Multi-axis magneto-resistance sensor annealing system, multi-axis magneto-resistance sensor, and method for manufacturing multi-axis magneto-resistance sensor

Abstract

Disclosed are a multi-axis magneto-resistance sensor annealing system, a multi-axis magneto-resistance sensor, and a method for manufacturing a multi-axis magneto-resistance sensor. A multi-axis magneto-resistance sensor annealing system according to one embodiment of the present invention comprises: multi-axis magneto-resistance sensors; magnetic flux guides positioned on the central parts of the plurality of multi-axis magneto-resistance sensors; magnetic field generation units that are positioned on the upper and lower parts of the multi-axis magneto-resistance sensors and the magnetic flux guides and generate a magnetic field; and a heating unit which accommodates the multi-axis magneto-resistance sensors, the magnetic flux guides, and the magnetic field generation units therein and performs an annealing process by heating same.

Description

Multi-axis magnetoresistance sensor annealing system, multi-axis magnetoresistance sensor, and method for manufacturing multi-axis magnetoresistance sensor

[0001] The present invention relates to a multi-axis magnetoresistance sensor annealing system, a multi-axis magnetoresistance sensor, and a method for manufacturing a multi-axis magnetoresistance sensor, and more particularly, to a multi-axis magnetoresistance sensor annealing system, a multi-axis magnetoresistance sensor, and a method for manufacturing a multi-axis magnetoresistance sensor, which can significantly improve the efficiency of the manufacturing process.

[0002] In general, a magnetic sensor is a device that detects changes in an applied magnetic field and converts them into an electrical signal.

[0003] A widely used commercially available magnetic sensor is the Hall sensor. A Hall sensor converts changes in the magnetic field passing through a cross-shaped semiconductor layer into a voltage difference. It has recently been used in the image stabilization function of smartphone cameras.

[0004] In addition to Hall sensors, there are magneto-resistance sensors that utilize magnetic resistance. These utilize the magnetoresistance effect, a phenomenon in which the electrical resistance of the material that makes up the sensor changes depending on the presence or absence of a magnetic field.

[0005] Magnetoresistive sensors utilize anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), or tunneling magnetoresistance (TMR). Magnetoresistive sensors have the advantage of being at least 10 times more sensitive than conventional Hall sensors.

[0006] In the prior art, a mechanism is used to detect a change in resistance in a direction parallel to the magnetic field when a magnetic field is applied in a direction perpendicular to the plane on which the magnetic layer is formed. If a sensing structure including an x-axis or y-axis is to be implemented, a method of sensing by providing multiple magnetic sensors may be proposed, but this entails the burden of requiring multiple sensors and separately providing multiple circuits to drive them or detect the operation pattern.

[0007] Meanwhile, magnetic annealing using local laser control is an effective method for precisely controlling exchange magnetic anisotropy and sensing direction. However, this process has a significant drawback: it requires expensive equipment, such as lasers. Laser-based processing equipment carries significant purchase costs, as well as maintenance and operating costs, which increase overall manufacturing costs. Especially in small-scale production or when cost efficiency is paramount, the use of such expensive equipment can be a financial burden. Furthermore, there is the potential for anisotropy loss due to heat applied during the sensor integration post-processing process.

[0008] Republic of Korea Patent Publication No. 10-2023-0089608 discloses a three-axis magnetoresistive sensor.

[0009] The prior art includes a magnetoresistance unit formed as a Wheatstone bridge on a substrate and a magnetic focusing unit, wherein the magnetic focusing unit is arranged so that a portion of the magnetoresistance unit overlaps or is arranged around the edge of one or two adjacent magnetoresistance elements.

[0010] However, the conventional technology has a problem in that the manufacturing process is complicated, which reduces the efficiency of the manufacturing process.

[0011] One embodiment of the present invention aims to provide a multi-axis magnetoresistance sensor annealing system capable of three-axis detection, a multi-axis magnetoresistance sensor, and a method for manufacturing a multi-axis magnetoresistance sensor by improving the manufacturing process efficiency through a single annealing process using a magnetic flux guide to overcome the problems of the above-mentioned prior art.

[0012] According to one aspect of the present invention, there is provided a multi-axis magnetic resistance sensor; a magnetic flux guide positioned on the center of the plurality of multi-axis magnetic resistance sensors; a magnetic field generator positioned above and below the multi-axis magnetic resistance sensors and the magnetic flux guide to generate a magnetic field; and a heating unit that accommodates the multi-axis magnetic resistance sensor, the magnetic flux guide, and the magnetic field generator therein and heats the multi-axis magnetic resistance sensor to perform an annealing process.

[0013] The exchange magnetic anisotropy of the above multi-axis magnetoresistive sensor is generated according to the direction of the leakage magnetic field of the magnetic flux guide through the annealing process of the above heating unit.

[0014] The multi-axis magnetoresistive sensor includes: a substrate; a plurality of first sensors positioned in the X-axis direction on the substrate; and a plurality of second sensors positioned in the Y-axis direction and perpendicular to the plurality of first sensors.

[0015] The plurality of first sensors and the plurality of second sensors are magnetoresistive sensor elements capable of detecting magnetoresistance.

[0016] The exchanged magnetic anisotropy of the plurality of first sensors and the plurality of second sensors is generated in a radial direction from the center of the magnetic flux guide.

[0017] The plurality of first sensors and the plurality of second sensors are spaced apart from each other at equal intervals based on the center of the magnetic flux guide.

[0018] The outer surface of the magnetic flux guide is arranged to pass through the central portions of each of the plurality of first sensors and the plurality of second sensors.

[0019] The above magnetic field generating unit is a magnet having magnetism.

[0020] The above magnetic field generating unit is a Helmholtz coil that generates a magnetic field.

[0021] The above heating unit is an oven equipped with a heater that generates heat.

[0022] The above heating unit is a hot plate capable of temperature control.

[0023] According to another aspect of the present invention, a multi-axis magnetoresistance sensor manufactured by a multi-axis magnetoresistance sensor annealing system is provided.

[0024] The above multi-axis magnetoresistive sensor is capable of detecting three-axis magnetic fields of the X-axis, Y-axis, and Z-axis.

[0025] According to another aspect of the present invention, there is provided a method for manufacturing a multi-axis magnetoresistance sensor by a multi-axis magnetoresistance sensor annealing system, the method comprising: arranging a plurality of first sensors in an X-axis direction and arranging a plurality of second sensors in a Y-axis direction on a substrate; arranging a magnetic flux guide on the plurality of first sensors and the plurality of second sensors; applying a magnetic field in a Z-axis direction; and performing an annealing process by heating.

[0026] The multi-axis magnetoresistance sensor annealing system, multi-axis magnetoresistance sensor and manufacturing method thereof according to the present invention have the following effects.

[0027] First, each magnetoresistive sensor element of the multi-axis magnetoresistive sensor can effectively form exchange magnetic anisotropy according to the direction of the local leakage magnetic field.

[0028] Second, the exchanged magnetic anisotropy of a large number of sensors can be formed simultaneously on a wafer in a single heating process.

[0029] Third, efficiency can be significantly improved with a single annealing process.

[0030] Fourth, it can reduce manufacturing costs by replacing the local heating method using conventional lasers.

[0031] FIG. 1 is a schematic diagram schematically illustrating a multi-axis magnetoresistive sensor annealing system according to one embodiment of the present invention.

[0032] FIG. 2 is a side schematic diagram schematically illustrating a multi-axis magnetoresistive sensor annealing system according to one embodiment of the present invention.

[0033] FIG. 3 is a side schematic diagram schematically illustrating a multi-axis magnetoresistive sensor annealing system according to another embodiment of the present invention.

[0034] FIG. 4 (a) and FIG. 4 (b) are schematic diagrams showing changes in exchange magnetic anisotropy before and after an annealing process in a multi-axis magnetoresistive sensor according to one embodiment of the present invention, respectively.

[0035] FIG. 5 is a diagram showing a magnetic field response in which the measurement direction changes according to the leakage magnetic field strength generated in a magnetic flux guide during a magnetic annealing process in a multi-axis magnetoresistive sensor annealing system according to one embodiment of the present invention.

[0036] FIG. 6 (a) and FIG. 6 (b) are diagrams showing planar Hall magnetoresistance (PHMR) response characteristics for x-axis and y-axis direction magnetic fields of a multi-axis magnetoresistance sensor according to one embodiment of the present invention, respectively.

[0037] FIG. 7 is a flowchart illustrating a method for manufacturing a multi-axis magnetoresistive sensor according to one embodiment of the present invention.

[0038] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed in this specification are merely illustrative for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described in this specification.

[0039] Embodiments according to the concept of the present invention may have various modifications and take various forms, and thus, embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit embodiments according to the concept of the present invention to specific disclosed forms, but rather includes modifications, equivalents, or alternatives that fall within the spirit and technical scope of the present invention.

[0040] FIG. 1 is a schematic diagram schematically showing a multi-axis magnetoresistance sensor annealing system according to one embodiment of the present invention, and FIG. 2 is a side schematic diagram schematically showing a multi-axis magnetoresistance sensor annealing system according to one embodiment of the present invention.

[0041] Referring to FIGS. 1 and 2 together, a multi-axis magnetic resistance sensor annealing system (1000) according to one embodiment of the present invention comprises a multi-axis magnetic resistance sensor (100), a magnetic flux guide (200), a magnetic field generator (300), and a heating unit (400).

[0042] A multi-axis magnetoresistive sensor (100) is configured as a single chip and includes a substrate (110), a plurality of first sensors (120), a plurality of second sensors (130), and a magnetic flux guide (200).

[0043] The substrate (110) may be a wafer substrate on which a plurality of first sensors (120) and a plurality of second sensors (130) are mounted as a base substrate.

[0044] A plurality of first sensors (120) are spaced apart from each other and positioned in the X-axis direction on the substrate (110).

[0045] A plurality of second sensors (130) are positioned perpendicular to the plurality of first sensors (120) and spaced apart from each other on the substrate (110) in the Y-axis direction.

[0046] The plurality of first sensors (120) and the plurality of second sensors (130) may each be magnetoresistance sensor elements capable of detecting magnetic resistance, and are magnetoresistance sensor elements that utilize the magnetoresistance effect, which is a phenomenon in which the resistance value of an object changes when a magnetic field is applied to the object.

[0047] The exchanged magnetic anisotropy of the plurality of first sensors (120) and the plurality of second sensors (130) is generated radially from the center of the magnetic flux guide (200) through the annealing process of the multi-axis magnetoresistive sensor annealing system (1000).

[0048] It is preferable that the plurality of first sensors (120) and the plurality of second sensors (130) are spaced apart from each other at equal intervals based on the center of the magnetic flux guide (200).

[0049] The magnetic flux guide (200) can be formed by depositing a magnetic material in a thin film form on a polymer material in the shape of a cylinder or a square column, or can be formed into a single structure by mixing the magnetic material with the polymer.

[0050] The magnetic flux guide (200) is located on the center of a plurality of multi-axis magnetic resistance sensors.

[0051] The magnetic flux guide (200) induces the magnetic field in the Z-axis direction to leak in a plane direction perpendicular to the central axis of the magnetic flux guide (200).

[0052] It is preferable that the outer surface of the magnetic flux guide (200) be arranged so as to pass through the centers of each of the plurality of first sensors (120) and the plurality of second sensors (130) based on the plane.

[0053] The magnetic flux guide (200) is preferably positioned on the center of the plurality of first sensors (120) and the plurality of second sensors (130) with respect to the plane to control the magnetic field, and is preferably positioned at the center of the substrate (110).

[0054] The magnetic field generating unit (300) is positioned at the upper and lower portions of the multi-axis magnetic resistance sensor and the magnetic flux guide, respectively, to generate a magnetic field.

[0055] The magnetic field generating unit (300) may be a magnet (310) having an S pole and an N pole.

[0056] Magnets (310) are positioned at the upper and lower portions of the multi-axis magnetic resistance sensor (100) to generate a magnetic field.

[0057] The magnet (310) has a S-pole N-pole magnet positioned on the upper side of the multi-axis magnetic resistance sensor (100), and a S-pole N-pole magnet positioned on the lower side of the multi-axis magnetic resistance sensor (100).

[0058] The magnet (310) applies a magnetic field in the Z-axis direction and flows from top to bottom.

[0059] The heating unit (400) may be an oven (410) equipped with a heater to perform an annealing process.

[0060] The heating unit (400) houses a multi-axis magnetic resistance sensor (100), a magnetic flux guide (200), and a magnetic field generator (300) inside and heats them to perform an annealing process.

[0061] A multi-axis magnetoresistive sensor annealing system (1000) according to one embodiment of the present invention forms exchange magnetic anisotropy of a multi-axis magnetoresistive sensor (100).

[0062] FIG. 3 is a side schematic diagram schematically showing a multi-axis magnetoresistance sensor annealing system according to another embodiment of the present invention, and FIGS. 4 (a) and 4 (b) are schematic diagrams showing changes in exchange magnetic anisotropy before and after an annealing process in a multi-axis magnetoresistance sensor according to one embodiment of the present invention, respectively.

[0063] Referring to FIGS. 3 and 4 together with FIGS. 1 and 2, a multi-axis magnetic resistance sensor annealing system (2000) according to another embodiment of the present invention comprises a multi-axis magnetic resistance sensor (100), a magnetic flux guide (200), a magnetic field generator (300), and a heating unit (400).

[0064] The magnetic field generator (300) may be a Helmholtz coil (320).

[0065] Helmholtz coils (320) are located at the upper and lower portions of the multi-axis magnetoresistive sensor (100) to generate a magnetic field.

[0066] The Helmholtz coil (320) applies a magnetic field in the Z-axis direction and flows from top to bottom.

[0067] In a multi-axis magnetic resistance sensor annealing system (2000) according to another embodiment of the present invention, the heating unit (400) may be a hot plate (420) capable of temperature control.

[0068] The hot plate (420) heats the multi-axis magnetoresistive sensor (100), the magnetic flux guide (200), and the Helmholtz coil (320) to perform an annealing process. An additional receiving chamber for performing the annealing process may be included, and descriptions of other similar parts are omitted.

[0069] Referring to FIG. 4, a multi-axis magnetoresistance sensor annealing system (1000, 2000) according to the present invention forms exchanged magnetic anisotropy of a plurality of first sensors (120) and a plurality of second sensors (130) according to the direction of the leakage magnetic field of the magnetic flux guide (200) through an annealing process in which the multi-axis magnetoresistance sensor (100) is heated.

[0070] In the multi-axis magnetoresistive sensor (100) of Fig. 4 (a), in the pre-heating state before the annealing process, the plurality of first sensors (120) have exchange magnetic anisotropy in the +Y-axis direction, and the plurality of second sensors (130) have exchange magnetic anisotropy in the +X-axis direction, and in the post-heating state after the annealing process of Fig. 4 (b), the plurality of first sensors (120) have exchange magnetic anisotropy in the -X-axis and +X-axis directions, respectively, and the plurality of second sensors (130) have exchange magnetic anisotropy in the -Y-axis and +Y-axis directions, respectively.

[0071] Accordingly, the multi-axis magnetoresistive sensor (100) can separate the x-component and z-component by adding or differentiating the signals detected from the two first sensors (120) or the two second sensors (130).

[0072] The multi-axis magnetoresistive sensor (100) can detect that a magnetic field is applied in the Z-axis direction when a magnetic field is detected in the X-axis direction or the Y-axis direction.

[0073] Accordingly, a multi-axis magnetoresistive sensor (100) according to one embodiment of the present invention can detect three-axis magnetic fields of the X-axis, Y-axis, and Z-axis that are orthogonal to each other, and can also recognize a magnetic field in a diagonal direction.

[0074] FIG. 5 is a diagram showing a magnetic field response in which the measurement direction changes according to the leakage magnetic field strength generated in a magnetic flux guide during a magnetic annealing process in a multi-axis magnetoresistive sensor annealing system according to one embodiment of the present invention.

[0075] Referring to Fig. 5, the response characteristics of the magnetoresistive sensor after the annealing process are shown.

[0076] The graphs show the variation of the Planar Hall magnetoresistance (PHMR) sensor signal with respect to an x-direction magnetic field. Each graph shows how the sensor response varies with the strength of the leakage magnetic field (Hx(Oe)) generated in the magnetic flux guide.

[0077] Before the annealing process, each sensor responded only to a magnetic field along a specific axis, but after the process, it was confirmed that it also responded to a magnetic field in the vertical direction. This suggests that the leakage magnetic field generated in the magnetic flux guide affects the direction of the exchange magnetic anisotropy of the sensor, and the response characteristics of the sensor are determined by the strength of the leakage magnetic field. In particular, since no change in the direction of the exchange magnetic anisotropy is observed when the leakage magnetic field is weak, it is proven that the height of the magnetic flux guide and the magnetic field strength play a decisive role in the response characteristics of the sensor.

[0078] FIG. 6 (a) and FIG. 6 (b) are diagrams showing planar Hall magnetoresistance (PHMR) response characteristics for x-axis and y-axis direction magnetic fields of a multi-axis magnetoresistance sensor according to one embodiment of the present invention, respectively.

[0079] In the graphs of Fig. 6 (a) and Fig. 6 (b), the X-axis represents the strength of the leakage magnetic field (Hx (0~300 Oe)), and the Y-axis represents the in-plane Hall magnetoresistance (PHMR).

[0080] A planar Hall magnetoresistance (PHMR) response graph showing the change in measurement direction of magnetoresistive sensors after the magnetic annealing process is shown.

[0081] Figure 6 (a) shows the planar Hall magnetoresistance response of the sensor to an external magnetic field in the X-direction, and Figure 6 (b) shows the planar Hall magnetoresistance response of the sensor to an external magnetic field in the Y-direction. Each graph shows how the sensor responds to a magnetic field according to the newly formed exchange magnetic anisotropy direction after the annealing process.

[0082] A sensor designed to respond to a Y-axis magnetic field before the annealing process shows a clear response to an X-axis magnetic field after the process, as shown in Fig. 7 (a), and similarly, a sensor designed to respond to an X-axis magnetic field shows a clear response to a Y-axis magnetic field after the heat treatment process, as shown in Fig. 7 (b).

[0083] This result confirms that the sensing directions of each of the plurality of first sensors (120) and the plurality of second sensors (130) are simultaneously changed to the X-axis and the Y-axis through a single annealing process, and proves that the magnetic annealing process of the present invention effectively controls the exchange magnetic anisotropy direction of the magnetoresistive sensor to successfully provide a multi-axis sensing function on a plane.

[0084] FIG. 7 is a flowchart illustrating a method for manufacturing a multi-axis magnetoresistive sensor according to one embodiment of the present invention.

[0085] Referring to FIG. 7 together with FIGS. 1 to 4, a method for manufacturing a multi-axis magnetic resistance sensor by a multi-axis magnetic resistance sensor annealing system according to one embodiment of the present invention will be described. A plurality of first sensors (120) are arranged in the X-axis direction on a substrate (110), and a plurality of second sensors (130) are arranged in the Y-axis direction (S110).

[0086] Next, a magnetic flux guide (200) is placed on a plurality of first sensors (120) and a plurality of second sensors (130) (S120).

[0087] Then, a magnetic field is applied in the Z-axis direction (from top to bottom or from top to bottom) from the magnet (310) (S130).

[0088] An annealing process is performed by heating in the heating unit (400) of the multi-axis magnetoresistance sensor annealing system (1000) (S140). The annealing process according to the present invention provides a multi-axis magnetoresistance sensor through a single heat treatment. Here, the heat treatment temperature range of the annealing process is preferably between 200°C and 400°C.

[0089] Therefore, the multi-axis magnetoresistive sensor and its manufacturing method according to the present invention can effectively form exchange magnetic anisotropy in each sensor according to the direction of the leakage magnetic field in a local area, and can simultaneously form exchange magnetic anisotropy in a large number of sensors on a wafer through a single heating process.

[0090] In addition, it can greatly improve the efficiency of the entire annealing process and reduce manufacturing costs by replacing the conventional local area heating method, laser.

[0091]

[0092] Although the embodiments described above have been described with limited drawings, those skilled in the art will recognize that various modifications and variations can be made based on the above description. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0093] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. Multi-axis magnetoresistive sensor; A magnetic flux guide positioned on the center of the plurality of multi-axis magnetic resistance sensors; A magnetic field generating unit positioned above and below the multi-axis magnetic resistance sensor and the magnetic flux guide, respectively, to generate a magnetic field; and A heating unit that houses the multi-axis magnetic resistance sensor, the magnetic flux guide, and the magnetic field generating unit inside and heats them to perform an annealing process; characterized by including: Multi-axis magnetoresistive sensor annealing system.

2. In paragraph 1, The exchange magnetic anisotropy of the above multi-axis magnetoresistive sensor is characterized in that it is generated according to the direction of the leakage magnetic field of the magnetic flux guide through the annealing process of the heating unit. Multi-axis magnetoresistive sensor annealing system.

3. In paragraph 1, The above multi-axis magnetoresistive sensor, substrate; a plurality of first sensors positioned in the X-axis direction on the substrate; and characterized in that it comprises a plurality of second sensors positioned perpendicular to the plurality of first sensors and in the Y-axis direction; Multi-axis magnetoresistive sensor annealing system.

4. In paragraph 3, The above plurality of first sensors and the above plurality of second sensors are each characterized in that they are magnetoresistive sensor elements capable of detecting magnetoresistance. Multi-axis magnetoresistive sensor annealing system.

5. In paragraph 3, The exchange magnetic anisotropy of the plurality of first sensors and the plurality of second sensors is characterized in that it is generated in a radial direction from the center of the magnetic flux guide. Multi-axis magnetoresistive sensor annealing system.

6. In paragraph 3, The plurality of first sensors and the plurality of second sensors are characterized in that they are spaced apart from each other at equal intervals based on the center of the magnetic flux guide. Multi-axis magnetoresistive sensor annealing system.

7. In paragraph 3, The outer surface of the magnetic flux guide is characterized in that it is arranged to pass through the central portions of each of the plurality of first sensors and the plurality of second sensors. Multi-axis magnetoresistive sensor annealing system.

8. In paragraph 1, The magnetic field generating unit is characterized in that it is a magnet having magnetism. Multi-axis magnetoresistive sensor annealing system.

9. In paragraph 1, The above magnetic field generating unit is characterized by being a Helmholtz coil that generates a magnetic field. Multi-axis magnetoresistive sensor annealing system.

10. In paragraph 1, The above heating unit is characterized in that it is an oven equipped with a heater that generates heat. Multi-axis magnetoresistive sensor annealing system.

11. In paragraph 1, The above heating unit is characterized by being a hot plate capable of temperature control. Multi-axis magnetoresistive sensor annealing system.

12. A multi-axis magnetoresistance sensor manufactured by a multi-axis magnetoresistance sensor annealing system according to any one of claims 1 to 11.

13. In paragraph 12, The above multi-axis magnetoresistive sensor is characterized in that it can detect three-axis magnetic fields of the X-axis, Y-axis, and Z-axis. Multi-axis magnetoresistive sensor.

14. A method for manufacturing a multi-axis magnetoresistance sensor by a multi-axis magnetoresistance sensor annealing system according to any one of claims 1 to 11, A step of arranging a plurality of first sensors in the X-axis direction on a substrate and arranging a plurality of second sensors in the Y-axis direction, A step of placing a magnetic flux guide on the plurality of first sensors and the plurality of second sensors, A step of applying a magnetic field in the Z-axis direction, and A step of performing an annealing process by heating, characterized in that it includes Method for fabricating a multi-axis magnetoresistive sensor.

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