Structural optimization design method of silicon-based resonant pressure sensor

Abstract

The invention discloses a structure optimization design method for a silicon-based resonant pressure sensor, and the method comprises the steps: obtaining the maximum stress variation delta sigma and the maximum deformation variation delta gamma of square units in an initial device layer after the i , i = 1... I square units are removed; obtaining an evolution parameter C of the ith square unit according to the maximum stress sigma 0 and the maximum deformation gamma 0 in all the square units in the initial device layer; based on the method, the device layer is evolved for three times, and after the device layer after the third structural evolution is obtained, the position and the basic shape of the resonant structure are determined, so that the final device layer of the resonant pressure sensor is determined, and the design of the resonant pressure sensor is completed. The three-time evolution of the device layer can solve the problem that the linearity of the sensor in a larger pressure range may be reduced along with the improvement of the sensitivity to cause the nonlinear change of frequency response, and has the characteristics of high sensitivity and low nonlinear error, and the measurement accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-mechanical electronic (MEMS) sensors, and in particular to a structural optimization design method for a silicon-based resonant pressure sensor. Background Art

[0002] Pressure sensors are widely used in industries such as industry, aerospace, energy and environmental monitoring. Compared with traditional piezoresistive and piezoelectric pressure sensors, resonant pressure sensors show unique advantages in measurement accuracy, stability and long-term reliability. Its working principle is based on detecting the change of the resonant frequency of the resonator, and indirectly reflecting the external pressure change through the frequency change, thereby achieving high-precision pressure measurement. This feature makes the resonant pressure sensor irreplaceable in applications requiring high precision and long-term stability. The advantages of resonant pressure sensors are not only reflected in their high-precision measurement capabilities, but also in the characteristics of their digital output signals, which makes the interface between the sensor and the computer or digital instrument easier. This high-precision and digital output characteristics make it widely used in high-demand occasions such as meteorological monitoring, atmospheric data acquisition, weapons and equipment monitoring and industrial process control. In addition, due to the high anti-interference ability, long service life and low maintenance cost of resonant pressure sensors, their demand in high-precision and high-reliability applications is increasing year by year.

[0003] However, despite the significant advantages of resonant pressure sensors in many applications, their development still faces some technical challenges, especially the balance between high sensitivity and low nonlinear error. The sensitivity of a resonant sensor is usually proportional to the response strength of its resonant frequency to pressure changes. In order to improve the sensitivity, it is usually necessary to design a more sensitive resonator structure or use high-performance materials. However, as the sensitivity increases, the linearity of the sensor over a larger pressure range may decrease, resulting in nonlinear changes in the frequency response, which in turn affects the accuracy of the measurement. Summary of the invention

[0004] The invention discloses a structural optimization design method of a silicon-based resonant pressure sensor to overcome the above technical problems.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A structural optimization design method for a silicon-based resonant pressure sensor comprises the following steps:

[0007] S1: Use finite element simulation software COMSOL to model the silicon substrate, isolation layer and initial device layer of the pressure-sensitive chip; divide the initial device layer into multiple square units of equal size; set constraints and boundary conditions of the pressure-sensitive chip;

[0008] S2: Apply a load perpendicular to the initial device layer to the pressure-sensitive chip to obtain the maximum stress σ0 and maximum deformation γ0 in all square units in the initial device layer;

[0009] S3: Obtain the maximum stress change Δσ and the maximum deformation change Δγ of the square unit in the initial device layer after removing the i-th, i=1…I square units, and then obtain the evolution parameter C of the i-th square unit according to the maximum stress σ0 and the maximum deformation γ0 of all the square units in the initial device layer; i represents the index of the square unit in the initial device layer; I represents the total number of square units in the initial device layer;

[0010] S4: performing a first structural evolution on the initial device layer according to the evolution parameter C of the i-th square unit to obtain a device layer after the first structural evolution;

[0011] S5: based on the device layer after the first structural evolution, re-execute S2-S4 to obtain the device layer after the second structural evolution;

[0012] S6: Based on the device layer after the second structural evolution, re-execute S2-S4 to obtain the device layer after the third structural evolution;

[0013] S7: According to the device layer after the third structural evolution, the position and basic shape of the resonant structure are determined to determine the final device layer of the resonant pressure sensor, thereby completing the design of the resonant pressure sensor.

[0014] Furthermore, the formula used to obtain the evolution parameter C of the i-th square unit is as follows:

[0015]

[0016] Wherein: C represents the evolution parameter; Δσ represents the change in the maximum stress of the square unit in the initial device layer after removing the i-th square unit; Δγ represents the change in the maximum deformation in the initial device layer after removing the i-th square unit; σ0 represents the maximum stress in all the square units in the initial device layer; γ0 represents the maximum deformation in all the square units in the initial device layer.

[0017] Furthermore, the method for obtaining the device layer after the first structural evolution is as follows:

[0018] If the evolution parameter C of the i-th square unit is not greater than 1, the i-th square unit is removed from the initial device layer;

[0019] Then all the square units whose evolution parameter C is greater than 1 constitute the device layer after the first structural evolution.

[0020] Further, the device layer of the final resonant pressure sensor includes: a resonant structure;

[0021] The resonant structure includes a central resonator and two edge resonators;

[0022] The two edge resonators are arranged on both sides of the central resonator;

[0023] The central resonator comprises a first resonant beam, two first silicon islands, two first resonator electrodes, two first excitation electrodes, and a plurality of first detection electrodes;

[0024] Two ends of the first resonant beam are respectively fixedly connected to the two first silicon islands;

[0025] The two first resonator electrodes are fixedly arranged on both sides of the first resonant beam;

[0026] The two first excitation electrodes are respectively connected to the two first resonator electrodes through an electric field;

[0027] A plurality of the first detection electrodes are evenly arranged on both sides of the first resonance beam, and are connected to the first resonator electrode through an electric field;

[0028] The first detection electrode is fixedly connected to the first metal electrode via a first signal lead-out beam;

[0029] The edge resonator comprises a second resonant beam, two second silicon islands, two second resonator electrodes, two second excitation electrodes, and a plurality of second detection electrodes;

[0030] Two ends of the second resonant beam are fixedly connected to the two second silicon islands respectively; two second resonant sub-electrodes are fixedly arranged on two sides of the second resonant beam;

[0031] The two second excitation electrodes are respectively connected to the two second resonator electrodes through an electric field;

[0032] A plurality of the second detection electrodes are evenly arranged on both sides of the second resonance beam, and are connected to the second resonance sub-electrode through an electric field;

[0033] The second detection electrode is fixedly connected to the second metal electrode via a second signal lead-out beam.

[0034] Furthermore, the pressure-sensitive chip is manufactured by using SOI technology.

[0035] Beneficial effects: The structural optimization design method of a silicon-based resonant pressure sensor of the present invention obtains the maximum stress change Δσ and the maximum deformation change Δγ of the square unit in the initial device layer after removing the i, i=1…I square units, and then obtains the evolution parameter C of the i-th square unit according to the maximum stress σ0 and the maximum deformation γ0 in all the square units in the initial device layer; based on this method, the device layer is evolved three times, and after obtaining the device layer after the third structural evolution, the position and basic shape of the resonant structure are determined to determine the final device layer of the resonant pressure sensor, and the design of the resonant pressure sensor is completed. The three-time evolution of the device layer of the present invention can solve the problem that the linearity of the sensor may decrease in a larger pressure range as the sensitivity increases, resulting in nonlinear changes in the frequency response. It has the characteristics of high sensitivity and low nonlinear error, and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 A flow chart of the structural optimization design method of the silicon-based resonant pressure sensor of the present invention;

[0038] Figure 2 is an overall schematic diagram of a MEMS pressure sensor in an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the layer structure of a MEMS pressure sensor device in an embodiment of the present invention;

[0040] Figure 4 for Figure 3 A magnified schematic diagram of the resonant structure of the MEMS pressure sensor at B in the middle;

[0041] Figure 5 for Figure 3 A cross-sectional view of the MEMS pressure sensor structure at center A;

[0042] Figure 6 is a flow chart of a method for designing a MEMS pressure sensor structure in an embodiment of the present invention;

[0043] Figure 7 FIG. 4 is a flow chart of the resonant structure evolution process of the MEMS pressure sensor device layer in an embodiment of the present invention.

[0044] Wherein: 1. silicon substrate; 2. silicon dioxide insulating isolation layer; 3. single crystal silicon device layer; 4. glass substrate; 5. central resonator; 51. first resonant beam; 52. first silicon island; 53. first resonant electrode; 54. first excitation electrode; 55. first detection electrode; 56. first metal electrode; 57. first signal lead-out beam; 6. edge resonator; 61. second resonant beam; 62. second silicon island; 63. second resonant electrode; 64. second excitation electrode; 65. second detection electrode; 66. second metal electrode; 67. second signal lead-out beam. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0046] This embodiment introduces a structural optimization design method for a silicon-based resonant pressure sensor. Figure 1 and Figure 6 As shown, the following steps are included:

[0047] S1: The silicon substrate 1, the isolation layer 2 and the initial device layer 3 of the pressure-sensitive chip processed by the SOI process are modeled using the finite element simulation software COMSOL; and the initial device layer 3 is divided into a plurality of square units of equal size; and the constraints and boundary conditions of the pressure-sensitive chip are set;

[0048] Specifically, the pressure-sensitive chip of the present embodiment includes a silicon substrate, a silicon dioxide insulating isolation layer, a single-crystal silicon device layer and a glass substrate 4 arranged in sequence from top to bottom; the pressure-sensitive chip of the MEMS pressure sensor of the present embodiment is formed by SOI process, a silicon dioxide insulating isolation layer 2 is covered on the silicon substrate 1, and then a thin single-crystal silicon device layer is formed on the insulating layer, and structures such as the resonator and the excitation electrode are all processed on the device layer by etching. The glass substrate is etched and the single-crystal silicon of the glass substrate and the device layer is anodically bonded to form a vacuum cavity, and finally the sensor silicon substrate is etched to form a pressure-sensitive diaphragm, the isolation layer is etched and Al metal is deposited to form a metal electrode, such as Figure 2 shown.

[0049] Specifically, this optimization method can be implemented through the finite element analysis software COMSOL, and its implementation steps are:

[0050] Specifically, the pressure sensor structure proposed in this embodiment is gradually optimized by an evolutionary method, which can maximize the sensitivity while ensuring linearity. The structural optimization design of the silicon-based resonant pressure sensor is realized by the finite element simulation software COMSOL. First, the silicon substrate 1, isolation layer 2 and initial device layer 3 of the pressure-sensitive chip processed based on the SOI process are modeled. When modeling, the shape of the device layer can be optimized arbitrarily, while the silicon substrate and isolation layer maintain a fixed structure. Thereafter, the initial device layer is divided into square units of equal size. For subsequent processing.

[0051] Specifically, the setting of constraints and boundary conditions in this embodiment adopts a solid mechanics model, wherein the edge of the pressure-sensitive chip is set as a fixed constraint to ensure that the initial device layer edge is fixed. After completing the boundary condition setting, the sensor model is meshed using the "sweep" method in the COMSOL software. Since this embodiment divides the device layer 3 of the pressure-sensitive chip into a plurality of square units of equal size, each square unit of the device layer can be meshed independently, thereby ensuring that in the subsequent steps, when any unit is removed, the mesh structure of other units will not be affected.

[0052] S2: Apply a load perpendicular to the initial device layer to the pressure-sensitive chip to obtain the maximum stress σ0 and maximum deformation γ0 in all square units in the initial device layer;

[0053] S3: Obtain the maximum stress change Δσ and the maximum deformation change Δγ of the square unit in the initial device layer after removing the i-th, i=1…I square units, and then obtain the evolution parameter C of the i-th square unit according to the maximum stress σ0 and the maximum deformation γ0 of all the square units in the initial device layer; i represents the index of the square unit in the initial device layer; I represents the total number of square units in the initial device layer;

[0054] Preferably, the formula used to obtain the evolution parameter C of the i-th square unit is as follows:

[0055]

[0056] Where: C represents the evolution parameter; Δσ represents the change in the maximum stress of the square unit in the initial device layer after the i-th square unit is removed; Δγ represents the change in the maximum deformation of the initial device layer after the i-th square unit is removed; σ0 represents the maximum stress of all square units in the initial device layer; γ0 represents the maximum deformation of all square units in the initial device layer;

[0057] S4: performing a first structural evolution on the initial device layer according to the evolution parameter C of the i-th square unit to obtain a device layer after the first structural evolution;

[0058] Preferably, the method for obtaining the device layer after the first structural evolution is as follows:

[0059] If the evolution parameter C of the i-th square unit is not greater than 1, the i-th square unit is removed from the initial device layer;

[0060] Then all the square units whose evolution parameter C is greater than 1 constitute the device layer after the first structural evolution.

[0061] S5: based on the device layer after the first structural evolution, re-execute S2-S4 to obtain the device layer after the second structural evolution;

[0062] S6: Based on the device layer after the second structural evolution, re-execute S2-S4 to obtain the device layer after the third structural evolution;

[0063] Specifically, in order to maximize the sensitivity while ensuring linearity, this embodiment sets the evolution parameter C to represent the ratio between the relative change in the maximum stress of the pressure-sensitive chip and the relative change in the maximum deformation after removing a certain unit, calculates the evolution parameter of each unit, and decides whether to retain the unit based on the value of the evolution parameter. Among them, removing a certain unit will increase the maximum stress σ and the maximum deformation γ of all square units in the device layer. Assume that after removing a certain unit, the maximum stress change of the device layer is Δσ, the maximum deformation change of the device layer is Δγ, and the initial maximum stress and maximum deformation of the device layer are σ0 and γ0 (i.e., the maximum stress and maximum strain of the device layer when the square unit is not removed). The optimization goal is to maximize the maximum stress σ and avoid the increase of the maximum deformation γ as much as possible, so the evolution parameter C is defined as: Analyzing the evolution parameter C of each unit and removing the units whose evolution parameter is not greater than 1 can achieve low deflection and high stress in the device layer, thereby improving the sensitivity of the pressure sensor without sacrificing linearity;

[0064] Specifically, after removing the square units whose evolution parameters are not greater than 1, the device layer after the first structural evolution is remodeled to complete the first structural evolution. Repeat the process of physical field setting and evolution parameter calculation, and perform three iterative optimizations. After the third evolution, determine the position and basic shape of the resonant structure to determine the final device layer of the resonant pressure sensor, including: selecting the area with the maximum stress to set the resonant beam, and arranging silicon islands, excitation electrodes, and detection electrodes on both sides. Finally, design the signal lead-out beam and metal electrode to complete the structural design of the device layer.

[0065] S7: According to the device layer after the third structural evolution, the position and basic shape of the resonant structure are determined to determine the final device layer of the resonant pressure sensor, thereby completing the design of the resonant pressure sensor.

[0066] Specifically, in this embodiment, after removing the square unit whose evolution parameter is not greater than 1 from the initial device layer, the device layer is remodeled, that is, the first structural evolution process of the pressure-sensitive chip is completed, and the structural evolution process of step S2 and step S4 is repeated. After completing the third structural evolution, the basic shape and position of the resonant structure are determined. Further, technicians in the field determine the final shape of the resonant structure based on the basic shape of the resonant structure based on conventional techniques in the field, such as Figure 7 As shown, the design of the final device layer of the resonant pressure-sensitive chip is completed.

[0067] Specifically, in this embodiment, according to the position of the resonant structure determined in step S7, a central resonator and two edge resonators are arranged. The structure of each resonator is set as two silicon islands fixing a resonant beam located at the center of the resonator, and excitation electrodes and detection electrodes are arranged on both sides of the resonant beam. Finally, a signal lead-out beam and a metal electrode are designed to complete the structural design of the device layer.

[0068] Preferably, the device layer of the final resonant pressure sensor comprises: a resonant structure;

[0069] The resonant structure includes a central resonator 5 and two edge resonators 6; the two edge resonators 6 are arranged on both sides of the central resonator 5; the central resonator 5 includes a first resonant beam 51, two first silicon islands 52; two first resonator electrodes 53, two first excitation electrodes 54; and a plurality of first detection electrodes 55; the two ends of the first resonant beam 51 are respectively fixedly connected to the two first silicon islands 52; the two first resonator electrodes 53 are fixedly arranged on both sides of the first resonant beam 51; the two first excitation electrodes 54 are respectively connected to the two first resonator electrodes 53 through an electric field; the plurality of first detection electrodes 55 are evenly arranged on both sides of the first resonant beam 51, and are connected to the first resonator electrodes 53 through an electric field; the first detection electrode 55 is fixedly connected to the first metal electrode 56 through a first signal lead-out beam 57;

[0070] The edge resonator 6 includes a second resonant beam 61, two second silicon islands 62; two second resonant sub-electrodes 63, two second excitation electrodes 64; and a plurality of second detection electrodes 65; the two ends of the second resonant beam 61 are respectively fixedly connected to the two second silicon islands 62; the two second resonant sub-electrodes 63 are fixedly arranged on both sides of the second resonant beam 61; the two second excitation electrodes 64 are respectively connected to the two second resonant sub-electrodes 63 through an electric field; the plurality of second detection electrodes 65 are evenly arranged on both sides of the second resonant beam 61, and are connected to the second resonant sub-electrodes 63 through an electric field; the second detection electrode 65 is fixedly connected to the second metal electrode 66 through a second signal lead-out beam 67;

[0071] Specifically, the first excitation electrode 54 and the second excitation electrode 64 of this embodiment are both connected to the back-end processing circuit through metal electrodes.

[0072] Specifically, the central resonator and the edge resonator of this embodiment are fixedly arranged on one side of the isolation layer 2; the sensitive elements of the resonant pressure sensor are mainly concentrated in the device layer 3, which is mainly composed of a resonant structure, an excitation structure and a detection structure, such as Figure 3 , Figure 4 , Figure 5 As shown, the resonant structure includes a central resonator 5 and two edge resonators 6. When the resonant pressure sensor is subjected to pressure, the pressure acts on the pressure-sensitive membrane, the pressure-sensitive chip is deformed as a whole, and the stress is transmitted to the resonant beam. The resonant beams of the central resonator 5 and the two edge resonators 6 are subjected to stress, and the inherent resonant frequency of the resonant beam changes. The first excitation electrode / the second excitation electrode outputs an alternating excitation signal, and the first resonator / the second resonator is displaced by the electrostatic force, and the first detection electrode / the second detection electrode arranged on both sides of the first resonator / the second resonator detects the displacement of the first resonator / the second resonator and converts it into a capacitance signal.

[0073] Specifically, in this embodiment, resonator electrodes are arranged on both sides of the resonant beam and a DC voltage is applied, and an alternating voltage is applied to the excitation electrode. The resonator is deformed by the alternating Coulomb force, and the capacitance formed by the resonator and the detection electrodes on both sides of the resonator changes. When the resonator enters the resonant state, the resonant frequency of the resonator can be measured by analyzing the capacitance signal output by the detection electrode, and then the pressure on the pressure-sensitive chip can be analyzed.

[0074] Specifically, the silicon substrate 1 of this embodiment is etched to form a pressure-sensitive diaphragm. The pressure to be measured applied to the resonant pressure sensor is first directly applied to the silicon substrate, and then transmitted to the isolation layer 2 and the device layer 3. The device layer 3 is used to convert the pressure into a resonant signal for measurement. The glass substrate 4 is used to support other structures of the pressure sensor. The glass substrate is etched and a getter is deposited to form a vacuum cavity, so that the pressure-sensitive film only bears the pressure to be measured.

[0075] Specifically, this embodiment performs three structural evolutions on the device layer to determine the position and basic shape of the resonant structure to optimize the structure of the device layer, thereby improving the performance of the resonant pressure sensor, including its sensitivity and linearity. Since there is a certain trade-off between the sensitivity and linearity of the resonant pressure sensor, improving the sensitivity requires the sensor to be subjected to as much stress as possible under the same load, which usually requires the pressure-sensitive chip to produce a large degree of strain, but a large strain may cause the output signal to be nonlinear, so in order to ensure linearity, the design of the sensor often needs to limit the chip strain. In order to achieve a balance between the two, it is necessary to optimize the resonant structure of the sensor. This embodiment performs three structural evolutions on the device layer and gradually evolves and eliminates some structures, which can maximize the sensitivity while ensuring linearity. Through precise design and optimization, the linearity of the sensor can be improved without significantly sacrificing sensitivity, thereby realizing a high-performance resonant pressure sensor.

[0076] The beneficial effects of this embodiment are:

[0077] The structural optimization design method of the silicon-based resonant pressure sensor of this embodiment provides a resonant pressure sensor structure that maximizes sensitivity without sacrificing linearity. The COMSOL finite element analysis software was used to complete the structural design of the device layer. During the design process, the device layer structure was gradually evolved with small deformation and high stress as indicators, increasing the maximum stress under the condition of reducing the deformation degree of the sensor, and maximizing the sensitivity of the resonant pressure sensor under the condition of ensuring linearity, solving the contradiction between high sensitivity and high linearity of the sensor.

[0078] The sensor of this embodiment uses electrostatic excitation capacitance detection. Within a fixed pressure range, there is a good linear relationship between the resonant frequency of the oscillator and the external pressure. By analyzing the resonant frequency of the oscillator, the external pressure can be detected. In view of the balance problem between the sensitivity and linearity of the resonant pressure sensor, this embodiment divides the device layer into multiple square units, analyzes the size of the evolution parameter of each unit to decide whether to retain the unit, and completes the sensor structure detail design according to the evolution results after three evolutions. The obtained resonant structure can improve the sensitivity and linearity of the sensor at the same time.

[0079] 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 structural optimization design method for a silicon-based resonant pressure sensor, characterized in that: The steps include: S1: The silicon substrate, isolation layer and initial device layer of the pressure-sensitive chip are modeled using the finite element simulation software COMSOL; the initial device layer is divided into multiple square units of equal size; the constraints and boundary conditions of the pressure-sensitive chip are set; S2: Apply a load perpendicular to the initial device layer to the pressure-sensitive chip to obtain the maximum stress σ0 and maximum deformation γ0 in all square units in the initial device layer; S3: Obtain the maximum stress change Δσ and the maximum deformation change Δγ of the square unit in the initial device layer after removing the i-th, i=1…I square units, and then obtain the evolution parameter C of the i-th square unit according to the maximum stress σ0 and the maximum deformation γ0 of all the square units in the initial device layer; i represents the index of the square unit in the initial device layer; I represents the total number of square units in the initial device layer; S4: performing a first structural evolution on the initial device layer according to the evolution parameter C of the i-th square unit to obtain a device layer after the first structural evolution; S5: based on the device layer after the first structural evolution, re-execute S2-S4 to obtain the device layer after the second structural evolution; S6: Based on the device layer after the second structural evolution, re-execute S2-S4 to obtain the device layer after the third structural evolution; S7: According to the device layer after the third structural evolution, the position and basic shape of the resonant structure are determined to determine the final device layer of the resonant pressure sensor, thereby completing the design of the resonant pressure sensor.

2. The structural optimization design method of a silicon-based resonant pressure sensor according to claim 1, characterized in that: The formula used to obtain the evolution parameter C of the i-th square unit is as follows: Where: C represents the evolution parameter; Δσ represents the change in the maximum stress of the square unit in the initial device layer after the i-th square unit is removed; Δγ represents the change in the maximum deformation in the initial device layer after removing the i-th square unit; σ0 represents the maximum stress in all square units in the initial device layer; γ0 represents the maximum deformation in all square units in the initial device layer.

3. The structural optimization design method of a silicon-based resonant pressure sensor according to claim 1, characterized in that: The method for obtaining the device layer after the first structural evolution is as follows: If the evolution parameter C of the i-th square unit is not greater than 1, the i-th square unit is removed from the initial device layer; Then all the square units whose evolution parameter C is greater than 1 constitute the device layer after the first structural evolution.

4. The structural optimization design method of a silicon-based resonant pressure sensor according to claim 1, characterized in that: The device layer of the final resonant pressure sensor includes: a resonant structure; The resonant structure comprises a central resonator (5) and two edge resonators (6); The two edge resonators (6) are arranged on both sides of the central resonator (5); The central resonator (5) comprises a first resonant beam (51), two first silicon islands (52); two first resonator electrodes (53), two first excitation electrodes (54); and a plurality of first detection electrodes (55); Two ends of the first resonant beam (51) are respectively fixedly connected to the two first silicon islands (52); The two first resonator electrodes (53) are fixedly arranged on both sides of the first resonant beam (51); The two first excitation electrodes (54) are respectively connected to the two first resonator electrodes (53) through an electric field; A plurality of the first detection electrodes (55) are evenly arranged on both sides of the first resonance beam (51), and are connected to the first resonator electrode (53) via an electric field; The first detection electrode (55) is fixedly connected to the first metal electrode (56) via a first signal lead-out beam (57); The edge resonator (6) comprises a second resonant beam (61), two second silicon islands (62); two second resonator electrodes (63), two second excitation electrodes (64); and a plurality of second detection electrodes (65); Two ends of the second resonant beam (61) are respectively fixedly connected to the two second silicon islands (62); Two of the second resonator electrodes (63) are fixedly arranged on both sides of the second resonant beam (61); The two second excitation electrodes (64) are respectively connected to the two second resonator electrodes (63) via an electric field; A plurality of the second detection electrodes (65) are evenly arranged on both sides of the second resonance beam (61), and are connected to the second resonator electrode (63) via an electric field; The second detection electrode (65) is fixedly connected to the second metal electrode (66) via a second signal lead-out beam (67).

5. The structural optimization design method of a silicon-based resonant pressure sensor according to claim 1, characterized in that: The pressure-sensitive chip is manufactured by adopting SOI technology.

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