阅读说明：本技术 一种基于电磁激励电磁检测的硅微谐振式表压传感器芯片 (Silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection ) 是由 赵立波 邱煜祥 王李 韩香广 李支康 皇咪咪 杨萍 朱楠 王淞立 赵虎 蒋庄德 于 2020-10-22 设计创作，主要内容包括：本发明公开了一种基于电磁激励电磁检测的硅微谐振式表压传感器芯片,包括谐振器、气压敏感膜和检测压力敏感膜。加载压力时,气压敏感膜和检测压力敏感膜受压产生变形,气压通过气压敏感膜和检测压力敏感膜在谐振器两端产生的拉应力和压应力平衡,使得传感器得以测量到表压。气压敏感膜与多晶硅层上表面通过键合形成整体并为谐振器所在空腔提供了真空环境,提高了传感器的品质因子。激振梁、拾振梁和连接梁上沉积有氧化硅层作为绝缘层,激振梁、拾振梁上的氧化硅层上沉积有多晶硅层作为电信号传导层。(The invention discloses a silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection. When pressure is loaded, the air pressure sensitive film and the detection pressure sensitive film are pressed to generate deformation, and the air pressure is balanced by tensile stress and compressive stress generated by the air pressure sensitive film and the detection pressure sensitive film at the two ends of the resonator, so that the sensor can measure gauge pressure. The air pressure sensitive film and the upper surface of the polycrystalline silicon layer are bonded to form a whole, a vacuum environment is provided for the cavity where the resonator is located, and the quality factor of the sensor is improved. Silicon oxide layers are deposited on the excitation beam, the vibration pickup beam and the connecting beam to serve as insulating layers, and polycrystalline silicon layers are deposited on the silicon oxide layers on the excitation beam and the vibration pickup beam to serve as electric signal conducting layers.)

1. A silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection is characterized by comprising an air pressure sensitive film (1), a polycrystalline silicon layer, a first silicon oxide layer (13), a resonator structure film (21), a second silicon oxide layer (22) and a bottom layer structure film (2) which are sequentially arranged from top to bottom; the polycrystalline silicon layer comprises an excitation beam polycrystalline silicon layer (11), a vibration beam polycrystalline silicon layer (12), an excitation polycrystalline silicon layer (26), a vibration polysilicon layer (27), a silicon island polycrystalline silicon layer (28) and other polycrystalline silicon layers (20) on the chip, and the air pressure sensitive film (1) is bonded with the excitation polycrystalline silicon layer (11), the vibration polysilicon layer (12), the silicon island polycrystalline silicon layer (28) and the other polycrystalline silicon layers (20) on the chip; the air pressure sensitive film (1) is made of glass or silicon material; a resonator (7) is arranged on the resonator structural film (21), and a pressure-sensitive detection film (3) is arranged on the bottom layer structural film (2).

2. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection of claim 1, wherein the thickness of the air pressure sensitive film (1) is 30 μm-60 μm.

3. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection as claimed in claim 1, wherein an H-shaped cavity (24) is formed in the bottom layer structural film (2), the resonator (7) is arranged in the H-shaped cavity (24), and the resonator (7) is a tuning fork type resonator.

4. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation electromagnetic detection according to claim 1 or 3, wherein the resonator (7) comprises an excitation beam (8), a vibration pickup beam (9) and two connecting beams (10), one end of each connecting beam (10) is connected with the excitation beam (8), and the other end of each connecting beam is connected with the vibration pickup beam (9); the utility model discloses a vibration-proof device, including exciting beam (8), pick-up beam (9), connecting beam (10), exciting beam polycrystalline silicon layer (11), exciting beam (8) up end face is provided with first silicon oxide layer (13) and exciting beam polycrystalline silicon layer (11) from bottom to top, pick-up beam (9) up end face from bottom to top and be provided with first silicon oxide layer (13) and pick-up beam polycrystalline silicon layer (12) from bottom to top, the deposit has first silicon oxide layer (13) on connecting beam (10), exciting beam polycrystalline silicon layer (11) both ends are connected through exciting polycrystalline silicon layer (26) and exciting electrode (5) electricity, pick-up vibrating beam polycrystalline silicon layer (12) both ends are.

5. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection according to claim 4, wherein the joint of the excitation beam (8) and the H-shaped cavity (24) is provided with chamfers (14) at two ends of the excitation beam, and the joint of the vibration pickup beam (9) and the H-shaped cavity (24) is provided with chamfers (25) at two ends of the vibration pickup beam.

6. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection according to claim 4, wherein a silicon island (4) is arranged in a cavity formed by enclosing the excitation beam (8), the vibration pickup beam (9) and the two connecting beams (10), the lower end of the silicon island (4) is connected with the lower end face of the H-shaped cavity (24), the upper end face is sequentially provided with a first silicon oxide layer (13) and a silicon island polycrystalline silicon layer (28) from bottom to top, and the silicon island polycrystalline silicon layer (28) is bonded with the air pressure sensitive film (1).

7. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection according to claim 6, wherein the distances between the four side walls of the silicon island (4) and the inner wall of the cavity where the silicon island is located are 5-15 μm.

8. The silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection as claimed in claim 4, wherein the thickness of the excitation beam polysilicon layer (11) and the thickness of the vibration pickup beam polysilicon layer (12) are both 200-500 nm.

Technical Field

The invention belongs to the technical field of micro-nano sensors, and particularly relates to a silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection.

Background

Compared with a capacitance pressure sensor and a piezoresistive pressure sensor, the silicon micro-resonance type pressure sensor has better precision and stability due to high signal-to-noise ratio and reliable half-digital output. The sensor technology which represents the highest level and has the most comprehensive technical advantages of the world pressure sensor is widely applied to the fields of airborne atmospheric data testing systems, aviation atmospheric data check meters, cabin pressure tests, aerospace ground testing systems, high-performance wind tunnels and the like. At present, most of the applied sensors are absolute pressure sensors, but in the process of being sensitive to air pressure, the measurement result of the absolute pressure sensor includes both air pressure and the pressure to be measured, and the measurement accuracy is reduced in the environment with large air pressure change, so that the production requirement cannot be fully met. Therefore, at present, the gauge pressure sensor is greatly required by industries such as electric power, petroleum, chemical industry, paper making, food, textile, metallurgy and the like.

Compared with an electromagnetic excitation and electromagnetic detection mechanism, other common excitation and detection modes of the silicon micro-resonance type pressure sensor have the following defects: (1) compared with electromagnetic excitation, common thermal excitation is a contact excitation mode, the surface of a resonator can be damaged, the frequency deviation of the resonator can be caused by heat generated in the excitation process, so that the stability and the measurement accuracy of the sensor can be influenced, and the conversion of electric energy-heat energy-mechanical energy needs to be completed by thermal excitation, so that the sensor generates larger power consumption during working; in addition, the thermal excitation process is slow in response, and the response speed of the sensor is reduced; (2) compared with electromagnetic detection, common capacitive detection is easily interfered by the environment, and is a detection mode with weak anti-interference capability; (3) the conventional electrostatic excitation and piezoresistive detection has the defects of complex structure, high technical difficulty and less research. In the world, only the DRUCK company in england realizes the mass production of silicon micro-resonance type pressure sensors based on electrostatic excitation and piezoresistive detection.

Disclosure of Invention

In order to solve the problem of high-precision pressure measurement, the invention provides a silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection, which reduces the preparation difficulty and improves the quality factor and the detection precision of a silicon micro-resonance type pressure sensor.

In order to achieve the purpose, the invention provides a silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation and electromagnetic detection, which comprises an air pressure sensitive film, a polycrystalline silicon layer, a first silicon oxide layer, a resonator structure film, a second silicon oxide layer and a bottom layer structure film which are sequentially arranged from top to bottom; the polycrystalline silicon layer comprises an excitation beam polycrystalline silicon layer, a vibration pickup beam polycrystalline silicon layer, an excitation polycrystalline silicon layer, a vibration pickup polycrystalline silicon layer, a silicon island polycrystalline silicon layer and other polycrystalline silicon layers on the chip, and the air pressure sensitive film is bonded with the excitation polycrystalline silicon layer, the vibration pickup polycrystalline silicon layer, the silicon island polycrystalline silicon layer and the other polycrystalline silicon layers on the chip; the air pressure sensitive film is made of glass or silicon material; the resonator structure film is provided with a resonator, and the bottom layer structure film is provided with a pressure detection sensitive film.

Further, the thickness of the air pressure sensitive film is 30 μm to 60 μm.

Furthermore, an H-shaped cavity is formed in the bottom layer structure film, the resonator is arranged in the H-shaped cavity, and the resonator is a tuning fork type resonator.

Furthermore, the resonator comprises an excitation beam, a vibration pickup beam and two connecting beams, wherein one end of each connecting beam is connected with the excitation beam, and the other end of each connecting beam is connected with the vibration pickup beam; the upper end face of the vibration excitation beam is provided with a first silicon oxide layer and a vibration excitation beam polycrystalline silicon layer from bottom to top, the upper end face of the vibration pickup beam is provided with a first silicon oxide layer and a vibration pickup beam polycrystalline silicon layer from bottom to top, the first silicon oxide layer is deposited on the connecting beam, two ends of the vibration excitation beam polycrystalline silicon layer are electrically connected with the vibration excitation electrode through the vibration excitation polycrystalline silicon layer, and two ends of the vibration pickup beam polycrystalline silicon layer are electrically connected with the vibration pickup electrode through the.

Furthermore, the joint of the vibration beam and the H-shaped cavity is provided with chamfers at two ends of the vibration beam, and the joint of the vibration pickup beam and the H-shaped cavity is provided with chamfers at two ends of the vibration pickup beam.

Furthermore, a silicon island is arranged in a cavity formed by enclosing the vibration exciting beam, the vibration picking beam and the two connecting beams, the lower end of the silicon island is connected with the lower end face of the H-shaped cavity, a first silicon oxide layer and a silicon island polycrystalline silicon layer are sequentially arranged on the upper end face from bottom to top, and the silicon island polycrystalline silicon layer is bonded with the air pressure sensitive film.

Furthermore, the distances between the four side walls of the silicon island and the inner wall of the cavity where the silicon island is located are 5-15 μm.

Furthermore, the thicknesses of the excitation beam polysilicon layer and the vibration pickup beam polysilicon layer are the same and are both 200-500 nm.

Compared with the prior art, the invention has at least the following beneficial technical effects:

the glass or silicon material covered on the detection pressure sensitive film is used as an air pressure sensitive film and a packaging layer, the air pressure sensitive film deforms under the action of air pressure, the air pressure sensitive film can effectively convert the air pressure into the pressure stress acting on two ends of the resonator by being bonded with the polycrystalline silicon layer, the detection pressure sensitive film deforms under the action of the air pressure and the detection pressure and can effectively convert the pressure stress acting on two ends of the resonator, and the pressure sensitive film and the detection pressure sensitive film are under the same air pressure, so that the tension stress and the pressure stress generated by the action of the air pressure are balanced mutually, and the sensor only detects the detected pressure, thereby realizing the function of gauge pressure measurement. Meanwhile, after being used as a packaging layer and bonded with the upper surfaces of the excitation polysilicon layer, the vibration pickup polysilicon layer, the silicon island polysilicon layer and other polysilicon layers on the chip, the glass or silicon material seals a cavity between the air pressure sensitive film and the pressure sensitive film for detection into a vacuum environment, so that the resistance to vibration of the resonator is reduced even if the resonator is in the vacuum environment, and the sensor is ensured to have higher quality factors.

The resonator resonance frequency selects the in-plane vibration mode. The motion speed is perpendicular to the magnetic induction line during vibration, so that the output quantity is increased, and the detection precision is improved; meanwhile, the movement speed is vertical to the deformation direction of the pressure sensitive film and the air pressure sensitive film, so that the mechanical coupling and the energy coupling of the resonator, the pressure sensitive film and the air pressure sensitive film are avoided, and the quality factor of the sensor is improved.

Furthermore, the junction of the excitation beam and the H-shaped cavity naturally forms chamfers at two ends of the excitation beam through an etching process, and the junction of the vibration pickup beam and the H-shaped cavity naturally forms chamfers at two ends of the vibration pickup beam through the etching process, so that the first silicon oxide layer, the excitation beam polycrystalline silicon layer and the vibration pickup beam polycrystalline silicon layer are gently excessive at the junction, and the stability of electric signals is facilitated.

Furthermore, the bonding area of the air pressure sensitive film and the silicon island polycrystalline silicon layer is increased by increasing the area of the silicon island. The distances between the four non-bonding surfaces of the silicon island and the resonator are 5-15 mu m, the area of the silicon island is increased as much as possible on the premise of not interfering the vibration of the resonator in the design, and the stability and the sensitivity of gauge pressure measurement can be improved after the bonding area is increased.

Furthermore, the polycrystalline silicon layer is arranged by using an etching and deposition process, so that the compatibility of a preparation process and an IC (integrated circuit) process is improved, the mass production is facilitated, and the manufacturing cost is reduced. Meanwhile, an electromagnetic excitation mechanism and an electromagnetic detection mechanism are used, so that the manufacturing difficulty is reduced, and the stability of the sensor is improved.

The silicon micro-resonance type pressure sensor adopting electromagnetic excitation and electromagnetic detection has the characteristics of high linearity and high sensitivity. Compared with other modes, the modes of electromagnetic excitation and electromagnetic detection have the obvious advantages of simpler structure, reduction of process difficulty and higher output quantity.

Drawings

FIG. 1 is an exploded view of the overall structure of the present invention;

FIG. 2 is an isometric view of the overall construction of the present invention;

FIG. 3 is a half-sectional view of FIG. 1;

FIG. 4 is an enlarged view of a portion of FIG. 3;

FIG. 5 is a partial cross-sectional view of FIG. 4 taken at plane E-E;

fig. 6 is a schematic diagram of the deformation of the resonant beam after loading;

FIG. 7 is a schematic diagram of a polysilicon layer according to the present invention;

fig. 8 is a cross-sectional view at F-F in fig. 7.

In the drawings: 1. the structure comprises a gas pressure sensitive film, a bottom layer structure film, a detection pressure sensitive film, a silicon island, a vibration exciting electrode, a vibration pickup electrode, a resonator, a vibration exciting beam, a vibration pickup beam, a connecting beam, a vibration exciting beam polycrystalline silicon layer, a vibration pickup beam polycrystalline silicon layer, a first silicon oxide layer, a second silicon oxide layer, a vibration exciting beam polycrystalline silicon layer, a second silicon oxide layer, a first silicon oxide layer, a second silicon oxide layer, a first silicon oxide layer, a; 26. exciting a polycrystalline silicon layer; 27. a vibration-pickup polysilicon layer; 28. and a silicon island polysilicon layer.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships that are illustrated in the drawings, are merely used for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, or a particular orientation configuration and operation, and thus, should not be considered as limiting the present invention.

Referring to fig. 1, 2 and 3, the silicon micro-resonance type gauge pressure sensor chip based on electromagnetic excitation electromagnetic detection comprises an air pressure sensitive film 1, a polycrystalline silicon layer, a first silicon oxide layer 13, a resonator structural film 21, a second silicon oxide layer 22 and a bottom layer structural film 2 from top to bottom in sequence, wherein the polycrystalline silicon layer comprises an excitation beam polycrystalline silicon layer 11, a vibration pickup beam polycrystalline silicon layer 12, an excitation polycrystalline silicon layer 26, a vibration pickup polycrystalline silicon layer 27, a silicon island polycrystalline silicon layer 28 and other polycrystalline silicon layers 20 on a chip, and an insulating layer comprises the first silicon oxide layer 13.

The air pressure sensitive film 1 is made of glass or silicon material with the thickness of 30-60 μm and is used for sensing air pressure. And the air pressure sensitive film 1 and the excitation polysilicon layer 26, the vibration pickup polysilicon layer 27, the silicon island polysilicon layer 28 and other polysilicon layers 20 on the chip in the polysilicon layer adopt a bonding process to complete the vacuum packaging of the sensor. The excitation polysilicon layer 26 and the vibration pick-up polysilicon layer 27 serve to conduct electrical signals through the resonator, and the first silicon oxide layer 13 serves to insulate. The resonator 7 is positioned on the resonator structure film 21, the detection pressure sensitive film 3 is positioned on the bottom layer structure film 2, and the detection pressure sensitive film 3 and the air pressure sensitive film 1 are both square films. The second silicon dioxide layer 22 may act as a sacrificial layer to assist in the processing of the void beneath the resonator 7.

Referring to fig. 4 and 5, an H-shaped cavity 24 is etched in the center above the pressure-sensitive detection membrane 3, and the resonator 7 is disposed in the H-shaped cavity 24. The H-shaped cavities 24 are formed by etching from the upper surface of the resonator structure film 21, and are symmetrically distributed on the plane by taking the center line of the opposite sides of the square air pressure sensitive film 1 as two symmetrical axes. The resonator 7 is a tuning fork type resonator including an excitation beam 8, a vibration pickup beam 9, and a connection beam 10. The vibration beam 8 and the vibration pickup beam 9 are equal in length and are parallel to each other, two connecting beams 10 are arranged between the vibration beam 8 and the vibration pickup beam 9, and the two connecting beams 10 are perpendicular to the vibration and vibration pickup beams simultaneously and are close to two ends of the two beams in a symmetrical distribution mode about the central line of the two beams.

Two symmetry axes of the resonator 7 on the plane are respectively superposed with two symmetry axes of the H-shaped cavity 24, namely superposed with two opposite side edges of the air pressure sensitive film 1, are equidistant to the upper surface of the pressure sensitive film 3 and the lower surface of the air pressure sensitive film 1 in the height direction, and gaps are reserved between the other outer surfaces and the inner wall of the cavity so as to ensure that the cavity does not interfere with the inner wall of the cavity when vibrating under the working condition. The joint of the vibration excitation beam 8 and the H-shaped cavity 24 is provided with chamfers 14 at two ends of the vibration excitation beam, and the joint of the vibration pickup beam 9 and the H-shaped cavity 24 is provided with chamfers 25 at two ends of the vibration pickup beam.

Wherein, the excitation beam 8 and the chamfers 14 at the two ends of the excitation beam, the chamfers 25 at the two ends of the excitation beam of the vibration pickup beam 9 and the connecting beam 10 are deposited with a first silicon oxide layer 13 as an insulating layer; the excitation beam polysilicon layer 11 is deposited on the excitation beam 8 and the first silicon oxide layer 13 of the chamfer 14 at the two ends of the excitation beam, the vibration pickup beam polysilicon layer 12 is deposited on the first silicon oxide layer 13 of the chamfer 25 at the two ends of the vibration pickup beam 9, the first silicon oxide layer 13 is used as an insulating layer, the conductive excitation beam polysilicon layer 11 is insulated from the lower excitation beam 8, and the conductive vibration pickup beam polysilicon layer 12 is insulated from the lower vibration pickup beam 9. The thickness of the first silicon oxide layer 13 is 200-500 nm. The thickness of the excitation beam polysilicon layer 11 is the same as that of the vibration pickup beam polysilicon layer 12, and both the thicknesses are 200nm and 500 nm.

A rectangular silicon island 4 is formed between the two connecting beams 10 after processing, the silicon island 4 is positioned at the central position of a cavity formed by the resonator exciting beam 8, the vibration pickup beam 9 and the two connecting beams 10, and the distances between the two ends of the silicon island 4 in the length direction and the two connecting beams 10 are equal; is positioned right in the middle of the vibration exciting beam 8 and the vibration pickup beam 9 in the width direction. The lower end of the silicon island 4 is connected with the lower end face of the H-shaped cavity 24, the first silicon oxide layer 13 and the silicon island polycrystalline silicon layer 28 are deposited on the upper end from bottom to top, and the silicon island polycrystalline silicon layer 28 is bonded with the air pressure sensitive film 1.

The direction of the magnetic induction line of the applied magnetic field 19 of the sensor is perpendicular to the upper surface of the resonator 7.

Preferably, the distance between the outer side wall (the opposite side to the side connected with the connecting beam 10) of the excitation beam 8 and the inner wall of the H-shaped cavity 24 on the same side is equal to the distance between the outer side wall (the opposite side to the side connected with the connecting beam 10) of the vibration pickup beam 9 and the inner wall of the H-shaped cavity 24 on the same side, and the distance is made to be less than 15 micrometers on the premise of not interfering the vibration of the resonator 7.

Preferably, on the premise of not interfering the vibration of the resonator 7, the distance between the silicon island 4 and the two connecting beams 10 in the length direction is less than 15 μm as much as possible, and the distance between the silicon island 4 and the excitation beam 8 and the vibration pickup beam 9 in the width direction is less than 15 μm as much as possible, so that the bonding area is increased, and the measurement stability is increased.

Preferably, the vibration mode of the beam is selected from the modes described in fig. 6, which is shown with reference to fig. 6, i.e., the mode in which the resonator 7 vibrates only in a plane parallel to the sensing pressure-sensitive membrane 3 and the gas pressure-sensitive membrane 1. During vibration, the vibration pickup beam 9 is in a shape shown as the contour 18 of the vibration pickup beam after vibration, the movement speed is vertical to the magnetic induction line, the output quantity is increased, and the detection precision is improved; meanwhile, the shape of the vibration beam 8 when the vibration beam is deformed is shown as the contour 17 after the vibration of the vibration beam. The movement speed of the vibration beam 8 and the vibration pickup beam 9 is vertical to the deformation direction of the pressure sensitive film and the air pressure sensitive film, so that the mechanical coupling and the energy coupling of the resonator and the film are avoided, and the quality factor of the sensor is improved.

Referring to fig. 5, 6, 7 and 8, the two excitation electrodes 5 connected to the external control circuit are connected to an alternating voltage for generating an alternating excitation current 15 applied to the excitation beam 8, and the two pickup electrodes 6 are connected to the detection circuit for detecting an induced current 16 generated during the process of cutting the magnetic induction lines from the pickup beam 9. The upper surface of the resonator structural film 21 is deposited with an excitation polysilicon layer 26, a vibration-pickup polysilicon layer 27 and other polysilicon layers 20 on the chip, and the thicknesses of the three layers are 200 nm-500 nm and are equal; the excitation polysilicon layer 26 is separated from the other polysilicon layers 20 on the chip, and the other polysilicon layers 20 on the chip are separated from the vibration-pickup polysilicon layer 27 by the cutting grooves 23. The excitation polysilicon layer 26 extends from the positions right above the chamfers 14 at the two ends of the excitation beam to the inner side of the edge of the resonator structural film 21 along the length direction of the excitation beam, and the excitation electrode 5 is attached to the tail end. The vibration-pickup polysilicon layer 27 extends from the upper part of the chamfers 25 at the two ends of the vibration-pickup beam to the inner side of the edge of the resonator structural film 21 along the two ends of the vibration-pickup beam, and the vibration-pickup electrode 6 is attached to the tail end.

The working process of the invention is as follows: when pressure is loaded, the air pressure sensitive film 1 and the detection pressure sensitive film 3 are pressed to generate deformation, and pressure stress and tensile stress are respectively generated at two ends in the length direction of the excitation beam and the vibration pickup beam, after the air pressure is balanced by the tensile stress and the pressure stress generated at two ends of the resonator 7 by the air pressure sensitive film 1 and the detection pressure sensitive film 3, the resonance frequency of the resonator 7 is changed by the tensile stress generated at two ends of the resonator 7 by the detected pressure. When the sensor works, a constant magnetic field is applied to the sensor, the magnetic induction lines vertically penetrate through the upper surface of the resonator 7, when periodic alternating voltage is applied between the excitation electrodes 5, the excitation beam polycrystalline silicon layer 11 on the excitation beam is subjected to Lorentz force due to the passing of current, and the direction of the Lorentz force is also periodically changed along with the change of the voltage direction, so that the excitation beam 8 generates vibration due to the force with the periodically changed direction, and the vibration pickup beam 9 is driven to vibrate at the same frequency through the middle connecting beam 10. When the vibration pickup beam 9 vibrates, the polysilicon layer 12 on the vibration pickup beam generates induced electromotive force between the vibration pickup electrodes 6 because of cutting magnetic lines, and the frequency of the induced electromotive force is the same as the voltage applied by the vibration excitation beam. When the frequency of the applied voltage is close to or equal to the natural frequency of the whole resonance beam 7 at the selected modal order, the resonance beam 7 will resonate at the mode, so that the amplitude of the vibration pickup beam 9 is maximized, and the amplitude of the induced electromotive force between the vibration pickup electrodes 6 is also maximized. At this time, the induced electromotive force generated by the vibration pickup beam 9, namely the induced electromotive force between the vibration pickup electrodes 6 is detected, so that the natural frequency of the resonance beam can be determined, and the purpose of detecting the pressure can be achieved. The resonator is designed to vibrate only in a plane under the selected mode, so that the direct energy exchange between the resonant beam and the two sensitive films is effectively avoided, and the quality factor of the sensor is improved.

The technical indexes which can be achieved by the preferred embodiment of the invention are as follows:

1) pressure range: 0-2.5MPa

2) And (3) measuring precision: 0.01% FS

The above description is only one embodiment of the present invention, and not all or only one embodiment, and any equivalent alterations to the technical solutions of the present invention, which are made by those skilled in the art through reading the present specification, are covered by the claims of the present invention.