TWI711833B - Magnetic field sensing device - Google Patents

Abstract

A magnetic field sensing device including at least one vortex magnetoresistor and at least one magnetization setting element is provided. The vortex magnetoresistor includes a pinning layer, a pinned layer, a spacer layer, and a round free layer. The pinned layer is disposed on the pinning layer, and the spacer layer is disposed on the pinned layer. The round free layer is disposed on the spacer layer, and has a magnetization direction distribution with a vortex shape. The magnetization setting element is alternately applied and not applied an electric current to. When the magnetization setting element is not applied the electric current to, the magnetization direction distribution with the vortex shape of the round free layer is varied with an external magnetic field, so as to achieve sensing the external fiend. When the magnetization setting element is applied the electric current to, a magnetic field generated by the magnetization setting element destroys the magnetization direction distribution with the vortex shape of the round free layer, and makes the round free layer achieve magnetic saturation.

Description

Magnetic field sensing device

The present invention relates to a magnetic field sensing device.

The magnetic field sensor is an important component that can provide an electronic compass and motion tracking for the system. In recent years, related applications have developed rapidly, especially for portable devices. In the new generation of applications, high accuracy, fast response, small size, low power consumption and reliable quality have become important features of magnetic field sensors.

In traditional giant magnetoresistance or tunneling magnetoresistance sensors, a pinning layer, pinned layer, spacer layer, and free layer are stacked in sequence The free layer has a magnetic easy-axis, which is perpendicular to the pinning direction of the pinned layer. To build a single-axis magnetic sensor with Wheatstone bridge, multiple magnetoresistances with different pinning directions are important. For a 3-axis magnetic sensor, multiple magnetic resistances with 6 pinning directions are required. However, from a manufacturing point of view, the production of the second pinning direction in the pinning layer in one wafer will cause a considerable increase in cost and will reduce the stability of the magnetization direction configuration in the pinned layer.

In addition, there is flicker noise (pink noise) in the signal output by the general magnetic field sensor, which will affect the accuracy of the magnetic field measured by the magnetic field sensor. .

The invention provides a magnetic field sensing device, which can effectively overcome the interference of flicker noise.

An embodiment of the present invention provides a magnetic field sensing device including at least one vortex magnetoresistor and at least one magnetization setting element. The at least one spiral magnetoresistance includes a pinned layer, a pinned layer, a spacer layer, and a circular free layer. The pinned layer is disposed on the pinned layer, the spacer layer is disposed on the pinned layer, and the circular free layer is disposed on the spacer layer and has a spiral magnetization direction distribution. The at least one magnetization setting element is arranged on one side of the at least one spiral magnetoresistance, and the at least one magnetization setting element is alternately energized and de-energized. When the at least one magnetization setting element is not energized, the vortex of the circular free layer The shape magnetization direction distribution changes with the external magnetic field to achieve the sensing of the external magnetic field. When the at least one magnetization setting element is energized, the magnetic field generated by the at least one magnetization setting element destroys the spiral magnetization direction distribution of the circular free layer, and the circular free layer reaches magnetic saturation.

In an embodiment of the present invention, the magnetic field sensing device further includes a substrate, a first insulating layer, and a second insulating layer. The magnetization setting element is arranged on the substrate, the first insulating layer covers the magnetization setting element, and the vortex magnetoresistance is arranged on the first insulating layer. The second insulating layer covers the spiral magnetic resistance.

In an embodiment of the present invention, the magnetic field sensing device further includes a substrate, a first insulating layer, and a second insulating layer. The spiral magnetoresistance is arranged on the substrate, the first insulating layer covers the spiral magnetoresistance, and the magnetization setting element is arranged on the first insulating layer. The second insulating layer covers the magnetization setting element.

In an embodiment of the present invention, the at least one magnetization setting element includes a first magnetization setting element and a second magnetization setting element, and the magnetic field sensing device further includes a substrate, a first insulation layer, and a second insulation. Layer and a third insulating layer. The first magnetization setting element is disposed on the substrate, the first insulating layer covers the first magnetization setting element, and the vortex magnetoresistance is disposed on the first insulating layer. The second insulating layer covers the spiral magnetoresistance, and the second magnetization setting element is disposed on the second insulating layer. The third insulating layer covers the second magnetization setting element.

In an embodiment of the present invention, the at least one vortex magnetoresistance is a plurality of vortex magnetoresistances electrically connected to form a Wheatstone bridge. When these vortex magnetoresistances are in the state of sensing the external magnetic field, the Wheatstone bridge outputs a differential signal corresponding to the external magnetic field.

In an embodiment of the invention, the Wheatstone bridge is electrically connected to an arithmetic unit. When these vortex magnetoresistances are in a state where their circular free layer is magnetically saturated, the Wheatstone bridge outputs a null signal. The arithmetic unit is used for subtracting the null signal from the differential signal corresponding to the external magnetic field to obtain a net output signal.

In an embodiment of the present invention, the vortex magnetoresistor includes a first vortex magnetoresistance, a second vortex magnetoresistance, a third vortex magnetoresistance, and a fourth vortex magnetoresistance. The first vortex magnetoresistance is electrically connected to the third vortex magnetoresistance and the fourth vortex magnetoresistance, the second vortex magnetoresistance is electrically connected to the third vortex magnetoresistance and the fourth vortex magnetoresistance, the first The pinning direction of the spiral magnetoresistor is the same as that of the second spiral magnetoresistor, the pinning direction of the third spiral magnetoresistor is the same as the pinning direction of the fourth spiral magnetoresistor, and the first spiral magnetoresistor The pinning direction of the resistor is opposite to the pinning direction of the third spiral magnetoresistor.

In an embodiment of the present invention, when the at least one magnetization setting element is energized, the direction of the magnetic field generated at the first to fourth spiral magnetoresistor is perpendicular to the pinning direction of the first to fourth spiral magnetoresistor.

In an embodiment of the present invention, the spacer layer is a non-magnetic metal layer, and the spiral magnetoresistance is a giant magnetoresistance.

In an embodiment of the present invention, the spacer layer is an insulating layer, and the spiral magnetoresistance is a tunneling magnetoresistance.

In an embodiment of the present invention, the at least one magnetization setting element is a conductive sheet, a conductive coil, a wire or a conductor.

In the magnetic field sensing device of the embodiment of the present invention, since a circular free layer with a spiral magnetization direction distribution is used, the direction of the external magnetic field that can be sensed by the spiral magnetoresistance is relatively unrestricted. In addition, in the magnetic field sensing device of the embodiment of the present invention, since the magnetization setting element that can destroy the spiral magnetization direction distribution of the circular free layer is used to measure the flicker noise existing in the magnetic field sensing device itself, The magnetic field sensing device of the embodiment of the present invention can effectively overcome the interference of flicker noise.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

1 is a schematic cross-sectional view of a magnetic field sensing device according to an embodiment of the present invention, FIG. 2 is a schematic top view of the vortex magnetoresistance and magnetization setting element in FIG. 1, and FIG. 3 is the vortex magnetoresistance in FIG. 1 The three-dimensional schematic diagram. 1 to 3, the magnetic field sensing device 100 of this embodiment includes at least one vortex magnetoresistance 200 and at least one magnetization setting element 110. The at least one spiral magnetoresistance 200 includes a pinned layer 210, a pinned layer 220, a spacer layer 230, and a circular free layer 240. The pinned layer 220 is disposed on the pinned layer 210, the spacer layer 230 is disposed on the pinned layer 220, and the circular free layer 240 is disposed on the spacer layer 230. In this embodiment, the pinning layer 210 provides a pinning direction P1, which fixes the magnetization direction of the pinned layer 220 to the pinning direction P1. In this embodiment, the material of the pinned layer 210 is an antiferromagnetic material, and the materials of the pinned layer 220 and the circular free layer 240 are ferromagnetic materials, and the circular free layer 240 is a ferromagnetic material. The material is soft magnetic material (soft magnetic material).

In this embodiment, the magnetic field sensing device 100 can be located in a space constructed by a first direction D1, a second direction D2, and a third direction D3, where the first direction D1, the second direction D2, and the third direction D3 are mutually Perpendicular to each other. In this embodiment, the pinning direction P1 is parallel to the second direction D2, and the pinning layer 210, the pinned layer 220, the spacer layer 230, and the circular free layer 240 are all parallel to the first direction D1 and The plane constructed by the second direction D2.

The circular free layer 240 has a spiral magnetization direction distribution. Specifically, when there is no external magnetic field, the magnetization direction ML of the circular free layer 240 is arranged into a plurality of circles along the circular contour of the circular free layer 240, and the diameters of these circles are gradually reduced to convergence. At the center of the circular outline. The arrangement of the magnetization direction ML may be clockwise or counterclockwise. A vortex core VC is formed in the center of the circular free layer 240, and the magnetization direction at the vortex core VC is perpendicular to the direction of the circular free layer 240, which can face upward (ie, toward FIGS. 2 and The third direction D3 in 3) or downward (that is, facing the direction opposite to the third direction D3). At this time, the net magnetization of the entire circular free layer 240 is zero.

In this embodiment, the vortex magnetoresistor 200 may be a giant magnetoresistor (GMR) or a tunneling magnetoresistor (TMR). When the spiral magnetic resistance 200 is a giant magnetic resistance, the spacer layer 230 is a non-magnetic metal layer; and when the spiral magnetic resistance 200 is a tunneling magnetic resistance, the spacer layer 230 is an insulating layer.

The at least one magnetization setting element 110 is arranged on one side of the at least one spiral magnetoresistance 200. In this embodiment, the magnetization setting element 110 is, for example, a conductive sheet, a conductive coil, a wire, or a conductor, which can generate a magnetic field by passing a current, so as to generate a magnetic field at the circular free layer 240 for setting the circular free layer 240 Magnetic field in the direction of magnetization.

The at least one magnetization setting element 110 is alternately energized and de-energized. When the at least one magnetization setting element 110 is not energized, the spiral magnetization direction distribution of the circular free layer 240 changes with the external magnetic field to achieve the sensing of the external magnetic field. When the at least one magnetization setting element 110 is energized, the magnetic field generated by the at least one magnetization setting element 110 destroys the spiral magnetization direction distribution of the circular free layer 240 and causes the circular free layer 240 to reach magnetic saturation.

Specifically, referring to FIG. 4A, when an external magnetic field H along the first direction D1 passes through the vortex magnetoresistor 200, the area on the side of the vortex center VC facing the second direction D2 will become larger. The area of the side of the vortex center VC facing the opposite direction of the second direction D2 will become smaller, and the magnetization directions in the areas of the two sides are opposite, resulting in the entire circular free layer 240 generating a magnetostatic amount toward the first direction D1 , And the vortex center VC moves in the opposite direction of the second direction D2.

4B, when an external magnetic field H along the opposite direction of the first direction D1 passes through the vortex magnetoresistance 200, the area at the side of the vortex center VC facing the second direction D2 will become smaller. The area of the side of the center VC facing the opposite direction of the second direction D2 will become larger, and the magnetization directions in the areas on these two sides will be opposite, resulting in the entire circular free layer 240 generating a static direction opposite to the first direction D1. The amount of magnetization, and the vortex center VC moves to the second direction D2.

4C, when an external magnetic field H along the second direction D2 passes through the vortex magnetoresistance 200, the area at the side of the vortex center VC facing the first direction D1 will become smaller, The area on the side opposite to the first direction D1 will become larger, and the magnetization directions in the areas on both sides will be opposite, resulting in the entire circular free layer 240 generating a magnetostatic amount toward the second direction D2, and the vortex center VC moves in the first direction D1.

4D, when an external magnetic field H along the opposite direction of the second direction D2 passes through the vortex type magnetoresistor 200, the area at the side of the vortex center VC facing the first direction D1 will become larger. The area of the side of the center VC facing the opposite direction of the first direction D1 will become smaller, and the magnetization directions in the areas on these two sides will be opposite, resulting in the entire circular free layer 240 generating a static direction opposite to the second direction D2. The amount of magnetization, and the vortex center VC moves in the opposite direction of the first direction D1.

FIG. 5 shows the change of the resistance value of the vortex magnetoresistance in FIG. 3 under the action of external magnetic fields in different directions and without external magnetic fields. Please refer to FIG. 3, FIG. 4A to FIG. 4D and FIG. 5. The graph in FIG. 5 shows the change of the resistance value R of the vortex magnetoresistor 200 with respect to the external magnetic field H. As shown in the upper left diagram of FIG. 5, when the vortex magnetoresistance 200 is applied with a magnetic field H outside the same direction as the pinning direction P1, the circular free layer 240 shown in FIG. 4C will move in the pinning direction P1. A net magnetization is generated, and the resistance value R decreases, that is, the value of the resistance value R corresponding to the black dot in the graph. As shown in the lower left diagram of FIG. 5, when the vortex magnetoresistance 200 is applied with a magnetic field H outside the direction opposite to the pinning direction P1, as shown in FIG. 4D, the circular free layer 240 is opposite to the pinning direction P1. Upward will produce a net magnetization, and make the resistance value R rise, that is, the value of the resistance value R corresponding to the black dot in the graph. As shown in the upper right diagram of FIG. 5, when the vortex magnetoresistance 200 is applied with an external magnetic field H perpendicular to the pinning direction P1, the circular free layer 240 is perpendicular to the pinning direction as shown in FIG. 4A or 4B. A net magnetization is produced in the direction of direction P1. The orthographic projection of this net magnetization in the pinning direction P1 is zero, and the resistance value R remains unchanged, that is, the resistance value R corresponding to the black dot in the graph The numerical value. In addition, as shown in the lower right diagram of FIG. 5, when no magnetic field is applied to the spiral magnetoresistor 200, its resistance value R remains unchanged, that is, the value of the resistance value R corresponding to the black circle in the graph.

6A to 6D show the directions of the saturation magnetization generated by the vortex magnetoresistance of FIGS. 1 and 2 after receiving the magnetic field applied by the magnetization setting element. Please refer to FIGS. 1, 2 and 6A. When the magnetization setting element 110 shown in FIGS. 1 and 2 is passed through the current I flowing in the second direction D2, the circular free layer 240 will generate a current I in the first direction D1. The strong magnetic field causes the circular free layer 240 to reach magnetic saturation and generate saturation magnetization in the first direction D1. At this time, the circular free layer 240 forms a single domain, and the magnetization direction of each position thereof faces the first direction D1. Since this saturation magnetization is perpendicular to the pinning direction P1 (ie, the second direction D2), the resistance value R of the vortex magnetoresistor 200 does not change in theory.

Please refer to FIGS. 1, 2 and 6B again. When the current I of the magnetization setting element 110 shown in FIGS. 1 and 2 is changed to flow in the opposite direction to the second direction D2, a direction will be generated at the circular free layer 240 The strong magnetic field in the opposite direction of the first direction D1 causes the circular free layer 240 to reach magnetic saturation and generate saturation magnetization in the opposite direction of the first direction D1. At this time, the circular free layer 240 forms a single magnetic domain, and the magnetization direction of each position thereof faces the opposite direction of the first direction D1. Since this saturation magnetization is perpendicular to the pinning direction P1 (ie, the second direction D2), the resistance value R of the vortex magnetoresistor 200 does not change in theory.

Please refer to Figure 1, Figure 2 and Figure 6C again, when the extension direction of the magnetization setting element 110 shown in Figures 1 and 2 is changed from the original second direction D2 to the first direction D1, and the flow direction of the current I is changed to the flow direction When the first direction D1 is opposite to the first direction D1, a strong magnetic field is generated at the circular free layer 240 toward the second direction D2, so that the circular free layer 240 reaches magnetic saturation and generates saturation magnetization in the second direction D2. At this time, the circular free layer 240 forms a single magnetic domain, and the magnetization direction of each position thereof faces the second direction D2. Since the saturation magnetization is consistent with the pinning direction P1 (ie, the second direction D2), the resistance value R of the vortex magnetoresistor 200 will be reduced to a minimum.

Please refer to FIGS. 1, 2 and 6D again, when the extension direction of the magnetization setting element 110 shown in FIGS. 1 and 2 is changed from the original second direction D2 to the first direction D1, and the flow direction of the current I is changed to the flow direction In the first direction D1, a strong magnetic field is generated at the circular free layer 240 in the opposite direction to the second direction D2, so that the circular free layer 240 reaches magnetic saturation and saturation magnetization is generated in the opposite direction to the second direction D2 the amount. At this time, the circular free layer 240 forms a single magnetic domain, and the magnetization direction of each position thereof faces the opposite direction of the second direction D2. Since this saturation magnetization is opposite to the pinning direction P1 (ie, the second direction D2), the resistance value R of the vortex magnetoresistance 200 will rise to the maximum.

When the magnetization setting element 110 does not pass current, the vortex magnetoresistance 200 is in a situation where it can sense the external magnetic field H, as shown in FIGS. 4A to 4D. At this time, the output signal of the vortex magnetoresistor 200 includes The part corresponding to the external magnetic field H and the part corresponding to the flicker noise of the system. When the magnetization setting element 110 passes current and the vortex magnetoresistance 200 reaches magnetic saturation, the output signal of the vortex magnetoresistance corresponds to the flicker noise of the system. Therefore, when the magnetization setting element 110 is alternately energized and de-energized, and the output signal of the vortex magnetoresistance 200 in these two states is subtracted, the influence of the flicker noise of the system can be deducted, and a more accurate correspondence can be obtained. Signal of external magnetic field H.

In this embodiment, the magnetic field sensing device 100 further includes a substrate 120, a first insulating layer 130 and a second insulating layer 140. The magnetization setting element 110 is disposed on the substrate 120, the first insulating layer 130 covers the magnetization setting element 110, the spiral magnetoresistor 200 is disposed on the first insulating layer 130, and the second insulating layer 140 covers the spiral magnetoresistor 200. on. In this embodiment, the substrate 120 is a circuit substrate, for example, a semiconductor substrate with a circuit.

FIG. 7 shows the transfer curve of the vortex magnetoresistance of FIG. 1. Referring to FIGS. 1, 2, 3, and 7, when a positive external magnetic field H or a negative external magnetic field H in the opposite direction of the pinning direction P1 is applied to the vortex magnetoresistance 200 At this time, the resistance value R of the vortex magnetoresistor 200 first increases or decreases as the absolute value of the external magnetic field H increases. When the _AN increases or decreases to H or -H _an intensity of the external magnetic field H, the magnetic resistance value whorl R 200 reaches a saturation value R + ΔR _s or R-ΔR _s, VC center of the vortex disappeared at this time, And the circular free layer 240 has a single magnetic domain and its net magnetization reaches the saturation magnetization.

When the absolute value of the external magnetic field H begins to decrease from the saturation point (i.e., at the beginning or is reduced from H _AN increases from -H _an), vortex-type magnetoresistance 200 remain at the saturation value (i.e., R or R + ΔR _s -ΔR _s ), until the absolute value of the external magnetic field H is less than H _re (that is, when the external magnetic field is less than H _re or greater than -H _re ), the vortex center VC does not reappear.

In this way, a first working range H _dy 'of the vortex magnetoresistance 200 can be defined as from -H _re to +H _re , and a second working range can be a range other than H _dy , that is, less than -H _an Or greater than the range of +H _an . In the first working range, the spiral magnetization direction distribution of the circular free layer 240 exists stably. In the second working range, the absolute value of the magnetic field set by the magnetization setting element 110 exceeds the absolute value of +H _an or -H _an , and the circular free layer 240 becomes a single magnetic domain with a saturated net magnetization.

FIG. 8 is a schematic top view of a magnetic field sensing device according to an embodiment of the invention. Please refer to FIG. 1, FIG. 2, FIG. 3 and FIG. 8. In FIG. 1, FIG. 2 and FIG. 3, a vortex magnetoresistance 200 and a magnetization setting element 110 are taken as examples for description. In one embodiment, As shown in FIG. 8, the magnetic field sensing device 100 may include a plurality of vortex magnetoresistor 200 (for example, a first vortex magnetoresistor R1, a second vortex magnetoresistor R2, a third vortex magnetoresistor R3, and a fourth vortex Four vortex type magnetoresistor R4, etc.) and a plurality of magnetization setting elements 110 (for example, two magnetization setting elements 110, one of the two magnetization setting elements 110 overlaps the vortex type magnetoresistor R1 and R3, and the other One overlaps with vortex magnetoresistance R2 and R4). In other words, the vortex magnetoresistor 200 is a plurality of vortex magnetoresistor 200 electrically connected to form a Wheatstone bridge, and when the vortex magnetoresistor 200 is in a state of sensing an external magnetic field (that is, magnetized When the setting element 110 is not energized), the Wheatstone bridge outputs a differential signal corresponding to the external magnetic field.

Specifically, the first spiral magnetic resistance R1 is electrically connected to the third spiral magnetic resistance R3 and the fourth spiral magnetic resistance R4, and the second spiral magnetic resistance R2 is electrically connected to the third spiral magnetic resistance R3 and The fourth vortex type magnetic resistance R4. In addition, the pinning direction P1 of the first spiral magnetoresistor R1 is the same as the pinning direction P1 of the second spiral magnetoresistor R2, both of which face the second direction D2. The pinning direction P1 of the third spiral magnetoresistor R3 is the same as the pinning direction P1 of the fourth spiral magnetoresistor R4, which are all opposite to the second direction D2. In addition, the pinning direction P1 of the first spiral magnetoresistor R1 is opposite to the pinning direction P1 of the third spiral magnetoresistor R3.

When the external magnetic field has a magnetic field component in the second direction D2, the resistance value of the first spiral magnetoresistor R1 changes -ΔR, and the resistance value of the second spiral magnetoresistor R2 changes -ΔR. In addition, since the pinning direction P1 of the third spiral magnetoresistor R3 and the fourth spiral magnetoresistor R4 is opposite to the second direction D2, the resistance value of the third spiral magnetoresistor R3 changes by +ΔR , And the resistance value of the fourth spiral magnetoresistor R4 has a +ΔR change. In this way, when the contact Q1 receives a reference voltage VDD and the contact Q2 is coupled to ground, the voltage difference between the contact Q3 and the contact Q4 will be (VDD)×(ΔR/R) , It can be an output signal, and the output signal is a differential signal, where small corresponds to the magnitude of the magnetic field component of the external magnetic field in the second direction D2. Wherein, the contact point Q1 is coupled to the conductive path between the first spiral type magnetic resistance R1 and the fourth spiral type magnetic resistance R4, and the contact point Q2 is coupled to the second spiral type magnetic resistance R2 and the third spiral type magnetic resistance R3 The contact Q3 is coupled to the conductive path between the first spiral magnetoresistor R1 and the third spiral magnetoresistor R3, and the contact Q4 is coupled to the second spiral magnetoresistor R2 and the fourth The conductive path between the vortex magnetoresistor R4.

In this embodiment, the aforementioned Wheatstone bridge is electrically connected to an arithmetic unit 160. When the vortex magnetoresistor 200 is in a state where the circular free layer 240 is in magnetic saturation, the Wheatstone bridge outputs a null signal, and the arithmetic unit 160 is used to subtract the null signal from the differential signal corresponding to the external magnetic field to Obtain a net output signal, and the net output signal has deducted the influence of flicker noise, and can more accurately reflect the size of the external magnetic field. In this embodiment, when the magnetization setting element 110 is energized, the current I flows in the second direction D2, so the direction of the magnetic field generated at the first to fourth spiral magnetoresistor R1, R2, R3, and R4 is perpendicular to the first direction. The pinning direction P1 to the fourth spiral magnetoresistor R1, R2, R3, and R4. At this time, the null signal only contains the part of the flicker noise. Therefore, subtracting the null signal from the differential signal corresponding to the external magnetic field can obtain a net output signal that can reflect the external magnetic field. However, when the magnetization setting element 110 is arranged such that the direction of the magnetic field generated at the first to fourth spiral magnetoresistor R1, R2, R3, and R4 is parallel or antiparallel to the first to fourth spiral magnetoresistor R1 When the pinning direction of R2, R3, and R4 is P1, the empty signal includes the saturation signal (which can be positive or negative) in addition to the part of the flicker noise, that is, the first to fourth spiral magnetic The resistance value of a part of the resistors R1, R2, R3, and R4 increases to the maximum value, and the resistance value of the other part increases to the minimum value. At this time, the arithmetic unit subtracts the null signal from the differential signal corresponding to the external magnetic field, and can add back or subtract the saturation signal to obtain a net output signal that can accurately correspond to the external magnetic field. In this embodiment, the arithmetic unit 160 is, for example, an arithmetic unit, which can be disposed on or in the substrate 120.

FIG. 9 is a schematic waveform diagram of the output signal of the Wheatstone bridge of FIG. 8. 8 and 9, when the Wheatstone bridge is alternately in the sensing state (that is, when the magnetization setting element 110 is not energized) and the null state (that is, when the magnetization setting element 110 has a current I). When switching between, the voltage signal output by the Wheatstone bridge in the sensing state is V _s , and the voltage signal output by the Wheatstone bridge in the empty state is V _n . The arithmetic unit calculates V _s -V _n to obtain the net output signal and output it.

10 is a schematic cross-sectional view of a magnetic field sensing device according to another embodiment of the invention. Please refer to FIG. 10, the magnetic field sensing device 100a of this embodiment is similar to the magnetic field sensing device 100 of FIG. 1, and the difference between the two is as follows. In the magnetic field sensing device 100a of this embodiment, the spiral magnetoresistor 200 is disposed on the substrate 120, and the first insulating layer 130 covers the spiral magnetoresistor 200. In addition, the magnetization setting element 110 is disposed on the first insulating layer 130, and the second insulating layer 140 covers the magnetization setting element 110. In this way, when the current I is passed through the magnetization setting element 110, a strong magnetic field can still be generated at the vortex magnetoresistance 200.

11 is a schematic cross-sectional view of a magnetic field sensing device according to another embodiment of the invention. Please refer to FIG. 10, the magnetic field sensing device 100b of this embodiment is similar to the magnetic field sensing device 100 of FIG. 1, and the difference between the two is as follows. The at least one magnetization setting element 110 of the magnetic field sensing device 100b of this embodiment includes a first magnetization setting element 1101 and a second magnetization setting element 1102, and the magnetic field sensing device 100b further includes a third insulating layer 150. In addition, the first magnetization setting element 1101 is disposed on the substrate 120, the first insulating layer 130 covers the first magnetization setting element 1101, the spiral magnetoresistance 200 is disposed on the first insulating layer 130, and the second insulating layer 140 covers The vortex type magnetoresistance 200 is on. In addition, the second magnetization setting element 1102 is disposed on the second insulating layer 140, and the third insulating layer 150 covers the second magnetization setting element 1102. In this way, when the first magnetization setting element 1101 and the second magnetization setting element 1102 have a current I, a strong magnetic field can still be generated at the vortex magnetoresistance 200.

In summary, in the magnetic field sensing device of the embodiment of the present invention, since a circular free layer with a spiral magnetization direction distribution is used, the direction of the external magnetic field that can be sensed by the spiral magnetoresistance is relatively unrestricted. . In addition, in the magnetic field sensing device of the embodiment of the present invention, since the magnetization setting element that can destroy the spiral magnetization direction distribution of the circular free layer is used to measure the flicker noise existing in the magnetic field sensing device itself, The magnetic field sensing device of the embodiment of the present invention can effectively overcome the interference of flicker noise.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

100, 100a, 100b‧‧‧Magnetic field sensing device 110‧‧‧Magnetization setting element 1101‧‧‧The first magnetization setting element 1102‧‧‧Second magnetization setting element 120‧‧‧Substrate 130‧‧‧First insulation layer 140‧‧‧Second insulating layer 150‧‧‧Third insulation layer 160‧‧‧Computer 200‧‧‧Vortex type magnetoresistance 210‧‧‧Pinning layer 220‧‧‧Pinned layer 230‧‧‧Interval layer 240‧‧‧Circular free layer D1‧‧‧First direction D2‧‧‧Second direction D3‧‧‧ Third party H‧‧‧External magnetic field I‧‧‧Current ML‧‧‧Magnetic direction P1‧‧‧Pinning direction Q1, Q2, Q3, Q4‧‧‧Contact R‧‧‧Resistance value R1‧‧‧First vortex magnetoresistance R2‧‧‧Second vortex magnetoresistance R3‧‧‧The third vortex magnetoresistance R4‧‧‧Fourth spiral magnetoresistance VC‧‧‧Vortex Center

FIG. 1 is a schematic cross-sectional view of a magnetic field sensing device according to an embodiment of the invention. Fig. 2 is a schematic top view of the spiral magnetoresistance and magnetization setting element in Fig. 1. FIG. 3 is a three-dimensional schematic diagram of the vortex magnetoresistance in FIG. 1. 4A to 4D respectively illustrate the changes in the distribution of the four magnetization directions of the circular free layer in FIG. 3 caused by external magnetic fields in four different directions. FIG. 5 shows the change of the resistance value of the vortex magnetoresistance in FIG. 3 under the action of external magnetic fields in different directions and without external magnetic fields. 6A to 6D show the directions of the saturation magnetization generated by the vortex magnetoresistance of FIGS. 1 and 2 after receiving the magnetic field applied by the magnetization setting element. FIG. 7 shows the conversion curve of the vortex magnetoresistance of FIG. 1. FIG. 8 is a schematic top view of a magnetic field sensing device according to an embodiment of the invention. FIG. 9 is a schematic waveform diagram of the output signal of the Wheatstone bridge of FIG. 8. 10 is a schematic cross-sectional view of a magnetic field sensing device according to another embodiment of the invention. 11 is a schematic cross-sectional view of a magnetic field sensing device according to another embodiment of the invention.

100‧‧‧Magnetic field sensing device

110‧‧‧Magnetization setting element

120‧‧‧Substrate

130‧‧‧First insulation layer

140‧‧‧Second insulating layer

200‧‧‧Vortex type magnetoresistance

240‧‧‧Circular free layer

D1‧‧‧First direction

D2‧‧‧Second direction

D3‧‧‧ Third party

I‧‧‧Current

Claims (11)

A magnetic field sensing device, including: At least one spiral magnetoresistance, including: A pinned layer A pinned layer, disposed on the pinned layer; A spacer layer disposed on the pinned layer; and A circular free layer disposed on the spacer layer and having a spiral magnetization direction distribution; and At least one magnetization setting element is arranged on one side of the at least one spiral magnetoresistance, wherein the at least one magnetization setting element is alternately energized and not energized. When the at least one magnetization setting element is not energized, the circular free layer The distribution of the spiral magnetization direction changes with the external magnetic field to achieve the sensing of the external magnetic field; when the at least one magnetization setting element is energized, the magnetic field generated by the at least one magnetization setting element destroys the free circle The spiral magnetization direction of the layer is distributed and the circular free layer reaches magnetic saturation. The magnetic field sensing device described in item 1 of the scope of patent application further includes: A substrate, wherein the magnetization setting element is disposed on the substrate; A first insulating layer covering the magnetization setting element, wherein the vortex magnetoresistance is disposed on the first insulating layer; and A second insulating layer covers the spiral magnetic resistance. The magnetic field sensing device described in item 1 of the scope of patent application further includes: A substrate, wherein the vortex magnetoresistance is disposed on the substrate; A first insulating layer covering the spiral magnetoresistance, wherein the magnetization setting element is disposed on the first insulating layer; and A second insulating layer covers the magnetization setting element. The magnetic field sensing device according to claim 1, wherein the at least one magnetization setting element includes a first magnetization setting element and a second magnetization setting element, and the magnetic field sensing device further includes: A substrate, wherein the first magnetization setting element is disposed on the substrate; A first insulating layer covering the first magnetization setting element, wherein the spiral magnetoresistance is disposed on the first insulating layer; A second insulating layer covering the spiral magnetoresistance, wherein the second magnetization setting element is disposed on the second insulating layer; and A third insulating layer covers the second magnetization setting element. The magnetic field sensing device according to the first item of the scope of patent application, wherein the at least one vortex type magnetoresistor is a plurality of vortex type magnetoresistors electrically connected to form a Wheatstone bridge, and when the vortex type magnetoresistor When measuring the state of the external magnetic field, the Wheatstone bridge outputs a differential signal corresponding to the external magnetic field. The magnetic field sensing device according to item 5 of the scope of patent application, wherein the Wheatstone bridge is electrically connected to an arithmetic unit, and when the vortex magnetoresistance is in a state of magnetic saturation of its circular free layer, The Wheatstone bridge outputs a null signal, and the arithmetic unit is used for subtracting the null signal from the differential signal corresponding to the external magnetic field to obtain a net output signal. The magnetic field sensing device according to item 5 of the scope of patent application, wherein the vortex magnetoresistor includes a first vortex magnetoresistance, a second vortex magnetoresistance, a third vortex magnetoresistance, and a fourth A vortex magnetoresistance, the first vortex magnetoresistance is electrically connected to the third vortex magnetoresistance and the fourth vortex magnetoresistance, and the second vortex magnetoresistance is electrically connected to the third vortex magnetoresistance And the fourth spiral magnetoresistor, the pinning direction of the first spiral magnetoresistor is the same as the pinning direction of the second spiral magnetoresistor, and the pinning direction of the third spiral magnetoresistor is the same as the fourth spiral magnetoresistor. The pinning direction of the spiral magnetoresistor, and the pinning direction of the first spiral magnetoresistor is opposite to the pinning direction of the third spiral magnetoresistor. The magnetic field sensing device according to item 7 of the scope of patent application, wherein the direction of the magnetic field generated at the first to fourth vortex magnetoresistor when the at least one magnetization setting element is energized is perpendicular to the first to fourth vortex Pinning direction of type magnetoresistance. According to the magnetic field sensing device described in claim 1, wherein the spacer layer is a non-magnetic metal layer, and the spiral magnetoresistance is a giant magnetoresistance. According to the magnetic field sensing device described in claim 1, wherein the spacer layer is an insulating layer, and the spiral magnetoresistance is a tunneling magnetoresistance. The magnetic field sensing device according to the first item of the scope of patent application, wherein the at least one magnetization setting element is a conductive sheet, a conductive coil, a wire or a conductor.

Images