阅读说明：本技术 一种单片集成三轴隧穿磁电阻的磁传感器及其制备方法 (Magnetic sensor with single-chip integrated three-axis tunneling magnetoresistance and preparation method thereof ) 是由 杨怀文 赵巍胜 曹志强 冷群文 于 2020-06-15 设计创作，主要内容包括：本发明提供了一种单片集成三轴隧穿磁电阻的磁传感器及其制备方法,该传感器包括：衬底、第一TMR磁阻单元、第二TMR磁阻单元、第三TMR磁阻单元、固定电阻、磁通导磁器、第一全桥电路、第二全桥电路以及半桥电路,其中：多个第一TMR磁阻单元位于第一全桥电路的四个桥臂上；多个第二TMR磁阻单元位于半桥电路的一对相对的桥臂上,多个固定电阻位于半桥电路的另一对相对的桥臂上；多个第三TMR磁阻单元位于第二全桥电路的四个桥臂上；第一全桥电路、第二全桥电路以及半桥电路均位于衬底上。本发明在单一衬底中且一次集成磁传感器的三轴,降低了成本,大幅度提高了器件的精度。(The invention provides a magnetic sensor of single-chip integrated three-axis tunneling magneto-resistance and a preparation method thereof, wherein the sensor comprises the following components: substrate, first TMR magnetic resistance unit, second TMR magnetic resistance unit, third TMR magnetic resistance unit, fixed resistance, magnetic conduction magnetizer, first full-bridge circuit, second full-bridge circuit and half-bridge circuit, wherein: the plurality of first TMR magnetic resistance units are positioned on four bridge arms of the first full bridge circuit; the plurality of second TMR magnetic resistance units are positioned on one pair of opposite bridge arms of the half-bridge circuit, and the plurality of fixed resistors are positioned on the other pair of opposite bridge arms of the half-bridge circuit; a plurality of third TMR magnetic resistance units are positioned on four bridge arms of the second full bridge circuit; the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are all located on the substrate. The invention integrates three axes of the magnetic sensor in a single substrate at one time, thereby reducing the cost and greatly improving the precision of the device.)

1. A monolithically integrated three-axis tunneling magnetoresistive magnetic sensor, comprising: substrate, first TMR magnetic resistance unit, second TMR magnetic resistance unit, third TMR magnetic resistance unit, fixed resistance, magnetic conduction magnetizer, first full-bridge circuit, second full-bridge circuit and half-bridge circuit, wherein:

the plurality of first TMR magneto-resistive units are positioned on four bridge arms of the first full-bridge circuit;

the plurality of second TMR magnetic resistance units are positioned on one pair of opposite bridge arms of the half-bridge circuit, and the plurality of fixed resistors are positioned on the other pair of opposite bridge arms of the half-bridge circuit;

the plurality of third TMR magneto-resistive units are positioned on four bridge arms of the second full-bridge circuit, one magnetic flux magnetic conductor is positioned on two adjacent bridge arms of the second full-bridge circuit, and the other magnetic flux magnetic conductor is positioned on the other two bridge arms of the second full-bridge circuit;

the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are all located on the substrate.

2. The magnetic sensor of claim 1, wherein the first full-bridge circuit is located on an X-axis or a Y-axis of the magnetic sensor, the half-bridge circuit is located on an X-axis or a Y-axis of the magnetic sensor, and the first full-bridge circuit and the half-bridge circuit are not located on the same axis;

the second full-bridge circuit is located on the Z axis of the magnetic sensor.

3. Magnetic sensor according to claim 1, characterized in that the material of the fixed resistance comprises one or more of Ta, Pt, Gr and Al.

4. Magnetic sensor according to claim 1, characterized in that the material of the magnetic flux conductor comprises one or more of NiFe soft magnetic, NiFeCr soft magnetic and CoAl based soft magnetic.

5. Magnetic sensor according to claim 1, characterized in that the material of the interconnect lines and the wires of the respective first full-bridge, second full-bridge and half-bridge circuits comprises one or more of Cr, Al, Au and Ti.

6. The magnetic sensor according to claim 1, wherein the magnetoresistive film stack of the TMR magnetoresistive cell includes an antiferromagnetic layer, an artificial antiferromagnetic layer, a spacer layer, and a ferromagnetic free layer;

the TMR magnetic resistance unit is in an elliptical shape with the length-to-width axial ratio of 3-10.

7. A method for preparing a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor according to any of claims 1 to 6, comprising:

adopting a magnetron sputtering instrument to grow a magnetic resistance film of the TMR magnetic resistance unit;

the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are annealed by applying magnetic fields along the positive direction of an X axis;

applying a magnetic field to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit in the X-axis direction for annealing, and

an X-axis, a Y-axis, and a Z-axis of the magnetic sensor are disposed on a single substrate.

8. The method of claim 7, wherein the magnetic pinning layer angle ranges from 0 to 90 degrees.

9. The method of claim 7, further comprising: soft magnetic materials with preset thickness grow on the outer surface of the magnetic flux permeability device, wherein the soft magnetic materials comprise one or more of NiFe soft magnetic, NiFeCr soft magnetic and CoAl-based soft magnetic; the magnetic conduction device is in an in-plane communication shape.

10. The method according to claim 9, wherein the predetermined thickness is 0.8 to 1.2 microns.

Technical Field

The invention relates to the technical field of design and preparation of magnetic electronic devices, in particular to a design and preparation technology of a sensor in the field of CMOS compatible magnetic electronics, and particularly relates to a magnetic sensor integrating a single chip with three-axis tunneling magnetoresistance and a preparation method thereof.

Background

Magnetic sensors are widely used in modern industry and electronic products to sense magnetic field strength to measure physical parameters such as current, position, direction, etc. Has wide application in many fields, such as electromechanical automatic control, biological detection, aerospace industry and the like. In the prior art, there are many different types of sensors for measuring magnetic fields and other parameters, such as magnetic sensors that use Hall (Hall) elements, anisotropic magneto-resistance (AMR) elements or giant magneto-resistance (GMR) elements as sensitive elements. Among them, the hall effect and anisotropic magnetoresistance effect have been matured, and the giant magnetoresistance has also been widely used in hard disk heads. Tunneling Magnetoresistive (TMR) elements are new magnetoresistive effect sensors that have been industrially used in recent years, and sense a magnetic field using the tunneling magnetoresistive effect of a magnetic multilayer film material, and have a larger resistance change rate than the AMR elements and GMR elements that have been found and put into practical use before. The MR ratios of AMR elements and GMR elements are about 3% and 12%, respectively, while TMR elements reach even 400%. With the development of high and new technologies such as artificial intelligence and unmanned driving, the requirement on the accuracy of the sensor is higher and higher, and the sensor is replaced by a TMR sensor in the high-end application field.

TMR is created by a Magnetic Tunnel Junction (MTJ) structure, typically a sandwich of ferromagnetic/nonmagnetic insulating/ferromagnetic (FM/I/FM) layers. In saturation magnetization, the magnetization directions of the two ferromagnetic layers are parallel to each other, but the coercive forces of the two ferromagnetic layers are usually different, so that in reverse magnetization, the magnetization vectors of the ferromagnetic layers with small coercive force are firstly inverted, so that the magnetization directions of the two ferromagnetic layers become antiparallel. The tunneling probability of electrons from one magnetic layer to the other is related to the magnetization direction of the two magnetic layers.

In order to eliminate the temperature influence, the magnetic sensor is generally made into a Wheatstone bridge structure with four bridge arms, and the changes of two adjacent bridge arms along with the external magnetic field are opposite. In contrast, the following disadvantages exist in the prior art: first, the magnetoresistance ratio of the anisotropic sensor and the giant magnetoresistance material is lower than that of tunneling magnetoresistance TMR, so the precision is lower than that of TMR. Secondly, the anisotropic sensor and the giant magnetoresistance effect sensor are difficult to integrate with respect to the third axis, and need to be spliced together to realize three-axis sensing, and the preparation process is complex. In addition, the conventional TMR sensor cannot integrate three-axis sensing on a substrate, and the Wheatstone bridge design is realized by splicing so as to realize three-axis sensing.

Disclosure of Invention

The single-chip integrated three-axis tunneling magneto-resistance magnetic sensor and the preparation method thereof provided by the invention integrate three axes of the magnetic sensor in a single substrate at one time, simplify the process, reduce the cost and greatly improve the precision of the device.

In order to achieve the above object, in one aspect, the present invention discloses a monolithically integrated three-axis tunneling magneto-resistance magnetic sensor, including:

substrate, first TMR magnetic resistance unit, second TMR magnetic resistance unit, third TMR magnetic resistance unit, fixed resistance, magnetic conduction magnetizer, first full-bridge circuit, second full-bridge circuit and half-bridge circuit, wherein:

the plurality of first TMR magneto-resistive units are positioned on four bridge arms of the first full-bridge circuit;

the plurality of second TMR magnetic resistance units are positioned on one pair of opposite bridge arms of the half-bridge circuit, and the plurality of fixed resistors are positioned on the other pair of opposite bridge arms of the half-bridge circuit;

the plurality of third TMR magneto-resistive units are positioned on four bridge arms of the second full-bridge circuit, one magnetic flux magnetic conductor is positioned on two adjacent bridge arms of the second full-bridge circuit, and the other magnetic flux magnetic conductor is positioned on the other two bridge arms of the second full-bridge circuit;

the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are all located on the substrate.

In one embodiment, the first full-bridge circuit is located on the X axis or the Y axis of the magnetic sensor, the half-bridge circuit is located on the X axis or the Y axis of the magnetic sensor, and the first full-bridge circuit and the half-bridge circuit are not located on the same axis;

the second full-bridge circuit is located on the Z axis of the magnetic sensor.

In one embodiment, the material of the fixed resistor includes one or more of Ta, Pt, Gr, and Al.

In one embodiment, the material of the magnetic flux conductor comprises one or more of NiFe soft magnetic, NiFeCr soft magnetic, and CoAl-based soft magnetic.

In one embodiment, the material of the interconnection lines and the conducting wires of the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit respectively comprises one or more of Ta, Cr, Al, Au and Ti.

In one embodiment, the magnetoresistive film stack of the TMR magnetoresistive cell includes an antiferromagnetic layer, an artificial antiferromagnetic layer, a spacer layer, and a ferromagnetic free layer;

the TMR magnetic resistance unit is in an elliptical shape with the length-to-width axial ratio of 3-10.

The invention also discloses a preparation method of the single-chip integrated three-axis tunneling magneto-resistance magnetic sensor, which comprises the following steps:

adopting a magnetron sputtering instrument to grow a magnetic resistance film of the TMR magnetic resistance unit;

the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are annealed by applying magnetic fields along the positive direction of an X axis;

applying a magnetic field to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit in the X-axis direction for annealing, and

an X-axis, a Y-axis, and a Z-axis of the magnetic sensor are disposed on a single substrate.

In one embodiment, the magnetic pinning layer angle ranges from 0 to 90 degrees.

In one embodiment, the method for manufacturing the monolithically integrated three-axis tunneling magnetoresistive magnetic sensor further includes: soft magnetic materials with preset thickness grow on the outer surface of the magnetic flux permeability device, wherein the soft magnetic materials comprise one or more of NiFe soft magnetic, NiFeCr soft magnetic and CoAl-based soft magnetic; the magnetic conduction device is in an in-plane communication shape.

In one embodiment, the predetermined thickness is 0.8 to 1.2 μm.

The magnetic sensor of the single-chip integrated three-axis tunneling magneto-resistance provided by the embodiment of the invention comprises: substrate, first TMR magnetic resistance unit, second TMR magnetic resistance unit, third TMR magnetic resistance unit, fixed resistance, magnetic conduction magnetizer, first full-bridge circuit, second full-bridge circuit and half-bridge circuit, wherein: the plurality of first TMR magnetic resistance units are positioned on four bridge arms of the first full bridge circuit; the plurality of second TMR magnetic resistance units are positioned on one pair of opposite bridge arms of the half-bridge circuit, and the plurality of fixed resistors are positioned on the other pair of opposite bridge arms of the half-bridge circuit; the plurality of third TMR magnetic resistance units are positioned on four bridge arms of the second full-bridge circuit, one magnetic flux magnetic conductor is positioned on two adjacent bridge arms of the second full-bridge circuit, and the other magnetic flux magnetic conductor is positioned on the other two bridge arms of the second full-bridge circuit; the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are all located on the substrate. In addition, the embodiment of the invention also provides a preparation method of the magnetic sensor with the single-chip integrated three-axis tunneling magnetoresistance, which specifically comprises the following steps: adopting a magnetron sputtering instrument to grow a magnetic resistance film of the TMR magnetic resistance unit; and applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis positive direction; then, the first full-bridge circuit, the second full-bridge circuit, and the half-bridge circuit are annealed by applying a magnetic field in the X-axis direction, and the X-axis, the Y-axis, and the Z-axis of the magnetic sensor are provided on the single substrate. The three-axis TMR sensor is monolithically integrated, three axes are integrated at one time, the process is simplified, the cost is reduced, and the precision of the device is greatly improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a diagram illustrating a Wheatstone full-bridge structure of a magnetic sensor with a single-chip integrated three-axis tunneling magnetoresistance according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a Wheatstone half-bridge structure of a magnetic sensor with monolithically integrated three-axis tunneling magnetoresistance according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a Z-axis structure of a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor in an embodiment of the invention;

FIG. 4 is a schematic diagram of a Wheatstone bridge interconnection structure in an embodiment of the invention;

FIG. 5 is a cross-sectional view of a Z-axis structure of a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor in an embodiment of the invention;

FIG. 6 is a schematic diagram showing a film structure of a TMR magnetoresistive cell in an embodiment of the invention;

FIG. 7 is a first flowchart of a method for manufacturing a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor according to an embodiment of the present invention;

FIG. 8 is a flow chart of a second method for manufacturing a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor according to an embodiment of the present invention;

FIG. 9 is a flow chart of a method for manufacturing a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor in an exemplary embodiment of the present invention;

FIG. 10 is a schematic diagram of the operation principle of a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor in an embodiment of the present invention;

fig. 11 is a schematic view of the magnetic field direction of the cross-sectional structure of the magnetic flux permeability apparatus in the embodiment of the invention.

Description of the symbols:

1 first TMR magnetoresistive cell

2 second TMR magnetoresistive unit

3 third TMR magnetoresistive cell

4 fixed resistance

5 magnetic flux magnetic conductor

6 first full bridge circuit

7 second full bridge circuit

8 half-bridge circuit

9 Ta electrode

10 gold electrode

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The embodiments disclosed herein are merely illustrative of specific structural and functional details for purposes of describing particular embodiments, and thus the invention may be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein, but rather should be construed to cover all modifications, equivalents, and alternatives falling within the scope of the invention. In the actual manufacturing process, the process selection, sequence arrangement and the like of each step are determined according to specific conditions and are included in the scope of the present disclosure.

At present, in the published related art, a full-bridge and half-bridge giant magnetoresistance GMR structure is designed, and one-time annealing two-axis sensing is realized. The full-bridge structure is composed of four 45-degree GMR strips, the sensitivity along with a single magnetic field direction is realized through annealing, and the change trends of adjacent bridge arms are opposite. The half-bridge structure is formed by two 0-degree GMR strips and two fixed resistors, and the sensitive change of the magnetic field direction is realized through annealing. The combination of full-bridge and half-bridge structures realizes in-plane two-axis magnetic sensing by one-time annealing, and it can be understood that the following disadvantages are present:

1) the magnetic resistance rate of the anisotropic sensor and the giant magnetoresistance material is lower than that of tunneling magnetoresistance TMR, so that the precision is lower than that of TMR.

2) The anisotropic sensor and the giant magnetoresistance effect sensor are difficult to integrate with a third shaft, and need to be spliced together to realize three-shaft sensing, and the preparation process is complex.

3) The traditional TMR sensor can not integrate three-axis sensing on a substrate at present, and realizes the Wheatstone bridge design by splicing to achieve three-axis sensing.

To address at least one of the above issues, according to one aspect of the present invention, the present embodiment discloses a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor.

In this embodiment, as shown in fig. 1 to 3, the monolithically integrated three-axis tunneling magnetoresistive magnetic sensor includes: a substrate (not shown), a first TMR magnetoresistive unit 1, a second TMR magnetoresistive unit 2, a third TMR magnetoresistive unit 3, a fixed resistor 4, a magnetic flux conductor 5, a first full bridge circuit 6, a second full bridge circuit 7, and a half bridge circuit 8, wherein:

a plurality of the first TMR magnetoresistive units 1 are located on four arms of the first full bridge circuit 6;

the plurality of second TMR magnetoresistive units 2 are positioned on one pair of opposite bridge arms of the half-bridge circuit 8, and the plurality of fixed resistors 4 are positioned on the other pair of opposite bridge arms of the half-bridge circuit 8;

the plurality of third TMR magnetoresistive units 3 are located on four arms of the second full-bridge circuit 7, and one magnetic flux conductor 5 is located on two adjacent arms of the second full-bridge circuit 7, it should be noted that, here, two adjacent arms refer to a line connecting the positive voltage and the negative voltage of the second full-bridge circuit 7, and two adjacent arms are respectively located on two sides of the line. The other magnetic flux conductor 5 is located on the other two legs of the second full-bridge circuit 7.

The first full-bridge circuit 6, the second full-bridge circuit 7 and the half-bridge circuit 8 are all located on the substrate.

The magnetic sensor of the single-chip integrated three-axis tunneling magneto-resistance provided by the embodiment of the invention comprises: substrate, first TMR magnetic resistance unit, second TMR magnetic resistance unit, third TMR magnetic resistance unit, fixed resistance, magnetic conduction magnetizer, first full-bridge circuit, second full-bridge circuit and half-bridge circuit, wherein: the plurality of first TMR magnetic resistance units are positioned on four bridge arms of the first full bridge circuit; the plurality of second TMR magnetic resistance units are positioned on one pair of opposite bridge arms of the half-bridge circuit, and the plurality of fixed resistors are positioned on the other pair of opposite bridge arms of the half-bridge circuit; the plurality of third TMR magnetic resistance units are positioned on four bridge arms of the second full-bridge circuit, one magnetic flux magnetic conductor is positioned on two adjacent bridge arms of the second full-bridge circuit, and the other magnetic flux magnetic conductor is positioned on the other two bridge arms of the second full-bridge circuit; the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are all located on the substrate. The three-axis TMR sensor is monolithically integrated, three axes are integrated at one time, the process is simplified, the cost is reduced, and the precision of the device is greatly improved.

In one embodiment, the first full-bridge circuit 6 is located on the X-axis or Y-axis of the magnetic sensor, the half-bridge circuit 8 is located on the X-axis or Y-axis of the magnetic sensor, and the first full-bridge circuit 6 and the half-bridge circuit 8 are not located on the same axis; the second full-bridge circuit 7 is located on the Z-axis of the magnetic sensor.

It should be understood that the first full-bridge circuit 6 and the second full-bridge circuit 7 are both referred to as a wheatstone full-bridge circuit, and similarly, the half-bridge circuit 8 is referred to as a wheatstone half-bridge. The Wheatstone bridge is a bridge circuit composed of four resistors, the four resistors are respectively called as bridge arms of the bridge, the Wheatstone bridge measures the change of the physical quantity by using the change of the resistors, the singlechip acquires and processes the voltages at the two ends of the variable resistor, and the change of the corresponding physical quantity can be calculated. Fig. 1 shows a wheatstone full-bridge circuit sensitive to the Y axis of the magnetic sensor (which may be the X axis of course), fig. 2 shows a wheatstone half-bridge circuit sensitive to the X axis of the magnetic sensor (which may be the Y axis of course, but is not coaxial with the wheatstone full-bridge circuit), and fig. 3 shows a wheatstone full-bridge flux collector sensitive to the Z axis.

In one embodiment, the orientation of the wheatstone full-bridge TMR magnetoresistive element can be changed from 0 degree to 90 degrees, preferably in a 45 degree structure, and the half-bridge is in a 0 degree structure; the out-of-plane single-axis TMR is designed into a Wheatstone bridge and magnetic flux magnetizer structure.

The interconnection structure of TMR magnetoresistive elements of wheatstone bridge is shown in fig. 4, two adjacent Magnetic Tunnel Junctions (MTJ) are connected at the bottom by a Ta electrode 9 and at the top by a gold electrode 10 each to the surrounding magnetic tunnel junctions. Fig. 5 is a cross-sectional view of a wheatstone bridge Z-axis magnetic flux conductor (cross-sectional view along line aa' in fig. 3).

In one embodiment, the material of the fixed resistor includes one or more of Ta, Pt, Gr, and Al.

In one embodiment, the material of the magnetic flux conductor comprises one or more of NiFe soft magnetic, NiFeCr soft magnetic, and CoAl-based soft magnetic.

In one embodiment, the material of the interconnection lines and the conducting wires of the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit respectively comprises one or more of Ta, Cr, Al, Au and Ti.

In one embodiment, the magnetoresistive film stack of the TMR magnetoresistive cell includes an antiferromagnetic layer, an artificial antiferromagnetic layer, a spacer layer (nonmagnetic interlayer), and a ferromagnetic free layer (sense layer); the TMR magnetic resistance unit is in an elliptical shape with the length-to-width axial ratio of 3-10.

It is understood that each of the bridge arm films of the first full-bridge circuit 6, the second full-bridge circuit 7 and the half-bridge circuit 8 adopts a TMR film structure formed by connecting TMR films in series, referring to fig. 6, preferably, the magnetoresistive film stack of the TMR magnetoresistive cell further includes a substrate, a seed layer and a cover layer, the layers are stacked in sequence as shown in the figure, and the TMR magnetoresistive cell is an ellipse with a length-to-width ratio of 3 to 10.

Based on the same principle, the embodiment also discloses a preparation method of the single-chip integrated three-axis tunneling magneto-resistance magnetic sensor. As shown in fig. 7, in this embodiment, the method includes:

step 100: and growing the magnetic resistance film of the TMR magnetic resistance unit by adopting a magnetron sputtering instrument.

Step 200: and (4) applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis positive direction.

Preferably, the prepared device is annealed by adding a 5T field for 270 degrees along the X direction, the temperature is maintained for one hour, the magnetic field is reduced to 0, the field is added for 500Oe along the reverse X-axis direction, the temperature is maintained for 15 minutes, the magnetic field is reduced to zero, and then the temperature is slowly reduced to the room temperature.

Step 300: and applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis in the reverse direction.

Based on step 200, an X-axis reverse magnetization annealing is performed to change the angle of the pinned layer from 0 to 90 degrees.

Step 400: an X-axis, a Y-axis, and a Z-axis of the magnetic sensor are disposed on a single substrate.

The preparation method of the single-chip integrated three-axis tunneling magneto-resistance magnetic sensor provided by the embodiment of the invention specifically comprises the following steps: adopting a magnetron sputtering instrument to grow a magnetic resistance film of the TMR magnetic resistance unit; and applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis positive direction; then, the first full-bridge circuit, the second full-bridge circuit, and the half-bridge circuit are annealed by applying a magnetic field in the X-axis direction, and the X-axis, the Y-axis, and the Z-axis of the magnetic sensor are provided on the single substrate.

In an embodiment, referring to fig. 8, the method for manufacturing a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor further includes:

step 500: and growing a soft magnetic material with a preset thickness on the outer surface of the magnetic flux permeability device.

The soft magnetic material comprises one or more of NiFe soft magnetic material, NiFeCr soft magnetic material and CoAl-based soft magnetic material; the magnetic conduction device is in an in-plane communication shape. Preferably, the predetermined thickness in step 500 is 0.8 to 1.2 micrometers.

To further illustrate the present solution, the present invention provides a specific application example of a method for manufacturing a monolithically integrated three-axis tunneling magnetoresistive magnetic sensor, which specifically includes the following contents, and refer to fig. 9.

S1: and (4) micro-processing to prepare a three-axis device.

Specifically, in step S1, processes such as ultraviolet exposure, etching of TMR bars and interconnection lines, ultraviolet exposure, etching of bottom interconnection lines, ultraviolet exposure, evaporation of SiN protection, ultraviolet exposure, and evaporation of top electrodes are sequentially required.

S2: and growing the magnetic resistance film of the TMR magnetic resistance unit by adopting a magnetron sputtering instrument.

Specifically, the Z axis adopts a Wheatstone bridge and magnetic flux conductor structure, after the Wheatstone bridge is finished, soft magnetic materials with the size of about 1 micron, such as NiFe, NiFeCr and the like, are grown, and an out-of-plane magnetic field is introduced into the plane so as to measure the size of an out-of-plane magnetic field.

S3: and (4) applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis positive direction.

Specifically, the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are annealed by applying a magnetic field along the positive direction of the X axis, and the range is 1-50000 Oe.

S4: and applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis in the reverse direction.

Specifically, the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are subjected to magnetic field annealing along the X-axis in the reverse direction, and the range is 1-50000 Oe.

S5: and growing a soft magnetic material with a preset thickness on the outer surface of the magnetic flux permeability device.

The soft magnetic material comprises one or more of NiFe soft magnetic material, NiFeCr soft magnetic material and CoAl-based soft magnetic material; the magnetic conduction device is in an in-plane communication shape, and the preset thickness is 0.8-1.2 microns.

Referring to fig. 10, the working principle of the monolithically integrated three-axis tunneling magnetoresistive magnetic sensor of this specific application example is as follows:

(1) referring to fig. 1, the sensor is sensitive to a Y-axis magnetic field and is insensitive to an X-axis magnetic field, i.e., Y-axis magnetic field measurement can be realized. The magnetic pinning direction is deviated to the short axis direction after the annealing along the X axis by increasing the field and then along the-X axis (the reverse direction of the X axis) by small field. The trend of the change of R1, R2, R3 and R4 along with the magnetic field is shown in the curve of FIG. 10.

(2) Aiming at fig. 2, a Wheatstone half-bridge structure is insensitive to a Y-axis magnetic field, a TMR bridge is linear to the change of an X-axis magnetic field, a fixed magnetic resistance is not changed along with an external field, and the measurement of the X-axis magnetic field can be realized.

(3) In the wheatstone full-bridge structure shown in fig. 3, a magnetic concentrator (magnetic flux conducting device) is added to introduce a magnetic field in the Z direction into a plane, the cross-sectional structure is shown in fig. 11, and for the R1 bridge arm magnetic flux along the left side and the R2 along the right side, adjacent change curves of the wheatstone bridge are opposite, so that the Z-axis magnetic field test can be realized.

The magnetic sensor of the single-chip integrated three-axis tunneling magneto-resistance provided by the embodiment of the invention comprises: substrate, first TMR magnetic resistance unit, second TMR magnetic resistance unit, third TMR magnetic resistance unit, fixed resistance, magnetic conduction magnetizer, first full-bridge circuit, second full-bridge circuit and half-bridge circuit, wherein: the plurality of first TMR magnetic resistance units are positioned on four bridge arms of the first full bridge circuit; the plurality of second TMR magnetic resistance units are positioned on one pair of opposite bridge arms of the half-bridge circuit, and the plurality of fixed resistors are positioned on the other pair of opposite bridge arms of the half-bridge circuit; the plurality of third TMR magnetic resistance units are positioned on four bridge arms of the second full-bridge circuit, one magnetic flux magnetic conductor is positioned on two adjacent bridge arms of the second full-bridge circuit, and the other magnetic flux magnetic conductor is positioned on the other two bridge arms of the second full-bridge circuit; the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit are all located on the substrate. In addition, the embodiment of the invention also provides a preparation method of the magnetic sensor with the single-chip integrated three-axis tunneling magnetoresistance, which specifically comprises the following steps: adopting a magnetron sputtering instrument to grow a magnetic resistance film of the TMR magnetic resistance unit; and applying magnetic field annealing to the first full-bridge circuit, the second full-bridge circuit and the half-bridge circuit along the X-axis positive direction; then, the first full-bridge circuit, the second full-bridge circuit, and the half-bridge circuit are annealed by applying a magnetic field in the X-axis direction, and the X-axis, the Y-axis, and the Z-axis of the magnetic sensor are provided on the single substrate. On the basis of a Wheatstone half-bridge structure and a full-bridge structure, the magnetic flux magnetizer is added by utilizing the TMR structure design, and finally the purposes of primary annealing, integration of a three-axis sensor and three-axis TMR sensing are realized on a substrate. The method has the advantages of simple process, high integration level and capability of accurately measuring the three-axis magnetic field.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the hardware + program class embodiment, since it is substantially similar to the method embodiment, the description is simple, and the relevant points can be referred to the partial description of the method embodiment.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

Although the present application provides method steps as in an embodiment or a flowchart, more or fewer steps may be included based on conventional or non-inventive labor. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution. When an actual apparatus or client product executes, it may execute sequentially or in parallel (e.g., in the context of parallel processors or multi-threaded processing) according to the embodiments or methods shown in the figures.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The principle and the implementation mode of the invention are explained by applying specific embodiments in the invention, and the description of the embodiments is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.