US-12618921-B2 - Magnetic sensor including magnetic detection element and magnetic field generator disposed on inclined surface

US12618921B2US 12618921 B2US12618921 B2US 12618921B2US-12618921-B2

Abstract

A magnetic sensor includes an insulating layer having a first inclined surface, a plurality of first MR elements disposed on the first inclined surface, and a plurality of first magnetic field generators disposed on the first inclined surface and configured to generate a magnetic field to be applied to the plurality of first MR elements. Each of the plurality of first magnetic field generators includes a ferromagnetic material section and an antiferromagnetic material section. The ferromagnetic material section and the antiferromagnetic material section are stacked in a direction intersecting the first inclined surface.

Inventors

Norikazu Ota
Hiraku Hirabayashi

Assignees

TDK CORPORATION

Dates

Publication Date: 20260505
Application Date: 20231212
Priority Date: 20221214

Claims (18)

1 . A magnetic sensor comprising: a support member having at least one inclined surface inclined relative to a reference plane; at least one magnetic detection element disposed on the at least one inclined surface and configured to detect a target magnetic field; and at least one magnetic field generator disposed on the at least one inclined surface and configured to generate a magnetic field to be applied to the at least one magnetic detection element, wherein the at least one magnetic field generator includes a ferromagnetic material section and an antiferromagnetic material section that is in contact with the ferromagnetic material section and is in exchange coupling with the ferromagnetic material section, the ferromagnetic material section and the antiferromagnetic material section are stacked in a direction intersecting the at least one inclined surface, the at least one magnetic detection element is at least one magnetoresistive element, the at least one magnetoresistive element includes a magnetization pinned layer having a magnetization whose direction is fixed, a free layer having a magnetization whose direction is variable depending on the target magnetic field, and a gap layer located between the magnetization pinned layer and the free layer, and the magnetization pinned layer is located between the at least one inclined surface and the gap layer.
2 . The magnetic sensor according to claim 1 , wherein the ferromagnetic material section and the antiferromagnetic material section each have a bottom surface opposed to the at least one inclined surface and inclined relative to the reference plane.
3 . The magnetic sensor according to claim 1 , wherein the at least one magnetic detection element includes a plurality of magnetic layers stacked in the direction intersecting the at least one inclined surface.
4 . The magnetic sensor according to claim 1 , wherein: the at least one magnetic detection element has a first bottom surface shaped along the at least one inclined surface; and the at least one magnetic field generator has a second bottom surface shaped along the at least one inclined surface and having substantially a same shape as a shape of the first bottom surface at least in part.
5 . The magnetic sensor according to claim 1 , wherein: the at least one magnetic field generator includes a first magnetic field generator and a second magnetic field generator; the ferromagnetic material section of the first magnetic field generator has a first magnetization; the ferromagnetic material section of the second magnetic field generator has a second magnetization; the first magnetization includes a component in a first direction; and the second magnetization includes a component in a second direction different from the first direction.
6 . The magnetic sensor according to claim 1 , wherein: the at least one magnetic field generator includes a first magnetic field generator and a second magnetic field generator; and the first magnetic field generator and the second magnetic field generator are not disposed on a same plane.
7 . The magnetic sensor according to claim 1 , wherein: the at least one magnetic detection element includes a first magnetic detection element and a second magnetic detection element; and the first magnetic detection element and the second magnetic detection element are not disposed on a same plane.
8 . The magnetic sensor according to claim 1 , wherein: the at least one inclined surface includes a specific inclined surface facing in a direction oblique to both the reference plane and a direction perpendicular to the reference plane; the specific inclined surface has a shape long in a direction parallel to the reference plane when seen in the direction perpendicular to the reference plane; and the at least one magnetic detection element includes two layered films disposed on the specific inclined surface and arranged in a direction intersecting a longitudinal direction of the specific inclined surface.
9 . The magnetic sensor according to claim 1 , further comprising: a power supply port; a ground port; a first output port; a second output port; a first resistor section provided between the power supply port and the first output port; a second resistor section provided between the ground port and the first output port; a third resistor section provided between the ground port and the second output port; and a fourth resistor section provided between the power supply port and the second output port, wherein the at least one magnetic detection element includes a plurality of first magnetic detection elements disposed in a first area and constituting the first resistor section, a plurality of second magnetic detection elements disposed in a second area and constituting the second resistor section, a plurality of third magnetic detection elements disposed in a third area and constituting the third resistor section, and a plurality of fourth magnetic detection elements disposed in a fourth area and constituting the fourth resistor section, the at least one magnetic field generator comprises a plurality of magnetic field generators, the plurality of magnetic field generators are disposed dividedly in the first area, the second area, the third area, and the fourth area, the ferromagnetic material section of each of the plurality of magnetic field generators disposed in two of the first, second, third, and fourth areas has a first magnetization, the ferromagnetic material section of each of the plurality of magnetic field generators disposed in the other two of the first, second, third, and fourth areas has a second magnetization, the first magnetization includes a component in a first direction, and the second magnetization includes a component in a second direction opposite to the first direction.
10 . The magnetic sensor according to claim 1 , wherein the target magnetic field is a magnetic field generated by a current to be detected flowing through a conductor.
11 . The magnetic sensor according to claim 1 , wherein: the at least one inclined surface has a shape long in a direction parallel to the reference plane when seen in a direction perpendicular to the reference plane; and the at least one magnetic detection element has a shape long along a longitudinal direction of the at least one inclined surface.
12 . The magnetic sensor according to claim 11 , wherein: the at least one magnetic detection element includes a specific magnetic detection element; and the at least one magnetic field generator includes two specific magnetic field generators located on both sides of the specific magnetic detection element in a longitudinal direction of the specific magnetic detection element.
13 . The magnetic sensor according to claim 11 , wherein the at least one magnetic field generator includes a plurality of magnetic field generators disposed along the longitudinal direction of the at least one inclined surface.
14 . The magnetic sensor according to claim 1 , wherein: the at least one inclined surface includes a first inclined surface and a second inclined surface each having a shape long in a direction parallel to the reference plane when seen in a direction perpendicular to the reference plane, the first and second inclined surfaces facing in respective different directions; the at least one magnetic detection element includes a plurality of first magnetic detection elements disposed on the first inclined surface and a plurality of second magnetic detection elements disposed on the second inclined surface; the at least one magnetic field generator includes a plurality of first magnetic field generators disposed on the first inclined surface and a plurality of second magnetic field generators disposed on the second inclined surface; the plurality of first magnetic detection elements constitute a first detection circuit that detects a component of the target magnetic field in a first direction oblique to both the reference plane and a direction perpendicular to the reference plane and generates a first detection signal; and the plurality of second magnetic detection elements constitute a second detection circuit that detects a component of the target magnetic field in a second direction oblique to both the reference plane and the direction perpendicular to the reference plane and generates a second detection signal.
15 . The magnetic sensor according to claim 14 , further comprising: another support member having a flat surface; a plurality of third magnetic detection elements disposed on the flat surface; and a plurality of third magnetic field generators disposed on the flat surface and configured to generate a magnetic field to be applied to the plurality of third magnetic detection elements, wherein the plurality of third magnetic detection elements constitute a third detection circuit that detects a component of the target magnetic field in a third direction parallel to the reference plane and generates a third detection signal.
16 . The magnetic sensor according to claim 15 , wherein the target magnetic field is an Earth's magnetic field.
17 . A magnetic sensor comprising: a support member having at least one inclined surface inclined relative to a reference plane; at least one magnetic detection element disposed on the at least one inclined surface and configured to detect a target magnetic field; at least one magnetic field generator disposed on the at least one inclined surface and configured to generate a magnetic field to be applied to the at least one magnetic detection element; a power supply port; a ground port; a first output port; a second output port; a first resistor section provided between the power supply port and the first output port; a second resistor section provided between the ground port and the first output port; a third resistor section provided between the ground port and the second output port; and a fourth resistor section provided between the power supply port and the second output port, wherein the at least one magnetic field generator includes a ferromagnetic material section and an antiferromagnetic material section that is in contact with the ferromagnetic material section and is in exchange coupling with the ferromagnetic material section, the ferromagnetic material section and the antiferromagnetic material section are stacked in a direction intersecting the at least one inclined surface, the at least one magnetic detection element includes a plurality of first magnetic detection elements disposed in a first area and constituting the first resistor section, a plurality of second magnetic detection elements disposed in a second area and constituting the second resistor section, a plurality of third magnetic detection elements disposed in a third area and constituting the third resistor section, and a plurality of fourth magnetic detection elements disposed in a fourth area and constituting the fourth resistor section, the at least one magnetic field generator comprises a plurality of magnetic field generators, the plurality of magnetic field generators are disposed dividedly in the first area, the second area, the third area, and the fourth area, the ferromagnetic material section of each of the plurality of magnetic field generators disposed in two of the first, second, third, and fourth areas has a first magnetization, the ferromagnetic material section of each of the plurality of magnetic field generators disposed in the other two of the first, second, third, and fourth areas has a second magnetization, the first magnetization includes a component in a first direction, and the second magnetization includes a component in a second direction opposite to the first direction.
18 . A magnetic sensor comprising: a support member having at least one inclined surface inclined relative to a reference plane; at least one magnetic detection element disposed on the at least one inclined surface and configured to detect a target magnetic field; at least one magnetic field generator disposed on the at least one inclined surface and configured to generate a magnetic field to be applied to the at least one magnetic detection element; another support member having a flat surface; a plurality of third magnetic detection elements disposed on the flat surface; and a plurality of third magnetic field generators disposed on the flat surface and configured to generate a magnetic field to be applied to the plurality of third magnetic detection elements, wherein the at least one magnetic field generator includes a ferromagnetic material section and an antiferromagnetic material section that is in contact with the ferromagnetic material section and is in exchange coupling with the ferromagnetic material section, the ferromagnetic material section and the antiferromagnetic material section are stacked in a direction intersecting the at least one inclined surface, the at least one inclined surface includes a first inclined surface and a second inclined surface each having a shape long in a direction parallel to the reference plane when seen in a direction perpendicular to the reference plane, the first and second inclined surfaces facing in respective different directions, the at least one magnetic detection element includes a plurality of first magnetic detection elements disposed on the first inclined surface and a plurality of second magnetic detection elements disposed on the second inclined surface, the at least one magnetic field generator includes a plurality of first magnetic field generators disposed on the first inclined surface and a plurality of second magnetic field generators disposed on the second inclined surface, the plurality of first magnetic detection elements constitute a first detection circuit that detects a component of the target magnetic field in a first direction oblique to both the reference plane and a direction perpendicular to the reference plane and generates a first detection signal, the plurality of second magnetic detection elements constitute a second detection circuit that detects a component of the target magnetic field in a second direction oblique to both the reference plane and the direction perpendicular to the reference plane and generates a second detection signal, and the plurality of third magnetic detection elements constitute a third detection circuit that detects a component of the target magnetic field in a third direction parallel to the reference plane and generates a third detection signal.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Japanese Priority Patent Application No. 2022-199521 filed on Dec. 14, 2022, the entire contents of which are incorporated herein by reference. BACKGROUND The technology relates to a magnetic sensor including a magnetic detection element disposed on an inclined surface. Magnetic sensors using magnetoresistive elements have been used for various applications in recent years. Examples of the magnetoresistive elements include a spin-valve magnetoresistive element. The spin-valve magnetoresistive element includes a magnetization pinned layer having a magnetization whose direction is fixed, a free layer having a magnetization whose direction is variable depending on the direction of a magnetic field applied thereto, and a gap layer disposed between the magnetization pinned layer and the free layer. A bias magnetic field can be applied to the magnetoresistive elements of the magnetic sensors for various purposes. For example, JP 2022-77691 A discloses a magnetic sensor including a plurality of bias magnetic field application units that apply respective opposite bias magnetic fields to one part and another part of a free magnetic layer in a giant magnetoresistive element to reduce an offset occurring in the resistance of the free magnetic layer. Each of the plurality of bias magnetic field application units has a structure that a magnetic layer is sandwiched between two antiferromagnetic layers. US 2016/0131687 A1 discloses a current sensor including a plurality of magnetic bodies that apply respective opposite bias magnetic fields to a magnetization free layer of each of two magnetoresistive elements constituting a full-bridge circuit and a magnetization free layer of each of two other magnetoresistive elements constituting the full-bridge circuit to detect an external magnetic field other than a current magnetic field based on a current to be measured. U.S. Patent Application Publication No. 2006/0176142 A1 discloses a magnetic sensor including an X-axis sensor, a Y-axis sensor, and a Z-axis sensor disposed on a substrate. Magnetoresistive elements constituting the Z-axis sensor are disposed on slopes of projections formed on an underlying film of the substrate. Some systems including a magnetic sensor are intended to detect a magnetic field including a component in a direction perpendicular to a substrate surface using magnetoresistive elements disposed on the substrate. In such a case, the magnetoresistive elements can be disposed on an inclined surface of the substrate. If magnetic field generators for applying a bias magnetic field to such magnetoresistive elements are provided, two magnetic field generators can be located with the inclined surface therebetween. In such a case, the bias magnetic field applied to the free layers of the magnetoresistive elements can change in strength or direction if at least either the magnetoresistive elements or the magnetic field generators deviate from their designed positions due to manufacturing variations. Such a problem becomes pronounced if the magnetic field generators include a plurality of layers like the bias magnetic field application units described in JP 2022-77691 A. SUMMARY A magnetic sensor according to one embodiment of the technology includes a support member having at least one inclined surface inclined relative to a reference plane, at least one magnetic detection element disposed on the at least one inclined surface and configured to detect a target magnetic field, and at least one magnetic field generator disposed on the at least one inclined surface and configured to generate a magnetic field to be applied to the at least one magnetic detection element. The at least one magnetic field generator includes a ferromagnetic material section and an antiferromagnetic material section that is in contact with the ferromagnetic material section and is in exchange coupling with the ferromagnetic material section. The ferromagnetic material section and the antiferromagnetic material section are stacked in a direction intersecting the at least one inclined surface. In the magnetic sensor according to one embodiment of the technology, the ferromagnetic material section and the antiferromagnetic material section of the at least one magnetic field generator are stacked in the direction intersecting the at least one inclined surface. According to the embodiment of the technology, a magnetic sensor capable of reducing variations in the magnetic field applied to the magnetic detection element by the magnetic field generator can thereby be implemented. Other and further objects, features and advantages of the technology will appear more fully from the following description. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exa