Micromechanical system resonator and sensor

Abstract

The invention discloses a micro-mechanical system resonator and a sensor. The micro-mechanical system resonator comprises a substrate, an input signal terminal, an output signal terminal and a plurality of resonant components, each resonance assembly comprises a fixed electrode which is arranged on the substrate; the vibration electrode is arranged above one side, far away from the substrate, of the fixed electrode in a parallel and suspended manner, and the orthographic projection of the electrode on the substrate covers the orthographic projection of the fixed electrode on the substrate; and the first supporting structure is arranged on one side, close to the vibration electrode, of the substrate and is connected with the vibration electrode. The micro-mechanical system resonator and the sensor provided by the invention have the advantages of simplified process, lower cost, small device mass, small device size and small required excitation level.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chips, in particular 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, it is necessary to process the SOI (Silicon-on-insulator) wafer, 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 electrode plate, resulting in a stray signal. In addition, the more the number of fingers is, and the larger the height of a single finger is, the larger the quality of the device is, the larger the excitation level required is, the higher the power consumption is, and the impedance and leakage current are also increased. SUMMARY

[0004] The present application provides a micro-mechanical system resonator and a sensor to solve the technical problems of high cost, great process difficulty, poor signal stability and large 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. Each of the resonant components 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, and the normal projection of the vibrating electrode on the substrate covers the normal projection of the fixed electrode on the substrate. a first support structure disposed on a side of the substrate close to the vibration electrode and connected with the vibration electrode.

[0007] Optionally, N resonant assemblies are connected in series, wherein the vibration 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 vibration electrode of the previous resonant assembly in the direction of current transmission.

[0008] Optionally, N resonant assemblies are connected in parallel.

[0009] 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.

[0010] Optionally, the fixed electrode of each resonant assembly is connected with the input signal terminal, and the vibration electrode of each resonant assembly is connected with the output signal terminal; or the vibration 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.

[0011] Optionally, further comprising: an insulating layer, a first conducting wire, a second support structure and a second conducting wire; 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; 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; a 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; 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.

[0012] Optionally, the end portions of the vibration electrodes of two adjacent resonant assemblies are in contact.

[0013] Optionally, the first support structure is connected with the vibration electrodes of two or more resonant assemblies.

[0014] Optionally, the first support structure comprises an anchor block and an anchor beam, and the substrate, the anchor block, the anchor beam and the vibration electrode are sequentially connected.

[0015] In a second aspect, a sensor is provided, comprising the micro-mechanical system resonator of the first aspect.

[0016] The technical scheme provided in the application has at least the following technical effects or advantages: The micro-mechanical system resonator and the sensor provided in the application have the following advantages. Firstly, the fixed electrode of the resonant assembly is directly arranged on the surface of the substrate, and the vibration 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, and 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 in the application further has the structure of series and parallel connection of multiple resonant assemblies, realizes differential output to increase the signal strength, and has high stability and strong anti-interference ability.

[0017] The above description is only a summary of the technical scheme of the application. In order to more clearly understand the technical means of the application, the application can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0018] 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 application. Moreover, the same reference numerals are used throughout the various drawings to designate the same or similar parts. In the drawings: Figure 1 A schematic diagram of a micro-mechanical system resonator in an embodiment of the application is shown in FIG. 1. Figure 2 A schematic diagram of a resonant assembly in an embodiment of the application is shown in FIG. 2. Figure 3 A schematic diagram of a first mode of a square electrode plate in an embodiment of the application is shown in FIG. 3. Figure 4 A schematic diagram of a second mode of a square electrode plate in an embodiment of the application is shown in FIG. 4. Figure 5 A schematic diagram of a square vibration electrode in an embodiment of the application is shown in FIG. 5. Figure 6 A first series connection schematic diagram of a resonant assembly in an embodiment of the application is shown in FIG. 6. Figure 7 A second series connection schematic diagram of a resonant assembly in an embodiment of the application is shown in FIG. 7. Figure 8 A first parallel connection diagram of a resonant assembly in an embodiment of the present application; Figure 9 A second parallel connection diagram of a resonant assembly in an embodiment of the present application; Figure 10 A third parallel connection diagram of a resonant assembly in an embodiment of the present application; Figure 11 A first end contact diagram of a vibrating electrode of a resonant assembly in an embodiment of the present application; Figure 12 A second end contact diagram of a vibrating electrode of a resonant assembly in an embodiment of the present application; Figure 13 A first common anchor block diagram of a vibrating electrode of a resonant assembly in an embodiment of the present application; Figure 14 A second common anchor block diagram of a vibrating electrode of a resonant assembly in an embodiment of the present application; Figure 15 A connection diagram of a resonant assembly in an embodiment of the present application; Figure 16 A Figure 15 A-A sectional view in an embodiment of the present application; Figure 17 A Figure 15 B-B sectional view in an embodiment of the present application; Figure 18 A process diagram of fabricating a micro-mechanical system resonator in an embodiment of the present application.

[0019] In the figure, 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 assembly, 401 is a fixed electrode, 402 is a vibrating electrode, 401a is an excitation electrode plate, 401b is a sensing 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

[0020] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings.

[0021] 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 certain details may be omitted. The shapes of various regions, layers shown in the diagrams, and their relative sizes and positional relationships are merely exemplary, and may deviate in actuality due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes, relative positions may be additionally designed by those skilled in the art according to actual needs.

[0022] In the context of the present disclosure, when one 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 one layer / element is located "on" another layer / element in one orientation, the layer / element 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 denoted by the same or similar reference numerals.

[0023] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with specific embodiments. 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, rather than 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.

[0024] All mechanical structures have fixed vibration modes, which are called modes (the "mode" can be understood as "a series of independent components that do not affect each other"). The same structure has multiple different vibration modes, which are called modes. Some vibration modes 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.

[0025] Taking a flat plate capacitive MEMS resonator as an example, it includes at least one pair of parallel electrode plates. One of the electrode plates serves as a vibrating component and vibrates under the action of an excitation current. The other electrode plate serves as a sensing electrode plate and outputs a sensing current outward. The existing flat plate capacitive MEMS resonator usually uses a DRIE (Deep Reactive Ion Etching) process to etch parallel electrode plates on an SOI wafer. The manufacturing cost and process difficulty are high. The etched parallel electrode plates need to have a certain longitudinal height. The greater the etching depth, the more the scallop-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 scallop-shaped morphology is present on the entire sidewall of the electrode plate. For example, etching a depth of 50 um is not completed at one time by the DRIE process, but is divided into many times, for example, etching 2 um at a time. Each etching time forms a scallop groove, resulting in a sawtooth-shaped flat plate electrode plate of the formed capacitor.

[0026] Therefore, the present application provides a micro-mechanical system resonator, as shown in Figure 1 which includes 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 respectively 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 2As shown, each resonant component 4 comprises 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 fixed electrode 401 away from the substrate 1, and 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. The first support structure 403 is arranged on the substrate 1 close to the vibrating electrode 402 and connected with the vibrating electrode 402.

[0027] As shown, the first support structure 403 comprises 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. Figure 2

[0028] It can be understood that the resonant component 4 can be directly formed on the substrate 1 through a deposition process, and is not limited to using an expensive SOI wafer and DRIE etching, so the substrate 1 can use a single crystal silicon wafer, an SOI wafer, a glass wafer, a gallium nitride wafer or a silicon carbide wafer, etc., and the substrate 1 uses a common wafer, which has low manufacturing cost and small process difficulty.

[0029] After the fixed electrode 401 and the anchor block 403a are deposited, a sacrificial layer is prepared and patterned, the vibrating electrode 402 and the anchor beam 403b are integrally deposited in the patterned window, and 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, and 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.

[0030] It can be understood that the micro-mechanical system resonator given in the embodiments of the present application has a fixed electrode 401 and a vibrating electrode 402 of the resonant component 4 constituting the upper and lower structure of the capacitive plate, and forms a longitudinal plate capacitive resonant component 4 on the substrate 1, excites the resonance of the vibrating electrode 402 through the excitation level, changes the distance between the capacitive plates, realizes the change of the capacitance, and obtains a stable harmonic signal.

[0031] 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 certain excitation is used, so that stable signal output can be realized.

[0032] 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 can be combined with each other, and the same or similar concepts or processes can not be described in detail in some embodiments. ​

[0033] For example, the square diaphragm is used for the vibration electrode 402, and the connection mode of the vibration electrode 402 to the anchor block 403a needs to be determined according to the mode of the vibration electrode 402. The square vibration electrode 402 has different vibration frequency modes under different current excitations. Through simulation, the 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, so that a better device structure is obtained, and the design and calculation cost is saved. 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 a capacitor is selected, and the anchor mode is selected according to the vibration mode; or the diaphragm size can be adjusted according to the resonant frequency required to be met 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.

[0034] As shown in Figure 3 , it is a mode of a square plate. It can be seen that the vibration mode has obvious and normative resonant deformation. The vibration electrode 402 of the resonant assembly 4 can use the square plate in this mode, Figure 3 The light area at the middle side corner is at the node where the displacement is almost 0 during vibration. Therefore, the anchor block 403a is arranged at these positions, and the energy loss is the least. Therefore, according to the vibration mode, four vertex anchors can be selected. Figure 3 The dark area at the middle side line is at the antinode where the amplitude is the largest during vibration. Therefore, the fixed electrode 401 is arranged directly below these positions, so as to realize stable signal output.

[0035] As shown in Figure 4 , in another mode of the square plate, the light area at the center has almost 0 displacement during vibration. Therefore, the anchor block 403a is connected at the center, and the energy loss is the least. The dark area at the corner has the largest amplitude during vibration. Therefore, the fixed electrode 401 is arranged at the opposite position.

[0036] It can be understood that, no matter whether the anchor block 403a is arranged at the Figure 3 middle side corner or the Figure 4 middle center, both of the two anchor modes select the position with the smallest motion deformation on the plate. The anchor point connected with the anchor block 403a has smaller loss. How to select can be determined according to actual requirements. No matter whether the fixed electrode 401 is arranged at the Figure 3 middle side line or the Figure 4Fixed 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.

[0037] 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.

[0038] 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.

[0039] When the fixed electrode 401 is connected to the input signal terminal 2, it can be used to apply excitation to the vibrating electrode 402; in this case, the fixed electrode 401 is the excitation electrode. When the fixed electrode 401 is connected to 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; in this case, the fixed electrode 401 is the sensing electrode. The vibrating electrode 402 can also be connected to the input signal terminal 2 to directly receive the excitation current, or connected to the output signal terminal 3 to directly output the vibration current. Since multiple resonant components 4 are formed on the substrate 1, these resonant components 4 can be interconnected in series or parallel. The specific connection method 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.

[0040] In an optional implementation, N resonant components are arranged in series. For example... Figure 6 As shown, Figure 6 This is a schematic diagram of the first series connection of resonant components in an embodiment of this application. Multiple resonant components 4 are connected in series between the input signal terminal 2 and the output signal terminal 3. Current is introduced into the series-connected resonant components 4 through the input signal terminal 2 and then led out through the output signal terminal 3. The vibration electrode 402 of each resonant component 4 is electrically connected to the fixed electrode 401 of the previous resonant component 4 along the current transmission direction. Thus, the vibration electrode 402 of the first resonant component 4 along the current transmission direction is connected to the input signal terminal 2, and the fixed electrode 401 of the last resonant component 4 along the current transmission direction is connected to the output signal terminal 3. The input signal terminal 2 sends the excitation current to the vibration electrode 402 of the first resonant component 4.

[0041] It can be understood that the vibrating electrode 402 is connected with the anchor block 403a through the anchor beam 403b, and the vibrating electrode 402 and the anchor beam 403b are integrally deposited during production. Therefore, the input signal terminal 2 is connected with the anchor beam 403b above the anchor block 403a through a wire, which represents that the input signal terminal 2 is directly connected with the vibrating electrode 402.

[0042] In Figure 6 In the series connection scheme shown in the figure, the input signal terminal 2 introduces an excitation current to load on the vibrating electrode 402 of the first resonant component 4, and the vibrating electrode 402 is excited to vibrate to generate an induced current on the fixed electrode 401 of the first resonant component 4. The induced current is transmitted to the vibrating electrode 402 of the second resonant component 4, and the vibrating electrode 402 of the second resonant component 4 is excited to vibrate to generate an induced current on the fixed electrode 401 of the second resonant component 4. In this way, the transmission mode of the induced current of the above resonant component 4 as the excitation current of the next resonant component 4 is formed along the current transmission direction, and the induced current signal generated on the fixed electrode 401 of the last resonant component 4 is sent to the outside of the micro-mechanical system resonator through the output signal terminal 3.

[0043] 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 with each vibrating electrode 402 only serve as an output induced current. Therefore, the four fixed electrodes 401 of each resonant component 4 can be connected through a wire to be equivalent to an induced electrode plate.

[0044] As Figure 7 shown, Figure 7 is a second series connection diagram of the resonant component in the embodiment of the present application. The input signal terminal 2 can also be connected with the fixed electrode 401 of the first resonant component 4, and the output signal terminal 3 is connected with the vibrating electrode 402 of the last resonant component 4, so as to connect a plurality of resonant components 4 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 with the vibrating electrode 402 of the above resonant component 4 along the current transmission direction. In this way, the transmission mode of the induced current of the above resonant component 4 as the excitation current of the next resonant component 4 is formed along the current transmission direction, and the vibrating current signal generated on the vibrating electrode 402 of the last resonant component 4 is sent to the outside of the micro-mechanical system resonator through the output signal terminal 3.

[0045] It can be understood that the vibrating electrode 402 is connected with the anchor block 403a through the anchor beam 403b, and the vibrating electrode 402, the anchor beam 403b and the anchor block 403a are integrally deposited during production. Therefore, the output signal terminal 3 is connected with the anchor block 403a through a wire, which means that the output signal terminal 3 is directly connected with the vibrating electrode 402.

[0046] In an optional embodiment, the N resonance assemblies 4 are connected in parallel. As shown in Figure 8 Figure 8 is a first parallel connection diagram of the resonance assembly in the embodiment of the present application. The fixed electrode 401 of each resonance assembly 4 is connected with the input signal terminal 2, and the vibrating electrode 402 of each resonance assembly 4 is connected with the output signal terminal 3; or as shown in Figure 9

[0047] In an optional embodiment, the fixed electrode 401 includes an excitation electrode plate 401a and an induction electrode plate 401b. The four fixed electrodes 401 can be divided into two oppositely arranged excitation electrode plates 401a and two oppositely arranged induction electrode plates 401b.

[0048] For example, as shown in Figure 10 Figure 10 is a third parallel connection diagram of the resonance assembly in the embodiment of the present application. When the plurality of resonance assemblies 4 are connected in parallel, the excitation electrode plate 401a of each resonance assembly 4 is connected with the input signal terminal 2, for introducing the current signal from the input signal terminal 2 to provide excitation for the vibrating electrode 402. The induction electrode plate 401b of each resonance assembly 4 is connected with the output signal terminal 3, for sending out the vibration current signal generated on the vibrating electrode 402 through the output signal terminal 3.

[0049] It can be understood that the excitation electrode plate 401a of each resonance assembly 4 connected with the input signal terminal 2 does not mean that each excitation electrode plate 401a is directly connected with the input signal terminal 2 through a wire. The excitation electrode plate 401a far away from the input signal terminal 2 can be interconnected through a wire and connected with the input signal terminal 2 through at least one excitation electrode plate 401a so that all excitation electrode plates 401a can receive the excitation current. Similarly, the induction electrode plate 401b far away from the output signal terminal 3 can be interconnected through a wire and connected with the output signal terminal 3 through at least one induction electrode plate 401b so that the induction current on all induction electrode plates 401b can be outputted.

[0050] ​​​This is because, if both of the excitation electrode plates 401a of each resonant component 4 are directly connected to the input signal terminal 2 through wires, a wire frame for inputting excitation current will be formed on the substrate 1, if both of the induction electrode plates 401b of each resonant component 4 are directly connected to the output signal terminal 3 through wires, a wire frame for outputting induction current will be formed on the substrate 1, and the induction electrode plates 401b are arranged apart from the excitation electrode plates 401a. If the wire frame for inputting excitation current and the wire frame for outputting induction current are both routed on the substrate 1, a cross between the two will be formed, which will conduct the excitation electrode plates 401a and the induction electrode plates 401b. If this is to be avoided, a more complex routing method needs to be set up to isolate the two wire frames.

[0051] Therefore, as shown in Figure 10 , the input signal terminal 2 is connected to at least one of the excitation electrode plates 401a of the plurality of resonant components 4, and the rest of the excitation electrode plates 401a can be interconnected as needed. Similarly, the output signal terminal 3 is connected to at least one of the induction electrode plates 401b of the plurality of resonant components 4, and the rest of the induction electrode plates 401b can be interconnected as needed. This connection method ensures that the excitation current input line and the induction current output line do not affect each other.

[0052] As an optional implementation, the ends of the vibration electrodes 402 of two adjacent resonant components 4 are in contact. The ends of the vibration electrodes 402 are in contact and have an electrical connection relationship. The end-to-end contact can make the distance between the resonant components 4 smaller, thereby reducing the overall device area and reducing the device mass.

[0053] For example, as shown in Figure 11 , the ends of the vibration electrodes of the plurality of resonant components are in contact. In a feasible solution, when the input signal terminal 2 is connected to one of the vibration electrodes 402 in the plurality of vibration electrodes 402 in end-to-end contact, all other vibration electrodes 402 do not need to be connected to the input signal terminal 2, Figure 11 , the input signal terminal 2 loads the excitation current to the closest vibration electrode 402, which transmits the excitation current to the vibration electrode 402 of each resonant component 4. After interconnecting the four fixed electrodes 401 of each resonant component 4 and interconnecting one fixed electrode 401 of a resonant component 4 with one fixed electrode 401 of an adjacent resonant component 4, connecting to the output signal terminal 3 can guide the induction current of all resonant components 4 out.

[0054] It can be understood that the distance between the fixed electrodes 401 of the two adjacent resonant components 4 is very close and can be integrally deposited.

[0055] For example, as shown in Figure 12The end contact example of the plurality of resonant components 4 is given. In a feasible solution, the fixed electrode 401 of each resonant component 4 is connected with the input signal terminal 2, and through one of the vibrating electrodes 402, the output signal terminal 3 is connected. From Figure 12 It can be seen that the fixed electrodes 401 of the adjacent two resonant components 4 can be made into an integrated type, because the end contact of the vibrating electrodes 402 of the two resonant components 4 shortens the distance between the resonant components 4, the integrated fixed electrode 401 has good conductivity, and does not increase the process difficulty. It can be understood that the vibrating electrodes 402 of the adjacent two resonant components 4 can also be made into an integrated type, the integrated vibrating electrode 402 has better conductivity, and also does not increase the process difficulty.

[0056] As an optional embodiment, the first support structure 403 is connected with the vibrating electrodes 402 of two or more resonant components 4. That is, the vibrating electrodes 402 of two or more resonant components 4 share an anchor block 403a, which can also save space and reduce the size and mass of the chip.

[0057] It can be understood that the vibrating electrodes 402 sharing the anchor block 403a also have an electrical connection relationship. The vibrating electrodes 402 are connected with the anchor block 403a through the anchor beams 403b, so the anchor beams 403b of the two vibrating electrodes 402 sharing the anchor block 403a are also interconnected, and the current on one vibrating electrode 402 can be transmitted to the other vibrating electrode 402 through the interconnected anchor beams 403b. For example, as shown in Figure 13 The anchor block shared by the plurality of resonant components is given. When the input signal terminal 2 is connected with one of the vibrating electrodes 402 sharing the anchor block 403a in turn, all the other vibrating electrodes 402 do not need to be connected with the input signal terminal 2, Figure 13 In the embodiment, when the input signal terminal 2 loads the excitation current to the vibrating electrode 402 of the first resonant component 4 closest to it, the excitation current will be transmitted to the vibrating electrode 402 of each resonant component 4 through the anchor beam 403b, and the fixed electrode 401 of each resonant component 4 is connected with the input signal terminal 2 respectively. The induced current of all the resonant components 4 can be led out.

[0058] For example, as shown in Figure 14 The anchor block shared by the plurality of resonant components is given. The input signal terminal 2 is connected with at least one of the excitation electrode plates 401a of the plurality of resonant components 4, and the remaining 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 plurality of resonant components 4, and the remaining induction electrode plates 401b are interconnected as needed.

[0059] As an optional embodiment, the micromechanical system resonator further comprises: an insulating layer 101, a first conducting wire 5, a second supporting structure 6, and a second conducting wire 7, the second supporting structure 6 is used to support the first conducting wire 5. As shown in Figure 15 , Figure 15 is a schematic diagram of the resonant assembly connection in the embodiment of the present application.

[0060] The first conducting 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 resonant assemblies 4. Exemplarily, the first conducting wire 5 can interconnect the resonant assemblies 4 by connecting the vibration electrodes 402 of two resonant assemblies 4, and the second supporting structure 6 of the first conducting wire 5 is adapted to connect the two anchor blocks 403a. The first conducting 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 in Figure 16 , Figure 16 is Figure 15 A-A sectional view in the figure. 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.

[0061] As shown in Figure 16 , the first conducting wire 5 is arranged on the side of the insulating layer 101 away from the substrate 1, and the second supporting structure 6 is arranged between the first conducting wire 5 and the insulating layer 101. The second supporting structure 6 comprises a groove penetrating the second supporting structure 6 in a direction perpendicular to the substrate 1, and the lower end of the first conducting wire 5 penetrates the groove to contact the insulating layer 101.

[0062] The second conducting wire 7 is arranged on the side of the insulating layer 101 away from the substrate 1, and the second conducting wire 7 connects the first conducting wire 5 with the fixed electrode 401, and interconnects the plurality of fixed electrodes 401. Exemplarily, the second conducting wire 7 interconnects the plurality of fixed electrodes 401 to realize the interconnection of the plurality of resonant assemblies 4. As shown in Figure 17 , the second conducting wire 7 directly connects the fixed electrodes 401 of two adjacent resonant assemblies 4.

[0063] It should be noted that, Figure 15 the interconnection mode of the resonant assembly given in the figure is only to represent an example of interconnecting the plurality of resonant assemblies by the first conducting wire 5 and the second conducting wire 7, Figure 16 is to show an example of interconnecting the resonant assemblies by the first conducting wire 5, Figure 16 is to show an example of interconnecting the resonant assemblies by the second conducting wire 7, Figure 15 , Figure 16 and Figure 17 are not used to limit the specific interconnection relationship between the actual resonant assemblies.

[0064] 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 through a patterning process, and thus can be collectively referred to as a lower electrode, that is, when the first wire 5 connects the vibration electrodes 402 of the two resonant assemblies 4 to achieve interconnection of the 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 at one time and then etched apart through a patterning process, and thus can be collectively referred to as an upper electrode.

[0065] The vibration electrode 402 of the resonant assembly 4 is located above the fixed electrode 401, and the heights of the two are inconsistent, so that two wiring modes are formed on the substrate 1. The first wire 5 is connected to the vibration electrode 402 at a consistent height, is deposited integrally 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 to connect the input signal terminal 2 and the output signal terminal 3 to the resonant assembly 4, and is mainly used to interconnect resonant assemblies 4 that are far apart. The second wire 7 is connected to the fixed electrode 401 at a consistent height, is deposited integrally with the fixed electrode 401 during preparation, and is mainly used for short-distance transmission between the fixed electrodes 401. The first wire 5 has good conductivity and is not suitable for short-distance transmission between the fixed electrodes 401. The reason is that it can form a transverse capacitor 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 the first wire 5, causing deviation of the induced current signal.

[0066] The following will be described in combination with Figure 18 A manufacturing process of the micro-mechanical system resonator in the embodiment of the present application is given.

[0067] 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 wire 7 belong to the same layer and have a connection relationship, can be deposited at one time by using the same raw material, and thus can be collectively referred to as a lower electrode. The vibration electrode 402, the anchor beam 403b, and the first wire 5 belong to the same layer and have a connection relationship, can be deposited at one time by using the same raw material, 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.

[0068] 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, silicon germanium, and the like. In-situ doping or ion implantation is selected according to the resistivity requirement, and a corresponding process is selected according to the deposition material to release residual stress.

[0069] S1802, patterning the first epitaxial layer by a photolithography process to form the 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 lead wire 7.

[0070] S1803, depositing a sacrificial layer and patterning the sacrificial layer. According to the selected material of the sacrificial layer, a corresponding annealing process is adopted to release the residual stress and eliminate the composition and thickness of the intermediate product stable material, such as TEOS of LPCVD, then 1050°C annealing for 2 hours; the thickness of the sacrificial layer determines the spacing between the fixed electrode 401 and the vibrating electrode 402, which is a key parameter in the process; the sacrificial layer is patterned by etching technology, and the patterned area reserves the vibrating electrode 402, the first lead wire 5 and the anchor beam 403b area, and also reserves the anchor window connecting the anchor beam 403b and the anchor block 403a, the electrical connection window connecting the first lead wire 5 and the terminal, and the support window connecting the first lead wire 5 and the insulating layer 101. Among them, the anchor window is connected to the anchor block 403a of the lower electrode plate, the electrical connection window is connected to the contact hole pre-processed on the substrate 1, and the support window is opened on the second support structure 6 and connected to the insulating layer 101.

[0071] S1804, depositing a second epitaxial layer to form the upper electrode and the terminal of the device, and selecting in-situ doping or ion implantation according to the resistivity requirement and patterning, 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 lead wire 5.

[0072] 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 lead 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 lead wire 5 connected with the anchor beam 403b also plays the role of interconnecting the resonator devices.

[0073] 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.

[0074] The vibrating electrode 402, the anchoring beam 403b, the first 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 wire 5 can be directly introduced from the contact hole through the terminal. The subsequent process can be selected according to the requirement to use a cap silicon wafer to directly bond and seal with the substrate 1, or to use an epitaxial sealing process to form a sealed cavity. It should be noted that the movable parts will be affected by air damping, so the higher the vacuum degree in the sealed cavity is, the better.

[0075] The technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 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.

[0076] 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.

[0077] 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 of the present application without departing from the spirit and scope of the application as disclosed in the claims. In the description and drawings, like or similar elements are referred to using the same reference numerals.

[0078] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that one skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended 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 means can be listed, comprising at least one of each device, but not only one of each device. The use of the word 'at least' followed by a list of one or more items means that any item in the list can be present or absent, but that one or more items will be present. The word 'first','second', 'third', and the like in the description do not necessarily have an chronological or sequential meaning. These words can be used to name 'first','second', 'third' etc. embodiments of an application.

Claims

1. A micromechanical system resonator, characterized by The micro-mechanical system resonator comprises: 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 arranged on the substrate, and the input signal terminal, the resonant components and the output signal terminal are electrically connected in sequence; 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, 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 arranged on the side of the substrate close to the vibrating electrode and connected with the vibrating electrode.

2. The micro-mechanical system resonator of claim 1, wherein, N resonant components are arranged in series, wherein the vibrating electrode of each resonant component is electrically connected with the fixed electrode of the previous resonant component in the current transmission direction, or the fixed electrode of each resonant component is electrically connected with the vibrating electrode of the previous resonant component in the current transmission direction.

3. The micro-mechanical system resonator of claim 1, wherein, N resonant components are arranged in parallel.

4. The micro-mechanical system resonator of claim 3, wherein, The fixed electrode comprises an excitation electrode plate and an induction electrode plate; the excitation electrode plate of each resonant component is connected with the input signal terminal, and the induction electrode plate of each resonant component is connected with the output signal terminal.

5. The micro-mechanical system resonator of claim 3, wherein, The fixed electrode of each resonant component is connected with the input signal terminal, and the vibrating electrode of each resonant component is connected with the output signal terminal; or the vibrating electrode of each resonant component is connected with the input signal terminal, and the fixed electrode of each resonant component is connected with the output signal terminal.

6. The micro-mechanical system resonator of claim 1, wherein, Further comprising: an insulating layer, a first wire, a second support structure and a second wire; the insulating layer is arranged on the side of the substrate close to the resonant components, and the resonant components are arranged on the insulating layer; the first wire is arranged on the side of the insulating layer close to the resonant components, and the first wire connects the input signal terminal and the output signal terminal with the resonant components and interconnects a plurality of resonant components; a second support structure arranged between the first wire and the insulating layer, 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 wire penetrates the groove to contact the insulating layer; the second wire is arranged on the side of the insulating layer close to the resonant components, and the second wire connects the first wire with the fixed electrode and interconnects a plurality of fixed electrodes.

7. The micro-mechanical system resonator of claim 1, wherein, The end portions of the vibrating electrodes of two adjacent resonant components are in contact.

8. The micro-mechanical system resonator of claim 1, wherein, The first support structure is connected with the vibrating electrodes of more than two resonant components.

9. The micro-mechanical system resonator of claim 1, wherein, 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 connected in sequence.

10. A sensor, characterized by The micro-mechanical system resonator comprises any one of claims 1 to 9.

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