High-response graphene Hall force sensor and preparation method thereof

Abstract

The invention relates to a Hall sensor, in particular to a high-response graphene Hall force sensor and a preparation method thereof. The high-response graphene Hall force sensor sequentially comprises a fourth substrate, a strain amplification layer, a bottom h-BN layer, a graphene layer, a top h-BN layer and a metal electrode from bottom to top, the metal electrode and the graphene layer form edge contact, and the Hall electrode area is highly symmetrical with the center of the device as the reference. The high-response graphene Hall force sensor provided by the invention not only can realize high-sensitivity stress response, but also can maintain low noise and good linearity, and strain is transmitted to graphene through the strain amplification layer by applying external force on the deformable substrate, so that the energy band structure and the carrier density of the graphene are changed, and the sensitivity of the graphene Hall force sensor is improved. Therefore, measurable change of the Hall resistor is caused. The structure not only realizes coupling detection of mechanical strain and Hall effect, but also has relatively high strain amplification efficiency and electrical stability, and is suitable for high-precision stress and pressure detection.

Description

Technical Field

[0001] This invention relates to a Hall sensor, and more particularly to a high-response graphene Hall force sensor and its preparation method. Background Technology

[0002] Force sensors are widely used in microelectromechanical systems (MEMS), pressure detection, flexible electronics, and biomedicine, among other fields. Their core function is to convert mechanical stress or strain into measurable electrical signals. Currently, the mainstream force sensors mainly include three types: piezoresistive, capacitive, and piezoelectric. Piezoresistive sensors have a simple structure, but their sensitivity primarily depends on changes in the volume resistivity of the material, making it difficult to achieve high-resolution detection under low-strain conditions. While capacitive and piezoelectric sensors have high sensitivity, they are relatively sensitive to environmental noise and temperature drift, and their fabrication processes are complex and inconsistent.

[0003] Graphene is a two-dimensional material consisting of a single atomic layer of sp² hybridized carbon atoms, possessing excellent electrical, mechanical, and thermal properties. Its in-plane Young's modulus reaches 1 TPa, its fracture strength is approximately 130 GPa, and its carrier mobility and concentration change significantly under strain, exhibiting excellent strain-controlled characteristics. Based on this, graphene has been widely explored as a novel force-sensitive material. However, current graphene force sensors mostly employ the piezoresistive effect, reflecting applied stress by measuring changes in resistance. Because graphene is a zero-bandgap material, its piezoresistive coefficient is low, resulting in a weak strain response signal, which is easily affected by factors such as temperature, adsorbed molecules, and residual stress, leading to signal drift. To improve the sensitivity of graphene force sensing, researchers have attempted to increase the strain concentration area by introducing microcantilever structures, petal-shaped films, and corrugated graphene; however, these methods typically result in complex structures, poor repeatability, or insufficient mechanical stability.

[0004] Furthermore, traditional graphene force sensors generally only measure resistance changes, failing to fully utilize the Hall response characteristics of graphene under magnetic fields. The Hall resistance of graphene is extremely sensitive to carrier concentration; when subjected to mechanical strain, its band structure and carrier density change, resulting in measurable changes in Hall voltage and resistance. Therefore, introducing the Hall effect into graphene force sensing can achieve higher signal gain and better anti-interference capabilities. However, with only a graphene layer, applied stress is often difficult to fully transmit, leading to limited strain modulation efficiency and insufficient sensitivity. Introducing a strain amplification layer (such as polycrystalline silicon, TiN, or high-density metal) between the graphene and the substrate can effectively amplify the transmission of external stress, enabling the graphene layer to achieve higher equivalent strain. Simultaneously, using hexagonal boron nitride (h-BN) as an encapsulation layer for graphene can reduce interfacial charge scattering, significantly improve mobility, and further enhance the output signal-to-noise ratio. Summary of the Invention

[0005] To address the above problems, this invention provides a high-response graphene Hall force sensor, the specific technical solution of which is as follows: A high-response graphene Hall force sensor comprises, from bottom to top: a fourth substrate, a strain amplification layer, a bottom h-BN layer, a graphene layer, a top h-BN layer, and a metal electrode; wherein the metal electrode forms an edge contact with the graphene layer, and the Hall electrode region is height-symmetrical with respect to the center of the device.

[0006] Preferably, the fourth substrate has a micron-sized hole at the center of its back side.

[0007] Preferably, the fourth substrate is one of single-crystal silicon, silicon-oxide-silicon, silicon nitride, flexible thin film, or metal / alloy substrate, and is preferably a metal / alloy substrate.

[0008] Preferably, the strain amplification layer is one of polycrystalline silicon, titanium nitride, silicon carbide, gallium nitride, silicon nitride, aluminum oxide, high-density metal, or transparent conductive oxide, and is preferably polycrystalline silicon.

[0009] Preferably, the Hall electrode is a Ti / Au composite structure with a thickness of 5nm / 50nm. The Hall structure includes a set of source and drain electrodes for applying a constant current source or a constant voltage source, and two pairs of Hall electrodes arranged perpendicularly thereto.

[0010] Preferably, the thickness of the top h-BN is 20-30 nm, the graphene is a single layer, and the thickness of the bottom h-BN is less than 2 nm.

[0011] A method for fabricating a high-response graphene Hall force sensor, used in the aforementioned high-response graphene Hall force sensor, includes the following steps: Step 1: Provide a first substrate, a second substrate, a third substrate, and a fourth substrate; Step 2: Process the fourth substrate by depositing a strain amplification layer on the fourth substrate using chemical vapor deposition; Step 3: Form a PDMS thin film on the first substrate and process the PDMS thin film to obtain a PDMS structure; Step 4: Form boron nitride sheets and graphene sheets on the second substrate and the third substrate, respectively; Step 5: Use the PDMS structure obtained in step 3 to adsorb the boron nitride sheet located on the second substrate in step 4 to form a PDMS-h-BN structure; Step 6: Using the PDMS-h-BN structure obtained in step 5, another boron nitride sheet located on the second substrate and a graphene sheet located on the third substrate are adsorbed sequentially to form a PDMS-top h-BN-graphene-bottom h-BN heterostructure. Step 7: Cover the fourth substrate with the strain amplification layer in Step 2 with the PDMS-top h-BN-graphene-bottom h-BN heterostructure formed in Step 6, and align the center of the heterostructure with the center of the fourth substrate to form a PDMS-top h-BN-graphene-bottom h-BN-strain amplification layer structure on the fourth substrate. Step 8: Remove the PDMS film to form a top h-BN-graphene-bottom h-BN-strain amplification layer structure on the fourth substrate; Step 9: Electron beam lithography is used to define a six-terminal Hall electrode region with the center as the reference height on the fourth substrate, and reactive ion etching is used to etch the top h-BN-graphene-bottom h-BN structure to expose its cross-sectional structure. Step 10: Deposit metal to cover the exposed top h-BN-graphene-bottom h-BN cross-sectional structure in step (9), so that the graphene and the metal electrode form edge contact; Step 11: Use electron beam lithography and reactive ion beam etching techniques to remove excess metal and materials outside the Hall electrode area to form the final sensor structure.

[0012] Preferably, the metal deposited in step 10 may be one or more of titanium, chromium, palladium, platinum, aluminum, and gold.

[0013] Preferably, the step of forming a polydimethylsiloxane film on the first substrate in step 3 includes finely cutting the formed film and placing it on a glass plate, heating it tightly at 150 degrees Celsius, and performing an activation treatment.

[0014] Preferably, the thickness of the strain amplification layer in step 8 is less than 2 μm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a high-response graphene Hall force sensor that can achieve high-sensitivity stress response while maintaining low noise and good linearity.

[0016] This invention employs a dry transfer technique to sequentially stack mechanically exfoliated graphene and hexagonal boron nitride (h-BN) films to form the core structure of a graphene force-sensitive device. Low-temperature dry transfer effectively avoids contamination and damage to the graphene lattice caused by wet processes, high temperatures, and cleaning steps, ensuring the cleanliness and integrity of the interlayer interfaces. Due to the excellent chemical stability, thermal stability, and atomically flat surface of the h-BN film, its use as a substrate and encapsulation layer for graphene significantly reduces scattering from surface dangling bonds and interface impurities, thereby maintaining the high mobility and low noise characteristics of graphene. A strain amplification layer is placed beneath the ultrathin h-BN layer in this invention to effectively amplify the mechanical stress applied to the substrate, allowing the strain to be more fully transferred to the graphene layer. Through the coupling between the strain amplification layer and the graphene layer, a significant change in carrier concentration can be generated under relatively small external forces, thereby enhancing the stress response sensitivity of the graphene Hall resistor. This invention employs metal electrodes with edge contact structures at both ends of the graphene layer, which reduces the metal contact area and lowers the contact resistance. This minimizes the damage to the graphene lattice caused by metal deposition in traditional surface contact structures, while maintaining its high mobility and strain sensitivity. This contact structure also helps improve the linear response and stability of the Hall signal.

[0017] By applying an external force to a deformable substrate, strain is transferred to graphene through a strain amplification layer, causing changes in its band structure and carrier density, thereby inducing a measurable change in Hall resistance. This structure not only achieves coupled detection of mechanical strain and the Hall effect but also possesses high strain amplification efficiency and electrical stability, making it suitable for high-precision stress and pressure detection. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of step 1; Figure 2 This is a schematic diagram of step 2; Figure 3 This is a schematic diagram of step 3, which shows the bonding of the second substrate with the top h-BN film. Figure 4 This is a schematic diagram of the bonding between the third substrate and the bottom h-BN thin film in step 3; Figure 5 This is a schematic diagram of step 4; Figure 6 This is a schematic diagram showing the bonding of the first substrate, the PDMS thin film, and the top h-BN thin film 21; Figure 7 This is a schematic diagram of step 5; Figure 8 This is a schematic diagram of the PDMS-toph-BN-graphene structure; Figure 9 This is a schematic diagram of step 6; Figure 10This is a schematic diagram of the PDMS-top h-BN-graphene-bottom h-BN structure; Figure 11 This is a schematic diagram of step 7; Figure 12 This is a schematic diagram of step 8; Figure 13 This is a schematic diagram of step 9; Figure 14 This is a schematic diagram of the structure of a high-response graphene Hall force sensor; Figure 15 This is a top view showing the central symmetry of the Hall element in this invention.

[0019] In the figure: first substrate 10, PDMS film 11, second substrate 20, top h-BN film 21, bottom h-BN film 21', third substrate 30, graphene film 31, fourth substrate 40, strain amplification layer 41, metal electrode 50. Detailed Implementation

[0020] The present invention will now be further described with reference to the accompanying drawings.

[0021] like Figure 14 and Figure 15 As shown, a high-response graphene Hall force sensor comprises, from bottom to top: a fourth substrate, a strain amplification layer, a bottom h-BN layer, a graphene layer, a top h-BN layer, and a metal electrode; wherein the metal electrode forms an edge contact with the graphene layer, and the Hall electrode region is height-symmetrical with respect to the center of the device.

[0022] The fourth substrate has micron-sized holes at its center to apply stress; the graphene Hall layer forms edge contact with the 6-terminal Hall electrodes, and the Hall electrodes are symmetrically distributed with the center of the fourth substrate as the reference height; The strain amplification layer is a conductive material with a thickness of ≤2μm, used to amplify external stress and transfer it to the graphene Hall layer; the bottom boron nitride layer has a thickness of ≤2nm, and the top boron nitride layer has a thickness of 20-30nm, used to provide an atomically flat interface, reduce impurity scattering, and stabilize electrical performance; the graphene Hall layer is a single-layer structure, and its carrier concentration changes with stress, and the force signal is detected by the change in Hall resistance.

[0023] The fourth substrate is one of single-crystal silicon, silicon-oxide-silicon, silicon nitride, flexible thin film or metal / alloy substrate, preferably a metal / alloy substrate.

[0024] The strain amplification layer is one of polycrystalline silicon, titanium nitride, silicon carbide, gallium nitride, silicon nitride, aluminum oxide, high-density metal or transparent conductive oxide, preferably polycrystalline silicon.

[0025] The Hall electrode is a Ti / Au composite structure with a thickness of 5nm / 50nm. The Hall structure includes a set of source and drain electrodes for applying a constant current source or a constant voltage source, and two pairs of Hall electrodes arranged perpendicular to it.

[0026] The thickness of the top h-BN is 20-30 nm, the graphene is a single layer, and the thickness of the bottom h-BN is less than 2 nm.

[0027] like Figures 1 to 15 As shown, a method for fabricating a high-response graphene Hall force sensor, used in a high-response graphene Hall force sensor, includes the following steps: Step 1: Provide a first substrate 10, and place a precisely cut polydimethylsiloxane (PDMS) film 11 on the first substrate 10; remove interfacial water and air at 150 degrees Celsius to ensure tight adhesion to the first substrate; then perform an activation treatment. This forms a PDMS structure on the first substrate. (See also...) Figure 1 As shown.

[0028] Step 2: Provide a fourth substrate with a central pressure-applying hole. The specific substrate can be prepared according to different substrate properties. Preferably, it is a metal substrate, and the hole can be made with a thickness on the order of micrometers to allow for subsequent application of external mechanical stress. Then, the surface of the fourth substrate is ultrasonically cleaned with alcohol, and a silicon film is grown on the surface using CVD technology, followed by annealing to form a polycrystalline silicon film. This forms the strain amplification layer 41 structure on the fourth substrate. (See also...) Figure 2 As shown.

[0029] Step 3, please refer to Figure 3 , 4 As shown, a second substrate 20 and a third substrate 30 are provided. On the second substrate 20 and the third substrate 30, a top boron nitride sheet 21, a bottom boron nitride sheet 21' and a single-layer graphene sheet 31 are formed by mechanical peeling.

[0030] Step 4, please refer to Figure 5 As shown, the PDMS structure obtained in step 1 is used to adsorb the top h-BN sheet 21 obtained in step 3. This forms a PDMS-top h-BN structure, as shown below. Figure 6As shown. Specifically, the PDMS film is smooth and transparent on both sides, serving as a support and adhesive in the subsequent transfer process. It also allows for good observation of the sample through an optical microscope. Heating removes moisture, and the film adheres well to the first substrate's transparent and clean glass slide via van der Waals forces. The entire assembly is placed on the operating stage. The film obtained in step 3 is then placed on a low-temperature (close to liquid nitrogen) sample holder. The sample is observed through an optical microscope. By adjusting the X / Y direction knobs of the sample holder, the h-BN film is aligned with the structure on the operating stage. The Z direction knob is then adjusted until the PDMS contacts the film. Finally, the Z direction knob is slowly raised, lifting the film upwards, causing it to be adsorbed onto the PDMS, forming a PDMS-top h-BN structure.

[0031] Step 5, please refer to Figure 7 As shown, the PDMS-toph-BN structure obtained in step 4 is used to adsorb the monolayer graphene sheet 31 obtained in step 3 in the same manner, forming a PDMS-toph-BN-graphene structure, as shown. Figure 8 As shown.

[0032] Step 6, please refer to Figure 9 As shown, the PDMS-top h-BN-graphene structure obtained in step 5 is used to adsorb the bottom h-BN sheet 21' obtained in step 3 in the same manner. This forms a PDMS-top h-BN-graphene-bottom h-BN structure, as shown. Figure 10 As shown.

[0033] Step 7, please refer to Figure 11 As shown, the PDMS-top h-BN-graphene-bottom h-BN structure obtained in step 6 is used to cover the fourth substrate 40-polycrystalline silicon 41 structure prepared in step 2. The center of the structure in step 6 is required to be placed on the center of the fourth substrate structure to form a PDMS-top h-BN-graphene-bottom h-BN-polycrystalline silicon thin film structure on the fourth substrate.

[0034] Step 8, please refer to the appendix Figure 12 As shown, the PDMS film 11 is peeled off to form a top h-BN-graphene-bottom h-BN-polycrystalline silicon device structure located on the fourth substrate.

[0035] Step 9, please refer to Figure 13 As shown, an EBL is used to define a 6-terminal Hall electrode region with a height symmetrical about the center on the fourth substrate, and reactive ion etching is used to etch the top h-BN-graphene-bottom h-BN structure on the fourth substrate to expose the cross-sectional structure; that is, to expose the atomic-level boundary of graphene.

[0036] Step 10: Deposit metal to form a 50-ohm contact between graphene and the metal electrode 50. Metal 50 is not in contact with the strain amplification layer 41. (See [link to previous step]). Figure 14 As shown.

[0037] Please continue to refer to Figure 15 As shown, in this embodiment, the preferred graphene Hall element has six electrodes, including a set of source and drain electrodes for applying a constant current source or a constant voltage source, and two pairs of Hall electrodes perpendicular to the source and drain electrodes.

[0038] The first substrate is preferably a transparent glass sheet. The second and third substrates can be SiO2 substrates, SiO2 / Si substrates, Al2O3, mica substrates, or flexible substrates, preferably silicon oxide sheets. The fourth substrate can be monocrystalline silicon, silicon-oxide-silicon, silicon nitride, flexible thin films, or metal / alloy substrates, preferably metal / alloy substrates, with micron-sized holes in the center of the back substrate for applying stress.

[0039] In step 1, PDMS is a transparent elastic film. Its activation treatment can be performed using oxygen or ozone. Under low temperature conditions, it sequentially adsorbs top h-BN, monolayer graphene, and bottom h-BN by van der Waals forces, eliminating contamination caused by irritating solutions during the transfer process, promoting atomic-level flat contact, enhancing interlayer adsorption contact, and making the entire structure cleaner and more robust.

[0040] In step 3, the h-BN and graphene mechanically exfoliated from the substrate can also be obtained by first mechanically exfoliating the top h-BN directly onto the PDMS in step 1), and then adsorbing the subsequent structures.

[0041] In the above steps, both the upper and lower encapsulation layers of the device are made of h-BN films obtained through mechanical exfoliation. The thin h-BN layer at the bottom of the device serves as a substrate for the graphene. Its atomically flat lattice structure and dangling bond-free surface not only improve the mobility of the graphene but also, due to its thinness, allows stress to be transferred more directly to the graphene, thereby enhancing the device's response to minor external mechanical disturbances. The thicker h-BN encapsulation layer above the graphene primarily isolates the device from moisture and adsorbed impurities, preventing oxidation, water absorption, or particulate contamination, and further improving overall mechanical stability and resistance to environmental disturbances.

[0042] In the above embodiments, the strain amplification layer is preferably made of polycrystalline silicon. Polycrystalline silicon possesses a moderate Young's modulus and engineerable stress-strain transfer characteristics. It exhibits good mechanical compliance in micro / nano structures, which is beneficial for effectively amplifying and transferring minute deformations applied to the substrate to the graphene Hall element in the middle. Furthermore, polycrystalline silicon can be deposited using mature semiconductor processes such as LPCVD and PECVD with precisely controllable thickness and residual stress, achieving stable and consistent strain distribution and ensuring batch-to-batch performance repeatability. Compared to other media, the mechanical matching of polycrystalline silicon is more suitable for coupling with the underlying substrate and the upper h-BN / graphene heterostructure. It avoids reduced strain transfer efficiency due to excessive stiffness and strain diffusion due to excessive flexibility. It combines process compatibility, mechanical adjustability, and high reliability.

[0043] In this embodiment, the graphene Hall sheet is placed at the very center of the membrane, and a centrally symmetrical electrode layout is adopted. The central region is the location with the most uniform and largest strain under stress, which can ensure that the graphene is subjected to consistent stress and improve output stability; the symmetrical structure can avoid parasitic voltages caused by edge constraints and geometric deviations, reduce false signals, and thus improve the accuracy of Hall measurement.

[0044] The entire device fabrication process employs a low-temperature dry transfer method, avoiding contamination and damage to the material surface caused by wet transfer and high temperatures. Graphene and the h-BN film are bonded together by van der Waals forces to form a clean atomic-level interface, reducing defects and charge trapping. Due to the low temperature, the entire process takes place in an inert environment, eliminating the interaction of water and oxygen.

[0045] The remaining embodiments are similar to the above embodiments in terms of preparation process and procedure. The differences are that one is not centrally symmetrical, and subsequent adjustments are made through digital-analog electrical methods; the other uses other similar materials for the strain amplification layer.

[0046] This invention addresses key issues in the structural design and fabrication process of graphene-based Hall force sensors, proposing a graphene Hall force sensor structure and its fabrication method. Using CVD and low-temperature dry transfer technology, a structure consisting of h-BN, graphene, and a strain amplification layer is accurately fabricated at the center of a pressure-bearing substrate, avoiding residual contamination and damage caused by wet transfer and temperature variations. The thin h-BN layer, serving as the substrate material beneath the graphene, possesses atomic-level flatness and a dangling bond-free surface, effectively maintaining the intrinsic mobility of graphene and reducing scattering during strain transmission. Simultaneously, the thicker h-BN encapsulation layer provides environmental isolation and improves overall mechanical stability. The strain amplification layer, made of polycrystalline silicon, generates sufficient in-plane deformation under external pressure and efficiently transmits it to the graphene, thereby amplifying the Hall resistance change. The graphene Hall element is positioned at the geometric center of the diaphragm, achieving the most uniform mechanical strain and improving the accuracy and repeatability of the force-induced Hall signal. The metal-graphene ohmic contact further reduces contact resistance, enhancing signal output amplitude and device stability.

[0047] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the claims of the present invention.

Claims

1. A high-response graphene Hall force sensor, characterized in that, From bottom to top, it includes: a fourth substrate, a strain amplification layer, a bottom h-BN layer, a graphene layer, a top h-BN layer, and a metal electrode; wherein, the metal electrode forms an edge contact with the graphene layer, and the Hall electrode region is height-symmetrical with respect to the center of the device.

2. The high-response graphene Hall force sensor according to claim 1, characterized in that, The fourth substrate has a micron-sized hole at the center of its back side.

3. The high-response graphene Hall force sensor according to claim 1, characterized in that, The fourth substrate is one of monocrystalline silicon, silicon-oxide-silicon, silicon nitride, flexible thin film, or metal / alloy substrate.

4. The high-response graphene Hall force sensor according to claim 1, characterized in that, The strain amplification layer is one of polycrystalline silicon, titanium nitride, silicon carbide, gallium nitride, silicon nitride, aluminum oxide, high-density metal, or transparent conductive oxide.

5. A high-response graphene Hall force sensor according to claim 1, characterized in that, The Hall electrode is a Ti / Au composite structure with a thickness of 5nm / 50nm. The Hall structure includes a set of source and drain electrodes for applying a constant current source or a constant voltage source, and two pairs of Hall electrodes arranged perpendicular to it.

6. A high-response graphene Hall force sensor according to claim 1, characterized in that, The thickness of the top h-BN is 20-30 nm, the graphene is a single layer, and the thickness of the bottom h-BN is less than 2 nm.

7. A method for fabricating a high-response graphene Hall force sensor, used in the high-response graphene Hall force sensor of claim 1, characterized in that, Includes the following steps: Step 1: Provide a first substrate, a second substrate, a third substrate, and a fourth substrate; Step 2: Process the fourth substrate by depositing a strain amplification layer on the fourth substrate using chemical vapor deposition; Step 3: Form a PDMS thin film on the first substrate and process the PDMS thin film to obtain a PDMS structure; Step 4: Form boron nitride sheets and graphene sheets on the second substrate and the third substrate, respectively; Step 5: Use the PDMS structure obtained in step 3 to adsorb the boron nitride sheet located on the second substrate in step 4 to form a PDMS-h-BN structure; Step 6: Using the PDMS-h-BN structure obtained in step 5, another boron nitride sheet located on the second substrate and a graphene sheet located on the third substrate are adsorbed sequentially to form a PDMS-top h-BN-graphene-bottom h-BN heterostructure. Step 7: Cover the fourth substrate with the strain amplification layer in Step 2 with the PDMS-top h-BN-graphene-bottom h-BN heterostructure formed in Step 6, and align the center of the heterostructure with the center of the fourth substrate to form a PDMS-top h-BN-graphene-bottom h-BN-strain amplification layer structure on the fourth substrate. Step 8: Remove the PDMS film to form a top h-BN-graphene-bottom h-BN-strain amplification layer structure on the fourth substrate; Step 9: Electron beam lithography is used to define a six-terminal Hall electrode region with the center as the reference height on the fourth substrate, and reactive ion etching is used to etch the top h-BN-graphene-bottom h-BN structure to expose its cross-sectional structure. Step 10: Deposit metal to cover the exposed top h-BN-graphene-bottom h-BN cross-sectional structure in step (9), so that the graphene and the metal electrode form edge contact; Step 11: Use electron beam lithography and reactive ion beam etching techniques to remove excess metal and materials outside the Hall electrode area to form the final sensor structure.

8. The method for fabricating a high-response graphene Hall force sensor according to claim 7, characterized in that, The metal deposited in step 10 may be one or more of titanium, chromium, palladium, platinum, aluminum, and gold.

9. The method for fabricating a high-response graphene Hall force sensor according to claim 7, characterized in that, The step of forming a polydimethylsiloxane film on the first substrate in step 3 includes finely cutting the formed film and placing it on a glass plate, heating it tightly at 150 degrees Celsius, and performing an activation treatment.

10. The method for fabricating a high-response graphene Hall force sensor according to claim 7, characterized in that, The thickness of the strain amplification layer in step 8 is less than 2 μm.

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