An advanced electromechanical ultrasonic transducer chip unit

Abstract

The present invention provides an advanced electro-accommodative electromechanical ultrasonic transducer chip unit, comprising a first component structure and a second component structure enclosed in the first component structure, wherein a cavity is formed between the first component structure and the second component structure, the first component structure comprising an anti-collision isolation column, a supporting bottom connected to the anti-collision isolation column, and a lower electrode layer located in the cavity, the cross-sectional shape of the lower electrode layer being a trapezoid, the second component structure comprising a spring coil arranged on the inner side of the anti-collision isolation column and a diaphragm connected to the side of the spring coil; the beneficial effects of the present invention are as follows: the present invention is applicable to both military and civilian use, the spring coil in the present invention realizes negative slope control, expands the amplitude and cavity ratio, and realizes a cavity utilization rate of 58%, which has exceeded the global theoretical limit of 33%, thereby breaking through insufficient elastic force and improving cavity utilization, and the inclined surface of the lower electrode layer with a trapezoidal cross-section can make the driving voltage lower.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit chips, and in particular to an advanced electromechanical ultrasonic transducer chip unit. Background Art

[0002] The CMUT array is composed of a highly doped silicon substrate, an oxide insulating layer, a circular silicon nitride vibration plate, and gold electrodes. The CMUT chip is based on the CMUT unit. For more information about the CMUT chip unit, please refer to Figure 1 and Figure 2 The existing parallel CMUT array (through-hole version) includes an upper electrode A, an insulator B, a substrate C, an air hole D, a diaphragm E, a cavity F, and a lower electrode G. The existing parallel CMUT array (non-through-hole version) also includes an upper electrode A, an insulator B, a substrate C, a diaphragm E, a cavity F, and a lower electrode G. The CMUT diaphragm movement is due to the electrostatic attraction between the positive and negative electrodes and gravity, which counteract the mechanical force on the diaphragm. Diaphragm force analysis (lumped parameter system): force balance Fs = Fe + Fg. The diaphragm is subject to three forces: electrostatic force Fe (surface force): downward; when the object size is less than 1000μm, it is reduced to 1 / 100 of its original value and becomes the dominant force. As the displacement w increases, Fe also increases; gravity Fg (body force): downward; when the object size is less than 1000μm, it is reduced to 1 / 1000 of its original value and is not the dominant force; mechanical restoring force Fs: upward. It is related to the material, not the size. When the displacement w increases, Fs also increases (in a linear manner). For details, please refer to Figure 3 ;

[0003] The voltage design defect of existing CMUT products A: The diaphragm displacement is less than 1 / 3 of the cavity height: the voltage between the upper (positive) and lower (ground) electrodes must not exceed the collapse voltage (in other words, the diaphragm amplitude can only be within 1 / 3 of the CMUT cavity height, about 33%). Otherwise, the upper electrode will quickly adhere to the upper layer of the substrate due to the small displacement of the diaphragm, and the electrostatic force Fe will increase as the square of the inverse of the displacement difference, causing the upper electrode to fail (failure principle). In actual applications, the diaphragm displacement is slightly less than 1 / 3 of the cavity height, so the CMU The application of CMUTs is very limited. Cavity utilization is low, voltage requirements are high (for every 5V reduction in drive voltage, the lifespan of the MEMS increases tenfold), and the breakdown voltage of insulating materials is limited. Consequently, CMUTs have a narrow application range (mostly in sensors: receiving sound waves and converting them into electrical signals), while actuators (converting electrical signals into sound waves) are rare. Existing theories assume that gravity is very small (negligible). Simulations have found that gravity is equal to 2.65*10^4N / m3, while the maximum electrostatic force is 4.796*10^8N / m3, a difference of four orders of magnitude. Therefore, when the acceleration due to gravity is 10,000 times greater, it is comparable in magnitude to the electrostatic force, and gravity must be considered. For details, please refer to [Note: The following sentences appear to be unrelated and should be omitted:] Figure 4 ;

[0004] Defect B of existing CMUT products: Lack of large amplitude design: Cause analysis: Limited by the structural design and the withstand voltage limit (breakdown voltage) of the material, the breakdown voltage between the diaphragm electrode and the substrate electrode: (reference Figure 5 and Figure 6), silicon nitride A (0.4um lower layer of the diaphragm, 1.6um upper layer of the substrate, totaling 2um) isolates 2200V, the stoichiometric ratio of SiNx (the nitrogen fraction x in SiNx): when x>1.32, at this time, the breakdown voltage of 2um thick SiN is 2200V, the air cavity is 17um*0.45V / um=7.65V, silicon nitride B (1.09um thick insulating layer on the diaphragm electrode) isolates 1090V, when x>1.32, at this time, the breakdown voltage of 1.09um thick SiN is 1090V. To ensure the safety of users, it must be lower than this pressure value; Conclusion: The amplitude of the voltage (bias voltage + AC voltage) of the actual parallel CMUT cannot exceed 1090V, which is about 42.3% of the collapse voltage of 2577V. Then the amplitude is even smaller at this time. After simulation, it is 1.8um (totally impractical. For such a low amplitude, a model with a closer cavity distance and lower voltage can be used). Because the existing structural design is unreasonable (no breakthrough), it is trapped by the nonlinear growth of the electrostatic force Fe and is limited to the displacement of 1 / 3 of the cavity height. Therefore, a design with large amplitude (high sound pressure) (making full use of more than 50% of the cavity height) cannot appear. The specific description is as follows: Assuming the frequency is fixed, the emitted ultrasonic sound pressure Pmax, Pmax = 2*∏*f*Dmax*Z*fa. Where: π: pi (constant), f: excitation signal frequency; Dmax: maximum displacement change (amplitude) of the diaphragm; Z: acoustic impedance of the working medium (acoustic impedance of air); fa: ratio of average displacement of the diaphragm to maximum displacement (usually 1 / 5 < fa < 1 / 3); the nested restrictions between voltage, structural design, distance, and material withstand voltage limit: for a larger amplitude Dmax (higher sound pressure), the distance between the positive and negative electrodes must be closer, or the voltage must be higher; for a higher voltage, it is limited by the breakdown voltage of the material (vacuum also has a breakdown voltage). Breakthrough voltage), closer distance: it will block the movement of the diaphragm, so the two cannot be taken into account at the same time. Conclusion: Based on the above reasons, most CMUT designs have an amplitude of 0.1 to 2 μm and a voltage of less than 600 V. According to the directional acoustic energy application of Stanford in 2008, using 380V and 350V DC bias voltages and 200V peak-to-peak AC excitation (a total of about 580V), the effective source levels generated by the device were 139dB and 131dB (re20μPa) respectively, with a 60μm thick film;

[0005] Defect C of existing CMUT products: The moisture-proof / anti-corrosion design for use in air is lacking. Reason analysis: It is a failure design, that is, it is not moisture-proof / corrosion-proof. The CMUT will fail quickly in practical use. In order to reduce the air damping in the cavity (the loss caused by compressed air) and improve the electromechanical coupling coefficient (increase efficiency), the existing products adopt a through-hole design (D air through-hole in the figure), that is, the cavity is connected to the atmosphere, but this design is obviously not well considered, that is, it does not take into account the air humidity in different regions (after all, there are rainy days, foggy days, or high humidity and humid environments with a percentage relative humidity RH = 100%). If the environment is not completely dry (most areas have precipitation every year), then on any hydrophilic surface, such as the intrinsic oxide on the silicon surface, there will be several monolayers of water, and the water adsorbed on the dielectric surface and between the electrodes provides a leakage path. flow channel so that current can pass through, surface current jwater ~ A*exp[b, RH]*exp[-Eactivation / (kB*T)]; there are 6 parameters in the formula, among which: A, b: constants (b is 0.1~0.3); Eactivation: 0.4~1.1; EvT: temperature; RH: relative humidity; when the percentage relative humidity RH is less than 50%, no leakage current will occur; when RH>50% (for example: rainy, hot and humid summer weather, most RH>88%), the upper electrode of polysilicon exposed to the air (when the voltage is + positive anode) is rapidly oxidized, measured in hours or minutes. From the formula, we know that the leakage current jwater increases exponentially with RH; Conclusion: The oxidation rate of the anode exposed to the air is proportional to the leakage current between the electrodes. More oxidation can be observed at the sharp corners where the electric field is concentrated. Anodic oxidation reaction in the figure: such as Figure 7 As shown, the positively biased electrode (donating holes, labeled H+) is oxidized so that its volume increases, while the negatively biased electrode (donating electrons, e-) is not affected. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an advanced electromechanical ultrasonic transducer chip unit for solving the problem in the prior art that the diaphragm displacement is less than 1 / 3 of the cavity height.

[0007] To achieve the above-mentioned objectives and other related objectives, the present invention provides an advanced electro-accommodative electromechanical ultrasonic transducer chip unit, comprising a first component structure and a second component structure enclosed in the first component structure, wherein a cavity is formed between the first component structure and the second component structure, the first component structure comprising an anti-collision isolation column, a supporting bottom connected to the anti-collision isolation column, and a lower electrode layer located in the cavity, the cross-sectional shape of the lower electrode layer being trapezoidal, the second component structure comprising a spring coil arranged on the inner side of the anti-collision isolation column and a diaphragm connected to the side of the spring coil, the spring coil comprising a shore support, a tripod spring connected to the shore support, and a sea gold hook connected to the tripod spring, the tripod spring being indirectly connected to the anti-collision isolation column through the shore support, and the tripod spring being connected to the diaphragm through the shore support.

[0008] In one embodiment of the present invention, the first component structure and the second component structure are both annular concave structures as a whole.

[0009] In one embodiment of the present invention, the lower electrode layer includes a first insulating layer, a positive electrode layer located directly below the first insulating layer, and a second insulating layer located directly below the positive electrode layer, the positive electrode layer is located between the first insulating layer and the second insulating layer, the upper surface of the first insulating layer is located in the cavity, and the lower surface of the second insulating layer is connected to the supporting bottom.

[0010] In one embodiment of the present invention, the diaphragm includes a third insulating layer, a negative electrode layer located directly below the third insulating layer, and a fourth insulating layer located directly below the negative electrode layer, the negative electrode layer is located between the third insulating layer and the fourth insulating layer, and the lower surface of the fourth insulating layer is located in the cavity.

[0011] In one embodiment of the present invention, a wing support is provided on the surface of the anti-collision isolation column, and the wing support includes a feather membrane and a support square connected to the feather membrane. The feather membrane is Z-shaped, and the support square is L-shaped. The connection between the feather membrane and the support square is located between the anti-collision isolation column and the shore wave support. The support square is connected to the lower electrode layer on the other side of the feather membrane, and the support square is located in the cavity.

[0012] In one embodiment of the present invention, the anti-collision isolation column and the support bottom are made of polycrystalline silicon or single crystal silicon, the first coil of the spring, the third insulating layer and the fourth insulating layer are all made of silicon nitride whiskers, the first insulating layer and the second insulating layer are both made of silicon nitride, the negative electrode layer and the positive electrode layer are both made of aluminum or other conductive materials, and the wing support is made of silicon nitride.

[0013] As described above, the advanced electromechanical ultrasonic transducer chip unit of the present invention has the following beneficial effects:

[0014] The present invention is suitable for both military and civilian use, can greatly improve the relevant performance of directional acoustic energy weapons and military applications, and is suitable for related civilian directional acoustic energy applications. In the present invention, one turn of the spring realizes negative slope control, expands the amplitude and cavity ratio, and achieves a cavity utilization rate of 58%, which has greatly exceeded the global theoretical limit of 33%, thereby breaking through the insufficient elastic force and improving the cavity utilization rate. The inclined surface of the lower electrode layer with a trapezoidal cross-section can make the driving voltage lower, greatly saving energy consumption. The material of the diaphragm is silicon nitride whiskers, which can provide material guarantee for the ultra-large tensile force on the diaphragm. As a nanoscale / nano-electromechanical chip, the present invention provides a solid chip design foundation for the application of ultrasonic directed energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagrams of top view and cross section of a conventional parallel CMUT array (through-hole version);

[0016] Figure 2 Schematic diagrams of top view and cross section of a conventional parallel CMUT array (non-through-hole version);

[0017] Figure 3 This is the schematic diagram of the existing parallel CMUT force analysis;

[0018] Figure 4 A panoramic diagram of an existing parallel CMUT cross section;

[0019] Figure 5 is a schematic cross-sectional view of a diaphragm in an existing parallel CMUT;

[0020] Figure 6 is a schematic cross-sectional view of a substrate in a conventional parallel CMUT;

[0021] Figure 7 Schematic diagram of the leakage anodic oxidation structure caused by the through-hole design of the existing parallel CMUT;

[0022] Figure 8 is a schematic cross-sectional view of an ultrasonic transducer chip according to an embodiment of the present invention;

[0023] Figure 9 1 is a three-dimensional schematic diagram of an ultrasonic transducer chip in an embodiment of the present invention;

[0024] Figure 10 2D geometric model cross-sectional diagram of an ultrasonic transducer chip in an embodiment of the present invention;

[0025] Figure 11 Detailed parameter diagram of one coil of spring in the ultrasonic transducer chip in an embodiment of the present invention;

[0026] Figure 12This is an enlarged schematic diagram of a spring coil in an ultrasonic transducer chip according to an embodiment of the present invention;

[0027] Figure 13 Graph showing normalized displacement and normalized voltage of an ultrasonic transducer chip in an embodiment of the present invention;

[0028] Figure 14 A panoramic diagram of the relationship between the amplitude and voltage of the ultrasonic transducer chip in an embodiment of the present invention;

[0029] Figure 15 This is a partial enlarged diagram of the negative slope amplitude and voltage of the ultrasonic transducer chip in an embodiment of the present invention;

[0030] Figure 16 Schematic diagram of geometric configuration parameters of the lower electrode layer in the ultrasonic transducer chip in an embodiment of the present invention;

[0031] Figure 17 Schematic cross-sectional view of the diaphragm and upper electrode layer in the ultrasonic transducer chip according to an embodiment of the present invention;

[0032] Figure 18 Schematic diagram of the cross section of the lower electrode layer in the ultrasonic transducer chip according to an embodiment of the present invention;

[0033] Figure 19 Schematic diagram of common parameters of silicon oxide whiskers in an ultrasonic transducer chip according to an embodiment of the present invention;

[0034] Figure 20 Schematic diagram of the (enhanced) tensile strength parameters of silicon oxide whiskers in an ultrasonic transducer chip according to an embodiment of the present invention;

[0035] Figure 21 Schematic diagram of the geometric distribution of silicon nitride whiskers in an ultrasonic transducer chip according to an embodiment of the present invention;

[0036] Figure 22 Schematic diagram of material parameters of ordinary silicon nitride in an ultrasonic transducer chip according to an embodiment of the present invention;

[0037] Figure 23 Schematic diagram of the geometric distribution of ordinary silicon nitride in the ultrasonic transducer chip in an embodiment of the present invention;

[0038] Figure 24 Schematic diagram of material parameters of aluminum in an ultrasonic transducer chip according to an embodiment of the present invention;

[0039] Figure 25 Schematic diagram of the geometric distribution of aluminum in the ultrasonic transducer chip according to an embodiment of the present invention;

[0040] Figure 26 Schematic diagram of the material properties of air in the cavity of an ultrasonic transducer chip in an embodiment of the present invention;

[0041] Figure 27 Schematic diagram of the geometric distribution of air in the cavity of the ultrasonic transducer chip in an embodiment of the present invention;

[0042] Figure 28 Schematic diagram of the properties of polysilicon material in an ultrasonic transducer chip according to an embodiment of the present invention;

[0043] Figure 29 Schematic diagram of the geometric distribution of polysilicon in an ultrasonic transducer chip according to an embodiment of the present invention;

[0044] Figure 30 Schematic diagram of geometric parameters of anti-collision isolation columns and supporting bases in an ultrasonic transducer chip according to an embodiment of the present invention;

[0045] Figure 31 Schematic diagram of fixed constraint parameters of an ultrasonic transducer chip in an embodiment of the present invention;

[0046] Figure 32 Schematic diagram of the fixed constraint area of ​​the ultrasonic transducer chip in an embodiment of the present invention

[0047] Figure 33 Schematic diagram of gravity parameter setting of an ultrasonic transducer chip in an embodiment of the present invention;

[0048] Figure 34 Schematic diagram of the chip gravity distribution area of ​​the ultrasonic transducer chip in an embodiment of the present invention;

[0049] Figure 35 Schematic diagram of the negative electrode arrangement of the ultrasonic transducer chip in an embodiment of the present invention;

[0050] Figure 36 Schematic diagram of the positive electrode arrangement of the ultrasonic transducer chip in an embodiment of the present invention;

[0051] Figure 37 Schematic diagram of the arrangement of the negative electrode and positive electrode regions of an ultrasonic transducer chip in an embodiment of the present invention;

[0052] Figure 38 Schematic diagram of multi-physics field coupling parameter settings of an ultrasonic transducer chip in an embodiment of the present invention;

[0053] Figure 39 Schematic diagram of meshing quality statistics of an ultrasonic transducer chip in an embodiment of the present invention;

[0054] Figure 40 Schematic diagram of the mesh division effect of the ultrasonic transducer chip in an embodiment of the present invention;

[0055] Figure 41 Schematic diagram of characteristic frequency analysis of an ultrasonic transducer chip in an embodiment of the present invention;

[0056] Figure 42 Schematic diagram of a summary of vibration modes of an ultrasonic transducer chip in an embodiment of the present invention;

[0057] Figure 43 Schematic diagram showing that the cavity utilization rate in the ultrasonic transducer chip in an embodiment of the present invention is better than that of the existing parallel CMUT;

[0058] Figure 44 Schematic diagram of reducing the operating voltage of a positive electrode with a trapezoidal cross section in an ultrasonic transducer chip in an embodiment of the present invention;

[0059] Figure 45 Schematic diagram of a negative slope curve constructed by one coil of a spring in an ultrasonic transducer chip according to an embodiment of the present invention;

[0060] Figure 46 Schematic diagram of comprehensive stress analysis of the ultrasonic transducer chip in an embodiment of the present invention.

[0061] Component number description

[0062] 1. Anti-collision isolation column; 2. Diaphragm; 201. Third insulating layer; 202. Negative electrode layer; 203. Fourth insulating layer; 3. One coil of spring; 301. Tripod spring; 302. Shore support; 303. One hook of sea gold; 4. Wing support; 401. Feather membrane; 402. Support square; 5. Support bottom; 6. Cavity; 7. Lower electrode layer; 701. First insulating layer; 702. Positive electrode layer; 703. Second insulating layer. DETAILED DESCRIPTION

[0063] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0064] See also Figures 8 to 46 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0065] The advanced electro-accommodative electromechanical ultrasonic transducer chip unit of the present invention is also called AHOCNUT chip. The innovations of the present invention are as follows: Innovation 1: Constructing a negative slope spring coil 3 structure (breaking through the 33% utilization limit of cavity 6, reaching more than 58%, and improving performance by 76%); Innovation 2: Constructing a lower electrode layer 7 with a trapezoidal low-voltage cross-section (containing insulating layers on the upper and lower surfaces); Innovation 3: Constructing an anti-collision isolation column 1 (large amplitude / package base) + corrosion-resistant passivated diaphragm 2 + cavity 6; Among them: the maximum spacing between the upper and lower electrodes: 19um / 19000nm, the height / physical spacing of cavity 6 (the lower surface of the diaphragm 2 and the upper surface of the lowest point of the lower electrode layer 7): 17um / 17000nm, the radius of the diaphragm 2: 135um / 135000nm, the thickness of the diaphragm 2: 1.5945um / 1594.5nm; the above core 4 parameters are the same as those of the parallel model for comparison, please refer to the details. Figure 10 .

[0066] See also Figures 1 to 46 The present invention provides an advanced electro-containment electromechanical ultrasonic transducer chip unit, comprising a first component structure and a second component structure enclosed in the first component structure, the first component structure and the second component structure are both annular concave structures as a whole, and a cavity 6 is formed between the first component structure and the second component structure, wherein, in view of the problems of air, water and oxidation corrosion: the structural design of the present invention has eliminated the air through-holes, and the cavity 6 is designed by vacuuming or filling with inert gases such as nitrogen / argon / helium. Since the application scenario of the present invention is in the air, for liquid application scenarios (for example: underwater, deep sea, etc.), it is necessary to use other liquid transitions (matching layers) in the air part of the present invention, and then put it into the corresponding liquid. The material and geometric distribution of the cavity 6: since the silicon nitride used in the present invention has achieved strong insulation, the lowest-cost air can be used in the cavity 6 (no need to improve the insulation capacity). Its material parameters can be found in Figure 26 : The cavity 6 can also be filled with replaceable media (materials with better insulation): nitrogen N2, helium He, neon Ne, argon Ar, krypton Kr, xenon Xe. The geometric distribution of air in the cavity 6 can be found in Figure 27 ;

[0067] The first component structure includes an anti-collision isolation column 1, a supporting bottom 5 connected to the anti-collision isolation column 1, and a lower electrode layer 7 located in the cavity 6. The cross-sectional shape of the lower electrode layer 7 is a trapezoid. The lower electrode layer 7 includes a first insulating layer 701, a positive electrode layer 702 located directly below the first insulating layer 701, and a second insulating layer 703 located directly below the positive electrode layer 702. The positive electrode layer 702 is located between the first insulating layer 701 and the second insulating layer 703. The upper surface of the first insulating layer 701 is located in the cavity 6, and the second insulating layer 703 is located directly below the positive electrode layer 702. The lower surface of 3 is connected to the supporting base 5, wherein the specific geometric configuration parameters of the lower electrode layer 7 with a low-voltage trapezoidal cross-section are as follows: the angle between the hypotenuse and the base: about 6.6 degrees; the length of the hypotenuse: 119180nm; the thickness of the substrate of the hypotenuse: 3973.7nm; the substrate width of the short parallel side of the trapezoid: 16600nm; the thickness of the substrate of the short parallel side of the trapezoid: 4000nm; the distance between the highest point of the hypotenuse and the lower surface of the diaphragm 2: 3345.1nm. For the specific geometric configuration parameters of the lower electrode layer 7 with a trapezoidal low-voltage cross-section, please refer to Figure 16 The low-voltage trapezoidal lower electrode layer 7 makes the operating voltage of the AHOCNUT chip 60.88% lower than that of the existing parallel CMUT. The specific value of the low-voltage trapezoidal lower electrode layer 7 making the AHOCNUT operating voltage lower can be found in the following table. Figure 44 ;

[0068] The second component structure includes a spring coil 3 arranged on the inner side of the anti-collision isolation column 1 and a diaphragm 2 connected to the side of the spring coil 3. The spring coil 3 includes a shore support 302, a tripod spring 301 connected to the shore support 302, and a sea gold hook 303 connected to the tripod spring 301. The tripod spring 301 is indirectly connected to the anti-collision isolation column 1 through the shore support 302, and the tripod spring 301 is connected to the diaphragm 2 through the shore support 302. For specific parameters of the spring coil 3, please refer to Figure 11 , Figure 11 In the example, L22.839 represents the arc length of 22.839um or 22839nm. For the specific structure of the spring coil 3, please refer to Figure 12 , Figure 12 In the middle, the spring coil 3 structure is divided into three blocks, Anboto 302, Dinghuang 301 and Haijinyigou 303;

[0069] Kishiboto 302: Both the inner and outer sides are ellipses (accurate to nanometers), with a sector angle of 90 degrees. Rotated 180 degrees and mirrored, the inner side is an ellipse with a major axis a = 7383 nm and a minor axis b = 5000 nm; the outer side is an ellipse with a major axis a = 10398.2 nm and a minor axis b = 5050 nm. The two ellipses share a common X = -180,000 nm and are axially symmetrical.

[0070] Dinghuang 301: Both the inner and outer sides are circles (accurate to nanometers), with a sector angle of 180 degrees and a rotation of 0 degrees. The inner side is a circle with a radius of r = 11600nm; the outer side is a circle with a radius of r = 14540nm; the two circles have different centers.

[0071] Haijinyigou 303: Both the inner and outer sides are ellipses (accurate to nanometers), with a sector angle of 90 degrees and a rotation of 180 degrees. The inner side is an ellipse with a major semi-axis a = 10460nm and a minor semi-axis b = 3955.5nm; the outer side is an ellipse with a major semi-axis a = 12398.2nm and a minor semi-axis b = 5050nm. The two ellipses share the same minor semi-axis center (concentric).

[0072] It can be seen that the elastic force of the diaphragm 2 is a linear force, and the spring coil 3 can achieve negative slope control, expand the amplitude and cavity 6 ratio, and the specific steady-state research results (normalized voltage and normalized displacement) are as follows Figure 13 ,Depend on Figure 13 It can be seen that due to the construction of the new structure (different mechanics), the utilization rate of cavity 6 reaches 1-41.88% = 58.12%>> 33% (the maximum value of the theoretical model of the existing global CMUT); the utilization rate of cavity 6 is improved by (58.12%-33%) / 33% = 76.11%; negative slope structure (wide voltage regulation / low-cost circuit): the amplitude increases with the increase of voltage, due to Figure 14 It can be seen that the positive slope improves the utilization of cavity 6 to 1-59.2% = 40.8% > 33% (the maximum value of the existing global CMUT theoretical model), negative slope / negative growth: the amplitude decreases with increasing voltage, amplifying the local amplitude image;

[0073] For details on the changes in amplitude and voltage negative slope, please refer to 15: Figure 15 As can be seen from the figure, from 679V to 694V, as the voltage increases, the amplitude gradually decreases. In other words, the voltage adjustment circuit has an adjustable range of 694-679=15V, and the amplitude is mostly between 9.6 and 9.88um. There is no mandatory requirement for precise voltage regulation and fluctuation. In other words, this provides good chip-level hardware design support for multi-amplitude, wide voltage applicability and low-cost circuits at the application level. The spring coil 3 constructs a negative slope curve to prevent the diaphragm 2 from failing due to maximum adsorption. For details on how to construct a negative slope curve to prevent the diaphragm 2 from failing due to adsorption, please refer to Figure 45 ;

[0074] The diaphragm 2 includes a third insulating layer 201, a negative electrode layer 202 located directly below the third insulating layer 201, and a fourth insulating layer 203 located directly below the negative electrode layer. The negative electrode layer 202 is located between the third insulating layer 201 and the fourth insulating layer 204. The lower surface of the fourth insulating layer 203 is located in the cavity 6. The surface of the anti-collision isolation column 1 is provided with a wing support 4. The wing support 4 includes a feather membrane 401 and a support square 402 connected to the feather membrane. The feather membrane 401 is in a Z-shape, and the support square 402 is in an L-shape. The connection between the feather membrane 401 and the support square 402 is located at Between the anti-collision isolation column 1 and the shore support 302, the support 402 is connected to the lower electrode layer 7 on the other side of the feather membrane 401, and the support 402 is located in the cavity 6. The anti-collision isolation column 1 and the support base 5 are made of polycrystalline silicon or single crystal silicon. The spring coil 3, the third insulating layer 201, and the fourth insulating layer 203 are all made of silicon nitride whiskers. The first insulating layer 701 and the second insulating layer 703 are made of silicon nitride, namely silicon nitride. The negative electrode layer 202 and the positive electrode layer 702 are both made of aluminum or other conductive materials. The wing support 4 is made of silicon nitride.

[0075] The cross-sectional structures of the diaphragm 2 and the lower electrode layer 7 are as follows: Figure 17 and Figure 18 , SiNx is added to the part in contact with the air as a passivation insulating layer; insulation description: silicon nitride A (0.4um lower layer of diaphragm 2, 1.6um upper layer of substrate, totaling 2um) isolates 2200V, the stoichiometric ratio of SiNx (the fraction of nitrogen in SiNx x), when x>1.32, at this time, the breakdown voltage of 2um thick SiN is 2200V, and the total difference in voltage amplitude between the upper and lower electrodes is: 694*2=1388V<<2200V, so even if the diaphragm 2 is adhered, it will not fail due to electrical breakdown; silicon nitride B (the insulating layer thickness on the electrode of the diaphragm 2 is 1.1um) isolates 1100V. At the same time, since the present invention adopts the "negative voltage" (-694V) of the upper electrode and the "positive voltage" (694V) of the lower electrode, the actual voltage difference relative to the zero potential of the air outside the diaphragm 2 is 694V<<1100V, so even if a person accidentally touches the diaphragm 2, it will not cause accidental injury to the user due to electric shock;

[0076] Screenshot of common parameters of silicon nitride whiskers: For common parameters of silicon nitride whiskers, please refer to Figure 19 Silicon nitride whisker (reinforced) tensile strength parameters: range from 13.8GPa (here using the industry's lowest value in 2007) to 130GPa (2022 industry average, particle size 1-3um, price 12 yuan / gram), silicon nitride whisker coverage: spring coil 3 (Haijin Yi Gou 303, Dinghuang 301, Anboto 302), the third insulating layer 201 and the fourth insulating layer 203. Silicon nitride whisker (reinforced) tensile strength parameters please refer to Figure 20 For details on the geometric distribution of silicon nitride whiskers, please refer to Figure 21 ; Ordinary silicon nitride (insulating effect) material parameters and geometric distribution: Ordinary silicon nitride (insulating effect) material parameters and geometric distribution please refer to Figure 22 and Figure 23 ;

[0077] Parameters and geometric distribution of conductive material aluminum AL: For parameters of conductive material aluminum AL, please refer to Figure 24 , the geometric distribution of conductive material aluminum AL please refer to Figure 25 , Replaceable materials, conductive materials: Since the present invention is applicable to air, especially for various special aircraft, aluminum (lightweight and inexpensive) is used as the main material for the positive and negative electrodes. For other scenarios requiring higher voltage or higher current, other more suitable materials can be used. Specific conductive materials are listed as follows: silver Ag, copper Cu, gold Au, platinum Pt, indium, ZnAl (alloy), etc.;

[0078] Supporting main material polysilicon Si material parameters and geometric distribution: Supporting main material polysilicon material parameters refer to Figure 28 For details on the geometric distribution of the main material polysilicon, please refer to Figure 29 , can also use single crystal silicon, according to the market price to make specific choices, only plays the role of physical support; AHOCNUT chip support main material polycrystalline silicon Si geometric parameters please refer to Figure 30 , Figure 30 Middle: Polysilicon high: The lowest end height of the supporting main material polysilicon Si is 79um / 79000nm, the highest end height is 123um / 123000nm, the total height of the array is 125um / 125000nm, the total width of the array is 190*2=380um / 380000nm;

[0079] Specifically, fixed constraints: AHOCNUT chip fixed constraint parameters refer to Figure 31 , AHOCNUT chip fixed constraint area please refer to Figure 32 , where gravity parameter: adopts the default earth gravity acceleration constant of simulation. For AHOCNUT chip gravity parameter setting, please refer to Figure 33 , please refer to the gravity distribution area of ​​AHOCNUT chip Figure 34 ; Electrostatic setting of the upper electrode layer 7: negative electrode -Vdc, AHOCNUT chip negative electrode setting please refer to Figure 35 ; Lower electrode layer 7 electrostatic setting: positive electrode Vdc: AHOCNUT chip positive electrode setting please refer to Figure 36 , AHOCNUT chip negative electrode area setting and AHOCNUT chip positive electrode area setting refer to Figure 37 ;

[0080] Multi-physics coupling: For the AHOCNUT chip multi-physics coupling parameter settings, please refer to Figure 38 ; Meshing: Mesh quality statistics: Average mesh quality 0.85, AHOCNUT chip meshing quality statistics please refer to Figure 39 In order to reduce unnecessary calculations, the silicon substrate that supports the substrate is not included in the grid calculation. For the grid division effect of the AHOCNUT chip, please refer to Figure 40 ; Eigenfrequency and vibration mode: AHOCNUT eigenfrequency analysis please refer to Figure 41 ,Down Figure 41 This is the vibration mode cross-section diagram corresponding to the six characteristic frequencies. For the AHOCNUT vibration mode summary diagram, please refer to Figure 42 ;

[0081] More specifically, the AHOCNUT chip's spring coil and three-coil structure has improved the following two points: 1. Positive slope curve: This allows the original elastic force of the diaphragm 2 to grow in the later stage to catch up with the charge growth force, causing the positive slope curve to continue to increase (the utilization rate of cavity 6 increases from 33% to 40.8%); 2. Negative slope curve: This prevents the maximum amplitude (the utilization rate of cavity 6 reaches 58%) from appearing at the collapse voltage, but isolates a voltage range, so that the adsorption failure caused by obtaining the maximum amplitude completely disappears in the AHOCNUT chip. In other words, the voltage at the maximum amplitude is not the collapse voltage. The negative slope curve increases the collapse voltage by approximately 76% (relative to the original 33%). The AHOCNUT chip has a trapezoidal lower electrode layer 7 structure: Due to the innovative layout of the lower electrode with a trapezoidal cross-section (while ensuring sufficient space for the diaphragm 2 to move), the driving voltage can be lowered. Simulation results of steady-state studies show that compared with existing parallel CMUTs, the present invention reduces the operating voltage by approximately 60%, significantly saving energy.

[0082] AHOCNUT uses silicon nitride whisker material: the material of the spring coil 3 and the non-electrode part of the diaphragm 2. The present invention uses silicon nitride whiskers to provide material protection for the extremely large tensile force on the diaphragm 2; Figure 46It is the AHOCNUT stress comprehensive analysis diagram, among which: the first diagram: stress analysis diagram, the middle diagram: force-displacement direction diagram of the 1st and 3rd extreme points, the last diagram: force-displacement direction diagram of the 2nd extreme point; from the stress analysis diagram of the simulation results, we know that when the amplitude of the diaphragm 2 reaches the extreme value of 9.88um: the 1st maximum stress point (located at positive and negative 140um): the tensile force on the structural part "Haijin Yi Gou 303" is 2.19GPa, which is about 15.87% (about one-seventh) of the tensile strength of the silicon nitride whisker of 13.8GPa, which is far from reaching the fracture limit. The second maximum stress point (located at + / - 180 μm): The tensile force between the shore support 302 and the silicon nitride isolation layer on the silicon sidewall of the substrate is 0.932 GPa, which is about 6.75% (about one-fifteenth) of the tensile strength of the silicon nitride whisker of 13.8 GPa, far from the fracture limit. The third maximum stress point (located at + / - 148.585 μm): The tensile force at the tripod spring 301 in the structure is 0.8095 GPa, which is about 5.87% (about one-seventeenth) of the tensile strength of the silicon nitride whisker of 13.8 GPa, far from the fracture limit.

[0083] Reduced packaging difficulty and cost (surface lead removal and installation of anti-collision isolation columns): Since the present invention is applied in air, the diaphragm 2 requires space for upward movement. Currently, 80% of the cost of existing CMUT chips is in the packaging. However, through chip design, we have cleverly integrated the packaging wire bonding and photolithography steps. The anti-collision isolation columns make it possible to package only by adding a mesh spacer above the isolation column. At the same time, the spacer is integrated with the chip's peripheral packaging material in a single step, reducing the packaging difficulty and cost. The diaphragm 2's cavity 6 utilization rate of 58% "exceeds" the global existing CMUT theoretical average of 33%. The cavity 6 utilization rate of AHOCNUT is significantly better than that of parallel CMUT. Please refer to Figure 43 Compared with the parallel CMUT (Figure 1), the present invention (Figure 2) has a higher utilization rate of the cavity 6 (the curve goes deeper).

[0084] In summary, the present invention is suitable for both military and civilian use, significantly improving the performance of directional acoustic energy weapons and military applications, and is also suitable for civilian-related directional acoustic energy applications. The spring coil 3 of the present invention achieves negative slope control, expanding the amplitude and cavity 6 ratio, achieving a 58% cavity 6 utilization rate, which has significantly exceeded the global theoretical limit of 33%. This overcomes the lack of elasticity and improves the utilization rate of cavity 6. The inclined surface of the lower electrode layer 7, with a trapezoidal cross-section, enables a lower driving voltage, greatly saving energy. The diaphragm 2 is made of silicon nitride whiskers, which can provide material support for the extremely large tensile forces on the diaphragm 2. As a nanoscale / nanoelectromechanical chip, the present invention provides a solid chip design foundation for the application of ultrasonic directional energy. Therefore, the present invention effectively overcomes the various shortcomings of the existing technology and has very high industrial utilization value.

[0085] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An advanced electromechanical ultrasonic transducer chip unit, characterized by: It includes a first component structure and a second component structure enclosed in the first component structure, a cavity is formed between the first component structure and the second component structure, the first component structure includes an anti-collision isolation column, a supporting bottom connected to the anti-collision isolation column and a lower electrode layer located in the cavity, the cross-sectional shape of the lower electrode layer is trapezoidal, the second component structure includes a spring coil arranged on the inner side of the anti-collision isolation column and a diaphragm connected to the side of the spring coil, the spring coil includes a shore support, a tripod spring connected to the shore support and a sea gold hook connected to the tripod spring, the tripod spring is indirectly connected to the anti-collision isolation column through the shore support, and the tripod spring is connected to the diaphragm through the sea gold hook.

2. The advanced electromechanical ultrasonic transducer chip unit according to claim 1, characterized in that: The first component structure and the second component structure are both annular concave structures as a whole.

3. The advanced electromechanical ultrasonic transducer chip unit according to claim 1, characterized in that: The lower electrode layer includes a first insulating layer, a positive electrode layer located directly below the first insulating layer, and a second insulating layer located directly below the positive electrode layer. The positive electrode layer is located between the first insulating layer and the second insulating layer. The upper surface of the first insulating layer is located in the cavity, and the lower surface of the second insulating layer is connected to the supporting bottom.

4. The advanced electromechanical ultrasonic transducer chip unit according to claim 3, characterized in that: The diaphragm includes a third insulating layer, a negative electrode layer located directly below the third insulating layer, and a fourth insulating layer located directly below the negative electrode layer. The negative electrode layer is located between the third insulating layer and the fourth insulating layer, and the lower surface of the fourth insulating layer is located in the cavity.

5. The advanced electromechanical ultrasonic transducer chip unit according to claim 4, characterized in that: A wing support is provided on the surface of the anti-collision isolation column, and the wing support includes a feather membrane and a support connected to the feather membrane. The feather membrane is Z-shaped, and the support is L-shaped. The connection between the feather membrane and the support is located between the anti-collision isolation column and the shore support. The support is connected to the lower electrode layer on the other side of the feather membrane, and the support is located in the cavity.

6. The advanced electromechanical ultrasonic transducer chip unit according to claim 5, characterized in that: The anti-collision isolation column and the support bottom are made of polycrystalline silicon or single crystal silicon, the first coil of the spring, the third insulating layer and the fourth insulating layer are all made of silicon nitride whiskers, the first insulating layer and the second insulating layer are both made of silicon nitride, i.e., silicon nitride tetranitride, the negative electrode layer and the positive electrode layer are both made of aluminum or other conductive materials, and the wing support is made of silicon nitride.

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