Micromechanical system resonator and sensor

Abstract

The application discloses a micro mechanical system resonator and sensor, which comprises a substrate, an input signal terminal, an output signal terminal and a plurality of resonant components; each resonant component comprises a fixed electrode arranged on the substrate; a vibrating electrode arranged in parallel and suspended above the side of the fixed electrode away from the substrate, wherein the orthographic projection of the vibrating electrode on the substrate covers the orthographic projection of the fixed electrode on the substrate; and a first support structure arranged on the side of the substrate close to the vibrating electrode and connected with the vibrating electrode. The micro mechanical system resonator and sensor provided by the application have the advantages of simple process, low cost, small device quality, small device volume and small required excitation level.

Description

TECHNICAL FIELD

[0001] The present application relates to the chip technical field, and particularly to a micro-mechanical system resonator and a sensor. BACKGROUND

[0002] The MEMS (Micro-electromechanical Systems) resonator is widely used in the fields of communication, radar, audio and clock circuit, etc. due to its advantages of easy temperature compensation, low jitter and easy integration.

[0003] The existing MEMS resonator is mostly a finger capacitor resonator. Since the finger capacitor is a transverse device, the capacitor area is related to the finger height. In order to increase the device height, the SOI (Silicon-on-insulator) wafer processing must be used, and the cost is relatively high. In order to increase the signal strength and ensure sufficient electrode area, the longitudinal height of a single finger should be larger, and the number of fingers should be more. Therefore, the DRIE (Deep Reactive Ion Etching) process is used to etch the silicon wafer. Since the process uniformity requirement is high, the process difficulty and cost are greatly increased. Moreover, the DRIE process forms a scallop structure on the finger capacitor plate, resulting in a stray signal. In addition, the more the number of fingers and the larger the height of a single finger, the larger the mass of the device, the larger the excitation level required, the higher the power consumption, and the increased impedance and leakage current. SUMMARY

[0004] The present application provides a micro-mechanical system resonator and a sensor to solve the technical problems of high cost, high process difficulty, poor signal stability and high power consumption of the existing technology of etching the SOI wafer by the DRIE process.

[0005] In view of the above problems, the present application is proposed to provide a micro-mechanical system resonator and a sensor which overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect, a micro-mechanical system resonator is provided, comprising: a substrate, an input signal terminal, an output signal terminal and a plurality of resonant components; the input signal terminal and the output signal terminal are respectively arranged on the substrate, and the input signal terminal, the resonant components and the output signal terminal are electrically connected in sequence.

[0007] Each of the resonant components comprises:

[0008] a fixed electrode arranged on the substrate;

[0009] a vibrating electrode, which is parallel and suspended above a side of the fixed electrode away from the substrate, a projection of the vibrating electrode on the substrate covering a projection of the fixed electrode on the substrate;

[0010] a first support structure, which is disposed on a side of the substrate close to the vibrating electrode and connected with the vibrating electrode.

[0011] Optionally, N resonant assemblies are connected in series, wherein the vibrating electrode of each resonant assembly is electrically connected with the fixed electrode of the previous resonant assembly in the direction of current transmission; or the fixed electrode of each resonant assembly is electrically connected with the vibrating electrode of the previous resonant assembly in the direction of current transmission.

[0012] Optionally, N resonant assemblies are connected in parallel.

[0013] Optionally, the fixed electrode comprises an excitation electrode plate and an induction electrode plate; the excitation electrode plate of each resonant assembly is connected with the input signal terminal, and the induction electrode plate of each resonant assembly is connected with the output signal terminal.

[0014] Optionally, the fixed electrode of each resonant assembly is connected with the input signal terminal, and the vibrating electrode of each resonant assembly is connected with the output signal terminal; or the vibrating electrode of each resonant assembly is connected with the input signal terminal, and the fixed electrode of each resonant assembly is connected with the output signal terminal.

[0015] Optionally, further comprising: an insulating layer, a first conducting wire, a second support structure and a second conducting wire;

[0016] The insulating layer is disposed on a side of the substrate close to the resonant assembly, and the resonant assembly is disposed on the insulating layer;

[0017] The first conducting wire is disposed on a side of the insulating layer close to the resonant assembly, and the first conducting wire connects the input signal terminal and the output signal terminal with the resonant assembly and interconnects a plurality of resonant assemblies;

[0018] The second support structure is disposed between the first conducting wire and the insulating layer, and the second support structure comprises a groove penetrating the second support structure in a direction perpendicular to the substrate, and the lower end of the first conducting wire penetrates the groove to contact the insulating layer;

[0019] The second conducting wire is disposed on a side of the insulating layer close to the resonant assembly, and the second conducting wire connects the first conducting wire with the fixed electrode and interconnects a plurality of fixed electrodes.

[0020] Optionally, the end of the vibrating electrode of two adjacent resonant assemblies is in contact.

[0021] Optionally, the first support structure is connected with the vibrating electrode of two or more resonant assemblies.

[0022] Optionally, the first support structure comprises an anchor block and an anchor beam, and the substrate, the anchor block, the anchor beam and the vibrating electrode are sequentially connected.

[0023] In a second aspect, a sensor is provided, comprising the micro-mechanical system resonator of the first aspect.

[0024] The technical scheme provided by the present application has at least the following technical effects or advantages:

[0025] The micro-mechanical system resonator and the sensor provided by the present application have the following advantages. Firstly, the fixed electrode of the resonant assembly is directly arranged on the surface of the substrate, and the vibrating electrode of the resonant assembly is arranged in parallel and suspended above the fixed electrode. The epitaxial process can be used to form the longitudinally arranged resonant assembly on the substrate on the surface of the ordinary wafer, so that the expensive SOI wafer does not need to be etched by the DRIE process, thereby reducing the production cost. Secondly, the device mass of the longitudinally arranged resonant assembly is relatively small, and the required excitation level is relatively small, so the power consumption is small. The micro-mechanical system resonator provided by the present application further realizes differential output to increase the signal strength, has high stability and strong anti-interference ability through the series-parallel structure of multiple resonant assemblies.

[0026] The above description is only a summary of the technical scheme of the present application. In order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0027] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Moreover, the same reference numerals in the accompanying drawings indicate the same or similar components. In the drawings:

[0028] Figure 1 FIG. 1 is a schematic diagram of a micro-mechanical system resonator in an embodiment of the present application;

[0029] Figure 2 FIG. 2 is a schematic diagram of a resonant assembly in an embodiment of the present application;

[0030] Figure 3 FIG. 3 is a schematic diagram of a first mode of a square plate in an embodiment of the present application;

[0031] Figure 4 Second mode of square plate in the embodiment of the application;

[0032] Figure 5 Square vibration electrode in the embodiment of the application;

[0033] Figure 6 First series connection of the resonant assembly in the embodiment of the application;

[0034] Figure 7 Second series connection of the resonant assembly in the embodiment of the application;

[0035] Figure 8 First parallel connection of the resonant assembly in the embodiment of the application;

[0036] Figure 9 Second parallel connection of the resonant assembly in the embodiment of the application;

[0037] Figure 10 Third parallel connection of the resonant assembly in the embodiment of the application;

[0038] Figure 11 First end contact of the vibration electrode of the resonant assembly in the embodiment of the application;

[0039] Figure 12 Second end contact of the vibration electrode of the resonant assembly in the embodiment of the application;

[0040] Figure 13 First common anchor block of the vibration electrode of the resonant assembly in the embodiment of the application;

[0041] Figure 14 Second common anchor block of the vibration electrode of the resonant assembly in the embodiment of the application;

[0042] Figure 15 Connection of the resonant assembly in the embodiment of the application;

[0043] Figure 16 Figure 15 A-A section in the embodiment of the application;

[0044] Figure 17 Figure 15 B-B section in the embodiment of the application;

[0045] Figure 18 Manufacturing process of the micro-mechanical system resonator in the embodiment of the application.

[0046] ​​Wherein, 1 is a substrate, 101 is an insulating layer, 2 is an input signal terminal, 3 is an output signal terminal, 4 is a resonant component, 401 is a fixed electrode, 402 is a vibrating electrode, 401a is an excitation electrode plate, 401b is an induction electrode plate, 403 is a first support structure, 403a is an anchor block, 403b is an anchor beam, 5 is a first lead wire, 6 is a second support structure, and 7 is a second lead wire. DETAILED DESCRIPTION

[0047] Exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0048] Various structural diagrams according to embodiments of the present application are shown in the accompanying drawings. These diagrams are not drawn to scale, in which certain details are exaggerated for the purpose of clarity and can omit certain details. The shapes of various regions, layers, and their relative sizes and positional relationships shown in the drawings are merely exemplary, and in actuality can deviate due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes, and relative positions can be additionally designed by those skilled in the art as needed.

[0049] In the context of the present disclosure, when a layer / element is referred to as being located "on" another layer / element, the layer / element can be directly on the other layer / element, or there can be an intervening layer / element therebetween. In addition, if a layer / element is located "on" another layer / element in one orientation, it can be located "under" the other layer / element when the orientation is reversed. In the context of the present disclosure, similar or identical components can be indicated by the same or similar reference numerals.

[0050] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with specific embodiments, and it should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, and not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0051] All mechanical structures have fixed vibration modes called modes (the "mode" can be understood as "a series of independent components that do not affect each other"), and the same structure has multiple different vibration modes called modes, some of which are easy to excite and stable, and can be used for the manufacture of MEMS resonators. MEMS resonators are widely used due to their easy temperature compensation, low jitter, easy integration, and other advantages.

[0052] Take the flat plate capacitive MEMS resonator as an example, it contains at least one pair of parallel electrode plates, one of which is a vibrating component that vibrates under the action of excitation current, and the other is an induction electrode plate that outputs induction current outward. The existing flat plate capacitive MEMS resonator usually uses DRIE (Deep Reactive Ion Etching) process to etch parallel electrode plates on SOI wafer, which has high manufacturing cost and process difficulty, and the etched parallel electrode plates need to have a certain longitudinal height. The greater the etching depth, the more the shell-shaped morphology of the sidewall of the electrode plate will be formed, resulting in the generation of stray signals. It can be understood that the shell-shaped morphology is the whole sidewall of the electrode plate, such as etching a depth of 50um, the DRIE process is not etched at one time, but many times, for example, etching 2um at a time, each etching will form a shell groove, resulting in the formation of a sawtooth-shaped capacitive flat plate electrode.

[0053] Therefore, the present application provides a micro-mechanical system resonator, as shown in Figure 1 including: a substrate 1, an input signal terminal 2, an output signal terminal 3 and a plurality of resonant components 4; the input signal terminal 2 and the output signal terminal 3 are arranged on the substrate 1, and the input signal terminal 2, the resonant component 4 and the output signal terminal 3 are electrically connected in sequence. As shown in Figure 2 each resonant component 4 includes: a fixed electrode 401, a vibrating electrode 402 and a first support structure 403, the fixed electrode 401 is arranged on the substrate 1, the vibrating electrode 402 is arranged in parallel and suspended above the side of the fixed electrode 401 away from the substrate 1, and the orthogonal projection of the vibrating electrode 402 on the substrate 1 covers the orthogonal projection of the fixed electrode 401 on the substrate 1. The first support structure 403 is arranged on the side of the substrate 1 close to the vibrating electrode 402 and connected with the vibrating electrode 402.

[0054] As shown in Figure 2 the first support structure 403 includes an anchor block 403a and an anchor beam 403b, the end of the vibrating electrode 402 is connected with the anchor block 403a through the anchor beam 403b, so that the vibrating electrode 402 has a certain torsional freedom.

[0055] It can be understood that the resonant component 4 can be formed on the substrate 1 directly by deposition process, not limited to using expensive SOI wafer and DRIE etching, so the substrate 1 can use single crystal silicon wafer, SOI wafer, glass wafer, gallium nitride wafer or silicon carbide wafer, etc. The substrate 1 uses ordinary wafer, which has low manufacturing cost and small process difficulty.

[0056] After the fixed electrode 401 and the anchor block 403a are deposited, a sacrificial layer is prepared and patterned, and the vibrating electrode 402 and the anchor beam 403b are integrally deposited in the patterned window. After the sacrificial layer is removed, the vibrating electrode 402 is formed in parallel and suspended above the fixed electrode 401 through the anchor block 403a and the anchor beam 403b. Since the orthographic projection of the vibrating electrode 402 on the substrate 1 covers the orthographic projection of the fixed electrode 401 on the substrate 1, a capacitive resonant structure is formed between the vibrating electrode 402 and the fixed electrode 401.

[0057] It can be understood that the micro-mechanical system resonator given in the embodiments of the present application has the fixed electrode 401 and the vibrating electrode 402 of the resonant assembly 4 constituting the upper and lower capacitive plates, and forms a longitudinal plate capacitive resonant assembly 4 on the substrate 1. The resonant vibration of the vibrating electrode 402 is excited by the excitation current, the distance between the capacitive plates is changed, the capacitance is changed, and a stable harmonic signal is obtained.

[0058] Still taking the plate capacitive MEMS resonator as an example, the vibrating electrode 402 is formed above the fixed electrode 401 to constitute the plate capacitive MEMS resonator, and the stable mode of the vibrating electrode 402 under a specific excitation is used to realize stable signal output.

[0059] The technical solutions of the present application will be described in detail below with specific embodiments. The following specific embodiments can be implemented independently or in combination, and the same or similar concepts or processes can not be described in detail in some embodiments.

[0060] For example, the vibrating electrode 402 adopts a square diaphragm, and the connection mode of the vibrating electrode 402 and the anchor block 403a needs to be determined according to the mode of the vibrating electrode 402. The square vibrating electrode 402 has different vibration frequency modes under different current excitations. Through simulation and simulation, an upper and lower plate structure capable of meeting a specific resonant frequency, the position of the anchor block 403a, and the width and length of the anchor beam 403b are obtained, and a better device structure is obtained, thereby saving design and calculation costs. The specific operation is as follows: a simulation model of the square diaphragm is established, the free mode of the square diaphragm is simulated, the vibration mode conducive to forming the capacitance is selected, and the anchor mode is selected according to the vibration mode; or the diaphragm size is adjusted according to the resonant frequency required by the resonator. Each object has its own natural resonant frequency, and these resonant frequencies and their modes are found. Because of energy consumption, an excitation current is needed to make the plate vibrate all the time, otherwise the vibration will dissipate. It can be understood that the excitation current does not need to be loaded in the design stage; the excitation current can be loaded in the device performance simulation stage, which is used to simulate the output, quality factor, and damping ratio of the device.

[0061] For example, the vibrating electrode 402 is formed on the fixed electrode 401, and the vibrating electrode 402 is connected to the anchor block 403a through the anchor beam 403b. Figure 3The diagram shows one mode of a square electrode plate. It can be seen that its mode shape exhibits obvious and regular resonant deformation. The vibrating electrode 402 of the resonant assembly 4 can utilize a square electrode plate in this mode. Figure 3 The light-colored areas at the middle and corners are nodes where the displacement is almost zero during vibration. Therefore, setting anchor blocks 403a at these locations minimizes energy loss. Thus, four vertices can be selected for anchoring based on the mode shape. Figure 3 The dark area at the middle edge is the antinode with the largest amplitude during vibration. Therefore, a fixed electrode 401 is set directly below these positions to achieve stable signal output.

[0062] like Figure 4 In another mode of the square electrode plate shown, the light-colored area at the center has almost zero displacement during vibration, so it is connected to the anchor block 403a at the center, resulting in minimal energy loss. The dark-colored areas at the corners have the largest amplitude during vibration, so fixed electrodes 401 are placed at these locations.

[0063] Understandably, regardless of Figure 3 The anchor block 403a is set at the middle corner, or... Figure 4 Anchor block 403a is set at the center. Both anchoring methods select the position with the least deformation on the plate, resulting in less wear at the anchoring point connected to anchor block 403a. The specific choice can be determined based on actual needs. Regardless of... Figure 3 The fixed electrode 401 set at the middle edge line is still... Figure 4 Fixed electrodes 401 are set at the middle and corners. Both of these sensing methods are implemented by optimizing the design of the resonant component 4 through finite element simulation to ensure that it meets the target frequency.

[0064] The following section uses the example of connecting the square electrode plate to the first support structure 403 of the anchor block at the corner to illustrate the technical solution of this application in detail.

[0065] like Figure 5 As shown, the resonant electrode 402 of the resonant component 4 adopts... Figure 3 The square membrane shown has wave nodes at the four corners of the vibrating electrode 402 connected to the anchor block 403a via anchor beam 403b. The fixed electrode 401 is disposed at the edge of the vibrating electrode 402, forming a capacitive resonant structure with the vibrating electrode 402.

[0066] When the fixed electrode 401 is connected with the input signal terminal 2, it can be used to apply excitation to the vibrating electrode 402, and at this time the fixed electrode 401 is the excitation electrode. When the fixed electrode 401 is connected with the output signal terminal 3, it can be used to send out the induced current generated when the vibrating electrode 402 is excited to vibrate, and at this time the fixed electrode 401 is the induction electrode. The vibrating electrode 402 can also be connected with the input signal terminal 2 to directly receive the excitation current, or connected with the output signal terminal 3 to directly output the vibration current. Due to the fact that the substrate 1 is formed with a plurality of resonant assemblies 4, which can be interconnected in series or in parallel, the specific connection mode of the fixed electrode 401, the vibrating electrode 402, the input signal terminal 2 and the output signal terminal 3 can be designed as needed.

[0067] In an optional embodiment, N resonant assemblies 4 are arranged in series. As shown in Figure 6 Figure 6 is a first series connection diagram of the resonant assembly in the embodiments of the present application. The plurality of resonant assemblies 4 are connected in series between the input signal terminal 2 and the output signal terminal 3, and the current is introduced into the series-connected resonant assemblies 4 through the input signal terminal 2 and then led out through the output signal terminal 3. The vibrating electrode 402 of each resonant assembly 4 is electrically connected with the fixed electrode 401 of the previous resonant assembly 4 in the current transmission direction. Thus, the vibrating electrode 402 of the first resonant assembly 4 in the current transmission direction is connected with the input signal terminal 2, and the fixed electrode 401 of the last resonant assembly 4 in the current transmission direction is connected with the output signal terminal 3. The input signal terminal 2 sends the excitation current to the vibrating electrode 402 of the first resonant assembly 4.

[0068] It can be understood that the vibrating electrode 402 is connected with the anchoring block 403a through the anchoring beam 403b, and the vibrating electrode 402 and the anchoring beam 403b are integrally deposited during production. Therefore, the input signal terminal 2 and the anchoring beam 403b above the anchoring block 403a are connected through a wire, which represents that the input signal terminal 2 is directly electrically connected with the vibrating electrode 402.

[0069] In Figure 6 ​In the series configuration shown, an excitation current is introduced into the input signal terminal 2 and applied to the vibration electrode 402 of the first resonant component 4. The vibration electrode 402 is excited to vibrate, generating an induced current on the fixed electrode 401 of the first resonant component 4. This induced current is transmitted to the vibration electrode 402 of the second resonant component 4, which is also excited to vibrate, generating an induced current on the fixed electrode 401 of the second resonant component 4. This process continues along the current transmission direction, where the induced current of the previous resonant component 4 serves as the excitation current for the next resonant component 4, until the induced current signal generated on the fixed electrode 401 of the last resonant component 4 is sent to the outside of the micromechanical system resonator through the output signal terminal 3.

[0070] It should be noted that in the series connection scheme of the resonant component 4, the four fixed electrodes 401 belonging to the same resonant component 4 as each vibrating electrode 402 only serve to output the induced current. Therefore, the four fixed electrodes 401 of each resonant component 4 can be connected by wires, which is equivalent to a sensing electrode plate.

[0071] like Figure 7 As shown, Figure 7 This is a schematic diagram of a second series connection of resonant components in an embodiment of this application. Alternatively, the input signal terminal 2 can be connected to the fixed electrode 401 of the first resonant component 4, and the output signal terminal 3 can be connected to the vibration electrode 402 of the last resonant component 4, so that multiple resonant components 4 are connected in series between the input signal terminal 2 and the output signal terminal 3. The fixed electrode 401 of each resonant component 4 is electrically connected to the vibration electrode 402 of the previous resonant component 4 along the current transmission direction. This creates a current transmission method where the induced current of the previous resonant component 4 serves as the excitation current for the next resonant component 4, until the vibration current signal generated on the vibration electrode 402 of the last resonant component 4 is sent to the outside of the micromechanical system resonator through the output signal terminal 3.

[0072] It is understandable that the vibration electrode 402 is connected to the anchor block 403a through the anchor beam 403b. During production, the vibration electrode 402, the anchor beam 403b and the anchor block 403a are integrally deposited. Therefore, the output signal terminal 3 is connected to the anchor block 403a through a wire, which means that the output signal terminal 3 is directly electrically connected to the vibration electrode 402.

[0073] In an optional implementation, N resonant components are connected in parallel. For example... Figure 8 As shown, Figure 8 This is a schematic diagram of a first parallel connection of resonant components in an embodiment of this application. The fixed electrode 401 of each resonant component 4 is connected to the input signal terminal 2, and the vibrating electrode 402 of each resonant component 4 is connected to the output signal terminal 3; or as...Figure 9 As shown in the figure, the vibration electrode 402 of each resonant component 4 is connected with the input signal terminal 2, and the fixed electrode 401 of each resonant component 4 is connected with the output signal terminal 3.

[0074] In an optional embodiment, the fixed electrode 401 comprises an excitation electrode plate 401a and a sensing electrode plate 401b. The four fixed electrodes 401 can be divided into two oppositely arranged excitation electrode plates 401a and two oppositely arranged sensing electrode plates 401b.

[0075] For example, as shown in the figure, Figure 10 As shown in the figure, Figure 10 is a third parallel schematic diagram of the resonant component in the embodiments of the present application. When the plurality of resonant components 4 are interconnected in parallel, the excitation electrode plate 401a of each resonant component 4 is connected with the input signal terminal 2, for introducing the excitation current signal from the input signal terminal 2 to provide excitation for the vibration electrode 402. The sensing electrode plate 401b of each resonant component 4 is connected with the output signal terminal 3, for sending out the vibration current signal generated on the vibration electrode 402 through the output signal terminal 3.

[0076] It can be understood that the connection of the excitation electrode plate 401a of each resonant component 4 with the input signal terminal 2 does not limit that each excitation electrode plate 401a is directly connected with the input signal terminal 2 through a wire. The excitation electrode plates 401a far away from the input signal terminal 2 can be interconnected through wires and connected with the input signal terminal 2 through at least one excitation electrode plate 401a, so that all the excitation electrode plates 401a can receive the excitation current. Similarly, the sensing electrode plates 401b far away from the output signal terminal 3 can be interconnected through wires and connected with the output signal terminal 3 through at least one sensing electrode plate 401b, so that the sensing current on all the sensing electrode plates 401b can be outputted.

[0077] This is because, if both the excitation electrode plates 401a of each resonant component 4 are directly connected with the input signal terminal 2 through wires, a wire frame for inputting the excitation current will be formed on the substrate 1, and if both the sensing electrode plates 401b of each resonant component 4 are directly connected with the output signal terminal 3 through wires, a wire frame for outputting the sensing current will be formed on the substrate 1. The sensing electrode plates 401b are arranged apart from the excitation electrode plates 401a, and if both the wire frame for inputting the excitation current and the wire frame for outputting the sensing current are routed on the substrate 1, the crossing between the two wire frames will conduct the excitation electrode plates 401a and the sensing electrode plates 401b. If this situation is to be avoided, a more complex routing mode needs to be set to isolate the two wire frames.

[0078] Therefore, still as shown in the figure, Figure 10As shown, input signal terminal 2 is connected to at least one of the excitation electrode plates 401a of the multiple resonant components 4, and the remaining excitation electrode plates 401a are interconnected nearby. Similarly, output signal terminal 3 is connected to at least one of the induction electrode plates 401b of the multiple resonant components 4, and the remaining induction electrode plates 401b are interconnected nearby. This connection method ensures that the excitation current input line and the induction current output line do not interfere with each other.

[0079] As an optional implementation, the ends of the oscillating electrodes 402 of two adjacent resonant components 4 are in contact. When the ends of the oscillating electrodes 402 are in contact, they are electrically connected. The end contact can reduce the distance between the resonant components 4, thereby reducing the overall device area and also reducing the device weight.

[0080] For example, such as Figure 11 In the example of end contact of multiple resonant components, in one feasible solution, when the input signal terminal 2 is connected to one of the multiple resonant electrodes 402 with end contact relationships, all other resonant electrodes 402 do not need to be connected to the input signal terminal 2. Figure 11 In the process, the input signal terminal 2 applies an excitation current to the nearest vibration electrode 402. The excitation current is transmitted to the vibration electrode 402 of each resonant component 4. The induced current of all resonant components 4 can be extracted by interconnecting the four fixed electrodes 401 of each resonant component 4 and interconnecting one fixed electrode 401 of the resonant component 4 with one fixed electrode 401 of the adjacent resonant component 4 and connecting it to the output signal terminal 3.

[0081] It is understandable that at this time, the distance between the fixed electrodes 401 between two adjacent resonant components 4 is very close, and they can be deposited as a single unit.

[0082] For example, such as Figure 12 In the second example of multiple resonant components 4 with end contacts, in one feasible scheme, the fixed electrode 401 of each resonant component 4 is connected to the input signal terminal 2, and one of the vibrating electrodes 402 is connected to the output signal terminal 3. Figure 12 It can be seen that the fixed electrodes 401 of two adjacent resonant components 4 can be made as a single piece. This is because the contact between the ends of the vibrating electrodes 402 of the two resonant components 4 brings the resonant components 4 closer together. The single-piece fixed electrode 401 has good conductivity and does not increase the manufacturing difficulty. It is understandable that the vibrating electrodes 402 of two adjacent resonant components 4 can also be made as a single piece. The single-piece vibrating electrode 402 has even better conductivity and similarly does not increase the manufacturing difficulty.

[0083] As an optional embodiment, the first support structure 403 is connected with the vibration electrodes 402 of two or more resonant assemblies 4. That is, the vibration electrodes 402 of two or more resonant assemblies 4 share one anchor block 403a, which can also save space and reduce the size and mass of the chip.

[0084] It can be understood that the vibration electrodes 402 also have an electrical connection relationship when sharing the anchor block 403a. The vibration electrodes 402 are connected with the anchor block 403a through the anchor beams 403b, so the anchor beams 403b of the two vibration electrodes 402 sharing one anchor block 403a are also interconnected, and the current on one vibration electrode 402 can be transmitted to the other vibration electrode 402 through the interconnected anchor beams 403b. For example, as shown in Figure 13 The anchor block sharing example one of the multiple resonant assemblies is given, when the input signal terminal 2 is connected with one of the vibration electrodes 402 sharing the anchor block 403a in turn, all the other vibration electrodes 402 do not need to be connected with the input signal terminal 2, Figure 13 In the anchor block sharing example two of the multiple resonant assemblies, when the input signal terminal 2 loads the excitation current to the vibration electrode 402 of the closest first resonant assembly 4, the excitation current will be transmitted to the vibration electrode 402 of each resonant assembly 4 through the anchor beams 403b, and the fixed electrodes 401 of each resonant assembly 4 are connected with the input signal terminal 2 respectively, so that the induced current of all the resonant assemblies 4 can be led out.

[0085] For example, as shown in Figure 14 The anchor block sharing example two of the multiple resonant assemblies is given, the input signal terminal 2 is connected with at least one of the excitation electrode plates 401a of the multiple resonant assemblies 4, and the rest of the excitation electrode plates 401a are interconnected as needed. The output signal terminal 3 is connected with at least one of the induction electrode plates 401b of the multiple resonant assemblies 4, and the rest of the induction electrode plates 401b are interconnected as needed.

[0086] As an optional embodiment, the micromechanical system resonator further comprises: an insulating layer 101, a first wire 5, a second support structure 6, and a second wire 7, wherein the second support structure 6 is used to support the first wire 5. As shown in Figure 15 , Figure 15 The connection diagram of the resonant assembly in the embodiment of the application is shown.

[0087] The first wire 5 is used to connect the input signal terminal 2 and the output signal terminal 3 with the resonant assembly 4, and to interconnect the multiple resonant assemblies 4. For example, the first wire 5 can interconnect the two resonant assemblies 4 by connecting the vibration electrodes 402 thereof, and the second support structure 6 of the first wire 5 is adapted to connect the two anchor blocks 403a. The first wire 5 is connected with the anchor beam 403b corresponding to the vibration electrode 402, that is, the connection with the vibration electrode 402 is realized. As shown inFigure 16 As shown, Figure 16 For Figure 15 A-A cross-sectional view. The insulating layer 101 is formed on the substrate 1, and the resonant assembly 4 is formed on the insulating layer 101. Exemplarily, the insulating layer 101 is generally two layers, the first layer is a silicon dioxide material, and the second layer is a silicon nitride material, which is not limited here.

[0088] As shown, the first wire 5 is disposed on the side of the insulating layer 101 away from the substrate 1, and the second support structure 6 is disposed between the first wire 5 and the insulating layer 101. The second support structure 6 includes a groove penetrating the second support structure 6 in a direction perpendicular to the substrate 1, and the lower end of the first wire 5 penetrates the groove to contact the insulating layer 101. Figure 16 The second wire 7 is disposed on the side of the insulating layer 101 away from the substrate 1, and the second wire 7 connects the first wire 5 with the fixed electrode 401 and interconnects multiple fixed electrodes 401. Exemplarily, the second wire 7 interconnects multiple resonant assemblies 4 by interconnecting multiple fixed electrodes 401.

[0089] Figure 17 As shown, the second wire 7 directly connects the fixed electrodes 401 of two adjacent resonant assemblies 4.

[0090] It should be noted that, Figure 15 The resonant assembly interconnection mode given in the above is only to represent an example of interconnecting multiple resonant assemblies 4 by the first wire 5 and the second wire 7, Figure 16 is to show an example of interconnecting resonant assemblies by the first wire 5, Figure 16 is to show an example of interconnecting resonant assemblies by the second wire 7, Figure 15 , Figure 16 and Figure 17 are not used to limit the specific interconnection relationship between actual resonant assemblies.

[0091] It can be understood that the fixed electrode 401, the anchor block 403a, the second support structure 6, and the second wire 7 can be deposited at one time and then etched apart by a patterning process, and thus can be collectively referred to as a lower electrode. That is, when the first wire 5 interconnects two resonant assemblies 4 by connecting the vibration electrodes 402 of the two resonant assemblies 4, the second support structure 6 of the first wire 5 is adapted to connect the two anchor blocks 403a. The vibration electrode 402, the anchor beam 403b, and the first wire 5 can also be deposited integrally and then etched apart by a patterning process, and thus can be collectively referred to as an upper electrode.

[0092] ​The vibration electrode 402 of the resonant component 4 is above the fixed electrode 401, and the two are not consistent in height, thus forming two wiring modes on the substrate 1. The first conductor 5 is consistent in height with the vibration electrode 402, is integrally deposited with the vibration electrode 402 during preparation, has the same material as the vibration electrode 402, can adopt a material with relatively good conductivity, is mainly used for connecting the input signal terminal 2 and the output signal terminal 3 with the resonant component 4, and is used for interconnecting resonant components 4 that are far apart. The second conductor 7 is consistent in height with the fixed electrode 401, is integrally deposited with the fixed electrode 401 during preparation, and is mainly used for short-distance transmission between the fixed electrodes 401. The first conductor 5 has good conductivity and is not suitable for short-distance transmission between the fixed electrodes 401, because it can form a transverse capacitance structure with the vibration electrode 402 plate at too close a distance, which can cause unnecessary vibration of the vibration electrode 402 plate when a transmission current signal is present on it, and cause deviation of the induced current signal.

[0093] The following will be described in combination with Figure 18 The following will be described in combination with

[0094] When the micro-mechanical system resonator is manufactured by using an epitaxy process, the fixed electrode 401, the anchor block 403a, the second support structure 6, and the second conductor 7 belong to the same layer and have a connection relationship, can be deposited by using the same raw material at one time, and thus can be collectively referred to as a lower electrode. The vibration electrode 402, the anchor beam 403b, and the first conductor 5 belong to the same layer and have a connection relationship, can be deposited by using the same raw material at one time, and thus can be collectively referred to as an upper electrode. The input signal terminal 2 and the output signal terminal 3 are collectively referred to as a terminal.

[0095] S1801, depositing a first epitaxial layer on the insulating layer 101. The first epitaxial layer material can adopt, but is not limited to, semiconductor materials such as polysilicon, silicon carbide, silicon, germanium, carbon, and silicon germanium. In-situ doping or ion implantation is selected according to the resistivity requirement, and the corresponding process is selected according to the deposition material to release residual stress.

[0096] S1802, patterning the first epitaxial layer by a photolithography process to form a lower electrode of the device. The lower electrode is divided into four parts, the fixed electrode 401, the anchor block 403a, the second support structure 6, and the second conductor 7.

[0097] S1803, depositing a sacrificial layer and patterning the sacrificial layer. According to the material of the sacrificial layer, a corresponding annealing process is adopted to release residual stress and eliminate the composition and thickness of the intermediate product stable material, such as TEOS of LPCVD, 1050℃ annealing for 2 hours; the thickness of the sacrificial layer determines the distance between the fixed electrode 401 and the vibrating electrode 402, which is a key parameter in the process; through etching technology, the sacrificial layer is patterned, and the patterned area reserves the area of the vibrating electrode 402, the first wire 5 and the anchor beam 403b, and also reserves the anchor window connecting the anchor beam 403b and the anchor block 403a, the electrical connection window electrically connecting the first wire 5 and the terminal, and the support window connecting the first wire 5 and the insulating layer 101. Among them, the anchor window is connected to the anchor block 403a of the lower plate, the electrical connection window is connected to the contact hole previously processed on the substrate 1, and the support window is opened on the second support structure 6 and connected to the insulating layer 101.

[0098] S1804, depositing a second epitaxial layer to form the upper electrode and the terminal of the device, selecting in-situ doping or ion implantation according to the resistivity requirement and patterning, and the patterned area of the sacrificial layer makes the upper electrode divided into three parts: the vibrating electrode 402, the anchor beam 403b and the first wire 5.

[0099] Among them, the anchor beam 403b deposited in the anchor window plays the role of anchoring and electrical connection. The terminal deposited in the electrical connection window and the first wire 5 deposited in the support window play the role of introducing the electrical signal of the device into the contact hole on the substrate 1 or leading out the electrical signal of the device, and the first wire 5 connected with the anchor beam 403b also plays the role of interconnecting the resonant device.

[0100] S1805, removing the sacrificial layer. The sacrificial layer isolates the vibrating electrode 402 from the fixed electrode 401, and the vibrating electrode 402 cannot vibrate with the sacrificial layer, so the sacrificial layer is removed to release the vibrating electrode 402, so that it can vibrate freely.

[0101] The vibrating electrode 402, the anchoring beam 403b, the first conducting wire 5 and the terminal are deposited integrally. The second epitaxial layer is the key to determine the frequency of the device, and the length, width, thickness and physical properties (including but not limited to Young's modulus, Poisson's ratio) need to be monitored. The doping elements can be but are not limited to phosphorus, arsenic, antimony, boron or known semiconductor materials such as variants thereof; in operation, the vibrating electrode 402 is excited to vibrate by an excitation current, and as the vibrating electrode 402 vibrates, the capacitance spacing between the vibrating electrode 402 and the fixed electrode 401 changes regularly, and the fixed electrode 401 receives the capacitance change signal and outputs. It can be understood that the excitation current can come from the excitation electrode plate 401a in the fixed electrode 401, or the first conducting wire 5 can be directly introduced from the contact hole through the terminal. The subsequent process can be sealed by directly bonding the cap silicon wafer to the substrate 1 according to the requirement, or the sealing cavity can be formed by using the epitaxial sealing process. It should be noted that the movable parts will be affected by air damping, so the higher the vacuum degree in the sealing cavity is, the better.

[0102] The technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0103] The micro-mechanical system resonator and the sensor provided by the embodiments of the present application have the following advantages. Firstly, the fixed electrode of the resonant assembly is directly arranged on the surface of the substrate, and the vibrating electrode of the resonant assembly is arranged in parallel and suspended above the fixed electrode. The resonant assembly can be arranged longitudinally on the surface of the substrate by using a common wafer and an epitaxial process, without using expensive SOI wafers and DRIE processes, thereby reducing production costs. Secondly, the device quality of the longitudinally arranged resonant assembly is relatively small, and the required excitation level is relatively small. The micro-mechanical system resonator provided by the embodiments of the present application further realizes differential output to increase signal strength and has strong stability and anti-interference ability through the series-parallel structure of multiple resonant assemblies.

[0104] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some examples, well-known methods, structures and techniques are not described in detail in order not to obscure the understanding of the present specification.

[0105] Similarly, it is to be understood that the embodiments of the present application can be used in any combination of hardware and software, and that the description and drawings, which set forth specific embodiments, are not intended to restrict the present application to those embodiments particularly disclosed. Furthermore, it will be appreciated that those of ordinary skill in the art will be able to devise various embodiments that, although not explicitly described or shown herein, embody the principles of the application and, thus, are within the spirit and scope of the application. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. Rather, the scope of the application will be defined by the appended claims.

[0106] It is to be understood that the embodiments of the present application that have been described are merely illustrative of the many applications of the principles of the present application. Numerous modifications can be made to the illustrative embodiments, and other implementations of the present application can be used without departing from the spirit and scope of the application. For these reasons, the scope of the application is not limited to the specific embodiments described herein, but only by the claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In a unitary claim, several devices or sub-claims can be joined by means of the word "and". The word "first", "second", "third", and the like can not imply any order but are used for identification purposes only. The use of the word "a" or "an" does not exclude the presence of a plurality of these elements, it is further understood that the claims can be drafted to exclude any additional technical equivalents.

Claims

1. A resonator for a micromechanical system, characterized in that, include: The system comprises a substrate, an input signal terminal, an output signal terminal, and multiple resonant components; the input signal terminal and the output signal terminal are respectively disposed on the substrate, and the input signal terminal, the resonant components, and the output signal terminal are electrically connected in sequence. Each of the resonant components includes: A fixed electrode is disposed on the substrate; A vibrating electrode is disposed parallel to and suspended above the fixed electrode on the side away from the substrate, and the orthogonal projection of the vibrating electrode on the substrate covers the orthogonal projection of the fixed electrode on the substrate. A first support structure is disposed on the side of the substrate near the vibrating electrode and connected to the vibrating electrode; The vibrating electrode is a square diaphragm, and each of the resonant components includes four fixed electrodes; The four fixed electrodes are respectively disposed at the edge of the vibrating electrode, and the area corresponding to the edge is the position where the amplitude of the vibrating electrode is the largest during vibration; or, The four fixed electrodes are respectively disposed at the corners of the vibrating electrode, and the area corresponding to the corners is the position where the amplitude of the vibrating electrode is the largest during the vibration process.

2. The micromechanical system resonator as described in claim 1, characterized in that, N resonant components are connected in series, wherein the vibrating electrode of each resonant component is electrically connected to the fixed electrode of the previous resonant component along the current transmission direction; or the fixed electrode of each resonant component is electrically connected to the vibrating electrode of the previous resonant component along the current transmission direction.

3. The micromechanical system resonator as described in claim 1, characterized in that, N resonant components are connected in parallel.

4. The micromechanical system resonator as described in claim 3, characterized in that, The fixed electrode includes an excitation electrode plate and an induction electrode plate; the excitation electrode plate of each resonant component is connected to the input signal terminal, and the induction electrode plate of each resonant component is connected to the output signal terminal.

5. The micromechanical system resonator as described in claim 3, characterized in that, The fixed electrode of each resonant component is connected to the input signal terminal, and the vibration electrode of each resonant component is connected to the output signal terminal; or the vibration electrode of each resonant component is connected to the input signal terminal, and the fixed electrode of each resonant component is connected to the output signal terminal.

6. The micromechanical system resonator as described in claim 1, characterized in that, Also includes: Insulating layer, first conductor, second support structure, and second conductor; The insulating layer is disposed on the side of the substrate near the resonant component, and the resonant component is disposed on the insulating layer; The first wire is disposed on the side of the insulating layer near the resonant component, and the first wire connects the input signal terminal and the output signal terminal to the resonant component, and interconnects the plurality of resonant components; A second support structure is disposed between the first conductor and the insulating layer. The second support structure includes a groove extending through the second support structure in a direction perpendicular to the substrate. The lower end of the first conductor passes through the groove to contact the insulating layer. The second wire is disposed on the side of the insulating layer near the resonant component, and the second wire connects the first wire to the fixed electrode and interconnects the plurality of fixed electrodes.

7. The micromechanical system resonator as described in claim 1, characterized in that, The ends of the vibrating electrodes of two adjacent resonant components are in contact.

8. The micromechanical system resonator as described in claim 1, characterized in that, The first support structure is connected to the vibration electrodes of two or more of the resonant components.

9. The micromechanical system resonator as described in claim 1, characterized in that, The first support structure includes an anchor block and an anchor beam, and the substrate, the anchor block, the anchor beam and the vibration electrode are connected in sequence.

10. A sensor, characterized in that, Including the micromechanical system resonator according to any one of claims 1 to 9.

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