density value of the local magnetic field B divided by a magnetic flux density value of the magnetic field component Bz_ext of the external magnetic field B_ext aligned along the third spatial axis z. The magnetic field line image shows the Fig. 1c, that the sensing area 14a is so successfully shielded by the layers 20a and 30a from the magnetic field component Bx_ext of the external magnetic field B_ext aligned along the first spatial axis x that the local quotient Qx within the sensing area 14a is (for example) below 0.1%. This can be seen from the magnetic field line image of the Fig. 1d also shows that the local quotient Qz within the sensing area 14a is (exemplarily) 1.5. Thus, by means of the layers 20a and 30a, no / barely any attenuation of the magnetic field component Bz_ext of the external magnetic field B_ext, aligned along the third spatial axis z, is caused within the sensing area 14a.

[0034] Fig. Figure 1e shows a coordinate system whose abscissa represents the magnetic flux density value Bx_ext (in millitesla, mT) of the magnetic field component Bx_ext of the external magnetic field B_ext aligned along the spatial axis x, and whose ordinate represents a maximum local quotient Qx within the sensing area 14a (in percent, %). Fig. 1e, a shielding capacity / shielding effect of the layers 20a and 30a is thus indicated depending on the magnetic flux density value Bx_ext of the magnetic field component Bx_ext of the external magnetic field B_ext aligned along the spatial axis x. As can be seen from the coordinate system of the Fig. As can be seen in Figure 1e, a reliable shielding capacity / shielding effect of layers 20a and 30a for the sensing area 14a is ensured at least up to a magnetic flux density value Bx_ext of the magnetic field component Bx_ext of the external magnetic field B_ext aligned along the spatial axis x of (for example) approximately 325 mT. The shielding capacity / shielding effect of layers 20a and 30a can thus be advantageously utilized until their soft magnetic materials are "magnetically saturated." (As long as layers 20a and 30a are not "magnetically saturated," they possess a magnetic permeability orders of magnitude higher than their non-magnetic environment.)

[0035] Based on the magnetic field line images of the Fig. 1f to 1h, the advantageous suitability of the first outer surface 22a of the first layer 20a as a flow diverter is illustrated: The magnetic field line pattern of the Fig. 1f indicates a local quotient Ky of a local magnetic flux density value of a local magnetic field component By of the local magnetic field B aligned along the second spatial axis y / sensing axis 18a divided by the magnetic flux density value of the magnetic field component Bz_ext of the external magnetic field B_ext aligned along the third spatial axis z. The quotient Ky can also be referred to as a conversion factor Ky, which reflects which portion of the magnetic field component Bz_ext of the external magnetic field B_ext aligned along the third spatial axis z is / will be deflected into the second spatial axis y / sensing axis 18a. For comparison, the magnetic field line image of the Fig. 1g a local quotient Kz of a local magnetic flux density value of a local magnetic field component Bz of the local magnetic field B aligned along the third spatial axis z divided by the magnetic flux density value of the magnetic field component Bz_ext of the external magnetic field B_ext aligned along the third spatial axis z is displayed. Fig. 1h is an enlarged partial view of the Fig. 1f.

[0036] As shown by the Fig. As can be seen in Figures 1f to 1h, the at least one partial surface 24a of the first outer surface 22a of the first layer 20a (due to its inclination by the local inclination angle greater than or equal to 2° and less than or equal to 70° relative to the substrate surface 12) can be effectively used to deflect the magnetic field component Bz_ext of the external magnetic field B_ext, oriented along the third spatial axis z, into the second spatial axis y / sensing axis 18a. (This is possible because the magnetic permeability decreases by several orders of magnitude during a transition from the first layer 20a to the at least one surrounding non-magnetic material, and therefore the local magnetic field in the non-magnetic material is oriented almost perpendicularly to the first outer surface 22a.)

[0037] Typical external magnetic fields B_ext to be measured have magnetic flux densities of ±20 mT (millitesla) to ±100 mT (millitesla). (However, the measuring range of conventional magnetoresistive sensing elements is usually a few millitesla.) Suitable values ​​for the conversion factor Ky are therefore below 1, typically between 0.05 and 0.25. This is easily achievable with the design of the first outer surface 22a of the first layer 20a. Even a conversion factor Ky of (almost) 0 is feasible, with the sensing elements 16a preferably being placed centrally in a region between two partial surfaces 24a.

[0038] The flux deflection function of at least the first layer 20a can be reliably scaled by specifying the shape of the first outer surface 22a, i.e., the respective local angle of inclination. A distance of the sensing elements 16a in the third spatial axis z from the first outer surface 22a of the first layer 20a can also be easily set such that the conversion factor Ky has a preferred value at the position of the sensing element 16a. Likewise, the position of the sensing elements 16a along the second spatial axis y can be easily set such that the conversion factor Ky at the position of the sensing element 16a corresponds to a preferred value.

[0039] As an optional development, a second outer surface 32a of the second layer 30a, which is aligned with the sensing region 16a, can also have at least one (not sketched) partial surface, which is aligned at a local inclination angle of greater than or equal to 2° and less than or equal to 70° to the substrate surface 12. Thus, the second outer surface 32a of the second layer 30a can also be corrugated and / or angled over at least part of its surface.

[0040] The at least one partial surface 24a of the first outer surface 22a of the first layer 20a and / or the at least one partial surface of the second outer surface 32a of the second layer 30a can in particular each be aligned with the substrate surface 12 at a local inclination angle greater than or equal to 2° and less than or equal to 60°, e.g. at a local inclination angle greater than or equal to 3° and less than or equal to 60°, especially at a local inclination angle greater than or equal to 3° and less than or equal to 50°, as well as at a local inclination angle greater than or equal to 5° and less than or equal to 50°.

[0041] Fig. 2 shows a schematic representation of a second embodiment of the magnetic sensor device.

[0042] The magnetic sensor device of the Fig. 2, in addition to the substrate 10 and a first sensor structure A with the components 14a to 32a, also has at least one second sensor structure B. The at least one second sensor structure B is each formed with at least one further (not sketched) sensing element, which is each arranged in a second sensing region 14b located directly on or adjacent to the substrate surface 12. A magnetic field component present in the second sensing region 14b can also be detected by means of the at least one further sensing element along a respectively assigned sensing axis 18b aligned parallel to the substrate surface 12. In addition, the at least one second sensor structure B each has at least one third layer 20b, which comprises the at least one and / or at least one further soft magnetic material.The third layer 20b lies between the substrate 10 and the second sensing region 14b lying directly on or adjacent to the substrate surface 12 or on a side of the second sensing region 14b facing away from the substrate 10. In addition, the third layer 20b has a third outer surface 22b aligned with the second sensing region 14b and with at least one partial surface (not shown) which is aligned at a local inclination angle of greater than or equal to 2° and less than or equal to 70° to the substrate surface 12. By equipping the magnetic sensor device described here with the at least two sensor structures A and B, its measurement accuracy and reliability can be improved. As shown in . Fig. 2, for all of the above-described components 14a to 32a of the at least one first sensor structure, components corresponding to each other, such as specifically a fourth layer 30b corresponding to the second layer 30a, can be formed on / in the at least one second sensor structure B.

[0043] Optionally, a first average distance of the at least one sensing element 16a in the first sensing region 14a from the first outer surface 22a of the first layer 20a can be different from a second average distance of the at least one sensing element in the second sensing region 14b from the third outer surface 22b of the third layer 20b. Alternatively or additionally, a first maximum local angle of inclination of the at least one inner partial surface 24a of the first outer surface 22a of the first layer 20a to the substrate surface 12 can also be different from a second maximum local angle of inclination of the at least one inner partial surface of the third outer surface 22b of the third layer 20b to the substrate surface 12.The at least two sensor structures A and B can thus have different sensitivities / response sensitivities, whereby a comparatively broad measuring range can be covered by optimizing a sensitivity of at least one of the at least two sensor structures A and B for a specific part of the measuring range.

[0044] Regarding further properties and features of the magnetic sensor device of the Fig. 2 and its advantages, please refer to the description of the previously explained embodiment of the Fig. 1.

[0045] Fig. 3 shows a schematic representation of a third embodiment of the magnetic sensor device.

[0046] As shown by the Fig. 3, an orientation of the respective first sensing axis 18a of the at least one first sensor structure A can also deviate from an orientation of the respective second sensing axis 18b of the at least one second sensor structure B. Alternatively or additionally, if the magnetic sensor device has at least two first sensor structures A and at least two second sensor structures B, a first intermediate distance ΔA between two adjacent first sensor structures A can be unequal to a second intermediate distance ΔB between two adjacent second sensor structures B.

[0047] The at least two sensor structures A and B can also be formed with different sensitivities / response sensitivities by forming a first layer thickness of the first layer 20a oriented perpendicular to the substrate surface 12 that is not equal to a second layer thickness of the third layer 20b oriented perpendicular to the substrate surface 12. Further possibilities include forming a first length of the first layer 20a oriented along the first sensing axis 18a that is not equal to a second length of the third layer 20b oriented along the second sensing axis 18b and / or forming a first width of the first layer 20a oriented perpendicular to the substrate surface 12 and perpendicular to the first sensing axis 18a that is not equal to a second width of the third layer oriented perpendicular to the substrate surface 12 and perpendicular to the second sensing axis 18b.If the at least two sensor structures A and B are also each formed with a second layer 30a or a fourth layer 30b, it is also possible to define a first interlayer distance of the first layer 20a to the second layer 30a of the same first sensor structure A unequal to a second interlayer distance of the third layer 20b to the fourth layer 30b of the same second sensor structure B.Furthermore, an arrangement or distribution of the at least one sensing element 16a in the first sensing region 14a of the at least one first sensor structure A with respect to a first volume center of the first sensing region 14a of the same first sensor structure A can also differ from an arrangement or distribution of the at least one sensing element in the second sensing region 14b of the at least one second sensor structure B with respect to a second volume center of the second sensing region 14b of the same second sensor structure B. All of the possibilities mentioned here for forming the at least two sensor structures A and B with different sensitivities / response sensitivities are easily implemented.

[0048] Regarding further properties and features of the magnetic sensor device of the Fig. 3 and its advantages, reference is made to the description of the previously explained embodiments of the Fig. 1 and Fig. 2.

[0049] In the embodiments explained above, the layers 20a, 20b, 30a, and 30b are depicted as cuboids. Alternatively, however, the layers 20a, 20b, 30a, and 30b can also have rounded corners and / or slanted flanks. Typical lengths of the layers 20a, 20b, 30a, and 30b are between 5 µm (micrometers) and 100 µm (micrometers) along the first spatial axis x, between 25 µm (micrometers) and 600 µm (micrometers) along the second spatial axis y, and between 2 µm (micrometers) and 20 µm (micrometers) along the third spatial axis z.

[0050] Fig. 4 shows a flowchart for explaining a first embodiment of the manufacturing method for a magnetic sensor device.

[0051] At least one sensor structure is formed by the method steps described below. If desired, a plurality of sensor structures can also be produced in this way.

[0052] In a method step S1 of the manufacturing method, at least one sensing element is arranged in a sensing region of the at least one sensor structure located directly on or adjacent to a substrate surface of a substrate in such a way that a magnetic field component present in the sensing region can be detected by means of the at least one sensing element along a respectively assigned sensing axis aligned parallel to the substrate surface. Furthermore, in a method step S2 of the manufacturing method, at least one first layer of the at least one sensor structure, which comprises at least one soft magnetic material, is formed between the substrate and the sensing region located directly on or adjacent to the substrate surface or on a side of the sensing region facing away from the substrate.Method step S2 also includes a sub-step S2a, in which a first outer surface of the first layer is formed, aligned with the sensing region, with at least one partial surface that is aligned with the substrate surface at a local inclination angle of greater than or equal to 2° and less than or equal to 70°. Thus, a magnetic sensor device produced using the manufacturing method described here has a first layer in which the flux deflection and shielding functions are jointly integrated at least into the first layer 20a.

[0053] Optionally, the manufacturing method can further comprise a method step S3, in which a second layer comprising the at least one and / or at least one further soft magnetic material is additionally formed. If the first layer lies between the substrate and the first sensing region located directly on or adjacent to the substrate surface, the second layer is formed on the side of the first sensing region facing away from the substrate. However, if the first layer lies on the side of the first sensing region facing away from the substrate, the second layer is formed between the substrate and the first sensing region located directly on or adjacent to the substrate surface.

[0054] With regard to an advantageous sequence for carrying out the method steps S1 to S3, reference is made to the following description.

[0055] Fig. 5A to 5D show cross sections of intermediate products for explaining a second embodiment of the manufacturing method for a magnetic sensor device.

[0056] In the method described here, the second layer 30a is first formed between the substrate surface 12 and the subsequent sensing region 14a lying adjacent to the substrate surface 12. Preferably, the second layer 30a is formed from a nickel-iron alloy. Since an alloy of nickel and iron is difficult to etch, a selective electrogalvanic process (selective plating) can be carried out to deposit the nickel-iron alloy. (Such a selective electrogalvanic process for forming the first layer 20a is described in Fig. 5C explains this in more detail.)

[0057] After forming the second layer 30a, the second layer 30a is completely covered by a dielectric, non-magnetic layer 40. The dielectric, non-magnetic layer 40 can be, for example, a silicon dioxide layer. Afterward, the at least one sensing element 16a is formed. Before and after the production of the at least one sensing element 16a, its contacting can also be carried out, which, however, is carried out in Fig. 5A is not depicted. The at least one sensing element 16a is then covered with a further dielectric, non-magnetic layer 42. The dielectric, non-magnetic layer 42 can also be, for example, a silicon dioxide layer. Optionally, after the deposition of the dielectric, non-magnetic layer 42, a planarization step, e.g., chemical mechanical polishing (CMP), can be performed. An etch stop layer 44 is then deposited.

[0058] In the embodiment of the manufacturing method described here, before forming the first layer 20a on the side of the sensing region 14a facing away from the substrate 10, a dielectric, non-magnetic layer 46a is formed on the side of the sensing region 14a facing away from the substrate 10, wherein the dielectric, non-magnetic layer 46a is formed at least partially with a wave shape and / or with a truncated pyramid shape. For this purpose, a starting material 46 of the (later) dielectric, non-magnetic layer 46a, such as silicon dioxide, is deposited on the etch stop layer 44. In the embodiment described here, the dielectric, non-magnetic layer 46a is formed at least partially with the truncated pyramid shape.This is done by means of an etching mask 48, which, in contrast to the starting material 46 of the (later) dielectric, non-magnetic layer 46a, has a significantly higher etching rate for an etching step carried out to structure the dielectric, non-magnetic layer 46a. Fig. 5A shows an intermediate product after the formation of the etching mask 48, but before the etching step. The structuring of the etching mask 48 can be carried out, for example, using a photolithographic process. In particular, the etching mask 48 can consist of cuboid-shaped regions that define the layers of the subsequent truncated pyramid shapes.

[0059] Subsequently, the etching of the starting material 46 is carried out using the etching mask 48. After that, the etching mask 48 is removed. The intermediate product is in Fig. 5B.

[0060] The first layer 20a is formed on the dielectric, non-magnetic layer 46a. Advantageously, the first layer 20a is formed from a nickel-iron alloy. For this purpose, a selective electrogalvanic process is carried out. First, an electrically conductive seed layer 50 is deposited on the intermediate product of the Fig. 5B. Subsequently, a non-conductive cover layer 52 is deposited onto the electrically conductive seed layer 50 and subsequently patterned in a lithography step such that the seed layer 50 is exposed only in the areas desired for the growth of the first layer 20a. The non-conductive cover layer 52 can be made of silicon dioxide, for example. The nickel-iron alloy can then be selectively grown on the exposed areas of the seed layer 50 using an electrogalvanic process. Fig. Figure 5C shows the intermediate product after performing the selective electroplating of the nickel-iron alloy.

[0061] The non-conductive cover layer 52 and exposed areas of the seed layer 50 can now be removed. If the cover layer 52 is made of a sufficiently stable and non-magnetic material, such as silicon dioxide, removal of the cover layer 52 can be omitted. Subsequently, the first layer 20a can be covered with a dielectric, non-magnetic layer 54, such as a silicon dioxide layer. Advantageously, materials surrounding the layers 20a and 30a are selected to be non-magnetic. The final product obtained in this way is Fig. 5D shown.

[0062] Fig. 6A to 6D show cross sections of intermediate products for explaining a third embodiment of the manufacturing method for a magnetic sensor device.

[0063] In the manufacturing method described here, in contrast to the previously explained embodiment, the etching mask 48 is formed with "hill-like structures." This can be done, for example, using a photolithographic process, such as specifically using grayscale lithography or a reflow process. When using grayscale lithography, the hill flanks can also be made straight. The intermediate product is in Fig. 6A.

[0064] As shown by the Fig. As can be seen in Figure 6B, the "hill-like structures" can be transferred into the dielectric, non-magnetic layer 46a by means of the subsequent etching. The etching rate ratio between the etching mask 48 and the starting material 46 of the dielectric, non-magnetic layer 46a determines the subsequent transfer geometry. Optionally, a directed, oblique ion beam etching process can be used for the etching to make the resulting flanks straighter.

[0065] After removing the etching mask 48, the electrically conductive seed layer 50 is deposited again. Using the photolithographic process, the non-conductive cover layer 52 (e.g., photoresist) can then be deposited and patterned as desired. Subsequently, a selective electroplating deposition can be performed again to form the first layer 20a. This is shown in Fig. 6C is shown pictorially.

[0066] Thereafter, the non-conductive cover layer 52 and the exposed areas of the seed layer 50 can be removed. Finally, the first layer 20a can be covered with the dielectric, non-magnetic layer 54. The final product thus produced is shown in Fig. 6D. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] US 11,209,503 B2

[0002]

Claims

[1] Magnetic sensor device comprising: a substrate (10) having a substrate surface (12); and at least a first sensor structure (A) with: - at least one sensing element (16a), which is arranged in a first sensing region (14a) lying directly on or adjacent to the substrate surface (12), and by means of which a magnetic field component present in the first sensing region (14a) can be detected along a respective associated first sensing axis (18a) aligned parallel to the substrate surface (12); and - a first layer (20a) comprising at least one soft magnetic material and which lies between the substrate (10) and the first sensing region (14a) lying directly on or adjacent to the substrate surface (12) or on a side of the first sensing region (14a) directed away from the substrate (10); characterized by , that a first outer surface (22a) of the first layer (20a) aligned with the first sensing region (14a) has at least one partial surface (24a) which is aligned with the substrate surface (12) at a local angle of inclination of greater than or equal to 2° and less than or equal to 70°. [2] Magnetic sensor device according to claim 1, wherein the first layer (20a) is designed such that by means of the first layer (20a) the first sensing region (14a) can be shielded from a magnetic field component (Bx_ext) of an external magnetic field (B_ext) aligned along a first spatial axis (x), and by means of the first layer (20a) a magnetic field component (Bz_ext) of the external magnetic field (B_ext) aligned along a vertical axis (z) can be deflected into the first sensing region (14a) along the first sensing axis (18a), wherein the first spatial axis (x) is aligned parallel to the substrate surface (12) and the vertical axis (z) is aligned perpendicular to the substrate surface (12), and wherein the first sensing axis (18a) is aligned along a second spatial axis (y) aligned parallel to the substrate surface (12) and perpendicular to the first spatial axis (x). [3] Magnetic sensor device according to claim 1, wherein the first layer (20a) is designed such that by means of the first layer (20a) the first sensing region (14a) can be shielded from a magnetic field component (Bx_ext) of an external magnetic field (B_ext) aligned along a first spatial axis (x), and by means of the first layer (20a) a magnetic field component (Bz_ext) of the external magnetic field (B_ext) aligned along a vertical axis (z) can be deflected into the first sensing region (14a) along the first sensing axis (18a), wherein the first spatial axis (x) is aligned parallel to the substrate surface (12) and the vertical axis (z) is aligned perpendicular to the substrate surface (12), and wherein the first sensing axis (18a) is aligned along the first spatial axis (x). [4] Magnetic sensor device according to claim 1, wherein the first layer (20a) is designed such that by means of the first layer (20a) the first sensing region (14a) can be shielded from a magnetic field component (Bx_ext) of an external magnetic field (B_ext) aligned along a first spatial axis (x) and a magnetic field component (By_ext) of the external magnetic field (B_ext) aligned along a second spatial axis (y), and by means of the first layer (20a) a magnetic field component (Bz_ext) of the external magnetic field (B_ext) aligned along a vertical axis (z) can be deflected into the first sensing region (14a) along the first sensing axis (18a), wherein the first spatial axis (x) and the second spatial axis (y) are aligned parallel to the substrate surface (12), the first spatial axis (x) is aligned perpendicular to the second spatial axis (y), and the vertical axis (z) is aligned perpendicular to the substrate surface (12) is aligned. [5] Magnetic sensor device according to one of the preceding claims, wherein the at least one first sensor structure (A) additionally has a second layer (30a) which comprises the at least one and / or at least one further soft magnetic material, and wherein, if the first layer (20a) lies between the substrate (10) and the first sensing region (14a) lying directly on or adjacent to the substrate surface (12), the second layer (30a) lies on the side of the first sensing region (14a) directed away from the substrate (10), or, if the first layer (20a) lies on the side of the first sensing region (14a) directed away from the substrate (10), the second layer (30a) lies between the substrate (10) and the first sensing region (14a) lying directly on or adjacent to the substrate surface (12). [6] Magnetic sensor device according to claim 5, wherein a second outer surface (32a) of the second layer (30a) aligned with the first sensing region (14a) has at least one partial surface which is aligned with the substrate surface (12) at a local inclination angle of greater than or equal to 2° and less than or equal to 70°. [7] Magnetic sensor device according to one of the preceding claims, wherein the first outer surface (22a) and / or the second outer surface (32a) are at least partially corrugated and / or angled. [8] Magnetic sensor device according to one of the preceding claims, additionally comprising: at least a second sensor structure (B) with: - at least one further sensing element, which is arranged in a second sensing region (14b) lying directly on or adjacent to the substrate surface (12), and by means of which a magnetic field component present in the second sensing region (14b) can be detected along a respective associated second sensing axis (18b) aligned parallel to the substrate surface (12); and - a third layer (20b) which comprises the at least one and / or at least one further soft magnetic material, and which lies between the substrate (10) and the second sensing region (14b) lying directly on or adjacent to the substrate surface (12) or on a side of the second sensing region (14b) directed away from the substrate (10), and which has a third outer surface (22b) aligned with the second sensing region (14b) and with at least one partial surface which is aligned at a local angle of inclination of greater than or equal to 2° and less than or equal to 70° to the substrate surface (12). [9] A magnetic sensor device according to claim 8, wherein: - a first average distance of the at least one sensing element (16a) in the first sensing region (14a) to the first outer surface (22a) of the first layer (20a) is not equal to a second average distance of the at least one sensing element in the second sensing region (14b) to the third outer surface (22b) of the third layer (20b); and / or - a first maximum local angle of inclination of the at least one inner partial surface (24a) of the first outer surface (22a) of the first layer (20a) to the substrate surface (12) is not equal to a second maximum local angle of inclination of the at least one inner partial surface of the third outer surface (22b) of the third layer (20b) to the substrate surface (12). [10] A magnetic sensor device according to claim 8 or 9, wherein: - a first layer thickness of the first layer (20a) oriented perpendicular to the substrate surface (12) is not equal to a second layer thickness of the third layer (20b) oriented perpendicular to the substrate surface (12); - a first length of the first layer (20a) aligned along the first sensing axis (18a) is not equal to a second length of the third layer (20b) aligned along the second sensing axis (18b); - a first width of the first layer (20a) oriented perpendicular to the substrate surface (12) and perpendicular to the first sensing axis (18a) is not equal to a second width of the third layer (20b) oriented perpendicular to the substrate surface (12) and perpendicular to the second sensing axis (18b); - a first interlayer distance of the first layer (20a) to the second layer (30a) is not equal to a second interlayer distance of the third layer (20b) to a fourth layer (30b) of the same second sensor structure (B), which comprises the at least one and / or at least one further soft magnetic material and, if the third layer (20b) lies between the substrate (10) and the second sensing region (14b) lying directly on or adjacent to the substrate surface (12), lies on the side of the second sensing region (14b) facing away from the substrate (10), or, if the third layer (20b) lies on the side of the second sensing region (14b) facing away from the substrate (10), lies between the substrate (10) and the second sensing region (14b) lying directly on or adjacent to the substrate surface (12); and / or - an arrangement or distribution of the at least one sensing element (16a) in the first sensing region (14a) with respect to a first volume center of the first sensing region (14a) deviates from an arrangement or distribution of the at least one sensing element in the second sensing region (14b) with respect to a second volume center of the second sensing region (14b). [11] Magnetic sensor device according to one of claims 8 to 10, wherein a first orientation of the first sensing axis (18a) deviates from a second orientation of the second sensing axis (18b). [12] Magnetic sensor device according to one of claims 8 to 11, wherein the magnetic sensor device comprises at least two first sensor structures (A) and at least two second sensor structures (B), and wherein a first intermediate distance (ΔA) between two adjacent first sensor structures (A) is not equal to a second intermediate distance (ΔB) between two adjacent second sensor structures (B). [13] Manufacturing method for a magnetic sensor device comprising the steps: Arranging at least one sensing element (16a) in each case in a sensing region (14a) of at least one sensor structure (A) lying directly on or adjacent to a substrate surface (12) of a substrate (10) such that by means of the at least one sensing element (16a) a magnetic field component present in the sensing region (14a) can be detected along a respectively assigned sensing axis (18a) aligned parallel to the substrate surface (12) (S1); and Forming a first layer (20a) of the at least one sensor structure (A), which comprises at least one soft magnetic material, between the substrate (10) and the sensing region (14a) lying directly on or adjacent to the substrate surface (12) or on a side of the sensing region (14a) directed away from the substrate (10) (S2); characterized by the step: Forming a first outer surface (22a) of the first layer (20a) aligned with the sensing region (14a) with at least one partial surface (24a), which is aligned at a local inclination angle of greater than or equal to 2° and less than or equal to 70° to the substrate surface (12) (S2a). [14] Manufacturing method according to claim 13, wherein additionally a second layer (30a) of the at least one sensor structure (A), which comprises the at least one and / or at least one further soft magnetic material, is formed, which, if the first layer (20a) lies between the substrate (10) and the first sensing region (14a) lying directly on or adjacent to the substrate surface (12), is formed on the side of the first sensing region (14a) directed away from the substrate (10), or, if the first layer (20a) lies on the side of the first sensing region (14a) directed away from the substrate (10), is formed between the substrate (10) and the first sensing region (14a) lying directly on or adjacent to the substrate surface (12) (S3). [15] Manufacturing method according to claim 14, wherein the second layer (30a) is formed between the substrate (10) and the first sensing region (14a) lying directly on or adjacent to the substrate surface (12), and, before forming the first layer (20a) on the side of the first sensing region (14a) directed away from the substrate (10), a dielectric, non-magnetic layer (46a) is formed on the side of the first sensing region (14a) directed away from the substrate (10), which dielectric, non-magnetic layer is formed at least in regions with a wave shape and / or with a truncated pyramid shape, and wherein the first layer (20a) is formed on the dielectric, non-magnetic layer (46a).

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