MEMS device multi-physical field simulation method based on Monte Carlo-finite element

Abstract

The invention discloses a Monte Carlo-finite element-based MEMS device multi-physical field simulation method, which is used for simulating the performance change of an MEMS device in an electron irradiation environment, performing Monte Carlo simulation on energy deposition in a high-energy particle irradiation process through Geant4, exporting energy deposition data as a heat source power density, and then importing the heat source power density into a COMSOL (Computational Metal Oxide Semiconductor Logic) so as to simulate the performance change of the MEMS device. A multi-physics field model is constructed in COMSOL, electric-thermal-mechanical multi-physics field coupling analysis is carried out, and the performance change of the MEMS device in a complex environment is comprehensively evaluated. According to the method disclosed by the invention, aiming at the comprehensive effect of interaction of multiple physical fields on the material, the structure and the function of the device, and considering the electric, thermal and force coupling influence of a radiation field on the device, a more accurate simulation analysis means is provided, so that the design of the MEMS device is optimized, and the reliability of the MEMS device under extreme conditions is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-electromechanical systems (MEMS), and in particular to a multi-physical field simulation method of a MEMS device based on Monte Carlo-finite element. Background Art

[0002] Micro-electromechanical systems (MEMS), as an advanced technology that integrates micro sensors, actuators and signal processing functions, have been widely used in a variety of fields such as aerospace, automotive electronics, biomedicine and consumer electronics. As the functions of MEMS devices become increasingly complex, their working environment has gradually expanded from traditional normal temperature and pressure to extreme high temperature, strong radiation and complex mechanical stress environments. These complex conditions place higher demands on the performance, reliability and service life of MEMS devices, especially in harsh scenarios such as aerospace, nuclear power plants and high-energy physics experiments, where the stability of the device is crucial.

[0003] MEMS devices are often affected by the coupling of multiple physical fields such as electric field, thermal field, force field and radiation field. The interaction of these physical fields will significantly change the mechanical, electrical and thermal properties of MEMS devices, thereby affecting the overall performance of the devices. Most of the existing simulation technologies for MEMS devices are concentrated in single or dual physical fields such as electricity, mechanics and heat, while the coupling analysis of the radiation field and other physical fields in high-radiation environments is relatively weak, resulting in the inability to effectively predict the performance degradation and failure of devices in certain application scenarios (such as aerospace and nuclear industry). At the same time, existing simulation software usually simulates specific physical fields. For example, although the multi-physics simulation software COMSOL has the function of coupling electric, thermal and force fields, it cannot directly simulate complex radiation fields; and Geant4, as a professional software for radiation simulation, cannot directly perform coupling analysis of electric, thermal and force fields.

[0004] Therefore, most traditional simulation methods can only analyze a single physical field, and it is difficult to comprehensively evaluate the comprehensive impact of multi-physical field coupling on MEMS devices. In addition, the coupling analysis between the irradiation field and other physical fields is insufficient, and there is a lack of a unified joint simulation platform, which increases the difficulty of MEMS device design optimization.

[0005] As an effective numerical simulation tool, finite element analysis (FEA) has been widely used in the performance analysis and optimization of MEMS devices. However, the current finite element simulation method for MEMS devices under the conditions of electrical, thermal, mechanical and radiation multi-physics coupling is still imperfect, and it is difficult to accurately simulate the interaction of physical fields in complex environments. Therefore, a finite element simulation method based on multi-physics coupling is urgently needed to improve the performance prediction and optimization capabilities of MEMS devices under extreme conditions. Summary of the invention

[0006] The problem to be solved by the present invention is to provide a multi-physical field simulation method for MEMS devices based on Monte Carlo-Finite Element, by using Geant4 to accurately model and simulate the irradiation field, and combining COMSOL to perform coupled simulation of physical fields such as electricity, heat, and force, accurately and comprehensively evaluate the performance changes of MEMS devices in complex environments, and improve the reliability of MEMS devices under extreme conditions.

[0007] The present invention adopts the following technical solution: a multi-physical field simulation method of MEMS device based on Monte Carlo-Finite Element, comprising the following steps:

[0008] S1. Definition of electron irradiation field: Define the electron irradiation environment in Geant4 and simulate the behavior of radiation particles in the electron irradiation environment;

[0009] S2. Create and import geometric models: Create the geometric model of the MEMS device and perform meshing;

[0010] S3. Material definition and physical process configuration: Define the types and physical properties of materials used in MEMS devices in Geant4, select the corresponding physical process model, and simulate the characteristics and behaviors of radiation particles in the material;

[0011] S4, Monte Carlo simulation and energy deposition calculation: Use the Monte Carlo method of Geant4 to perform large-scale particle incident simulation and calculate the energy deposition of radiation particles in MEMS devices;

[0012] S5. Data export and processing: The energy deposition data obtained by Geant4 simulation is exported, converted into power density, and input into COMSOL as a heat source;

[0013] S6. Multi-physics coupling analysis: Construct a multi-physics model in COMSOL to perform electrical-thermal-mechanical coupling analysis.

[0014] Preferably, step S1 electron irradiation field definition: define the electron irradiation environment in Geant4, specifically including the type of radiation source (such as electron irradiation), energy range (tens of keV to several MeV) and key parameters such as incident direction and position. According to the application scenario, select the corresponding electron energy for simulation. By configuring the physical model in Geant4, the trajectory of the radiation particles and their interaction with the material are accurately simulated to ensure that the radiation conditions are consistent with the actual application environment.

[0015] Preferably, step S2 geometric model creation and import: according to the actual size of the MEMS model, a geometric model is created by the three-dimensional modeling software SolidWorks, and meshing is performed by FreeCAD software to generate an STL file for Geant4 to perform geometric analysis, so as to achieve accurate coupling of the geometric model and the physical process.

[0016] Preferably, step S3 material definition and physical process configuration: define the types of materials used in MEMS devices and their related physical properties (such as atomic number, molar mass, etc.), and select the corresponding physical process model in Geant4 to simulate the energy deposition, radiation energy transfer and material damage of radiation particles in the material, to ensure that the physical model accurately reflects the material characteristics and behaviors in the actual environment.

[0017] Preferably, step S4 Monte Carlo simulation and energy deposition calculation: simulate the large-scale particle incident process through the Monte Carlo method of Geant4, count the energy deposition of the radiation particles in the MEMS device material, and calculate the irradiation dose and energy deposition distribution of different parts. After the simulation is completed, the energy deposition distribution data is exported in TXT format for subsequent analysis of the key parameters of the MEMS device under different irradiation conditions.

[0018] Preferably, step S5 data export and processing: the energy deposition data obtained by Geant4 simulation is exported, converted into power density by the following formula, and input into COMSOL as a heat source to perform electrical-thermal-mechanical coupling analysis.

[0019]

[0020] Where: Q represents the power density of the heat source per unit volume, η is the efficiency of converting energy deposition into thermal energy in the material, E dep It represents the energy deposition per unit volume calculated in Geant4, Δt is the time step used in the energy deposition process, and V is the unit volume.

[0021] Preferably, step S6 constructs a multi-physics model in COMSOL, including the following sub-steps:

[0022] S6.1.1. Importing geometric models and defining materials: Use the COMSOL Livelink for SolidWorks module to import the MEMS device geometric model created in SolidWorks into COMSOL, define the thermal, electrical, and mechanical properties of the material, associate the material properties with the temperature and the particle energy during irradiation, and perform appropriate meshing to ensure that the accuracy of the geometric model can support subsequent multi-physics simulations.

[0023] S6.1.2. Heat source input and temperature field calculation: In the global definition of COMSOL, add an interpolation function, import the processed TXT file (heat source power density distributed in time and space) into COMSOL as the heat source input of the solid heat transfer module, and calculate the temperature distribution and thermal stress inside the device as well as the corresponding thermal-mechanical coupling effect;

[0024] S6.1.3. Physical field selection and boundary condition setting: Select the solid heat transfer module, electrostatic module and solid mechanics module in COMSOL, set the relevant boundary conditions and initial conditions to ensure that the simulation environment is consistent with the actual operating conditions; construct a multi-physics field model to simulate the electrical, thermal and mechanical coupling effects of MEMS devices in an irradiation environment through the multi-physics field model.

[0025] Preferably, step S6 performs multi-physical field coupling analysis: by coupling the electric field, force field and thermal field in COMSOL, the influence of temperature change on the structural stress, electrical characteristics and mechanical properties of the MEMS device is analyzed as follows:

[0026] S6.2.1. Calculate the temperature field change under the action of current by coupling the Joule heating effect caused by current density with the heat conduction equation;

[0027] S6.2.2. Simulate thermal expansion stress and deformation caused by temperature change by coupling temperature field with mechanical field.

[0028] S6.2.3. Based on the piezoelectric effect or electric field force, the stress and deformation induced by the electric field can be simulated by coupling the electrostatic field with the solid mechanics equations;

[0029] S6.2.4. Through the joint solution of multiple physical fields, the fully coupled simulation of electrical, thermal and force fields is realized to obtain the temperature field, stress field and electrical performance change data of MEMS devices in the electron irradiation environment;

[0030] S6.2.5. Analyze the impact of temperature changes on the structural stress, electrical characteristics, and mechanical properties of MEMS devices to provide data support for device optimization design and reliability assessment.

[0031] The technical solution of the present invention also provides: an electronic device, comprising:

[0032] one or more processors;

[0033] a storage device having one or more programs stored thereon;

[0034] When the one or more programs are executed by the one or more processors, the one or more processors implement any of the above-mentioned Monte Carlo-finite element-based multi-physics field simulation methods for MEMS devices.

[0035] The technical solution of the present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in any of the above-mentioned Monte Carlo-finite element-based MEMS device multi-physics field simulation methods are implemented.

[0036] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0037] 1. Accurate analysis of multi-physics coupling: The multi-physics simulation method of MEMS devices in the present invention can effectively analyze the performance changes of MEMS devices in electron irradiation environments, especially the impact of energy deposition on device temperature, stress and electrical characteristics. Through the precise irradiation simulation of Geant4 and the multi-physics coupling analysis of COMSOL, we can fully understand the multiple physical effects of electron irradiation on devices.

[0038] 2. Improve the reliability prediction accuracy: The multi-physics field simulation method of MEMS devices of the present invention can more accurately predict the reliability of MEMS devices in complex radiation environments through comprehensive analysis of coupled thermal fields, electric fields and force fields, making up for the shortcomings of traditional single-field simulation and providing more representative results, especially in the prediction of device behavior under extreme conditions (such as high temperature and high-energy radiation environment).

[0039] 3. Design optimization support: The multi-physics field simulation method of MEMS devices of the present invention not only provides a more accurate simulation tool, but also provides a data basis for material selection, structural design and process improvement of MEMS devices, helping designers to optimize device performance and improve its reliability under extreme conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a flow chart of a multi-physics field simulation method for MEMS devices based on Monte Carlo-Finite Element;

[0041] Figure 2 The model conversion and import flow chart of the present invention;

[0042] Figure 3 This is a structural diagram of the Geant4 model of the present invention;

[0043] Figure 4 This is a visualization result diagram of the Geant4 model of the present invention;

[0044] Figure 5 This is a schematic diagram of the energy deposition TXT file output by Geant4 in an embodiment of the present invention;

[0045] Figure 6 This is a diagram of energy deposition space distribution after data processing in an embodiment of the present invention;

[0046] Figure 7It is the overall structure diagram of the model in COMSOL of the embodiment of the present invention;

[0047] Figure 8 It is a schematic diagram of the local mesh division results of the ADXL345 model according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the application is further elaborated in detail below in conjunction with the accompanying drawings. The described embodiments are only a part of the embodiments involved in the present invention. All non-innovative embodiments of other researchers in the field on this embodiment belong to the protection scope of the present invention. At the same time, for the step numbering in the embodiment of the present invention, it is only set for the convenience of explanation, and the order between the steps is not limited in any way. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0049] In one embodiment of the present invention, a multi-physics field simulation method for MEMS devices based on Monte Carlo-Finite Element is provided. Figure 1 As shown, the specific steps are as follows:

[0050] Operation steps in Geant4:

[0051] (1) Definition of electron irradiation field: Define the irradiation environment in Geant4 according to the target application scenario.

[0052] The model defined in this embodiment is the internal sensitive area of ​​the ADXL345 accelerometer. The irradiation environment is set to vacuum, and electrons with an energy of 1 MeV are used for vertical irradiation at a distance of 1 m from the center of the device. By configuring the physical model in Geant4, the behavior of radiation particles in this environment is accurately simulated to ensure that the simulation conditions are consistent with the actual application environment.

[0053] (2) Geometry model creation and import

[0054] like Figure 2 As shown in the figure, according to the actual size of the ADXL345 device model, the geometric model of the MEMS device is created through the 3D modeling software SolidWorks, and the model is exported as a STEP file; then the STEP file is imported through the FreeCAD software, and the mesh is divided to generate an STL file for Geant4 to perform geometric analysis.

[0055] The Geant4 model structure obtained in this embodiment is as follows: Figure 3 shown.

[0056] (3) Material definition and physical process configuration

[0057] In this embodiment, the material of the MEMS device is defined as single crystal silicon. The physical process model in Geant4 is selected and configured in Geant4. The macro file uses a rectangular shape for regional grid division, which is divided into 50×50×9 grid units in total, which is convenient for detailed statistics of the spatial distribution of energy deposition and subsequent data processing.

[0058] (4) Monte Carlo simulation and energy deposition calculation

[0059] The Monte Carlo method of Geant4 is used to simulate large-scale particle injection and to count the energy deposition of radiation particles in MEMS devices. Since Geant4 has high requirements for computing resources and large-scale particle injection will significantly increase the simulation time, the number of particles is reduced in this embodiment to optimize the computing efficiency. Figure 4 As shown, 10 4 The vertical incidence process of a particle.

[0060] After the simulation is completed, the spatial distribution data of energy deposition is output in TXT format, such as Figure 5 As shown, the energy deposition space distribution is Figure 6 as shown.

[0061] According to theoretical calculations, the actual number of incident particles should be 2×10 11 , since the number of particles in the simulation is reduced, the 4 The energy deposition data of the vertically incident particles is about 2×10 7 times, and obtained the energy deposition value consistent with the actual situation.

[0062] (5) Data export and processing

[0063] The energy deposition data obtained from the Geant4 simulation was exported in TXT format, converted into power density using the following formula, and imported into the multi-physics simulation software COMSOL as a heat source input for further electro-thermal-mechanical coupling analysis.

[0064]

[0065] Where: Q represents the power density of the heat source per unit volume, η is the efficiency of converting energy deposition in the material into thermal energy, E dep It represents the energy deposition per unit volume calculated in Geant4, Δt is the time step used in the energy deposition process, and V is the unit volume.

[0066] It should be noted that for electron-irradiated silicon materials, the efficiency of converting energy into heat is usually very high. When electrons interact with silicon materials, the kinetic energy of electrons is converted into heat energy mainly through ionization and excitation.

[0067] In the case of low-energy electrons (tens of keV to several MeV), most of the energy of electrons is deposited in the material as heat when they ionize and excite silicon atoms. The contribution of high-speed electrons to braking radiation (Brönstrahl radiation) in silicon is small, especially at low energies, and the proportion of this energy escaping is extremely low.

[0068] Therefore, in the range of tens of keV to several MeV, the efficiency of energy conversion into heat is usually close to 100%. When the electron energy exceeds 10MeV, although part of the energy may be deposited outside the material as the electron penetration depth increases, 90%-100% of the energy is still converted into heat energy in the material.

[0069] The steps in COMSOL are:

[0070] (1) Geometry model import and material definition:

[0071] Use COMSOL's Livelink for SolidWorks module to import the MEMS device geometry model created in SolidWorks into COMSOL, such as Figure 7 shown.

[0072] The thermal, electrical and mechanical properties of Si (density, thermal expansion coefficient, heat capacity at constant pressure, thermal conductivity, Young's modulus, Poisson's ratio and relative dielectric constant, etc.) are defined, and the material properties are related to temperature and particle energy during irradiation, so as to accurately simulate the influence of material properties caused by temperature rise during irradiation, so as to better carry out multi-physics field coupling; at the same time, appropriate meshing is carried out, considering that the spring is the main structure that undergoes deformation.

[0073] In this embodiment, the elastic support area is refined, and the local mesh diagram of the optimized micro-accelerometer solid model is as follows: Figure 8 As shown;

[0074] (2) Heat source input and temperature field calculation:

[0075] In COMSOL, first add relevant parameters in the global definition, as shown in Table 1;

[0076] Table 1 COMSOL parameter settings

[0077]

[0078] Next, add the interpolation function int1 and import the processed TXT file (spatiotemporal distribution of heat source power density) into COMSOL. The first three columns of the TXT file represent the spatial coordinate variables x, y, and z, whose units are um, and the fourth column is the value of the interpolation function int1, whose units are MeV.

[0079] At the same time, add variable Q1 in component 1, the expression is Its unit is W / m 3 , n represents the energy deposition conversion efficiency, t1 and V1 represent the duration and unit grid volume used in the energy deposition process, respectively, which makes it easy to load it into the solid heat transfer module as input to calculate the temperature distribution and thermal stress inside the device.

[0080] (3) Physical field selection and boundary condition setting:

[0081] The solid heat transfer module, electrostatic module and solid mechanics module in COMSOL were selected, and the boundary conditions and initial conditions were set.

[0082] First, in the Solid Heat Transfer Module, set the outer surface to a convective heat flux boundary condition with a heat transfer coefficient of 20 W / (m 2 ·K), the external temperature is set to dT+273.15[K], and the generalized heat source is set to Q1 for the whole.

[0083] Then, in the solid mechanics module, set fixed constraints on the anchor points and set body loads on the entire structure. The load forces on the X, Y, and Z axes are

[0084] F x =accelerationx×solid.rho×g const

[0085] F y =accelerationy×solid.rho×g const

[0086] F z =accelerationz×solid.rho×g const

[0087] Among them, accelerationx, accelerationy, accelerationz represent the acceleration along the XYZ axis, the unit is 1, solid.rho represents the density of the material, the unit is kg / m^3, g const Represents the gravitational acceleration constant, the value is 9.81m / s^2

[0088] Finally, in the electrostatic module, set the left fixed comb to 2.5mV, the right fixed comb to -2.5mV, and the mass block to floating potential. Ensure that the simulation environment matches the actual operating conditions.

[0089] These modules can be used to simulate the electrical, thermal and mechanical coupling effects of MEMS devices in electron irradiation environments.

[0090] (4) Multi-physics field coupling analysis:

[0091] Using the electric, force, and thermal field equations in COMSOL:

[0092] Heat transfer equation

[0093]

[0094] Mechanical equations

[0095]

[0096] Maxwell's equations

[0097]

[0098] Where ρ represents density in kg / m^3, C p Represents specific heat capacity in J / (kg*K), Indicates the rate of change of temperature over time, in K / s. represents the convection term, which represents the temperature gradient transport due to the velocity field u, Indicates the divergence of heat flux, describing the spatial distribution change of heat, with the unit of W / m^3, Q, Q ted They represent the internal heat source term and the heat source caused by the thermoelastic effect, respectively, and the unit is W / m^3, It represents the second-order time derivative of displacement, i.e. acceleration, in m / s^2. FS represents the stress tensor, which describes the stress distribution in the structure, in Pa. F v represents body force in N / m^3, μ represents magnetic permeability in H / m, E represents electric field strength in V / m, k0 represents wave number in 1 / m, ε r , ε0 represent the relative dielectric constant (dimensionless) and vacuum dielectric constant, respectively, with the unit of F / m, and ω represents the angular frequency, with the unit of rad / s.

[0099] Through mathematical equations, electrothermal coupling, electromechanical coupling, thermal coupling, and electrothermal-mechanical coupling, the influence of temperature changes on the structural stress, electrical characteristics, and mechanical properties of MEMS devices is further analyzed. Under electron irradiation conditions, the energy deposition of electrons in the thermal field is equivalent to a heat source, and its thermal effect can be used as a key input.

[0100] During the simulation process, the effect of radiation on material properties can be imported into the COMSOL material library through experimental measurement data and set as a function that changes with temperature and radiation energy. Through simulation, the performance change data of the device in a complex radiation environment, including temperature distribution, stress distribution, electrical performance changes, etc., can be obtained to provide data support for the device's optimal design and reliability evaluation.

[0101] (5) Device optimization design and reliability evaluation

[0102] Combined with the multi-physics simulation results, the effects of different materials, geometric structures and process designs on the performance of MEMS devices are analyzed, and the device design is optimized to improve its reliability and stability in high-energy electron irradiation environments. Through accurate simulation of energy deposition and its thermal conversion, the results of this embodiment can provide reliable data support for the long-term use and performance evaluation of MEMS devices.

[0103] In an embodiment of the present invention, an electronic device is also provided, including: one or more processors; a storage device on which one or more programs are stored; when the one or more programs are executed by the one or more processors, the one or more processors implement the multi-physics field simulation method of MEMS devices based on Monte Carlo-finite element described in any of the above embodiments.

[0104] In an embodiment of the present invention, a computer-readable storage medium is further provided, on which a computer program is stored. When the program is executed by a processor, the steps in any one of the multi-physics field simulation methods of MEMS devices based on Monte Carlo-FEM in the above embodiments are implemented.

[0105] In summary, the present invention provides a simulation method that can effectively combine Geant4 and COMSOL software to analyze the behavior of MEMS devices under the coupling conditions of multiple physical fields of electricity, heat, force, and radiation, thereby improving the design optimization efficiency and reliability prediction accuracy of the device.

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-physics field simulation method for MEMS devices based on Monte Carlo-Finite Element, characterized in that: The steps include: S1. Definition of electron irradiation field: Define the electron irradiation environment in Geant4 and simulate the behavior of radiation particles in the electron irradiation environment; S2. Create and import geometric models: Create the geometric model of the MEMS device and perform meshing; S3. Material definition and physical process configuration: Define the material types and physical properties used in MEMS devices in Geant4, select the corresponding physical process model, and simulate the characteristics and behaviors of radiation particles in the material; S4, Monte Carlo simulation and energy deposition calculation: Use the Monte Carlo method of Geant4 to perform large-scale particle incident simulation and calculate the energy deposition of radiation particles in MEMS devices; S5. Data export and processing: The energy deposition data obtained by Geant4 simulation is exported, converted into power density, and input into COMSOL as a heat source; S6. Multi-physics coupling analysis: Construct a multi-physics model in COMSOL to perform electrical-thermal-mechanical coupling analysis.

2. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 1 is characterized in that: Define the electron irradiation environment and parameters in Geant4, including: radiation source type, energy range, incident direction and position; select the corresponding electron energy for simulation according to the application scenario, and simulate the trajectory of radiation particles and the interaction between radiation particles and materials by configuring the physical model in Geant4.

3. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 1 is characterized in that: In step S2, according to the actual size of the MEMS device, a geometric model is created using the 3D modeling software SolidWorks, meshing is performed using the FreeCAD software, and an STL file is generated and imported into Geant4 for geometric analysis to couple the geometric model with the physical process.

4. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 1, characterized in that: In step S3, the physical properties include atomic number and molar mass; a physical process model corresponding to the material and physical properties used in the MEMS device is selected in Geant4 to simulate the energy deposition of radiation particles in the material, radiation energy transfer and material damage.

5. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 1, characterized in that: Through the Monte Carlo method of Geant4, the large-scale particle incident process is simulated, the energy deposition of radiation particles in the MEMS device material is statistically analyzed, the irradiation dose and energy deposition distribution of different parts are calculated, and the obtained energy deposition data is exported in TXT format.

6. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 5, characterized in that: In step S5, the energy deposition data obtained by Geant4 simulation is converted into power density, and the formula is as follows: Where: Q represents the power density of the heat source per unit volume, η represents the efficiency of converting energy deposition in the material into thermal energy, E dep It represents the energy deposition per unit volume calculated in Geant4, Δt is the time step used in the energy deposition process, and V is the unit volume.

7. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 6 is characterized in that: In step S6, a multi-physics model is constructed in COMSOL, including the following sub-steps: S6.1.

1. Importing geometric models and defining materials: Use the COMSOL Livelink for SolidWorks module to import the MEMS device geometry model created in SolidWorks into COMSOL, define the thermal, electrical, and mechanical properties of the material, relate the material properties to the temperature and the particle energy during irradiation, and perform appropriate meshing; S6.1.

2. Heat source input and temperature field calculation: In the global definition of COMSOL, add an interpolation function and input the obtained power density into COMSOL as the heat source input of the solid heat transfer module to perform temperature field calculation, calculate the temperature distribution and thermal stress inside the device and the corresponding thermal-mechanical coupling effect; S6.1.

3. Physical field selection and boundary condition setting: Select the solid heat transfer module, electrostatic module and solid mechanics module in COMSOL, set the relevant boundary conditions and initial conditions, build a multi-physics field model, and use the multi-physics field model to simulate the electrical, thermal and mechanical coupling effects of MEMS devices in an irradiation environment.

8. The multi-physics field simulation method of MEMS device based on Monte Carlo-Finite Element according to claim 7, characterized in that: In step S6, an electric-thermal-mechanical coupling analysis is performed, which is implemented in COMSOL by jointly solving the electric field, force field and thermal field equations as follows: S6.2.

1. Calculate the temperature field change under the action of current by coupling the Joule heating effect caused by current density with the heat conduction equation; S6.2.

2. Simulate thermal expansion stress and deformation caused by temperature change by coupling temperature field with mechanical field. S6.2.

3. Based on the piezoelectric effect or electric field force, the stress and deformation induced by the electric field can be simulated by coupling the electrostatic field with the solid mechanics equations; S6.2.

4. Through the joint solution of multiple physical fields, the fully coupled simulation of electrical, thermal and force fields is realized to obtain the temperature field, stress field and electrical performance change data of MEMS devices in the electron irradiation environment; S6.2.

5. Analyze the impact of temperature changes on the structural stress, electrical characteristics, and mechanical properties of MEMS devices to provide data support for device optimization design and reliability assessment.

9. An electronic device, characterized in that: include: one or more processors; a storage device having one or more programs stored thereon; When the one or more programs are executed by the one or more processors, the one or more processors implement the multi-physics field simulation method of MEMS devices based on Monte Carlo-FEM as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the steps in the multi-physical field simulation method of MEMS devices based on Monte Carlo-Finite Element described in any one of claims 1 to 8 are implemented.

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