Three-dimensional magnetic field sensor with 3D aliasing structure and method of manufacturing the same

Abstract

The application provides a three-dimensional magnetic field sensor of 3D mixed structure and a preparation method thereof, and belongs to the technical field of sensor packaging. The three-dimensional magnetic field sensor comprises a peripheral integrated circuit unit and three magnetic sensitive units, the peripheral integrated circuit unit and the three magnetic sensitive units are arranged in a vertical direction; the three magnetic sensitive units comprise a Z-axis magnetic sensitive unit based on a Hall effect and X-axis and Y-axis magnetic sensitive units based on an anisotropic magnetoresistance (AMR) effect; the three magnetic sensitive units and the peripheral integrated circuit unit are electrically connected to each other through a through-silicon via wire. The through-silicon via technology and the 3D stacking technology can effectively overcome the defects of large area and volume consumption and low integration degree caused by a traditional bonding wire interconnection method, and bring the possibility of miniaturization and commercial application of an AMR / Hall mixed three-axis magnetic field sensor.

Description

Technical Field

[0001] This invention relates to the field of sensor packaging technology, specifically to a three-dimensional magnetic field sensor with a 3D hybrid structure and a method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure. Background Technology

[0002] The magnetoresistance effect refers to the change in resistivity of a magnetic material under the influence of an external magnetic field compared to when no external magnetic field is applied. Anisotropic magnetoresistance (AMR) occurs when, under the influence of a magnetic field parallel to the plane of the magnetic film, the magnetization direction of at least one magnetic film in a multilayer magnetic structure changes with the magnitude of the magnetic field. In AMR magnetic sensors, the magnetoresistance is proportional to the square of the cosine of the angle between the magnetization direction of the magnetic material and the current direction. There is a correspondence between the magnetoresistance extrema and the external magnetic field, thus it can be used to measure the magnitude of the external magnetic field. Serpentine-shaped resistance strips are often formed using microfabrication techniques. The width and length of these strips can be used to create larger resistances, making them suitable for applications with extremely low power consumption requirements.

[0003] Traditional AMR sensors are limited by their structure and material properties. The magnetization direction of the thin-film material is usually parallel to the substrate plane (XY), thus it is only sensitive to magnetic fields within the plane (XY), but insensitive to magnetic fields perpendicular to the thin-film plane. To achieve Z-axis sensing, methods such as vertical packaging, fabrication of magnetoresistive materials on inclined substrates, utilization of vertically anisotropic materials, and the use of flux concentrators are commonly employed. Depositing magnetoresistive materials and fabricating magnetoresistive cells on inclined substrates is technically quite difficult. When magnetoresistive materials are deposited on inclined surfaces, defects increase, and material performance degrades. Using vertically anisotropic materials instead of soft magnetic thin-film materials in magnetoresistive sensors can also achieve Z-axis magnetic measurement, but currently, such magnetic sensors have low sensitivity, large hysteresis curves, and poor stability, making commercialization difficult. Summary of the Invention

[0004] The purpose of this invention is to provide a three-dimensional magnetic field sensor with a 3D hybrid structure and its fabrication method. The three-dimensional magnetic field sensor uses a Z-axis magnetic sensing unit based on the Hall effect and an X-axis and Y-axis magnetic sensing units based on the anisotropic magnetoresistive effect. By combining AMR and Hall sensors, the magnetic field in the XY plane and the Z-axis magnetic field can be detected respectively while ensuring that the device structure is a planar stack.

[0005] To achieve the above objectives, a first aspect of the present invention provides a three-dimensional magnetic field sensor with a 3D hybrid structure. The three-dimensional magnetic field sensor includes a peripheral integrated circuit unit and three magnetic sensing units, which are stacked vertically. The three magnetic sensing units include a Z-axis magnetic sensing unit based on the Hall effect, and X-axis and Y-axis magnetic sensing units based on the anisotropic magnetoresistive (AMR) effect. The three magnetic sensing units are electrically connected to the peripheral integrated circuit unit via through-silicon vias (TSVs). By employing TSV technology and 3D stacking technology, the disadvantages of large area and volume consumption and low integration density associated with traditional bonding wire interconnection methods can be effectively overcome, making the miniaturization and commercial application of AMR / Hall hybrid triaxial magnetic field sensors possible.

[0006] In this embodiment, both the magnetic sensing unit and the peripheral integrated circuit unit include a silicon substrate, an isolation layer, and a functional layer. The isolation layer is formed on the silicon substrate, and the functional layer is formed on the isolation layer. The functional layer is either a sensing layer or an integrated circuit layer.

[0007] In this embodiment, the sensitive layer includes an electrode structure, and different magnetically sensitive units are connected to the electrode structure through silicon vias penetrating the silicon substrate to achieve signal transmission.

[0008] In this embodiment, the electrode structure is provided with bonding microbumps, and the through-silicon via wire is connected to the bonding microbumps.

[0009] In this embodiment, the bonding microbumps are fabricated using Cu-Sn-Cu eutectic alloy bonding technology. The bonding temperature range of Cu-Sn-Cu eutectic alloy bonding technology is 250℃~350℃ to avoid excessively high bonding temperatures (350℃~400℃) and bonding pressures during Cu-Cu direct hot-press bonding, thus ensuring the reliability of the packaged device.

[0010] In this embodiment, the Z-axis magnetic sensing unit is positioned below the X-axis magnetic sensing unit, the Y-axis magnetic sensing unit, and the peripheral integrated circuit unit. Positioning the Z-axis magnetic sensing unit at the bottom effectively ensures the accuracy of Z-axis magnetic field acquisition.

[0011] In this embodiment, the three-dimensional magnetic field sensor further includes a carrier silicon wafer, on which the peripheral integrated circuit unit and the three magnetic sensing units are disposed. The carrier silicon wafer can further enhance the strength of the device and ensure its reliability.

[0012] In this embodiment of the application, the peripheral integrated circuit unit is further provided with pins.

[0013] A second aspect of the present invention provides a method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure, the method comprising:

[0014] Through-silicon vias for electrical connection were fabricated on the prepared peripheral integrated circuit unit and three magnetically sensitive units;

[0015] Fill the through-silicon vias with wire material and fabricate bonding microbumps;

[0016] A peripheral integrated circuit unit with bonding microbumps and three magnetically sensitive units are stacked on a carrier silicon wafer;

[0017] The peripheral integrated circuit unit and the three magnetic sensing units are bonded together, so that the three magnetic sensing units are electrically connected to the peripheral integrated circuit unit through silicon via wires;

[0018] The three magnetic sensing units include a Z-axis magnetic sensing unit based on the Hall effect, and X-axis and Y-axis magnetic sensing units based on anisotropic magnetoresistive effects. The above method enables mass production of three-dimensional magnetic field sensors. The 3D stacking technology is simple to use, and the resulting three-dimensional magnetic field sensors have relatively small area and volume, and higher integration.

[0019] In this embodiment, the peripheral integrated circuit unit is fabricated through the following steps:

[0020] An isolation layer integrated circuit is grown on a silicon substrate, and through-silicon vias are left.

[0021] The completed structure is cut to obtain the peripheral integrated circuit unit;

[0022] The magnetic sensing unit is manufactured through the following steps:

[0023] An isolation layer and a magnetically sensitive layer are grown on a silicon substrate;

[0024] The fabricated structure is cut to obtain the magnetic sensing unit. Both the magnetic sensing unit and the peripheral integrated circuit unit can be mass-produced using the same material, saving on manufacturing processes.

[0025] In this embodiment of the application, through-silicon vias for electrical connection are fabricated on the prepared peripheral integrated circuit unit and three magnetically sensitive units, including:

[0026] Using Bosch's process, through-silicon vias are formed vertically downwards at the electrode locations of the peripheral integrated circuit units and the three magnetically sensitive units by cyclically introducing SF6 and C4F8 gases and alternating etching and passivation.

[0027] In this embodiment of the application, the method further includes: encapsulating the bonded peripheral integrated circuit unit and the three magnetic sensing units with a housing, while reserving pin interfaces.

[0028] This invention utilizes 3D vertical stacking technology and TSV (Through-Shipment Via) technology to achieve three-dimensional magnetic field detection through the stacking and electrical interconnection of two AMR (Active Magnetically Modulated Magnetic) sensing layers, one Hall sensing layer, and one peripheral integrated circuit layer. It also fully utilizes vertical space to achieve high-density chip integration, offering advantages such as high sensitivity, small size, low power consumption, high reliability, good temperature characteristics, and integrability. Because the device is multi-layered and the silicon processing technology used is highly precise, the angles of adjacent planes can be strictly parallel, resulting in good structural stability and high integration density in the integrated package. This allows for excellent three-dimensional magnetic sensing capabilities within a very small planar area.

[0029] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 This is a schematic diagram of a three-dimensional magnetic field sensor structure with a 3D hybrid structure provided in one embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a three-dimensional magnetic field sensor structure with a 3D hybrid structure provided in another embodiment of the present invention;

[0033] Figure 3 This is a flowchart of a method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure according to one embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of an ellipsoid calibration algorithm for a triaxial magnetic field sensor provided in one embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 1-Carrier silicon wafer, 2-Z-axis magnetic sensing unit, 201-Silicon substrate, 202-Isolation layer, 203-Functional layer, 3-X-axis magnetic sensing unit, 4-Y-axis magnetic sensing unit, 5-Peripheral integrated circuit unit, 6-Bonding microbump, 7-Through silicon via wire, 8-Pin. Detailed Implementation

[0037] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0038] Example 1

[0039] Figure 1 This is a schematic diagram of a three-dimensional magnetic field sensor structure with a 3D hybrid structure provided in one embodiment of the present invention. Figure 1 As shown, the three-dimensional magnetic field sensor includes: a peripheral integrated circuit unit 5 and three magnetic sensing units, which are stacked vertically together. The three magnetic sensing units include a Z-axis magnetic sensing unit 2 based on the Hall effect, an X-axis magnetic sensing unit 3 based on the anisotropic magnetoresistive (AMR) effect, and a Y-axis magnetic sensing unit 4. The three magnetic sensing units are electrically connected to the peripheral integrated circuit unit 5 via through-silicon vias (TSVs) 7. The use of TSV technology and 3D stacking technology effectively overcomes the disadvantages of traditional bonding wire interconnection methods, such as large area and volume consumption and low integration density, making miniaturization and commercial application of AMR / Hall hybrid triaxial magnetic field sensors possible.

[0040] like Figure 1 As shown, in this embodiment, the Z-axis magnetic sensing unit 2 based on the Hall effect is located at the bottom layer, the Y-axis magnetic sensing unit 4 is located above it, the X-axis magnetic sensing unit 3 is located above the Y-axis magnetic sensing unit 4, and the peripheral integrated circuit unit 5 is located at the top.

[0041] In this embodiment, both the magnetically sensitive unit and the peripheral integrated circuit unit 5 include a silicon substrate 201, an isolation layer 202, and a functional layer 203. The isolation layer 202 is formed on the silicon substrate 201, and the functional layer 203 is formed on the isolation layer 202. The functional layer 203 is either a sensitive layer or an integrated circuit layer. In some embodiments, the silicon substrate 201 is a polished thin silicon wafer, typically with a thickness not exceeding 50 μm, and the isolation layer 202 is a SiO2 oxide layer. The sensitive layer is a thin film. In some embodiments, the silicon substrate 201 is square.

[0042] In this embodiment, the sensitive layer includes an electrode structure, and different magnetically sensitive units are connected to the electrode structure through a through-silicon via (TSV) wire 7 penetrating the silicon substrate 201 to achieve signal transmission. In some embodiments, copper is used as the main material of the TSV wire 7.

[0043] In some embodiments, the sensitivity range of the Z-axis magnetic sensing unit 2 based on the Hall effect is 0.002mV / V / Oe to 0.05mV / V / Oe, and the sensitivity range of the X-axis magnetic sensing unit 3 and the Y-axis magnetic sensing unit 4 based on the anisotropic magnetoresistance effect is 0.05mV / V / Oe to 1.5mV / V / Oe.

[0044] Both the X-axis magnetic sensing unit 3 and the Y-axis magnetic sensing unit 4, based on the anisotropic magnetoresistive effect, adopt a Wheatstone bridge structure, and the electrode structure is set at the four ends.

[0045] In this embodiment, the electrode structure is provided with bonding microbumps 6, and the through-silicon via (TSV) wires 7 are connected to the bonding microbumps 6. The peripheral integrated circuit unit 5 and the three magnetic sensing units are combined together using bonding technology.

[0046] In this embodiment, the bonding microbump 6 is fabricated using Cu-Sn-Cu eutectic alloy bonding technology. The bonding temperature range of Cu-Sn-Cu eutectic alloy bonding technology is 250℃~350℃ to avoid excessively high bonding temperatures (350℃~400℃) and bonding pressures during Cu-Cu direct hot-press bonding, thus ensuring the reliability of the packaged device.

[0047] In this embodiment, the Z-axis magnetic sensing unit 2 is disposed below the X-axis magnetic sensing unit 3, the Y-axis magnetic sensing unit 4, and the peripheral integrated circuit unit 5. Distributing the Z-axis magnetic sensing unit 2 at the bottom effectively ensures the accuracy of Z-axis magnetic field acquisition.

[0048] In this embodiment, the three-dimensional magnetic field sensor further includes a carrier silicon wafer 1, on which the peripheral integrated circuit unit 5 and the three magnetic sensing units are all disposed. The carrier silicon wafer 1 can further enhance the strength of the device and ensure its reliability.

[0049] In this embodiment of the application, the peripheral integrated circuit unit 5 is further provided with pin 8.

[0050] In this embodiment, the three-dimensional magnetic field sensor is also encapsulated in a housing. The encapsulated sensor has dimensions of approximately 2000μm × 2000μm × 1000μm.

[0051] It should be noted that, for ease of drawing, Figure 1 The diagram only schematically shows some of the through-silicon vias and bonding microbumps 6; the actual design needs to be tailored to the specific circuit connections required during manufacturing. An interface is provided at the top of the sensor for easy connection to external circuits.

[0052] This invention employs two types of magnetic field sensitive layers: a Hall sensitive layer and an AMR sensitive layer. Due to the addition of through-silicon via (TSV) technology, the characteristics of each sensitive layer are inevitably disturbed during the via fabrication process. Furthermore, the material properties dictate a natural difference of approximately one order of magnitude in the sensitivity of the Hall and AMR sensitive layers. Therefore, the device performance needs to be calibrated before three-dimensional magnetic field sensing. For a typical triaxial magnetic field sensor, there is also a certain zero-point drift error in the X, Y, and Z directions, meaning that the output voltage of each axis is not zero under zero magnetic field. In addition, it should be considered that during the fabrication of multi-layer structures, due to limitations in fabrication precision, the actual included angles between the sensitive axes of each sensitive layer cannot be perfectly maintained at 90 degrees, i.e., non-orthogonal errors exist.

[0053] The sensitivity error, zero-point drift error, and non-orthogonality error mentioned above will directly alter the sensor's measurement results, leading to inaccuracies and unreliability in the performance indicators of the triaxial magnetic field sensor. The traditional solution to these problems is single-axis calibration, which can only directly calibrate sensitivity and zero-point drift errors, and requires sequential calibration of each axis, a cumbersome process that introduces new measurement errors. If the non-orthogonality error is directly calculated based on the raw data from each single-axis calibration, the accumulated angle errors from each test in the single-axis calibration will negatively impact the calibration effect. Therefore, in practical implementation, an ellipsoidal calibration algorithm for triaxial magnetic field sensors is used for calibration, achieving "one-time calibration for direct use." Only a comprehensive calibration of the packaged three-dimensional magnetic field sensor is needed to resolve all the aforementioned errors.

[0054] In actual testing, the specific configuration of the embodiment is as follows: the applied DC magnetic field strength is a fixed value of 2 Oe, and the direction is the positive X-axis; the magnetic field sensitivities of the sensitive layer in the X, Y, and Z directions are 0.3100mV / V / Oe, 0.2900mV / V / Oe, and 0.010mV / V / Oe, respectively, and each output signal channel Vout1, Vout2, and Vout3 is connected to an AD 620 voltage amplification module, with the amplification factor set to 1000 times; the zero-point drift voltages in the X, Y, and Z directions are 0.3000V, -0.3000V, and 0.1000V, respectively; the three angle values ​​used to describe the non-orthogonality between the X, Y, and Z sensitive axes are 5.00°, 10.00°, and 15.00°, respectively; and there is 0.001V of random noise in each of the X, Y, and Z directions.

[0055] In the ellipsoid fitting calibration experiment, the initial placement of the device is required to ensure that the coordinate system O-XYZ of the ideal device coincides with the geodetic coordinate system o-xyz of the applied magnetic field. After placement, two sets of rotating platforms are used to control the rotation of the three-dimensional sensor in the magnetic field space. The device rotation method is as follows: deflection angle interval of 30.00 degrees, pitch angle interval of 30.00 degrees, deflection angle range of 0.00 degrees to 180.00 degrees (excluding 180.00 degrees), and pitch angle range of 0.00 degrees to 360.00 degrees (excluding 360.00 degrees). With appropriate program configuration, the sensor orientation can traverse all directions in space. At each combination of angle values, the rotating platform will pause for 2 seconds to allow the sensor to stabilize and then read and record the measurement data of each channel.

[0056] It should be noted that, to verify the calibration effect of the ellipsoid calibration algorithm for the triaxial magnetic field sensor, all the above-mentioned key characteristics have been measured or configured in advance. In the actual ellipsoid calibration algorithm and operation process of the triaxial magnetic field sensor, only the external magnetic field information needs to be known and the measurement data of the three channels need to be recorded. All other information does not need to be obtained in advance, which can significantly reduce the complexity of the calibration process.

[0057] Based on the measurement data recorded during the testing process, and through an ellipsoidal fitting algorithm and subsequent algorithms, the device specifications were calculated as follows: the magnetic field sensitivities in the X, Y, and Z directions are 0.3102 mV / V / Oe, 0.2908 mV / V / Oe, and 0.0100 mV / V / Oe, respectively; the zero-point drifts in the X, Y, and Z directions are 0.3011 V, -0.3009 V, and 0.1000 V, respectively; and the three angle values ​​used to describe the non-orthogonality between the X, Y, and Z sensitive axes are 5.12°, 9.98°, and 14.89°, respectively. The comparison shows that the calculated results accurately reflect the true specifications of the triaxial magnetic field sensor and demonstrate good performance.

[0058] Based on the obtained parameters of the triaxial magnetic field sensor, the original measurement data can be analyzed to obtain calibrated magnetic measurement data, which should be distributed near an ideal magnetic sphere. Figure 2 As shown in the figure, the closer the calibrated magnetic measurement data is to the ideal magnetic sphere, the better the calibration effect.

[0059] In summary, the ellipsoidal calibration algorithm for the triaxial magnetic field sensor used in this application can effectively calibrate the error of the triaxial magnetic field sensor, greatly improving the practicality of the proposed AMR / Hall hybrid 3D cascade structure three-dimensional magnetic field sensor.

[0060] Example 2

[0061] like Figure 3The image shows a three-dimensional magnetic field sensor with a 3D hybrid structure provided by another embodiment of the present invention, such as... Figure 3 As shown, the three-dimensional magnetic field sensor includes: a peripheral integrated circuit unit 5 and three magnetic sensing units, which are stacked vertically together. The three magnetic sensing units include a Z-axis magnetic sensing unit 2 based on the Hall effect, an X-axis magnetic sensing unit 3 based on the anisotropic magnetoresistive effect, and a Y-axis magnetic sensing unit 4. The three magnetic sensing units are electrically connected to the peripheral integrated circuit unit 5 via through-silicon vias (TSVs) 7. The use of TSV technology and 3D stacking technology effectively overcomes the drawbacks of traditional bonding wire interconnection methods, such as large area and volume consumption and low integration density, making miniaturization and commercial applications of AMR / Hall hybrid triaxial magnetic field sensors possible.

[0062] like Figure 3 As shown, in this embodiment, the Y-axis magnetic sensing unit 4 is located at the bottom layer, the Z-axis magnetic sensing unit 2 based on the Hall effect is located above it, the X-axis magnetic sensing unit 3 is located above the Z-axis magnetic sensing unit 2, and the peripheral integrated circuit unit 5 is located at the top.

[0063] like Figure 4 As shown, a second aspect of the present invention provides a method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure, the method comprising:

[0064] Silicon vias for electrical connection are fabricated on the prepared peripheral integrated circuit unit 5 and three magnetically sensitive units. In this embodiment, Bosch process is used to form silicon vias downwards on the vertical plane of the electrode positions of the peripheral integrated circuit unit 5 and the three magnetically sensitive units by cyclically introducing SF6 and C4F8 gases and alternating etching and passivation.

[0065] In this embodiment of the application, a conductive material is filled into the through-silicon via and a bonding microbump 6 is fabricated. In this embodiment, a metal Cu is filled into the through-silicon via as a conductive material using an electroplating process, and copper bumps are electroplated in the desired bonding location area. Tin solder is then electroplated on the copper bumps to form the bonding microbump 6.

[0066] The peripheral integrated circuit unit 5 with bonding microbumps 6 and three magnetic sensing units are stacked on the carrier silicon wafer 1; in some embodiments, they are stacked in the following order, from bottom to top: carrier silicon wafer 1, Z-axis sensing unit, X-axis sensing unit, Y-axis sensing unit, peripheral integrated circuit unit 5.

[0067] The peripheral integrated circuit unit 5 and the three magnetic sensing units are bonded together, so that the three magnetic sensing units are electrically connected to the peripheral integrated circuit unit 5 through silicon via wires 7.

[0068] The three magnetic sensing units include a Z-axis magnetic sensing unit 2 based on the Hall effect, an X-axis magnetic sensing unit 3 (with the X-axis as the difficult axis), and a Y-axis magnetic sensing unit 4 (with the Y-axis as the difficult axis), both based on the anisotropic magnetoresistive effect. The above method enables the mass production of three-dimensional magnetic field sensors. The 3D stacking technology is simple to use, and the resulting three-dimensional magnetic field sensors have relatively small area and volume, and higher integration.

[0069] In this embodiment, the peripheral integrated circuit unit is fabricated through the following steps:

[0070] An isolation layer integrated circuit is grown on a silicon substrate, and through-silicon vias are left.

[0071] The completed structure is cut to obtain the peripheral integrated circuit unit;

[0072] The magnetic sensing unit is manufactured through the following steps:

[0073] An isolation layer and a magnetically sensitive layer are grown on a silicon substrate;

[0074] The fabricated structure is cut to obtain the magnetic sensing unit. In this embodiment, the silicon substrate is a polished thin silicon wafer with a thickness not exceeding 50 μm. The cut magnetic sensing unit and peripheral integrated circuit unit are 1000 μm × 1000 μm sheet structures. Both the magnetic sensing unit and the peripheral integrated circuit unit can be mass-produced from the same material, saving on manufacturing processes.

[0075] In this embodiment of the application, the method further includes: encapsulating the bonded peripheral integrated circuit unit and the three magnetic sensing units with a housing, while reserving a pin 8 interface.

[0076] In this application, the combination of AMR and Hall sensors enables the detection of magnetic fields in the XY plane and the Z-axis magnetic field while maintaining a planar stacked device structure. Furthermore, the use of TSV technology and 3D silicon wafer stacking effectively overcomes the drawbacks of traditional bonding wire interconnect methods, such as large area and volume consumption and low integration density, thus enabling the miniaturization and commercial application of AMR / Hall hybrid triaxial magnetic field sensors.

[0077] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0078] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0079] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A three-dimensional magnetic field sensor with a 3D hybrid structure, characterized in that, The three-dimensional magnetic field sensor includes: a peripheral integrated circuit unit and three magnetic sensing units, wherein the peripheral integrated circuit unit and the three magnetic sensing units are stacked in the vertical direction; The three magnetic sensing units include: a Z-axis magnetic sensing unit based on the Hall effect, and an X-axis and Y-axis magnetic sensing units based on the anisotropic magnetoresistive effect; the three magnetic sensing units are electrically connected to the peripheral integrated circuit unit through silicon via wires; The Z-axis magnetic sensing unit is located below the X-axis magnetic sensing unit, the Y-axis magnetic sensing unit, and the peripheral integrated circuit unit.

2. The three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 1, characterized in that, Both the magnetic sensing unit and the peripheral integrated circuit unit include a silicon substrate, an isolation layer, and a functional layer. The isolation layer is formed on the silicon substrate, and the functional layer is formed on the isolation layer. The functional layer is either a sensing layer or an integrated circuit layer.

3. The three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 2, characterized in that, The sensitive layer includes an electrode structure, and different magnetically sensitive units are connected to the electrode structure through silicon vias penetrating the silicon substrate to achieve signal transmission.

4. The three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 3, characterized in that, The electrode structure is provided with bonding microbumps, and the through-silicon via wires are connected to the bonding microbumps.

5. The three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 4, characterized in that, The bonding microbumps are made using Cu-Sn-Cu eutectic alloy bonding technology.

6. The three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 1, characterized in that, The three-dimensional magnetic field sensor also includes a carrier silicon wafer, on which the peripheral integrated circuit unit and the three magnetic sensing units are disposed.

7. The three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 1, characterized in that, The peripheral integrated circuit unit is also provided with pins.

8. A method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure, characterized in that, The method includes: Through-silicon vias for electrical connection were fabricated on the prepared peripheral integrated circuit unit and three magnetically sensitive units; Fill the through-silicon vias with wire material and fabricate bonding microbumps; A peripheral integrated circuit unit with bonding microbumps and three magnetically sensitive units are stacked on a carrier silicon wafer; The peripheral integrated circuit unit and the three magnetic sensing units are bonded together, so that the three magnetic sensing units are electrically connected to the peripheral integrated circuit unit through silicon via wires; The three magnetic sensing units include: a Z-axis magnetic sensing unit based on the Hall effect, an X-axis magnetic sensing unit based on the anisotropic magnetoresistive effect, and a Y-axis magnetic sensing unit. The Z-axis magnetic sensing unit is disposed below the X-axis magnetic sensing unit, the Y-axis magnetic sensing unit, and the peripheral integrated circuit unit.

9. The method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 8, characterized in that, The peripheral integrated circuit unit is fabricated through the following steps: An isolation layer integrated circuit is grown on a silicon substrate, and through-silicon vias are left. The completed structure is cut to obtain the peripheral integrated circuit unit; The magnetic sensing unit is manufactured through the following steps: An isolation layer and a magnetically sensitive layer are grown on a silicon substrate; The fabricated structure is cut to obtain the magnetically sensitive unit.

10. The method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 8, characterized in that, Through-silicon vias (TSVs) for electrical connection are fabricated on the prepared peripheral integrated circuit unit and three magnetically sensitive units, including: Using Bosch's process, through-silicon vias are formed vertically downwards at the electrode locations of the peripheral integrated circuit units and the three magnetically sensitive units by cyclically introducing SF6 and C4F8 gases and alternating etching and passivation.

11. The method for fabricating a three-dimensional magnetic field sensor with a 3D hybrid structure according to claim 8, characterized in that, The method further includes: encapsulating the bonded peripheral integrated circuit unit and three magnetic sensing units with a housing, while reserving pin interfaces.

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