Piezoresistor-capacitor-Mortat memristor synergistically integrated MEMS pressure sensor and preparation method thereof

Abstract

The invention discloses a piezoresistor-capacitor-mott memristor synergistically integrated MEMS pressure sensor and a preparation method thereof. The piezoresistor-capacitor-mott memristor synergistically integrated MEMS pressure sensor comprises a first substrate, a piezoresistor, an ohmic contact, a first insulating layer, an adhesion layer, a first electrode, a phase change layer, a second electrode, a fixed resistor R0, a pressure sensitive film, a second insulating layer, an upper polar plate, a second substrate, a lower polar plate and a cavity. And the first electrode, the phase change layer and the second electrode form a Mott memristor. Under the action of external pressure, the output oscillation frequency is reduced when the resistance value of the piezoresistor is increased and the capacitance value of the capacitor is reduced, and the sensitivity of the sensor is effectively improved through the synergistic effect of the piezoresistor and the capacitor. According to the invention, the Mott memristor, the piezoresistor and the capacitor form an oscillation circuit on a device level, so that stable electrical oscillation is realized. According to the MEMS pressure sensor, the piezoresistor, the capacitor and the mott memristor are integrated in a monolithic mode through a vertical structure, and the space utilization rate is increased.

Description

Technical Field

[0001] This invention belongs to the field of MEMS (Micro-Electro-Mechanical System), and particularly relates to a MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration and its fabrication method. Background Technology

[0002] Pressure sensors convert environmental pressure into electrical signals to measure pressure, and are widely used in industrial control, aerospace, automotive electronics, and other fields. Pressure sensors manufactured using MEMS technology have advantages such as small size, high accuracy, and easy integration. Common MEMS pressure sensors include piezoresistive pressure sensors and capacitive pressure sensors. However, existing MEMS pressure sensors typically rely on a single sensing mechanism. For these sensors, it is usually necessary to reduce the thickness of the sensitive film or increase the effective area of ​​the film to improve sensitivity. However, this leads to a decrease in film stiffness, introducing greater deflection, which in turn results in poorer sensor linearity, a smaller measurement range, and a decline in overload resistance and long-term stability. Furthermore, existing MEMS pressure sensors generally output analog signals, which are susceptible to noise interference during transmission, reducing sensor measurement accuracy. Obtaining digital signals requires external calibration modules and analog-to-digital conversion circuits for digitization, which not only increases the design complexity and economic cost of the system but may also introduce new errors due to the additional circuitry. Summary of the Invention

[0003] The purpose of this invention is to provide a MEMS pressure sensor and its fabrication method that integrates a piezoresistive-capacitive-Mott memristor. This effectively improves the sensitivity of the MEMS pressure sensor without altering the thin-film structure parameters or affecting other performance indicators. Furthermore, by utilizing the synergistic effect of the Mott memristor with the piezoresistive and capacitive elements, an oscillation circuit is constructed at the device level, thereby achieving digital encoding and output of the signal. This effectively reduces the impact of noise interference on measurement accuracy, thus solving the technical problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows: A MEMS pressure sensor integrating piezoresistive-capacitive-Mott memristor comprises a first substrate, a piezoresistor, an ohmic contact, a first insulating layer, an adhesive layer, a first electrode, a phase change layer, a second electrode, a fixed resistor R0, a pressure-sensitive thin film, a second insulating layer, an upper electrode, a second substrate, a lower electrode, and a cavity. The first substrate is used to achieve vacuum sealing of the cavity and to provide mechanical support for the sensor chip; The first substrate is located above the second substrate; The cavity is located between the first substrate and the second substrate, and serves as a sealed reference cavity for the sensor and a dielectric gap for the capacitor C; The third insulating layer is disposed on the upper surface of the second substrate to achieve electrical isolation between the lower electrode plate and the second substrate; The lower electrode plate is disposed on the upper surface of the third insulating layer; The second insulating layer is disposed on the lower surface of the first substrate to achieve electrical isolation between the upper electrode plate and the first substrate; The upper electrode plate is disposed on the lower surface of the second insulating layer, covering the area of ​​maximum amplitude of the pressure-sensitive film, thereby increasing the effective area of ​​the upper electrode plate; The pressure-sensitive film is located in the center of the upper surface of the first substrate, facing the cavity; The upper plate, the lower plate, and the cavity constitute a capacitor C; under pressure, the pressure-sensitive film undergoes bending deformation, the gap between the plates of capacitor C changes, thereby causing a change in the capacitance value. The varistor is placed in the stress concentration area at the edge of the pressure-sensitive film; The ohmic contacts are located at both ends of the varistor and are made of P-type heavily doped single-crystal silicon. The thickness of the contacts is the same as that of the varistor R. S Similarly, the ohmic contact is used to realize the varistor R S Electrical interconnection between the metal electrode and the adhesion layer; The first insulating layer completely covers the upper surface of the first substrate to ensure electrical isolation protection of the varistor layer; The fixed resistor is disposed on the upper surface of the first insulating layer and is located in the non-stress-sensitive area of ​​the pressure-sensitive film; An adhesion layer is disposed on the upper surface of one end of the ohmic contact to improve the adhesion between the first electrode and the substrate; The first electrode is located on the upper surface of the adhesion layer; The phase change layer is disposed on the upper surface of the first electrode; The second electrode is disposed on the upper surface of the phase change layer, forming a symmetrical structure with the first electrode; The first electrode, the phase change layer, and the second electrode constitute a Mott memristor; A varistor, a fixed resistor, a capacitor C, and a Mott memristor are interconnected by metal wires to form an oscillating circuit.

[0005] Furthermore, the first substrate material is monocrystalline silicon with a thickness of 200-1000 μm; the second substrate material is at least one of monocrystalline silicon or glass with a thickness of 200-2000 μm.

[0006] Furthermore, the cavity depth is 1-50 μm.

[0007] Furthermore, the first insulating layer material is at least one of silicon dioxide or silicon nitride, with a thickness of 100-500 nm; the second insulating layer material is at least one of silicon dioxide or silicon nitride, with a thickness of 100-500 nm; and the third insulating layer material is at least one of silicon dioxide or silicon nitride, with a thickness of 100-500 nm.

[0008] Furthermore, the upper electrode material is at least one of metals Al and Au, with a thickness of 0.1-5 μm; the lower electrode material is at least one of metals Al and Au, with a thickness of 0.1-5 μm.

[0009] Furthermore, the varistor material is P-type doped single-crystal silicon with a thickness of 0.1-3 μm; the ohmic contact material is P-type heavily doped single-crystal silicon with the same thickness as the varistor; and the fixed resistor material is at least one of Al, Pt, NiCr, and TiW with a thickness of 0.1-5 μm.

[0010] Furthermore, the adhesion layer has a T-shaped cross-section, is made of at least one of Ti, Cr, and Ta, and has a thickness of 5-20 nm.

[0011] Furthermore, the first electrode material is at least one of Pt, TiN, Ru and W, with a thickness of 50-200 nm; the phase change layer is at least one of NbO2 and VO2, with a thickness of 5-50 nm; the second electrode material is the same as the first electrode, with a thickness of 50-200 nm. Furthermore, the varistor, fixed resistor, capacitor C, and Mott memristor form an oscillating circuit through metal interconnects, and the material is at least one of Al, Cu, Au, Ti, W, or their alloys.

[0012] This invention also discloses a method for fabricating a MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration, comprising the following steps: Step 1: Select a 500 μm thick N-type silicon wafer as the first substrate; Step 2: A P-type varistor with a thickness of 2 μm is fabricated on the first substrate by photolithography and ion implantation; Step 3: Form ohmic contacts with a thickness of 2 μm by performing P-type heavy doping on both ends of the varistor. Step 4: A 200 nm thick SiO2 layer is grown on the upper surface of the first substrate as a first insulating layer by plasma-enhanced chemical vapor deposition (PECVD). Step 5: Create vias in the first insulating layer by photolithography and RIE reactive ion etching to expose the upper surface of the ohmic contact for subsequent electrical connection with the first electrode. Step 6: Fill the via with Ti by magnetron sputtering and photolithography, and prepare a 10 nm thick Ti layer on the upper surface of the first insulating layer to form a T-shaped adhesion layer to ensure electrical connection continuity. Step 7: Prepare a 100 nm thick Pt layer as the first electrode on the upper surface of the adhesion layer by magnetron sputtering and photolithography; Step 8: Deposit on the surface of the first electrode by magnetron sputtering and photolithography. The material, with a thickness of 20 nm, forms a phase change layer; Step 9: Deposit a 100 nm thick Pt layer on the surface of the phase transition layer as a second electrode using magnetron sputtering and photolithography, symmetrical to the first electrode; Step 10: Deposit Al as a fixed resistor on the surface of the first insulating layer by magnetron sputtering and photolithography, with a thickness of 3 μm; Step 11: Photolithographically pattern the lower surface of the first substrate, and form a pressure-sensitive film with the required shape and thickness of 10 μm for the cavity by wet etching; Step 12: Prepare a 200 nm thick SiO2 layer as a second insulating layer on the lower surface of the first substrate and the upper surface of the cavity by PECVD and photolithography to achieve electrical isolation between the upper electrode plate and the first substrate; Step 13: Prepare a 3 μm thick Al film on the lower surface of the second insulating layer by magnetron sputtering and photolithography to form the upper electrode plate; Step 14: Select a 500 μm thick BF33 glass sheet as the second substrate, and prepare a 3 μm thick Al film on the upper surface of the third insulating layer by magnetron sputtering and photolithography to form the lower electrode plate; Step 15: The lower surface of the first substrate is tightly bonded to the second substrate through anodizing process to form a cavity, thus completing the fabrication of the sensor.

[0013] The present invention provides a MEMS pressure sensor and its fabrication method that integrates piezoresistive-capacitive-Mott memristor, which has the following advantages: (1) The MEMS pressure sensor of the present invention breaks the limitation of existing sensors that rely on a single sensitive principle. Under the action of external pressure, the increase of the resistance of the piezoresistor and the decrease of the capacitance of the capacitor will both cause the output oscillation frequency to decrease. The two work together to effectively improve the sensitivity of the sensor.

[0014] (2) The MEMS pressure sensor of the present invention achieves stable electrical oscillation by constructing an oscillation circuit using a Mott memristor, piezoresistor, and capacitor at the device level. When a pressure signal is input, the operating state of the oscillation circuit changes accordingly, converting the pressure signal into a digital code of the oscillation frequency. This digital signal has excellent anti-interference capability, significantly reducing the influence of noise and interference during transmission and improving the measurement accuracy of the sensor.

[0015] (3) The MEMS pressure sensor of the present invention adopts a vertical structure to integrate piezoresistive, capacitive and Mott memristor on a single chip, thereby improving space utilization. It can be fabricated with high precision, high consistency and low cost through MEMS technology. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of a MEMS pressure sensor that integrates piezoresistive-capacitive-Mott memristor according to the present invention. Figure 2 This is a schematic diagram of the circuit structure of a MEMS pressure sensor that integrates piezoresistive-capacitive-Mott memristor according to the present invention. Figure 3 This is a schematic cross-sectional view of the completed structure in step 1 of the present invention. Figure 4 This is a schematic diagram of the cross-sectional structure after step 2 of the present invention has been completed; Figure 5 This is a schematic cross-sectional view of the completed structure in step 3 of the present invention. Figure 6 This is a schematic diagram of the cross-sectional structure after step 4 of the present invention is completed; Figure 7 This is a schematic cross-sectional view of the completed structure in step 5 of the present invention. Figure 8 This is a schematic cross-sectional view of the structure after step 6 of the present invention is completed. Figure 9 This is a schematic cross-sectional view of the structure after step 7 of the present invention is completed. Figure 10 This is a schematic cross-sectional view of the completed structure in step 8 of the present invention. Figure 11 This is a schematic cross-sectional view of the structure after step 9 of the present invention is completed. Figure 12 This is a schematic cross-sectional view of the completed structure in step 10 of the present invention. Figure 13 This is a schematic cross-sectional view of the completed structure in step 11 of the present invention. Figure 14 This is a schematic diagram of the cross-sectional structure after step 12 of the present invention is completed; Figure 15 This is a schematic cross-sectional view of the completed structure in step 13 of the present invention. Figure 16 This is a schematic cross-sectional view of the completed structure in step 14 of the present invention. Figure 17 This is a schematic cross-sectional view of the completed structure in step 15 of the present invention. The markings in the figure are as follows: 1. First substrate; 2. Varistor; 3. Ohmic contact; 4. First insulating layer; 5. Adhesion layer; 6. First electrode; 7. Phase change layer; 8. Second electrode; 9. Fixed resistor; 10. Pressure-sensitive film; 11. Second insulating layer; 12. Upper electrode; 13. Second substrate; 14. Lower electrode; 15. Cavity. Detailed Implementation

[0017] To better understand the purpose, structure, and function of this invention, the following detailed description, in conjunction with the accompanying drawings, provides a MEMS pressure sensor with piezoresistive-capacitive-Mott memristor synergistic integration and its fabrication method.

[0018] like Figure 1 As shown, a MEMS pressure sensor integrating piezoresistive-capacitive-Mott memristor co-integration includes a first substrate 1, a piezoresistive resistor 2, an ohmic contact 3, a first insulating layer 4, an adhesive layer 5, a first electrode 6, a phase change layer 7, a second electrode 8, a fixed resistor 9, a pressure-sensitive film 10, a second insulating layer 11, an upper electrode plate 12, a second substrate (13), a lower electrode plate 14, and a cavity 15; The first substrate 1 is used to achieve vacuum sealing of the cavity 15 and to provide mechanical support for the sensor chip; The first substrate 1 is located above the second substrate 13; The cavity 15 is located between the first substrate 1 and the second substrate 13, and serves as a sealed reference cavity for the sensor and a dielectric gap for the capacitor C; The third insulating layer 14 is disposed on the upper surface of the second substrate 13 to achieve electrical isolation between the lower electrode plate 14 and the second substrate 13; The lower electrode plate 14 is disposed on the upper surface of the third insulating layer 14; The second insulating layer 11 is disposed on the lower surface of the first substrate 1 to achieve electrical isolation between the upper electrode plate 12 and the first substrate 1; The upper electrode plate 12 is disposed on the lower surface of the second insulating layer 11, covering the area of ​​maximum amplitude of the pressure-sensitive film 10, thereby increasing the effective area of ​​the upper electrode plate 12 to enhance the capacitance change and further improve the output sensitivity of the sensor.

[0019] The pressure-sensitive thin film 10 is located at the center of the upper surface of the first substrate 1 and faces the cavity; The upper electrode 12, the lower electrode 14, and the cavity 15 constitute a capacitor C; under pressure, the pressure-sensitive film 10 undergoes bending deformation, the gap between the electrodes of the capacitor C changes, thereby causing a change in the capacitance value. The varistor 2 is disposed in the stress concentration area at the edge of the pressure-sensitive film 10; The ohmic contact 3 is disposed at both ends of the varistor 2. The material is P-type heavily doped single crystal silicon, and the thickness is the same as that of the varistor 2. The ohmic contact 3 is used to achieve good electrical interconnection between the varistor 2, the metal electrode, and the adhesion layer 5. The first insulating layer 4 completely covers the upper surface of the first substrate 1 to ensure electrical isolation protection of the varistor layer; The fixed resistor 9 is disposed on the upper surface of the first insulating layer 4 and is located in the non-stress-sensitive area of ​​the pressure-sensitive film 10; An adhesion layer 5 is disposed on the upper surface of one end of the ohmic contact 3 to improve the adhesion between the first electrode 6 and the substrate. The first electrode 6 is located on the upper surface of the adhesion layer 5 to achieve good conductivity and interface compatibility with the functional layer. The phase change layer 7 is disposed on the upper surface of the first electrode 6; The second electrode 8 is disposed on the upper surface of the phase change layer 7, forming a symmetrical structure with the first electrode 6; The first electrode 6, the phase change layer 7, and the second electrode 8 constitute a Mott memristor. Under the action of an applied voltage, the Mott material can undergo a bidirectional phase change between the insulating state and the metallic state, causing its resistance to change between high and low resistance states. Based on this characteristic, an oscillating circuit can be constructed.

[0020] The varistor 2, fixed resistor 9, capacitor C, and Mott memristor form an oscillating circuit through metal interconnects, as shown in the specific connection method. Figure 2 The circuit structure diagram is shown.

[0021] Furthermore, the first substrate 1 is made of single-crystal silicon with a thickness of 200-1000 μm. A suitable thickness selection provides sufficient mechanical support, enhances the structural rigidity of the sensor, and enables the sensor to respond sensitively to pressure changes. The second substrate 13 is made of at least one of single-crystal silicon or glass, with a thickness of 200-2000 μm.

[0022] Furthermore, the depth of cavity 15 is 1-50 μm.

[0023] Furthermore, the first insulating layer 4 is made of at least one of silicon dioxide or silicon nitride, with a thickness of 100-500 nm; the second insulating layer 11 is made of at least one of silicon dioxide or silicon nitride, with a thickness of 100-500 nm; and the third insulating layer 14 is made of at least one of silicon dioxide or silicon nitride, with a thickness of 100-500 nm.

[0024] Furthermore, the upper electrode 12 is made of at least one of metals Al and Au, with a thickness of 0.1-5 μm; the lower electrode 14 is made of at least one of metals Al and Au, with a thickness of 0.1-5 μm.

[0025] Furthermore, the varistor 2 is made of P-type doped single-crystal silicon with a thickness of 0.1-3 μm; the ohmic contact 3 is made of heavily doped P-type single-crystal silicon with the same thickness as the varistor 2, and its shape is determined by the specific layout and wiring; the fixed resistor 9 is made of at least one of Al, Pt, NiCr and TiW with a thickness of 0.1-5 μm.

[0026] Furthermore, the adhesion layer 5 has a T-shaped cross-section, is made of at least one of Ti, Cr and Ta, and has a thickness of 5-20 nm.

[0027] Furthermore, the first electrode 6 is made of at least one of Pt, TiN, Ru, and W, with a thickness of 50-200 nm; the phase change layer 7 is made of... At least one of VO2, with a thickness of 5-50 nm; the second electrode 8 is made of the same material as the first electrode 6, with a thickness of 50-200 nm; Furthermore, the varistor 2, fixed resistor 9, capacitor C, and Mott memristor form an oscillating circuit through metal interconnects, and the material is at least one of Al, Cu, Au, Ti, W, or their alloys.

[0028] The working principle of the MEMS pressure sensor of the present invention is as follows: Its circuit structure is as follows Figure 2 As shown, the Mott memristor is connected in series with the fixed resistor R0, forming a parallel branch with the capacitor C. This parallel branch is connected to the varistor R. S The circuit is formed by connecting the series resistors, and the output voltage V is measured by leading out the electrodes of the two ends of the fixed resistor R0. out .

[0029] After a constant voltage is applied, capacitor C begins to charge. When the potential difference across the Mott memristor exceeds the threshold voltage V... th When the Mott memristor switches from a high-resistance state to a low-resistance state, capacitor C discharges through the low-resistance Mott memristor. When the potential difference across the Mott memristor is less than the holding voltage V... hold When the memristor returns to a high-resistance state, it recharges capacitor C. This charging and discharging process repeats continuously, achieving stable electrical oscillation.

[0030] By fixing the resistor R0, the current flowing through the Mott memristor can be converted into a voltage signal V. out When the memristor switches from a high-resistance state to a low-resistance state, the circuit current increases sharply, and the voltage across the fixed resistor R0 rises sharply, generating a sharp "positive pulse". When the memristor returns to the high-resistance state, the current drops sharply, and the voltage across the fixed resistor R0 returns to the low voltage baseline (close to 0 V), thus outputting a voltage spike. The number of spikes per unit time is the oscillation pulse frequency.

[0031] When external pressure is applied to the sensor, the pressure-sensitive film 10 undergoes bending deformation. Based on the piezoresistive effect, the pressure-sensitive resistor R... S Under stress, the resistance increases, thus reducing the capacitor charging current and slowing down the charging process, leading to a decrease in the output oscillation frequency. Simultaneously, the upper plate 12 of capacitor C deforms along with the pressure-sensitive film 10, reducing the distance between the upper and lower plates. Based on the parallel-plate capacitor principle, the capacitance of capacitor C increases as the plate distance decreases, further reducing the charging rate and consequently lowering the output oscillation frequency. Therefore, the pressure signal is mapped to an oscillation frequency signal, which is influenced by the synergistic effect of changes in the resistance of the piezoresistor Rs and the capacitance of capacitor C. Specifically, under pressure, the increased resistance of the piezoresistor Rs and the increased capacitance of capacitor C have a combined effect that lowers the oscillation frequency. By jointly regulating the output oscillation frequency through the dual mechanisms of piezoresistive and variable capacitance effects, the sensitivity of the sensor is effectively improved.

[0032] This invention also discloses a method for fabricating a MEMS pressure sensor, comprising the following steps: (a) A 500 μm thick N-type silicon wafer is selected as the first substrate 1, such as Figure 3 As shown; (b) A P-type varistor 2 with a thickness of 2 μm was fabricated on the first substrate 1 by photolithography and ion implantation, as shown below. Figure 4 As shown; (c) An ohmic contact 3 with a thickness of 2 μm is formed by p-type heavy doping at both ends of the varistor 2, as shown in the figure. Figure 5 As shown; (d) A 200 nm thick SiO2 layer is grown on the upper surface of the first substrate 1 as the first insulating layer 4 by PECVD (Plasma Enhanced Chemical Vapor Deposition), as shown below. Figure 6 As shown; (e) Through-holes are fabricated in the first insulating layer 4 by photolithography and RIE (Reactive Ion Etching) to expose the upper surface of the ohmic contact 3 for subsequent electrical connection with the first electrode 6, such as... Figure 7 As shown; (f) Ti is filled into the vias by magnetron sputtering and photolithography, and a 10 nm thick Ti layer is prepared on the upper surface of the first insulating layer 4 to form a T-shaped adhesion layer 5 to ensure electrical connection continuity, such as... Figure 8 As shown; (g) A 100 nm thick Pt layer is fabricated on the upper surface of the adhesion layer 5 as the first electrode 6 by magnetron sputtering and photolithography, as shown below. Figure 9 As shown; (h) Deposition on the surface of the first electrode 6 by magnetron sputtering and photolithography The material, with a thickness of 20 nm, forms a phase change layer 7, such as... Figure 10 As shown; (i) A 100 nm thick Pt layer is deposited on the surface of the phase transition layer 7 by magnetron sputtering and photolithography as a second electrode 8, symmetrical to the first electrode 6, as shown below. Figure 11 As shown; (j) Al was deposited as a fixed resistor 9 on the upper surface of the first insulating layer 4 by magnetron sputtering and photolithography, with a thickness of 3 μm, as shown. Figure 12 As shown; (k) Photolithographically pattern the lower surface of the first substrate 1, and form the cavity 15 with the required shape and a pressure-sensitive thin film 10 with a thickness of 10 μm by wet etching, such as Figure 13 As shown; (l) A 200 nm thick SiO2 layer 11 is prepared as a second insulating layer 11 on the lower surface of the first substrate 1 and the upper surface of the cavity 15 by PECVD and photolithography to achieve electrical isolation between the upper electrode 12 and the first substrate 1, such as... Figure 14 As shown; (m) A 3 μm thick Al film is prepared on the lower surface of the second insulating layer 11 by magnetron sputtering and photolithography to form the upper electrode 12, as shown. Figure 15 As shown; (n) A 500 μm thick BF33 glass sheet is selected as the second substrate 13. A 3 μm thick Al film is prepared on the upper surface of the third insulating layer (14) by magnetron sputtering and photolithography to form the lower electrode plate 14, as shown. Figure 16 As shown; (o) The lower surface of the first substrate 1 is tightly bonded to the second substrate 13 using an anodic bonding process to form a cavity 15, thus completing the fabrication of the sensor. Figure 17 As shown; The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0033] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration, characterized in that, It includes a first substrate (1), a varistor (2), an ohmic contact (3), a first insulating layer (4), an adhesive layer (5), a first electrode (6), a phase change layer (7), a second electrode (8), a fixed resistor (9), a pressure-sensitive film (10), a second insulating layer (11), an upper electrode plate (12), a second substrate (13), a lower electrode plate (14), and a cavity (15). The first substrate (1) is used to achieve vacuum sealing of the cavity (15) and to provide mechanical support for the sensor chip; The first substrate (1) is located above the second substrate (13); The cavity (15) is located between the first substrate (1) and the second substrate (13) and serves as a sealed reference cavity for the sensor and a dielectric gap for the capacitor C; A third insulating layer (14) is disposed on the upper surface of the second substrate (13) to achieve electrical isolation between the lower electrode plate (14) and the second substrate (13); The lower electrode plate (14) is disposed on the upper surface of the third insulating layer (14); The second insulating layer (11) is disposed on the lower surface of the first substrate (1) to achieve electrical isolation between the upper electrode plate (12) and the first substrate (1); The upper electrode plate (12) is disposed on the lower surface of the second insulating layer (11) and covers the area of ​​maximum amplitude of the pressure-sensitive film (10), thereby increasing the effective area of ​​the upper electrode plate (12); The pressure-sensitive film (10) is located at the center of the upper surface of the first substrate (1) and faces the cavity; The upper electrode (12), the lower electrode (14), and the cavity (15) constitute a capacitor C; under pressure, the pressure-sensitive film (10) undergoes bending deformation, the gap between the electrodes of the capacitor C changes, thereby causing a change in the capacitance value; The varistor (2) is placed in the stress concentration area at the edge of the pressure-sensitive film (10); The ohmic contact (3) is disposed at both ends of the varistor (2), and the material is P-type heavily doped single crystal silicon with the same thickness as the varistor (2). The ohmic contact (3) is used to realize the electrical interconnection between the varistor (2), the metal electrode and the adhesion layer (5). The first insulating layer (4) completely covers the upper surface of the first substrate (1) to ensure electrical isolation protection of the varistor layer; The fixed resistor (9) is disposed on the upper surface of the first insulating layer (4) and is located in the non-stress-sensitive area of ​​the pressure-sensitive film (10); An adhesion layer (5) is disposed on the upper surface of one end of the ohmic contact (3) to improve the adhesion between the first electrode (6) and the substrate; The first electrode (6) is located on the upper surface of the adhesive layer (5); A phase change layer (7) is disposed on the upper surface of the first electrode (6); The second electrode (8) is disposed on the upper surface of the phase change layer (7) and forms a symmetrical structure with the first electrode (6); The first electrode (6), the phase change layer (7), and the second electrode (8) constitute a Mott memristor; A varistor (2), a fixed resistor (9), a capacitor C, and a memristor are connected by metal interconnects to form an oscillating circuit.

2. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The first substrate (1) is made of monocrystalline silicon and has a thickness of 200-1000 μm; the second substrate (13) is made of at least one of monocrystalline silicon or glass and has a thickness of 200-2000 μm.

3. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The cavity (15) has a depth of 1-50 μm.

4. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The first insulating layer (4) is made of at least one of silicon dioxide or silicon nitride and has a thickness of 100-500 nm; the second insulating layer (11) is made of at least one of silicon dioxide or silicon nitride and has a thickness of 100-500 nm; the third insulating layer (14) is made of at least one of silicon dioxide or silicon nitride and has a thickness of 100-500 nm.

5. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The upper electrode (12) is made of at least one of metals Al and Au, with a thickness of 0.1-5 μm; the lower electrode (14) is made of at least one of metals Al and Au, with a thickness of 0.1-5 μm.

6. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The varistor (2) is made of P-type doped single-crystal silicon with a thickness of 0.1-3 μm; the ohmic contact (3) is made of P-type heavily doped single-crystal silicon with the same thickness as the varistor (2); the fixed resistor (9) is made of at least one of Al, Pt, NiCr and TiW with a thickness of 0.1-5 μm.

7. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The adhesion layer (5) has a T-shaped cross-section and is made of at least one of Ti, Cr and Ta, with a thickness of 5-20 nm.

8. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The first electrode (6) is made of at least one of Pt, TiN, Ru and W, with a thickness of 50-200 nm; the phase change layer (7) is made of at least one of NbO2 and VO2, with a thickness of 5-50 nm; the second electrode (8) is made of the same material as the first electrode (6), with a thickness of 50-200 nm.

9. The MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration according to claim 1, characterized in that, The metal interconnect material is at least one of Al, Cu, Au, Ti, W or their alloys.

10. A method for fabricating a MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration, used in the MEMS pressure sensor with piezoresistive-capacitive-Mott memristor co-integration as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Select an N-type silicon wafer as the first substrate (1); Step 2: A P-type varistor (2) is fabricated on the first substrate (1) by photolithography and ion implantation. Step 3: Form an ohmic contact (3) by performing P-type heavy doping on both ends of the varistor (2); Step 4: A SiO2 layer is grown on the upper surface of the first substrate (1) as a first insulating layer (4) by PECVD plasma-enhanced chemical vapor deposition. Step 5: Through holes are made in the first insulating layer (4) by photolithography and RIE reactive ion etching to expose the upper surface of the ohmic contact (3) for subsequent electrical connection with the first electrode (6); Step 6: Fill the via with Ti by magnetron sputtering and photolithography, and prepare Ti on the upper surface of the first insulating layer (4) to form an adhesion layer (5) with a T-shaped cross-section to ensure the continuity of electrical connection; Step 7: Prepare a first electrode (6) with a thickness of Pt on the upper surface of the adhesion layer (5) by magnetron sputtering and photolithography. Step 8: Deposit on the surface of the first electrode (6) by magnetron sputtering and photolithography. The material forms a phase change layer (7); Step 9: Pt is deposited on the upper surface of the phase change layer (7) as a second electrode (8) by magnetron sputtering and photolithography, which is symmetrical to the first electrode (6); Step 10: Deposit Al as a fixed resistor (9) on the upper surface of the first insulating layer (4) by magnetron sputtering and photolithography. Step 11: Photolithographically pattern the lower surface of the first substrate (1) and form a pressure-sensitive thin film (10) of the required shape for the cavity (15) by wet etching. Step 12: SiO2 is prepared as a second insulating layer (11) on the lower surface of the first substrate (1) and the upper surface of the cavity (15) by PECVD and photolithography to achieve electrical isolation between the upper electrode plate (12) and the first substrate (1); Step 13: Prepare an Al thin film on the lower surface of the second insulating layer (11) by magnetron sputtering and photolithography to form the upper electrode plate (12). Step 14: Select a glass sheet as the second substrate (13), and prepare an Al thin film on the upper surface of the third insulating layer (14) by magnetron sputtering and photolithography to form the lower electrode plate (14). Step 15: The lower surface of the first substrate (1) is tightly bonded to the second substrate (13) through anodizing bonding process to form a cavity (15), thus completing the fabrication of the sensor.

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