MEMS accelerometer based on piezoresistance-avalanche effect and measurement method thereof

Abstract

The invention provides an MEMS accelerometer based on a piezoresistance-avalanche effect and a measurement method thereof, and relates to the technical field of MEMS sensing. The accelerometer comprises a base and a beam body arranged on the base, the beam body is provided with a stress change area, the stress change area is provided with an effect junction with a piezoresistive-avalanche effect, and the accelerometer further comprises a reverse bias power supply and a measurement module which are both connected to the two ends of the effect junction, the reverse bias power supply is used for applying reverse voltage to the effect junction to enable the effect junction to enter a breakdown state, the measurement module is used for measuring breakdown electrical parameters of the effect junction, and the reverse bias power supply and the measurement module are both in communication connection with the control module. The accelerometer meets the requirements of high measurement sensitivity, simple structure, low manufacturing cost and small size.

Description

Technical Field

[0001] The present invention relates to the field of micro-electromechanical sensing technology, and in particular to a MEMS accelerometer based on piezoresistive-avalanche effect and a measurement method thereof. Background Art

[0002] MEMS (Micro-Electro-Mechanical System) accelerometers are widely used to measure acceleration, mainly including capacitive accelerometers, piezoresistive accelerometers and piezoelectric accelerometers. Among them, capacitive accelerometers have high requirements for manufacturing process and poor measurement sensitivity; piezoresistive accelerometers have low measurement sensitivity, complex structure and large size; piezoelectric accelerometers are difficult to manufacture and have high costs. Therefore, there is an urgent need for an accelerometer that can simultaneously meet the requirements of high measurement sensitivity, simple structure, low manufacturing cost and small size. Summary of the invention

[0003] The object of the present invention is to provide a MEMS accelerometer based on piezoresistive-avalanche effect and a measurement method thereof, so as to meet the requirements of high measurement sensitivity, simple structure, low manufacturing cost and small size.

[0004] To achieve the above effects, the present invention provides a MEMS accelerometer based on piezoresistive-avalanche effect, comprising a base and a beam disposed on the base, wherein the beam has a stress change region and the stress change region is provided with an effect junction having a piezoresistive-avalanche effect:

[0005] The accelerometer also includes a reverse bias power supply and a measurement module both connected to the two ends of the effect junction, wherein the reverse bias power supply is used to apply a reverse voltage to the effect junction to make it enter a breakdown state, and the measurement module is used to measure the breakdown electrical parameters of the effect junction, and the reverse bias power supply and the measurement module are both communicatively connected to the control module.

[0006] Optionally, the reverse bias power supply is a reverse bias voltage source with a constant voltage, the measuring module is used to measure the breakdown current of the effector junction, and the control module determines the acceleration according to the following formula:

[0007]

[0008] in,

[0009] V Th =k B T / q;

[0010] In the formula, a in is the acceleration of the accelerometer, m / s 2; △I is the breakdown current change value of the effect junction when the accelerometer is subjected to acceleration, A; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the reverse constant voltage applied by the reverse bias voltage source to the effect junction, V; I0 is the initial breakdown current of the effect junction when the accelerometer is not subjected to acceleration, A; n is the error coefficient; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0011] Optionally, the reverse bias power supply is a reverse bias current source with a constant current, the measuring module is used to measure the breakdown voltage of the effector junction, and the control module determines the acceleration according to the following formula:

[0012]

[0013] In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the accelerometer is subjected to acceleration, V; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; V BR0 is the initial breakdown voltage of the effect junction when the accelerometer is not subjected to acceleration, V; E g0 The initial band gap of the material used for the beam, eV; k B is the Boltzmann constant; T is the absolute temperature of the environment where the beam is located, K; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m.

[0014] Optionally, the effect junction is a PN junction.

[0015] Optionally, the beam body is connected to the base through an anchoring area, and a connection area between the beam body and the anchoring area serves as the stress change area.

[0016] Optionally, the anchor region is provided with a first electrode and a second electrode, the first electrode is connected to the first end of the effect junction, and the second electrode is connected to the second end of the effect junction; the two power supply ends of the reverse bias power supply are connected to the first electrode and the second electrode one by one, and the two connection ends of the measurement module are connected to the first electrode and the second electrode one by one.

[0017] Optionally, the beam body is a cantilever beam, and a mass block is provided at the suspended end of the beam body.

[0018] Optionally, the measuring module comprises an amplifier.

[0019] Optionally, the circuit formed by the effector junction and the reverse bias power supply is provided with an amplifier circuit.

[0020] The present invention also provides an acceleration measurement method based on piezoresistive-avalanche effect, using the above-mentioned MEMS accelerometer, the measurement method comprising:

[0021] adjusting the reverse bias power supply to apply a reverse voltage to the effect junction so that the effect junction enters a breakdown state;

[0022] The measuring module detects the breakdown electrical parameters of the effector junction and feeds back the parameters to the control module;

[0023] The control module determines the acceleration according to a preset formula, wherein the parameters of the preset formula include the initial breakdown electrical parameters of the effect junction before the accelerometer is subjected to acceleration, the breakdown electrical parameter change value of the effect junction when the accelerometer is subjected to acceleration, and the structure-related parameters of the accelerometer.

[0024] Optionally, the reverse bias power supply is a reverse bias voltage source with a constant voltage, and the step of the control module determining the acceleration according to a preset formula includes:

[0025] The control module calculates the acceleration according to the following formula:

[0026]

[0027] in,

[0028] V Th =k B T / q;

[0029] In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △I is the breakdown current change value of the effect junction when the accelerometer is subjected to acceleration, that is, the breakdown electrical parameter change value, A; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; q is the electron charge constant, 1.602×10 -19C; V Th is the thermal voltage, V; V BR0 is the reverse constant voltage applied by the reverse bias voltage source to the effect junction, V; I0 is the initial breakdown current of the effect junction when the accelerometer is not subjected to acceleration, that is, the initial breakdown electrical parameter, A; n is the error coefficient; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0030] Optionally, the reverse bias power supply is a reverse bias current source with a constant current, and the step of the control module determining the acceleration according to a preset formula includes:

[0031] The control module calculates the acceleration according to the following formula:

[0032]

[0033] In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the accelerometer is subjected to acceleration, that is, the breakdown electrical parameter change value, V; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; V BR0 is the initial breakdown voltage of the effect junction when the accelerometer is not subjected to acceleration, that is, the initial breakdown electrical parameter, V; E g0 The initial band gap of the material used for the beam, eV; k B is the Boltzmann constant; T is the absolute temperature of the environment where the beam is located, K; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m.

[0034] The MEMS accelerometer provided by the present invention can amplify and display the stress change in the stress change zone through the initial breakdown electrical parameter and the breakdown electrical parameter change value with a large change amplitude according to the piezoresistance-avalanche effect of the effect junction, so as to improve the sensing sensitivity of the accelerometer to the acceleration, and at the same time comprehensively consider the relationship between the acceleration, the structural related parameters, the stress in the stress change zone, the initial breakdown electrical parameter and the breakdown electrical parameter change value, so as to more accurately obtain the acceleration, thereby greatly improving the measurement sensitivity of the accelerometer; at the same time, the MEMS accelerometer only needs to set a simple effect junction in the stress change zone of its beam body and connect it to a reverse bias power supply, and then cooperate with a measurement module and a control module to perform high-precision acceleration measurement, and has a simple structure, a small size, low manufacturing difficulty and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A top view of a MEMS accelerometer based on piezoresistive-avalanche effect provided by an embodiment of the present invention in a first form;

[0037] Figure 2 A front cross-sectional view of a MEMS accelerometer based on piezoresistive-avalanche effect provided by an embodiment of the present invention in a first form;

[0038] Figure 3 A top view of a MEMS accelerometer based on piezoresistive-avalanche effect provided by an embodiment of the present invention in a second form;

[0039] Figure 4 A schematic flow chart of a measurement method of a MEMS accelerometer based on piezoresistive-avalanche effect provided in an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 100- beam body; 200- effector junction; 300- anchor region; 410- first electrode; 420- second electrode; 500- mass block. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] This embodiment provides a MEMS accelerometer based on piezoresistive-avalanche effect, such as Figure 1 and Figure 2 As shown, it includes a base and a beam body 100 arranged on the base, the beam body has a stress change zone and the stress change zone is provided with an effect junction 200 with a piezoresistive-avalanche effect: the accelerometer also includes a reverse bias power supply and a measurement module both connected to both ends of the effect junction 200, wherein the reverse bias power supply is used to apply a reverse voltage to the effect junction 200 to make it enter a breakdown state, and the measurement module is used to measure the breakdown electrical parameters of the effect junction 200, and the reverse bias power supply and the measurement module are both communicatively connected to the control module.

[0046] This embodiment also provides an acceleration measurement method based on piezoresistive-avalanche effect, using the above-mentioned MEMS accelerometer, such as Figure 4 As shown, the measurement methods include:

[0047] S402 adjusts the reverse bias power supply to apply a reverse voltage to the effect junction to put the effect junction into a breakdown state.

[0048] When in use, the reverse voltage applied to the effect junction by adjusting the reverse bias power supply causes the effect junction to enter a breakdown state. In the breakdown state, the effect junction has a piezoresistive-avalanche effect. Specifically, when the vibration source applies acceleration to the accelerometer, according to the Euler-Bernoulli beam theory, a corresponding stress is generated in the stress change zone. This stress can cause the electron mobility and the energy band gap at the effect junction to change, thereby causing a significant change in the breakdown electrical parameters such as the breakdown voltage / breakdown current of the effect junction, and approximately linearly amplifying the mechanical stress in the stress change zone, thereby making the breakdown electrical parameters of the effect junction highly sensitive to the mechanical stress in the stress change zone.

[0049] S404 measurement module detects the breakdown electrical parameters of the effector junction and feeds back to the control module.

[0050] S406 The control module determines the acceleration according to a preset formula, wherein the parameters of the preset formula include the initial breakdown electrical parameters of the effect junction before the accelerometer is subjected to acceleration, the breakdown electrical parameter change value of the effect junction when the accelerometer is subjected to acceleration, and the structural related parameters of the accelerometer.

[0051] The control module stores structural parameters related to the mechanical structure of the accelerometer itself, the connection circuit structure, the environment in which it is located, and preset formulas for calculating acceleration. The structural parameters can correlate the acceleration received by the accelerometer and the magnitude of the stress received by the stress change zone. The measurement module detects the breakdown electrical parameters of the effect junction in real time and feeds them back to the control module, and controls the breakdown electrical parameters fed back by the measurement module when the accelerometer is not subjected to acceleration as the initial breakdown electrical parameters, and the breakdown electrical parameters fed back by the measurement module when the accelerometer is subjected to acceleration and the change value of the initial breakdown electrical parameters as the breakdown electrical parameter change value, wherein the initial breakdown electrical parameters and the breakdown electrical parameter change value with a large change amplitude can amplify and characterize the stress magnitude of the stress change zone; subsequently, the control module substitutes the structural parameters, the initial breakdown electrical parameters and the breakdown electrical parameter change value into the preset formula to calculate the acceleration.

[0052] The MEMS accelerometer of this embodiment can amplify and display the stress change in the stress change zone through the initial breakdown electrical parameters and the breakdown electrical parameter change values ​​with a large change amplitude according to the piezoresistive-avalanche effect of the effect junction, so as to improve the sensing sensitivity of the accelerometer to the acceleration, and at the same time comprehensively consider the relationship between the acceleration, structural related parameters, the stress in the stress change zone, the initial breakdown electrical parameters and the breakdown electrical parameter change values, so as to more accurately obtain the acceleration, thereby greatly improving the measurement sensitivity of the accelerometer; at the same time, the MEMS accelerometer only needs to set a simple effect junction in the stress change zone of its beam body and connect it to a reverse bias power supply, and then cooperate with the measurement module and the control module to perform high-precision measurement of acceleration, and has a simple structure, small size, low manufacturing difficulty and low cost.

[0053] Specifically, the measurement module may include an amplifier to ensure its measurement sensitivity and accuracy for the breakdown electrical parameters of the effector junction, and correspondingly ensure the measurement sensitivity and accuracy of the accelerometer for acceleration. Specifically, the amplifier may be a lock-in amplifier.

[0054] Specifically, the reverse bias power supply may be a reverse bias voltage source with a constant voltage, the measuring module is used to measure the breakdown current of the effect junction, and the control module determines the acceleration according to the following formula:

[0055]

[0056] in,

[0057] V Th =k B T / q;

[0058] In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △I is the breakdown current change of the accelerometer when it is subjected to acceleration, A; α is the material parameter related to the beam body and the energy band gap, eV / Pa; E is Young's modulus, GPa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the reverse constant voltage applied by the reverse bias voltage source to the effect junction, V; I0 is the initial breakdown current of the effect junction when the accelerometer is not subjected to acceleration, A; n is the error coefficient; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0059] Among them, a in is the acceleration measured by the accelerometer; △I is the change value of the breakdown current, i.e., the change value of the breakdown electrical parameter; I0 is the initial breakdown current, i.e., the initial breakdown electrical parameter; α, E, q, V Th 、V BR0 , n, k B , T, h, L, M eff , K eff is the structural parameters related to the micromechanical structure itself, the connection circuit structure, the environment, etc. According to the above formula, the known quantitative parameters and the measured variable parameters, the acceleration a can be accurately measured. in .

[0060] In addition to the reverse bias voltage source mentioned above, in this embodiment, the reverse bias power supply may also use a reverse bias current source with a constant current. The measurement module is used to measure the breakdown voltage of the effect junction, and the control module determines the acceleration according to the following formula:

[0061]

[0062] In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △V BR is the breakdown voltage change of the accelerometer when it is subjected to acceleration, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; E is Young's modulus, GPa; V BR0 is the initial breakdown voltage of the accelerometer when it is not subjected to acceleration, V; E g0 is the initial energy band gap of the material used for the beam, eV; k B is the Boltzmann constant; T is the absolute temperature of the environment where the beam is located, K; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m.

[0063] Among them, a in Acceleration measured by the accelerometer; △V BR V is the breakdown voltage change value, i.e. the breakdown electrical parameter change value; BR0 is the initial breakdown voltage, i.e. the initial breakdown electrical parameter; α, E g0 , k B , T, E, h, L, M eff , K eff is the structural parameters related to the accelerometer's own structure, connection circuit structure, environment, etc.; based on the above formula, known quantitative parameters and measured variable parameters, the acceleration a can be accurately measured in .

[0064] Specifically, in this embodiment, the effect junction 200 may be a PN junction. During manufacturing, a lightly doped PN junction may be obtained at the beam body through a doping process.

[0065] Optionally, in this embodiment, the beam body is connected to the base through the anchor area 300, and the connection area between the beam body 100 and the anchor area 300 is used as the stress change area. When the accelerometer is subjected to the same acceleration, the stress change induced in the connection area between the beam body 100 and the anchor area 300 is relatively large, and the degree of triggering the piezoresistance-avalanche effect of the effect junction is greater. Accordingly, the change amplitude of the breakdown electrical parameter of the effect junction 200 is larger, and the amplification effect of the stress and acceleration in the stress change area is further improved, thereby further improving the measurement sensitivity of the accelerometer.

[0066] Of course, in some other embodiments, the effect junction may also be disposed in any other region of the beam body 100 that can sense stress changes.

[0067] Specifically, in this embodiment, Figure 3 As shown, a first electrode 410 and a second electrode 420 may be provided in the anchor region 300, the first electrode 410 being connected to the first end of the effect junction, and the second electrode 420 being connected to the second end of the effect junction; two power supply ends of the reverse bias power supply are connected to the first electrode 410 and the second electrode 420 in a one-to-one correspondence, and two connection ends of the measurement module are connected to the first electrode 410 and the second electrode 420 in a one-to-one correspondence. The effect junction is relatively small in size, and the first electrode and the second electrode with a fixed position and a relatively large volume are provided in the anchor region. When connected, the reverse bias power supply and the measurement module can be connected to the effect junction through the connection with the first electrode and the second electrode, thereby improving the connection convenience and connection stability, and correspondingly improving the manufacturing convenience and use stability of the accelerometer.

[0068] Specifically, in this embodiment, Figure 1 and Figure 2 As shown, the beam body 100 is a cantilever beam, and a mass block 500 is provided at the suspended end of the beam body 100. When the accelerometer is subjected to acceleration, the beam body with one end suspended and connected to the mass block 500 is subjected to stronger elastic vibration and greater induced stress change, and the degree of triggering the piezoresistance-avalanche effect of the effect junction is enhanced to further improve the amplification effect of the breakdown electrical parameters of the effect junction on the stress of the stress change area and the acceleration, and accordingly further improve the measurement sensitivity of the accelerometer.

[0069] Of course, in some other embodiments, the beam body can also be a fixed beam with both ends fixed or a membrane beam with a smaller thickness. At the same time, the beam body can be in the form of a single beam, a double beam or multiple beams.

[0070] In this embodiment, an amplifier circuit may be provided in the circuit formed by the effect junction and the reverse bias power supply. When in use, the amplifier circuit can amplify the variation amplitude of the breakdown electrical parameter of the effect junction, thereby further enhancing the amplification effect of the effect junction on the stress and acceleration of the stress change area, and correspondingly further improving the measurement sensitivity and accuracy of the accelerometer.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A MEMS accelerometer based on piezoresistive-avalanche effect, characterized in that: It comprises a base and a beam body (100) arranged on the base, wherein the beam body has a stress change region and the stress change region is provided with an effect junction (200) having a piezoresistance-avalanche effect: The accelerometer further comprises a reverse bias power supply and a measurement module both connected to two ends of the effect junction (200), wherein the reverse bias power supply is used to apply a reverse voltage to the effect junction (200) to cause it to enter a breakdown state, and the measurement module is used to measure the breakdown electrical parameters of the effect junction, and the reverse bias power supply and the measurement module are both communicatively connected to a control module.

2. The MEMS accelerometer according to claim 1, characterized in that: The reverse bias power supply is a reverse bias voltage source with a constant voltage. The measuring module is used to measure the breakdown current of the effect junction. The control module determines the acceleration according to the following formula: in, V Th =k B T / q; In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △I is the breakdown current change value of the effect junction when the accelerometer is subjected to acceleration, A; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the reverse constant voltage applied by the reverse bias voltage source to the effect junction (200), V; I0 is the initial breakdown current of the effect junction (200) when the accelerometer is not subjected to acceleration, A; n is the error coefficient; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam (100) is located, K.

3. The MEMS accelerometer according to claim 1, characterized in that: The reverse bias power supply is a reverse bias current source with a constant current, the measuring module is used to measure the breakdown voltage of the effect junction (200), and the control module determines the acceleration according to the following formula: In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the accelerometer is subjected to acceleration, V; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; V BR0 is the initial breakdown voltage of the effect junction when the accelerometer is not subjected to acceleration, V; E g0 The initial band gap of the material used for the beam, eV; k B is the Boltzmann constant; T is the absolute temperature of the environment where the beam is located, K; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m.

4. The MEMS accelerometer according to any one of claims 1 to 3, characterized in that: The effective junction is a PN junction.

5. The MEMS accelerometer according to any one of claims 1 to 3, characterized in that: The beam body is connected to the base through an anchoring area (300), and the connection area between the beam body (100) and the anchoring area (300) serves as the stress change area.

6. The MEMS accelerometer according to claim 5, characterized in that: The anchor region is provided with a first electrode (410) and a second electrode (420), the first electrode (410) is connected to the first end of the effect junction (200), and the second electrode (420) is connected to the second end of the effect junction (200); the two power supply ends of the reverse bias power supply are connected to the first electrode (410) and the second electrode (420) in a one-to-one correspondence, and the two connection ends of the measurement module are connected to the first electrode (410) and the second electrode (420) in a one-to-one correspondence.

7. The MEMS accelerometer according to any one of claims 1 to 3, characterized in that: The beam body (100) is a cantilever beam, and a mass block (500) is provided at the suspended end of the beam body (100).

8. An acceleration measurement method based on piezoresistive-avalanche effect, characterized in that: Using the MEMS accelerometer of claim 1, the measuring method comprises: adjusting the reverse bias power supply to apply a reverse voltage to the effect junction so that the effect junction enters a breakdown state; The measuring module detects the breakdown electrical parameters of the effector junction and feeds back the parameters to the control module; The control module determines the acceleration according to a preset formula, wherein the parameters of the preset formula include the initial breakdown electrical parameters of the effect junction before the accelerometer is subjected to acceleration, the breakdown electrical parameter change value of the effect junction when the accelerometer is subjected to acceleration, and the structure-related parameters of the accelerometer.

9. The acceleration measurement method according to claim 8, characterized in that: The reverse bias power supply is a reverse bias voltage source with a constant voltage, and the step of the control module determining the acceleration according to a preset formula includes: The control module calculates the acceleration according to the following formula: in, V Th =k B T / q; In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △I is the breakdown current change value of the effect junction when the accelerometer is subjected to acceleration, that is, the breakdown electrical parameter change value, A; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the reverse constant voltage applied by the reverse bias voltage source to the effect junction, V; I0 is the initial breakdown current of the effect junction when the accelerometer is not subjected to acceleration, that is, the initial breakdown electrical parameter, A; n is the error coefficient; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

10. The acceleration measurement method according to claim 8, characterized in that: The reverse bias power supply is a reverse bias current source with a constant current, and the step of the control module determining the acceleration according to a preset formula includes: The control module calculates the acceleration according to the following formula: In the formula, a in is the acceleration of the accelerometer, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the accelerometer is subjected to acceleration, that is, the breakdown electrical parameter change value, V; α is the material parameter of the beam body related to the energy band gap, eV / Pa; E is Young's modulus, GPa; V BR0 is the initial breakdown voltage of the effect junction when the accelerometer is not subjected to acceleration, that is, the initial breakdown electrical parameter, V; E g0 The initial band gap of the material used for the beam, eV; k B is the Boltzmann constant; T is the absolute temperature of the environment where the beam is located, K; h is the thickness of the beam, m; L is the length of the beam, m; M eff is the equivalent movable mass of the accelerometer, kg; K eff is the equivalent stiffness of the accelerometer, N / m.

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