Piezoresistance-avalanche effect-based parameter measurement method and micro-mechanical structure

Abstract

The invention provides a piezoresistance-avalanche effect-based parameter measurement method and a micro-mechanical structure, and relates to the technical field of micro-electro-mechanical sensing. The parameter measurement method based on the piezoresistance-avalanche effect comprises the steps that an effect junction is adjusted to enter a breakdown state; obtaining structure related parameters of the micro-mechanical structure, initial breakdown electrical parameters of the effect junction and a breakdown electrical parameter change value of the effect junction when the stress change region is stressed; calculating a target parameter according to the structure related parameter, the initial breakdown electrical parameter and the breakdown electrical parameter change value; wherein the micro-mechanical structure comprises a beam body, and a stress change region of the beam body is provided with an effect junction with a piezoresistance-avalanche effect. The parameter measurement method is high in measurement sensitivity, and the adopted micro-mechanical structure is simple in structure, small in size, low in manufacturing cost and high in manufacturing convenience.

Description

Technical Field

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

[0002] Micro-electromechanical sensors with silicon as the main material are widely used and can be used to measure physical quantities such as acceleration, angular velocity, and pressure. These sensors usually use micro-mechanical structures, which can convert the target parameters to be obtained into mechanical stress or displacement, and then further convert them into changes in electrical performance parameters, and solve the target parameters by measuring the electrical performance parameters. However, the existing micro-mechanical structures are complex in structure, large in size, high in manufacturing cost, and low in measurement sensitivity. Summary of the invention

[0003] The purpose of the present invention is to provide a parameter measurement method and a micromechanical structure based on piezoresistive-avalanche effect, so as to solve the technical problems of the existing micromechanical structure, such as complex structure, large volume, high manufacturing cost and low measurement sensitivity.

[0004] In order to solve the above problems, the present invention provides a parameter measurement method based on piezoresistive-avalanche effect, which is applied to the measurement of target parameters in a micromechanical structure. The micromechanical structure includes a beam body, and an effect junction with piezoresistive-avalanche effect is provided in a stress change region of the beam body. The method includes:

[0005] regulating the effector junction to enter a breakdown state;

[0006] Acquiring structural related parameters of the micromechanical structure, initial breakdown electrical parameters of the effect junction, and breakdown electrical parameter change values ​​of the effect junction when the stress change region is subjected to stress;

[0007] The target parameter is calculated according to the structure-related parameter, the initial breakdown electrical parameter and the breakdown electrical parameter change value.

[0008] Optionally, a constant reverse voltage is applied to the effect junction to put the effect junction into a breakdown state, the initial breakdown electrical parameter includes an initial breakdown current, the breakdown electrical parameter change value includes a breakdown current change value, and the target parameter includes at least the stress applied to the stress change zone, the strain applied to the stress change zone when the stress is applied, the acceleration of the micromechanical structure, and the angular velocity of the micromechanical structure.

[0009] Optionally, the target parameter is the stress on the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises:

[0010] The stress is calculated according to the following formula:

[0011]

[0012] in,

[0013] V Th =k B T / q;

[0014] Wherein, σ is the stress in the stress change zone, Pa; △I is the breakdown current change value of the effect junction when the stress change zone is stressed, A; I 0 is the initial breakdown current, A; α is the material parameter of the beam body related to the energy band gap, eV / Pa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the constant reverse voltage, V; n is the error coefficient; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0015] Optionally, the target parameter is the strain of the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises:

[0016] The strain is calculated according to the following formula:

[0017]

[0018] in,

[0019] V Th =k B T / q;

[0020] Wherein, ε is the strain of the stress change zone; △I is the change value of the breakdown current of the effect junction when the stress change zone is subjected to stress, A; I 0 is the initial breakdown current, A; α is the material parameter of the beam body related to the energy band gap, eV / Pa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the constant reverse voltage, V; n is the error coefficient; E is the Young's modulus, GPa; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0021] Optionally, the target parameter is the acceleration of the micromechanical structure; and the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises:

[0022] The acceleration is calculated according to the following formula:

[0023]

[0024] in,

[0025] V Th =k B T / q;

[0026] In the formula, a in is the acceleration to which the micromechanical structure is subjected, m / s 2 ; △I is the breakdown current change value of the effect junction when the stress change zone is subjected to stress, 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 constant reverse voltage, V; I 0 is the initial breakdown current, 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 micromechanical structure, kg; K eff is the equivalent stiffness of the micromechanical structure, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0027] Optionally, a constant reverse current is applied to the effect junction to put the effect junction into a breakdown state, the initial breakdown electrical parameters include an initial breakdown voltage, the breakdown electrical parameter change value includes a breakdown voltage change value, and the target parameters include at least the stress applied to the stress change zone, the strain applied to the stress change zone when the stress change zone is subjected to stress, the acceleration of the micromechanical structure, and the angular velocity of the micromechanical structure.

[0028] Optionally, the target parameter is the stress on the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises:

[0029] The stress is calculated according to the following formula:

[0030]

[0031] Where, △V BR is the breakdown voltage change value of the effect junction when the stress change region is subjected to stress, V; V BR0is the initial breakdown voltage, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; 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 in which the beam is located, K; σ is the stress in the stress change zone, Pa.

[0032] Optionally, the target parameter is the strain of the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises:

[0033] The strain is calculated according to the following formula:

[0034]

[0035] Where, ε is the strain in the stress change zone; △V BR is the breakdown voltage change value of the effect junction when the stress change region is subjected to stress, V; V BR0 is the initial breakdown voltage, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; 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 in which the beam is located, K; E is the Young's modulus, GPa.

[0036] Optionally, the target parameter is the acceleration of the micromechanical structure; and the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises:

[0037] The acceleration is calculated according to the following formula:

[0038]

[0039] In the formula, a in is the acceleration to which the micromechanical structure is subjected, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the stress change zone is subjected to stress, 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, 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 effis the equivalent movable mass of the micromechanical structure, kg; K eff is the equivalent stiffness of the micromechanical structure, N / m.

[0040] The present invention also provides a micromechanical structure that can be applied to the above parameter measurement method. The micromechanical structure includes a beam body, and a stress change region of the beam body is provided with an effect junction with a piezoresistive-avalanche effect.

[0041] The parameter measurement method 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, and at the same time comprehensively consider the relationship between the target action, the target parameter, 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 corresponding target parameter, thereby greatly improving the measurement sensitivity of the target parameter of the micromechanical structure; at the same time, the micromechanical mechanism adopted by the method only needs to set a simple effect junction in the stress change zone of its beam body to execute the parameter measurement method, and has a simple structure, a small size, low manufacturing difficulty and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] 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.

[0043] Figure 1 A schematic diagram of a micromechanical structure provided by an embodiment of the present invention;

[0044] Figure 2 The figure is a flow chart of a parameter measurement method based on piezoresistive-avalanche effect according to an embodiment of the present invention.

[0045] Description of reference numerals:

[0046] 100- beam body; 200- effector junction; 310- first electrode; 320- second electrode; 400- mass block; 500- anchor region. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] 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.

[0050] This embodiment provides a parameter measurement method and a micromechanical structure based on piezoresistive-avalanche effect, such as Figure 1 and Figure 2 The micromechanical structure can be applied to the above parameter measurement method, specifically, Figure 1 A schematic diagram of a micromechanical structure provided by an embodiment of the present invention, such as Figure 1 As shown, the micromechanical structure includes a beam body 100, and a PN junction with a piezoresistive-avalanche effect is provided in the stress change region of the beam body 100 as an effect junction 200. Taking the PN junction as the effect junction 200 for example, when in use, a reverse bias power supply is connected to both ends of the PN junction and the reverse voltage applied to the PN junction is adjusted to make the PN junction enter a breakdown state. In the breakdown state, the PN junction has a piezoresistive-avalanche effect. Specifically, the stress in the stress change region can cause the electron mobility and the energy band gap at the PN junction to change, thereby causing a significant change in the breakdown voltage / breakdown current, and correspondingly making the breakdown current / breakdown voltage of the PN junction highly sensitive to the mechanical stress in the stress change region.

[0051] Figure 2 FIG. 1 is a flow chart of a parameter measurement method based on piezoresistive-avalanche effect according to an embodiment of the present invention. Figure 2 As shown, the parameter measurement method includes:

[0052] S202 regulates the effector junction 200 to enter a breakdown state.

[0053] Taking the PN junction as the effect junction 200 as an example, as pointed out above, a reverse bias power supply can be connected to both ends of the PN junction and the reverse voltage applied to the PN junction can be adjusted to make the PN junction enter a breakdown state. In the breakdown state, the PN junction has a piezoresistive-avalanche effect.

[0054] S204 obtains structural related parameters of the micromechanical structure, initial breakdown electrical parameters of the effect junction, and breakdown electrical parameter change values ​​of the effect junction when the stress change region is subjected to stress.

[0055] S206 calculates the target parameters according to the structure-related parameters, the initial breakdown electrical parameters and the breakdown electrical parameter change values.

[0056] When the micromechanical structure performs a target action, the target action can be characterized by a target parameter. For example, when the target action is a compressive action, stress can be used as a target parameter to characterize the degree of compression of the compressive action, or strain can be used as a target parameter to characterize the deformation performance of the micromechanical structure. For example, when the target action is a rotational motion, angular velocity can be used as a target parameter to characterize the speed of the rotational motion. Or when the target action is an accelerated motion, acceleration can be used as a target parameter to characterize the speed of the accelerated motion, and so on.

[0057] The beam body 100 adapts to the target action of the micromechanical structure and forms corresponding stress in its stress change area. Different structures of the micromechanical structure will cause the magnitude of the stress in the stress change area to be different. Accordingly, the structural related parameters of the micromechanical structure can associate the target action with the stress magnitude in the stress change area.

[0058] The breakdown voltage / breakdown current of the PN junction as a breakdown electrical parameter can adapt to the stress in the stress change zone to produce a piezoresistive-avalanche effect and produce a large change, and the stress change in the stress change zone is amplified accordingly to improve the measurement sensitivity; wherein, when the micromechanical structure does not undergo a target action, that is, when the stress change zone is not subjected to stress, the breakdown electrical parameter of the PN junction is used as the initial breakdown electrical parameter; when the micromechanical structure performs a target action, that is, when the stress change zone is subjected to stress, the breakdown electrical parameter of the PN junction at this time undergoes a large change and the change value compared to the initial breakdown electrical parameter is the breakdown electrical parameter change value, and the stress magnitude of the stress change zone can be amplified and characterized by the initial breakdown electrical parameter and the breakdown electrical parameter change value with a large change amplitude. Specifically, a detection module can be connected at both ends of the PN junction to detect its breakdown electrical parameter in real time.

[0059] The parameter measurement method 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 200, and at the same time comprehensively consider the relationship between the target action, target parameters, 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 corresponding target parameters, thereby greatly improving the measurement sensitivity of the target parameters of the micromechanical structure; at the same time, the micromechanical mechanism adopted in this method only needs to set a simple effect junction in the stress change zone of its beam body to execute the parameter measurement method, and has a simple structure, small size, low manufacturing difficulty and low cost.

[0060] Specifically, in this embodiment, a constant reverse voltage can be applied to the effect junction to make the effect junction enter a breakdown state, the initial breakdown electrical parameter includes an initial breakdown current, the breakdown electrical parameter change value includes a breakdown current change value, and the target parameter includes at least the stress on the stress change zone, the strain when the stress change zone is stressed, the acceleration of the micromechanical structure, and the angular velocity of the micromechanical structure. A reverse bias voltage source with a constant voltage is connected to both ends of the effect junction to apply a constant breakdown voltage to the effect junction to make it enter a breakdown state. When the micromechanical structure performs a target action, the stress in the stress change zone of the beam body changes. The effect junction will produce a piezoresistive-avalanche effect under the stress, causing the breakdown current to change significantly, and there is an approximately linear relationship between the breakdown current and the stress. By detecting the initial breakdown current of the PN junction when the micromechanical structure does not perform the target action and the breakdown current change value of the PN junction when the micromechanical structure performs the target action, the stress in the stress change zone can be linearly amplified, and the measurement sensitivity of the target parameter can be correspondingly improved.

[0061] Specifically, the target action can be the compressive action of the micromechanical structure, and the corresponding target parameter can be the stress and strain of the stress change zone; the target action can be the acceleration movement of the micromechanical structure, and the corresponding target parameter can be the acceleration of the micromechanical structure; the target action can also be the rotational movement of the micromechanical structure, and the corresponding target parameter can be the acceleration of the micromechanical structure. Then, the stress, strain, acceleration and angular velocity of the micromechanical structure can be obtained through the structural related parameters, initial breakdown current and breakdown current change value of the micromechanical structure.

[0062] Specifically, in this embodiment, when the target action is a force action of the micromechanical structure and the target parameter is the stress in the stress change zone, the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameters and the breakdown electrical parameter change value includes: calculating the stress according to the following formula:

[0063]

[0064] Thus, we can conclude that:

[0065]

[0066] in,

[0067] V Th =k B T / q;

[0068] Where, σ is the stress in the stress change zone, Pa; △I is the change in the breakdown current of the effect junction when the stress change zone is stressed, A; I 0 is the initial breakdown current, A; α is the material parameter related to the beam body and the energy band gap, eV / Pa; when the beam body is made of silicon material, α=-1.5×10 -11 eV / Pa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the constant reverse voltage, V; n is the error coefficient; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0069] Wherein, σ is the target parameter; △I is the breakdown current change value, i.e., the breakdown electrical parameter change value; I 0 is the initial breakdown current, i.e. the initial breakdown electrical parameter; α, V Th 、V BR0 , n, q, k B , T are 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 stress σ can be obtained to characterize the pressure of the micromechanical structure under pressure.

[0070] When the target action is a force action of the micromechanical structure, the beam body is an elastic beam, and the target parameter can also be the strain of the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameters and the breakdown electrical parameter change value includes: calculating the strain according to the following formula:

[0071]

[0072] Thus, we can conclude that:

[0073]

[0074] in,

[0075] V Th =k B T / q;

[0076] Where ε is the strain in the stress change zone; △I is the change in breakdown current of the effect junction when the stress change zone is stressed, A; I0 is the initial breakdown current, A; α is the material parameter related to the beam body and the energy band gap, eV / Pa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the constant reverse voltage, V; n is the error coefficient; E is the Young's modulus, GPa; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K; σ is the stress in the stress change zone, Pa.

[0077] Among them, ε is the target parameter; △I is the breakdown current change value, that is, the breakdown electrical parameter change value; I 0 is the initial breakdown current, i.e. the initial breakdown electrical parameter; α, V Th 、V BR0 , n, q, k B , T, and E are structural parameters related to the micromechanical structure itself, the connection circuit structure, the environment, etc.; the strain in the stress change zone is calculated based on Young's modulus and the stress in the stress change zone of the beam to characterize the deformation performance of the beam and the micromechanical structure.

[0078] In this embodiment, when the target action is the acceleration motion of the micromechanical structure and the target parameter is the acceleration of the micromechanical structure, the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value includes: calculating the acceleration according to the following formula:

[0079]

[0080] Thus, we can conclude that:

[0081]

[0082] in,

[0083] V Th =k B T / q;

[0084] In the formula, a in is the acceleration of the micromechanical structure, m / s 2 ; △I is the breakdown current change value of the effect junction when the stress change area is subjected to stress, 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 a constant reverse voltage, V; I 0 is the initial breakdown current, A; n is the error coefficient; h is the thickness of the beam, m; L is the length of the beam, m; M effis the equivalent movable mass of the micromechanical structure, kg; K eff is the equivalent stiffness of the micromechanical structure, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

[0085] Among them, a in is the target parameter; △I is the breakdown current change value, i.e. the breakdown electrical parameter change value; I 0 is the initial breakdown current, i.e. the initial breakdown electrical parameters; 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 obtained in , thereby characterizing the speed of the acceleration motion of the micromechanical structure.

[0086] In addition to connecting a constant reverse bias voltage source to the effect junction to break it down as mentioned above, a reverse bias current source with a constant current can also be connected to both ends of the effect junction to apply a constant reverse current to the effect junction to put the effect junction into a breakdown state. Accordingly, the initial breakdown electrical parameters include the initial breakdown voltage, the breakdown electrical parameter change value includes the breakdown voltage change value, and the target parameters include at least the stress applied to the stress change zone, the strain applied to the stress change zone when the stress is applied, the acceleration of the micromechanical structure, and the angular velocity of the micromechanical structure.

[0087] A reverse bias current source with a constant current is connected to both ends of the effect junction to apply a constant breakdown current to the effect junction to put it into a breakdown state. When the micromechanical structure performs a target action, the stress in the stress change zone of the beam body changes. Under the action of this stress, the effect junction will produce a piezoresistive-avalanche effect, causing the breakdown voltage to change significantly, and there is an approximately linear relationship between the breakdown voltage and the stress. By detecting the initial breakdown voltage of the PN junction when the micromechanical structure does not perform the target action and the change in the breakdown voltage of the PN junction when the micromechanical structure performs the target action, the stress in the stress change zone can be linearly amplified, thereby correspondingly improving the measurement sensitivity of the target parameter.

[0088] Specifically, the target action may be a compressive action of the micromechanical structure, and the target parameter may be the stress in the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value includes: calculating the stress according to the following formula:

[0089]

[0090] Thus, we can conclude that:

[0091]

[0092] Where, △V BR is the breakdown voltage change value of the junction when the stress change area is subjected to stress, V; V BR0 is the initial breakdown voltage, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; 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 in which the beam is located, K; σ is the stress in the stress change zone, Pa.

[0093] Among them, σ is the target parameter; △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 are 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 stress σ can be obtained to characterize the pressure of the micromechanical structure under pressure.

[0094] When the target action is a force-bearing action of the micromechanical structure, the beam body is an elastic beam, and the target parameter can also be the strain of the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameters and the breakdown electrical parameter change value includes: calculating the strain according to the following formula:

[0095]

[0096] Thus, we can conclude that:

[0097]

[0098] Where ε is the strain in the stress change zone; △V BR is the breakdown voltage change value of the junction when the stress change area is subjected to stress, V; V BR0 is the initial breakdown voltage, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; 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 in which the beam is located, K; σ is the stress in the stress change zone, Pa; E is Young's modulus, GPa.

[0099] Among them, ε is the target parameter; △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, Eg0 , k B , T, and E are structural parameters related to the micromechanical structure itself, the connection circuit structure, the environment, etc.; the strain in the stress change zone is calculated based on Young's modulus and the stress in the stress change zone of the beam to characterize the deformation performance of the beam and the micromechanical structure.

[0100] In this embodiment, the target action is the acceleration motion of the micromechanical structure, and the target parameter is the acceleration of the micromechanical structure; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value includes:

[0101] Calculate the acceleration using the following formula:

[0102]

[0103] In the formula, a in is the acceleration of the micromechanical structure, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the stress change zone is subjected to stress, 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, 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 micromechanical structure, kg; K eff is the equivalent stiffness of the micromechanical structure, N / m.

[0104] Among them, a in is the target parameter; △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 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 obtained in , thereby characterizing the speed of the acceleration motion of the micromechanical structure.

[0105] Specifically, the beam body 100 can be a cantilever beam or a fixed beam with both ends fixed, and a mass block 400 can be set at one end or the middle of the beam body 100; or the beam body 100 can also be a membrane beam with a smaller thickness; a PN junction can be formed on the beam body 100 through a doping process as an effect junction 200 with a piezoresistive-avalanche effect, and preferably, when the beam body 100 is a cantilever beam, the connection between it and the anchor area 500 can be used as a stress change area to set a PN junction.

[0106] Optionally, the first electrode 310 and the second electrode 320 can be fixedly connected at both ends of the PN junction respectively, and the reverse bias power supply and the control module can realize circuit connection with the PN junction by connecting with the first electrode 310 and the second electrode 320, thereby improving the connection convenience and the convenience of use of the micromechanical structure.

[0107] Of course, in addition to the above-mentioned PN junction, other structures with piezoresistive-avalanche effect that can amplify the stress in the stress change area can be used as the effect junction.

[0108] 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 parameter measurement method based on piezoresistive-avalanche effect, characterized in that: The invention is applied to the measurement of target parameters in a micromechanical structure, wherein the micromechanical structure comprises a beam body (100), and an effect junction (200) having a piezoresistance-avalanche effect is provided in a stress change region of the beam body (100); the method comprises: regulating the effector junction (200) to enter a breakdown state; Acquiring structural related parameters of the micromechanical structure, initial breakdown electrical parameters of the effect junction (200), and breakdown electrical parameter change values ​​of the effect junction (200) when the stress change region is subjected to stress; The target parameter is calculated according to the structure-related parameter, the initial breakdown electrical parameter and the breakdown electrical parameter change value.

2. The parameter measurement method according to claim 1, characterized in that: A constant reverse voltage is applied to the effect junction (200) to cause the effect junction (200) to enter a breakdown state, the initial breakdown electrical parameter includes an initial breakdown current, the breakdown electrical parameter change value includes a breakdown current change value, and the target parameter includes at least the stress applied to the stress change region, the strain applied to the stress change region when the stress is applied, the acceleration of the micromechanical structure, and the angular velocity of the micromechanical structure.

3. The parameter measurement method according to claim 2, characterized in that: The target parameter is the stress on the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises: The stress is calculated according to the following formula: in, V Th =k B T / q; Wherein, σ is the stress in the stress change zone, Pa; △I is the breakdown current change value of the effect junction when the stress change zone is stressed, A; I0 is the initial breakdown current, A; α is the material parameter related to the beam body and the energy band gap, eV / Pa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the constant reverse voltage, V; n is the error coefficient; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

4. The parameter measurement method according to claim 2, characterized in that: The target parameter is the strain of the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises: The strain is calculated according to the following formula: in, V Th =k B T / q; Wherein, ε is the strain of the stress change zone; △I is the breakdown current change value of the effect junction when the stress change zone is stressed, A; I0 is the initial breakdown current, A; α is the material parameter related to the beam body and the energy band gap, eV / Pa; q is the electron charge constant, 1.602×10 -19 C; V Th is the thermal voltage, V; V BR0 is the constant reverse voltage, V; n is the error coefficient; E is the Young's modulus, GPa; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

5. The parameter measurement method according to claim 2, characterized in that: The target parameter is the acceleration of the micromechanical structure; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises: The acceleration is calculated according to the following formula: in, V Th =k B T / q; In the formula, a in is the acceleration to which the micromechanical structure is subjected, m / s 2 ; △I is the breakdown current change value of the effect junction when the stress change zone is subjected to stress, 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 constant reverse voltage, V; I0 is the initial breakdown current, 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 micromechanical structure, kg; K eff is the equivalent stiffness of the micromechanical structure, N / m; k B is the Boltzmann constant; T is the absolute temperature of the environment in which the beam is located, K.

6. The parameter measurement method according to claim 1, characterized in that: A constant reverse current is applied to the effect junction to make the effect junction enter a breakdown state, the initial breakdown electrical parameter includes an initial breakdown voltage, the breakdown electrical parameter change value includes a breakdown voltage change value, and the target parameter includes at least the stress applied to the stress change zone, the strain applied to the stress change zone when the stress is applied, the acceleration of the micromechanical structure, and the angular velocity of the micromechanical structure.

7. The parameter measurement method according to claim 6, characterized in that: The target parameter is the stress on the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises: The stress is calculated according to the following formula: Where, △V BR is the breakdown voltage change value of the effect junction when the stress change region is subjected to stress, V; V BR0 is the initial breakdown voltage, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; 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 in which the beam is located, K; σ is the stress in the stress change zone, Pa.

8. The parameter measurement method according to claim 6, characterized in that: The target parameter is the strain of the stress change zone; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises: The strain is calculated according to the following formula: Where, ε is the strain in the stress change zone; △V BR is the breakdown voltage change value of the effect junction when the stress change region is subjected to stress, V; V BR0 is the initial breakdown voltage, V; α is the material parameter related to the beam body and the energy band gap, eV / Pa; 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 in which the beam is located, K; E is the Young's modulus, GPa.

9. The parameter measurement method according to claim 6, characterized in that: The target parameter is the acceleration of the micromechanical structure; the step of calculating the target parameter according to the structure-related parameters, the initial breakdown electrical parameter and the breakdown electrical parameter change value comprises: The acceleration is calculated according to the following formula: In the formula, a in is the acceleration to which the micromechanical structure is subjected, m / s 2 ; △V BR is the breakdown voltage change value of the effect junction when the stress change zone is subjected to stress, 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, 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 micromechanical structure, kg; K eff is the equivalent stiffness of the micromechanical structure, N / m.

10. A micromechanical structure, characterized in that: The parameter measurement method can be applied to any one of claims 1 to 9, wherein the micromechanical structure comprises a beam body, and a stress change region of the beam body is provided with an effect junction having a piezoresistive-avalanche effect.

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