MEMS resonator

Abstract

An MEMS resonator disclosed by the present invention comprises a resonance main body, an anchoring area and an electrode area, the resonance main body comprises a plurality of resonance rings arranged at intervals and a connecting beam connecting the resonance rings and the anchoring area, and the electrode area and the resonance rings are correspondingly arranged. Comprising a first electrode area which is arranged outside the resonant ring and is separated from the outer edge of the resonant ring, and a second electrode area which is arranged in the resonant ring and is separated from the inner edge of the resonant ring; positive electrodes are arranged in parts of the first electrode area and the second electrode area, negative electrodes are arranged in parts of the first electrode area and the second electrode area, the positive electrodes comprise positive driving electrodes and / or positive sensing electrodes, the negative electrodes comprise negative driving electrodes and / or negative sensing electrodes, and the capacitance area formed by the positive electrodes at intervals relative to the base substrate is the same as the capacitance area formed by the negative electrodes at intervals relative to the base substrate. The parasitic capacitance generated by the positive electrode and the negative electrode is the same and can be counteracted, so that the parasitic capacitance is reduced, and the signal-to-noise ratio of signals and the stability of high-frequency output are improved.

Description

Technical Field

[0001] The present invention relates to the field of micro-electromechanical technology, and in particular to a MEMS resonator. Background Art

[0002] An oscillator is a device that provides a fundamental frequency signal in a circuit system. The resonator, as the core component of the oscillator, determines the foundation of the oscillator's performance. The resonator of a traditional oscillator is usually made of quartz material, which is relatively low in cost, but has certain difficulties in miniaturization and compatibility with mainstream semiconductor processes. In contrast, MEMS (Micro-Electro-Mechanical Systems) resonators based on semiconductor processes are easier to miniaturize and integrate into semiconductor processes. At the same time, MEMS oscillators have advantages such as impact resistance, high reliability, and programmability, which have enabled MEMS oscillators to gradually replace traditional quartz oscillators in multiple application fields.

[0003] Parasitic capacitance refers to the capacitance effect that exists in the circuit design but is not explicitly considered. It is usually caused by the mutual capacitance between wires, components, or chip pins. In the case of low-frequency vibration, the effect of parasitic capacitance on the MEMS resonator is relatively small. However, in the case of high-frequency vibration, the equivalent value of parasitic capacitance will be amplified, affecting the operation of the MEMS resonator, for example, affecting the stability of the MEMS resonator's frequency output and the signal-to-noise ratio. Therefore, how to reduce the parasitic capacitance of MEMS resonators has become a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a MEMS resonator capable of effectively reducing parasitic capacitance to ground.

[0005] The present application provides a MEMS resonator, comprising a resonant body, an anchoring region, and an electrode region. The resonant body comprises a plurality of resonant rings spaced apart from each other, and a connecting beam connecting the resonant rings and the anchoring region. The electrode region is disposed corresponding to the resonant rings, and comprises a first electrode region disposed outside the resonant rings and spaced apart from the outer edge of the resonant rings, and a second electrode region disposed inside the resonant rings and spaced apart from the inner edge of the resonant rings.

[0006] Positive electrodes are partially set in the first electrode area and negative electrodes are partially set in the second electrode area, the positive electrodes include positive driving electrodes and / or positive sensing electrodes, the negative electrodes include negative driving electrodes and / or negative sensing electrodes, and the capacitance area formed by the positive electrodes relative to the base substrate is the same as the capacitance area formed by the negative electrodes relative to the base substrate.

[0007] In some embodiments, the plurality of resonant rings form a first resonant group and a second resonant group, the first electrode regions corresponding to the resonant rings of the first resonant group are all positive driving electrodes, and the second electrode regions corresponding to the resonant rings of the first resonant group are all positive sensing electrodes; the first electrode regions corresponding to the resonant rings of the second resonant group are all negative driving electrodes, and the second electrode regions corresponding to the resonant rings of the second resonant group are all negative sensing electrodes.

[0008] In some embodiments, the positive electrode includes a positive driving electrode and a positive sensing electrode, the negative electrode includes a negative driving electrode and a negative sensing electrode, the positive driving electrode and the negative driving electrode have the same capacitance area relative to the base substrate, and the positive sensing electrode and the negative sensing electrode have the same capacitance area relative to the base substrate.

[0009] In some embodiments, the anchoring region includes a central connecting portion and a plurality of reinforcing portions arranged around the connecting portion, adjacent reinforcing portions are spaced apart from each other, and the reinforcing portions are respectively connected to the connecting portion;

[0010] A plurality of resonant rings surround the outer circumference of the reinforcement portion, and a connecting beam corresponding to each resonant ring passes through the adjacent reinforcement portion to connect the corresponding resonant ring with the connecting portion.

[0011] In some embodiments, an opening is provided on a side of the second electrode region close to the reinforcement portion, the connecting beam passes through the opening, and planes parallel to and spaced from the edge of the reinforcement portion are provided on both sides of the opening in the second electrode region.

[0012] In some embodiments, the MEMS resonator includes a base substrate, a device layer spaced apart from the base substrate, and a separation layer located between the base substrate and the device layer, and the anchor region and the electrode region are respectively fixedly connected to the base substrate through the separation layer.

[0013] In some embodiments, the positive driving electrode and the negative driving electrode are located on the same side of the resonant ring, and the capacitance area of any positive driving electrode is the same as the capacitance area of the negative driving electrode; and / or,

[0014] The positive sensing electrode and the negative sensing electrode are located on the other side of the resonant ring, and the capacitance area of any one of the positive sensing electrodes is the same as the capacitance area of the negative sensing electrode.

[0015] In some embodiments, the positive driving electrode and the negative driving electrode have the same shape and size; and / or,

[0016] The positive sensing electrode and the negative sensing electrode have the same shape and size.

[0017] In some embodiments, the resonant ring forms widened regions and narrowed regions alternately arranged along its circumference between the inner edge and the outer edge.

[0018] In some embodiments, the inner edge is a circle, an irregular circle, a polygon, or a polygon with rounded corners, and the outer edge is a circle, an irregular circle, a polygon, or a polygon with rounded corners.

[0019] The MEMS resonator provided by the present invention has the same capacitance area formed by arranging the positive electrode and the negative electrode relative to the base substrate. When the signal strengths applied to the positive electrode and the negative electrode of the same type are the same and the phases are opposite, the parasitic capacitance generated by the positive electrode and the base substrate and the parasitic capacitance generated by the negative electrode and the base substrate are the same in magnitude, and the parasitic capacitance generated by the positive electrode and the parasitic capacitance generated by the negative electrode can offset each other, thereby reducing the parasitic capacitance of the MEMS resonator, improving the signal-to-noise ratio of the signal and the stability of the high-frequency output, and enhancing the overall performance of the MEMS resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a MEMS resonator provided in Example 1 of the present invention;

[0021] Figure 2 for Figure 1 A cross-sectional view of the MEMS resonator shown in FIG.

[0022] Figure 3 for Figure 1 Schematic diagram of a driving method of the MEMS resonator shown in;

[0023] Figure 4 for Figure 3 Schematic diagram of the working mode of the MEMS resonator shown in;

[0024] Figure 5 for Figure 1 Schematic diagram of the anchorage area and connecting beam shown in;

[0025] Figure 6 A schematic diagram of the structure of a resonant ring having a circular inner edge and a polygonal outer edge with rounded corners provided in one embodiment of the present invention;

[0026] Figure 7 A schematic diagram of the structure of a resonant ring with a circular inner edge and an irregular circular outer edge provided in one embodiment of the present invention;

[0027] Figure 8A schematic diagram of the structure of a resonant ring having a rounded inner edge and an irregular circular outer edge provided in one embodiment of the present invention;

[0028] Figure 9 A schematic diagram of the structure of a resonant ring with a circular inner edge and a regular hexagonal outer edge provided in one embodiment of the present invention;

[0029] Figure 10 A schematic diagram of the structure of a resonant ring with a circular inner edge and an irregular octagonal outer edge provided in one embodiment of the present invention;

[0030] Figure 11 A schematic diagram of the structure of a resonant ring with a circular inner edge and a regular pentagonal outer edge provided in one embodiment of the present invention;

[0031] Figure 12 Schematic diagram of TCF of MEMS resonator.

[0032] In the figure: 10, MEMS resonator; 12, resonant body; 14, anchoring area; 16, electrode area; 18, resonant ring; 20, connecting beam; 22, first resonant group; 24, second resonant group; 26, base substrate; 28, device layer; 30, separation layer; 31, first electrode area; 32, second electrode area; 33, positive electrode; 34, negative electrode; 36, positive drive electrode; 38, positive sensing electrode; 40, negative drive electrode; 42, negative sensing electrode; 44, connecting part; 46, reinforcing part; 48, base; 50, extension part; 52, fixed beam; 54, opening; 56, inner edge; 58, outer edge; 60, widening area; 62, narrowing area. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside, top, bottom, etc.) are only used to explain the relative position relationship between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] It should also be noted that when an element is referred to as being “fixed on” or “disposed on” another element, the element may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0036] See also Figure 1 A MEMS resonator 10 provided by one embodiment of the present invention includes a resonating body 12, an anchoring region 14, and an electrode region 16. The resonating body 12 is used to resonate. The anchoring region 14 is connected to the resonating body 12 and serves to support the resonating body 12. The electrode region 16 is arranged corresponding to the resonating body 12 to drive the resonating body 12 to resonate and sense the resonance of the resonating body 12.

[0037] The resonant body 12 includes a resonant ring 18 and a connecting beam 20 . There are multiple resonant rings 18 arranged at intervals. Each resonant ring 18 is connected to the anchoring region 14 via a corresponding connecting beam 20 . The electrode region 16 is arranged corresponding to the resonant ring 18 .

[0038] The specific number of the resonant rings 18 is not limited, for example, two, four, six, eight, etc. In one embodiment, a plurality of resonant rings 18 form a first resonant group 22 and a second resonant group 24, and the first resonant group 22 and the second resonant group 24 include the same number of resonant rings 18, which is at least two.

[0039] In an optional example, the number of resonant rings 18 is four, and the first resonant group 22 and the second resonant group 24 each include two resonant rings 18, each resonant ring 18 is connected to a connecting beam 20. The four connecting beams 20 are arranged in a cross shape, and the ends of the four connecting beams 20 away from the anchoring area 14 are respectively connected to a resonant ring 18.

[0040] Among the four resonant rings 18, two separated resonant rings 18 form a first resonant group 22, and the other two resonant rings 18 form a second resonant group 24. The two resonant rings 18 of the first resonant group 22 are symmetrically arranged relative to the connecting beam 20 connected to the second resonant group 24, and the two resonant rings 18 of the second resonant group 24 are symmetrically arranged relative to the connecting beam 20 connected to the first resonant group 22. In this way, the energy generated by the two resonant rings 18 of the first resonant group 22 and the two resonant rings 18 of the second resonant group 24 during resonance can be better offset, thereby reducing anchor point loss and improving the overall performance of the MEMS resonator 10.

[0041] See also Figure 2 In one embodiment, the MEMS resonator 10 includes a base substrate 26, a device layer 28, and a spacer layer 30. The base substrate 26 and the device layer 28 are spaced apart from each other, and the spacer layer 30 is located between the device layer 28 and the base substrate 26 to separate them. The device layer 28 includes a resonant body 12, an anchor region 14, and an electrode region 16. The anchor region 14 and the electrode region 16 are each fixedly connected to the base substrate 26 via the spacer layer 30, so that the resonant body 12 is suspended relative to the base substrate 26.

[0042] Optionally, the device layer 28 and the base substrate 26 are made of single crystal silicon, and the separation layer 30 is made of silicon oxide. Therefore, the separation layer 30 can not only separate the device layer 28 from the base substrate 26 but also provide insulation.

[0043] In other embodiments, the device layer 28 and the base substrate 26 may also be made of other semiconductor single crystal or polycrystalline materials such as polysilicon, germanium, silicon nitride, gallium nitride, silicon carbide, etc. The device layer 28 and the base substrate 26 may be made of one or more of the materials mentioned above.

[0044] There is a separation layer 30 between the electrode region 16 and the base substrate 26, and the two are separated by a certain distance. When the MEMS resonator 10 is working, parasitic capacitance will be generated between the electrode region 16 and the base substrate 26. The size of the parasitic capacitance is related to the capacitor area. Under the premise that other conditions remain unchanged, the larger the capacitor area, the larger the parasitic capacitance. Conversely, the smaller the capacitor area, the smaller the parasitic capacitance.

[0045] In one optional example, the side of the electrode region 16 close to the base substrate 26 is a plane and is spaced apart and parallel to the base substrate 26. The capacitance area of the electrode region 16 relative to the base substrate 26 is the area of the plane of the electrode region 16 close to the base substrate 26. The side of the electrode region 16 away from the base substrate 26 is also a plane. The side of the electrode region 16 away from the base substrate 26 and the side close to the base substrate 26 are parallel to each other and have the same area. In other words, the capacitance area of the electrode region 16 is the area of the plane of the electrode region 16 away from the base substrate 26.

[0046] See also Figure 3 and Figure 4 In one embodiment, the resonant ring 18 is annular and includes an inner edge 56 and an outer edge 58. The electrode region 16 includes a first electrode region 31 and a second electrode region 32. The first electrode region 31 is located on the outside of the resonant ring 18 and is spaced apart from the outer edge 58 of the resonant ring 18. The second electrode region 32 is located on the inside of the resonant ring 18 and is spaced apart from the inner edge 56 of the resonant ring 18 to leave space required for the resonant ring 18 to resonate.

[0047] Positive electrodes 33 are partially provided in the first electrode region 31 and the second electrode region 32, and negative electrodes 34 are partially provided. The positive electrodes 33 include positive drive electrodes 36 and / or positive sensing electrodes 38, and the negative electrodes 34 include negative drive electrodes 40 and / or negative sensing electrodes 42. The positive drive electrodes 36 and the negative drive electrodes 40 are respectively used to drive the corresponding resonant ring 18 to resonate. The two electrodes are of the same type and have opposite phases. The positive sensing electrodes 38 and the negative sensing electrodes 42 are respectively used to sense the resonance of the corresponding resonant ring 18. The two electrodes are of the same type and have opposite phases. The capacitance area formed by the positive electrode 33 relative to the base substrate 26 is the same as the capacitance area formed by the negative electrode 34 relative to the base substrate 26, that is, the capacitance area formed by the same type of positive electrode and negative electrode relative to the base substrate 26 is the same, which may mean that the capacitance area of the positive driving electrode 36 is the same as that of the negative driving electrode 40, or the capacitance area of the positive sensing electrode 38 is the same as that of the negative sensing electrode 42, or the capacitance area of the positive driving electrode 36 is the same as that of the negative driving electrode 40, and the capacitance area of the positive sensing electrode 38 is the same as that of the negative sensing electrode 42. Since the capacitance area of the positive electrode 33 is the same as the capacitance area of the negative electrode 34, when the signal strengths applied to the same type of positive electrode 33 and negative electrode 34 are the same and the phases are opposite, the parasitic capacitance generated by the positive electrode 33 and the base substrate 26 and the parasitic capacitance generated by the negative electrode 34 and the base substrate 26 can be made the same in size, and the parasitic capacitance generated by the positive electrode 33 and the parasitic capacitance generated by the negative electrode 34 can be offset, thereby reducing the parasitic capacitance of the MEMS resonator 10, improving the signal-to-noise ratio of the signal and the stability of the high-frequency output, and improving the overall performance of the MEMS resonator 10.

[0048] In an optional example, the positive electrode 33 includes a positive drive electrode 36 and a positive sensing electrode 38, and the negative electrode 34 includes a negative drive electrode 40 and a negative sensing electrode 42. The capacitance area of the positive drive electrode 36 is the same as the capacitance area of the negative drive electrode 40, and the phases of the positive drive electrode 36 and the negative drive electrode 40 are opposite. Therefore, the parasitic capacitance generated by the positive drive electrode 36 is the same as the parasitic capacitance generated by the negative drive electrode 40 and can offset each other; the capacitance area of the positive sensing electrode 38 is the same as the capacitance area of the negative sensing electrode 42, and the phases of the positive sensing electrode 38 and the negative sensing electrode 42 are opposite. Therefore, the parasitic capacitance generated by the positive sensing electrode 38 is the same as the parasitic capacitance generated by the negative sensing electrode 42 and can offset each other, thereby reducing the parasitic capacitance of the MEMS resonator 10.

[0049] The number of positive driving electrodes 36 and the number of negative driving electrodes 40 are the same and both are multiple, the number of positive sensing electrodes 38 and the number of negative sensing electrodes 42 are the same and both are multiple, and the number of positive driving electrodes 36 is the same as the number of positive sensing electrodes 38, and each resonant ring 18 corresponds to one driving electrode and one sensing electrode.

[0050] The capacitance area of the positive drive electrode 36 is the same as the capacitance area of the negative drive electrode 40. This may mean that the sum of the capacitance areas of multiple positive drive electrodes 36 is the same as the sum of the capacitance areas of multiple negative drive electrodes 40, while the capacitance areas between some positive drive electrodes 36 and / or the capacitance areas between some negative drive electrodes 40 are different. Alternatively, this may mean that the capacitance area of each positive drive electrode 36 is the same, the capacitance area of each negative drive electrode 40 is the same, and the capacitance area of each positive drive electrode 36 is the same as the capacitance area of the negative drive electrode 40. Similarly, the capacitance area of the positive sensing electrode 38 is the same as the capacitance area of the negative sensing electrode 42. This may mean that the total capacitance area of the positive sensing electrode 38 is the same as the total capacitance area of the negative sensing electrode 42, or that the capacitance area of any one positive sensing electrode 38 is the same as the capacitance area of the negative sensing electrode 42. For details, please refer to the description of the positive and negative drive electrodes, which will not be repeated here.

[0051] The positive drive electrode 36 and the negative drive electrode 40 are located on the same side of the resonant ring 18, and the positive sense electrode 38 and the negative sense electrode 42 are located on the other side of the resonant ring 18. That is, the positive drive electrode 36 and the negative drive electrode 40 are both located on the inside of the resonant ring 18, and the positive sense electrode 38 and the negative sense electrode 42 are both located on the outside of the resonant ring 18, or the positive drive electrode 36 and the negative drive electrode 40 are both located on the outside of the resonant ring 18, and the positive sense electrode 38 and the negative sense electrode 42 are both located on the inside of the resonant ring 18. The capacitance area of any positive drive electrode 36 is the same as the capacitance area of the negative drive electrode, and the capacitance area of any positive sense electrode 38 is the same as the capacitance area of the negative sense electrode 42. Therefore, the parasitic capacitance generated by each positive drive electrode 36 is the same as the parasitic capacitance generated by the negative drive electrode 40, and the parasitic capacitance generated by each positive sense electrode 38 is the same as the parasitic capacitance generated by the negative sense electrode 42.

[0052] Positive drive electrode 36 and negative drive electrode 40 have the same shape and size. If the capacitive gaps and dielectric constants between positive drive electrode 36 and negative drive electrode 40 and base substrate 26 are the same, the capacitive area of positive drive electrode 36 is the same as the capacitive area of negative drive electrode 40, so that the parasitic capacitances of the two electrodes are the same. Similarly, positive sense electrode 38 and negative sense electrode 42 have the same shape and size. If the capacitive gaps and dielectric constants between positive sense electrode 38 and negative sense electrode 42 and base substrate 26 are the same, the capacitive area of positive sense electrode 38 is the same as the capacitive area of negative sense electrode 42, so that the parasitic capacitances of the two electrodes are the same.

[0053] The dielectric constant between the electrode and the base substrate includes the dielectric constant of the separation layer located between the electrode and the base substrate, and the dielectric constant of the partial device layer located between the electrode and the base substrate. The thickness of the separation layer between different electrodes and the base substrate is the same, and the thickness of the partial device layer is the same, so that the parasitic capacitance of different electrodes with the same area relative to the base substrate is the same.

[0054] The positive driving electrode 36 and the negative driving electrode 40 are electrodes of the same type, and are both used to drive the resonant ring 18 to resonate. The positive sensing electrode 38 and the negative sensing electrode 42 are electrodes of the same type, and are both used to sense the resonance of the resonant ring 18. The electrodes of the same type are respectively located on the same side of the multiple resonant rings 18, and the electrodes of different types are respectively located on opposite sides of the multiple resonant rings 18. During the production process, the positive and negative electrodes of the same type can be prepared by the same production equipment so that they have the same shape and size. In this way, the capacitance area of all electrodes of the same type can be the same to meet the condition of the same capacitance area, thereby avoiding the problem that the positive and negative electrodes of the same type have different shapes due to being located on different sides of the resonant ring 18, and the need to specially adjust their shapes to meet the same capacitance, which helps to reduce the difficulty of production.

[0055] Multiple resonant rings 18 form a first resonant group 22 and a second resonant group 24. The first electrode regions 31 corresponding to the resonant rings 18 of the first resonant group 22 are all positive drive electrodes 36, and the second electrode regions 32 corresponding to the resonant rings 18 of the first resonant group 22 are all positive sensing electrodes 38. That is, among the multiple resonant rings 18 of the first resonant group 22, the outer side of the resonant ring 18 is provided with a positive drive electrode 36, and the inner side is provided with a positive sensing electrode 38. The first electrode regions 31 corresponding to the resonant rings 18 of the second resonant group 24 are all negative drive electrodes 40, and the second electrode regions 32 corresponding to the resonant rings 18 of the second resonant group 24 are all negative sensing electrodes 42.

[0056] The first resonant group 22 and the second resonant group 24 include the same number of resonant rings 18. The sum of the number of positive drive electrodes 36 and the number of negative drive electrodes 40 is equal to the number of resonant rings 18. The sum of the number of positive sense electrodes 38 and the number of negative sense electrodes 42 is also equal to the number of resonant rings 18. Among the multiple resonant rings 18 of the MEMS resonator 10, half of the resonant rings 18 have positive drive electrodes 36 on the outside and positive sense electrodes 38 on the inside, and the other half of the resonant rings 18 have negative drive electrodes 40 on the outside and negative sense electrodes 42 on the inside.

[0057] In an optional example, the first resonance group 22 includes two resonant rings 18, and the second resonance group 24 includes two resonant rings 18. The two resonant rings 18 of the first resonance group 22 and the two resonant rings 18 of the second resonance group 24 are alternately distributed, so that the positive driving electrodes 36 and the negative driving electrodes 40 are alternately distributed, and the positive sensing electrodes 38 and the negative sensing electrodes 42 are alternately distributed, thereby achieving an operating mode in which the two opposite resonant rings 18 resonate in the same direction and the two adjacent resonant rings 18 resonate in opposite directions.

[0058] Optionally, the anchor region 14, the connecting beam 20, and the resonant ring 18 are electrically connected in sequence, and a DC bias voltage (DC) is applied through the anchor region 14, so that the anchor region 14, the connecting beam 20, and the resonant ring 18 have the same potential. The two positive drive electrodes 36 and the two positive sense electrodes 38 corresponding to the first resonant group 22 are electrically connected, and the two negative drive electrodes 40 and the two negative sense electrodes 42 corresponding to the second resonant group 24 are electrically connected. The positive drive electrodes 36 on the outside of the first resonant group 22 and the negative drive electrodes 40 on the outside of the second resonant group 24 are respectively connected to drive signals with opposite phases, i.e., with a phase difference of 180°. The positive sense electrodes 38 on the inside of the first resonant group 22 and the negative sense electrodes 42 on the inside of the second resonant group 24 are respectively connected to sense signals with a phase difference of 180°. The positive drive electrodes 36 and the negative drive electrodes 40 have the same parasitic capacitance and cancel each other out. The positive sense electrodes 38 and the negative sense electrodes 42 have the same parasitic capacitance and cancel each other out, thereby reducing the influence of the parasitic capacitance and improving the signal-to-noise ratio.

[0059] In other embodiments, the positive driving electrode 36, the negative driving electrode 40, the positive sensing electrode 38 and the negative sensing electrode 42 can be arranged in other ways. For example, the positive driving electrode 36 is set on the outside of the resonant ring 18 of the first resonant group 22, and the negative sensing electrode 42 is set on the inside; the negative driving electrode 40 is set on the outside of the resonant ring 18 of the second resonant group 24, and the positive sensing electrode 38 is set on the inside; or, the positive sensing electrode 38 and the negative sensing electrode 42 are set on the outside of the resonant ring 18 of the first resonant group 22 and the second resonant group 24, and the positive driving electrode 36 and the negative driving electrode 40 are set on the inside; or, the positive driving electrode 36 and the negative driving electrode 40 are respectively set on the inside and outside of the resonant ring 18 of the first resonant group 22, and the positive sensing electrode 38 and the negative sensing electrode 42 are respectively set on the inside and outside of the resonant ring 18 of the second resonant group 24. In this case, electrodes of the same type and opposite phases are located on different sides of the resonant ring 18.

[0060] See also Figure 1 and Figure 5In one embodiment, the anchoring region 14 includes a central connecting portion 44 and a plurality of reinforcing portions 46 disposed around the connecting portion 44. Adjacent reinforcing portions 46 are spaced apart from each other, and each of the reinforcing portions 46 is connected to the connecting portion 44. Multiple resonant rings 18 surround the outer circumference of the reinforcing portion 46. The connecting beam 20 corresponding to each resonant ring 18 passes between two adjacent reinforcing portions 46 and connects to the connecting portion 44, thereby connecting the corresponding resonant ring 18 to the connecting portion 44. The connecting portion 44 can connect the multiple resonant rings 18 together, while the multiple reinforcing portions 46 are connected to the base substrate 26, thereby supporting the resonant rings 18, the connecting beam 20, and the connecting portion 44, so that the resonant rings 18 and the connecting beam 20 are suspended relative to the base substrate 26. Multiple resonant rings 18 are respectively connected to the connecting parts 44 of the anchoring area 14 through the connecting beams 20, which is beneficial to reducing the anchor point loss, thereby improving the overall performance of the MEMS resonator 10. At the same time, the reinforcement part 46 can increase the contact area between the anchoring area 14 and the base substrate 26, facilitating the fixed connection between the anchoring area 14 and the base substrate 26. Therefore, by further providing the anchoring area 14 including the connecting part 44 and the multiple reinforcement parts 46, and the multiple resonant rings 18 are all connected to the connecting part 44, it can achieve the effect of reducing the anchor point loss and facilitating the fixation of the anchoring area 14 and the base substrate 26.

[0061] Optionally, the two resonant rings 18 of the first resonant group 22 and the two resonant rings 18 of the second resonant group 24 are symmetrically arranged relative to the connecting portion 44, so that the energy generated by the two resonant rings 18 of the first resonant group 22 when resonating can be offset in the connecting portion 44, and the energy generated by the two resonant rings 18 of the second resonant group 24 when resonating can be offset in the connecting portion 44, thereby reducing the energy transferred to the reinforcement portion 46, thereby reducing the anchor point loss.

[0062] A reinforcement portion 46 is provided between any two adjacent connecting beams 20 to provide a more balanced support effect for the resonant body 12. In an optional example, the number of the connecting beams 20 and the number of the reinforcement portions 46 are both four.

[0063] The connecting portion 44 includes a base 48 and a plurality of extensions 50 extending outward from the periphery of the base 48. The plurality of extensions 50 are arranged at intervals along the circumference of the base 48. Each resonant ring 18 is connected to a corresponding extension 50 via a connecting beam 20. That is, the number of resonant rings 18, connecting beams 20, and extensions 50 are the same and are connected one-to-one.

[0064] The specific shape of the reinforcing portion 46 is not limited, for example, rectangular, fan-shaped, circular, etc. In an optional example, the outer contour of the reinforcing portion 46 is rectangular, and its two adjacent side surfaces are respectively arranged in parallel with the corresponding connecting beam 20 to prevent the reinforcing portion 46 from affecting the resonance of the connecting beam 20.

[0065] A fixed beam 52 is provided on the outer side of the reinforcement portion 46. Each reinforcement portion 46 is fixedly connected to two adjacent extension portions 50 through two fixed beams 52. That is, a fixed beam 52 is connected to the opposite sides of each extension portion 50, and the spacing between the multiple fixed beams 52 and the base 48 is the same, so that the multiple fixed beams 52 are arranged in a centrally symmetrical manner relative to the base 48, and the two fixed beams 52 on the opposite sides of the same extension portion 50 are arranged in an axially symmetrical manner, forming an effect that multiple reinforcement portions 46 are connected to the same equivalent area, so as to reduce anchor point loss.

[0066] Optionally, the fixed beam 52 may be a curved structure, a serpentine structure, an S-structure, a hollow structure, or the like, so as to reduce the energy of the connecting beam 20 and the reinforcement portion 46 and further reduce the anchor loss.

[0067] An opening 54 is defined on the side of the second electrode region 32 adjacent to the reinforcement portion 46 . The end of the connecting beam 20 away from the connecting portion 44 passes through the opening 54 and is connected to the resonant ring 18 . When passing through the opening 54 , the connecting beam 20 is spaced a certain distance from the inner wall of the opening 54 . Planes parallel to and spaced apart from the edge of the reinforcement portion 46 are defined on both sides of the opening 54 . The side of the second electrode region 32 away from the reinforcement portion 46 is a curved surface.

[0068] See also Figures 6 to 11 In one embodiment, the resonant ring 18 is annular. Each resonant ring 18 includes an inner edge 56 and an outer edge 58 that are opposite to each other. The resonant ring 18 forms a widened region 60 and a narrowed region 62 between the inner edge 56 and the outer edge 58. Along the radial direction of the resonant ring 18, the thickness of the widened region 60 is greater than the thickness of the narrowed region 62. Multiple widened regions 60 and multiple narrowed regions 62 are alternately arranged along the circumference of the resonant ring 18. By configuring the resonant ring 18 to include a widened region 60 and a narrowed region 62, a design of unequal width is formed. The widened region 60 and the narrowed region 62 have different equivalent stiffnesses, and their deformation amounts and directions in which they are more easily deformed will be different during resonance. Therefore, the deformation direction of the resonant ring 18 can be adjusted by designing the widened region 60 and the narrowed region 62, thereby adjusting the equivalent crystal orientation of the resonant ring 18, optimizing the TCF characteristics of the MEMS resonator 10, making the TCF in a relatively stable range, reducing the overall TCF variation of the MEMS resonator 10, and making the frequency output of the MEMS resonator 10 more stable.

[0069] The specific shape of the resonant ring 18 is not limited, and may be a circular ring, a polygonal ring, an irregular circular ring, etc., and the shape of the inner edge 56 may be the same as or different from the shape of the outer edge 58. In the present application, the shapes of the inner edge 56 and the outer edge 58 are different to form a widened region 60 and a narrowed region 62.

[0070] Optionally, the shape of the inner edge 56 may be a circle, an irregular circle, a polygon, or a polygon with rounded corners, and the shape of the outer edge 58 may be a circle, an irregular circle, a polygon, or a polygon with rounded corners.

[0071] Figures 6 to 11 Several different shapes of resonant rings 18 are shown. Figure 6 In the embodiment shown, the inner edge 56 of the resonant ring 18 is circular, and the outer edge 58 is a polygon with rounded corners; Figure 7 In the embodiment shown, the inner edge 56 of the resonant ring 18 is circular, and the outer edge 58 is an irregular circle; Figure 8 In the embodiment shown, the inner edge 56 of the resonant ring 18 is a rectangle with rounded corners, and the outer edge 58 is an irregular circle; Figure 9 In the embodiment shown, the inner edge 56 of the resonant ring 18 is circular, and the outer edge 58 is a regular hexagon; Figure 10 In the embodiment shown, the inner edge 56 of the resonant ring 18 is circular, and the outer edge 58 is a regular octagon; Figure 11 In the illustrated embodiment, the inner edge 56 of the resonant ring 18 is circular, and the outer edge 58 is a regular pentagon.

[0072] Figure 12 This is a TCF curve diagram of the MEMS resonator, where the solid line is the TCF curve of the MEMS resonator of the present application, and the dotted line is the TCF curve of the existing MEMS resonator. It can be seen from the figure that the slope of the solid line TCF curve is smaller than the slope of the dotted line TCF curve. The smaller slope means that the MEMS resonator has better stability, so as to enhance the stability of the frequency output.

[0073] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A MEMS resonator, characterized in that: The invention comprises a resonant body, an anchoring region and an electrode region, wherein the resonant body comprises a plurality of resonant rings arranged at intervals, and a connecting beam connecting the resonant rings and the anchoring region; the electrode region is arranged corresponding to the resonant rings, and comprises a first electrode region arranged outside the resonant rings and spaced apart from the outer edge of the resonant rings, and a second electrode region arranged inside the resonant rings and spaced apart from the inner edge of the resonant rings; Positive electrodes are partially set in the first electrode area and negative electrodes are partially set in the second electrode area, the positive electrodes include positive driving electrodes and / or positive sensing electrodes, the negative electrodes include negative driving electrodes and / or negative sensing electrodes, and the capacitance area formed by the positive electrodes relative to the base substrate is the same as the capacitance area formed by the negative electrodes relative to the base substrate.

2. The MEMS resonator according to claim 1, wherein The plurality of resonant rings form a first resonant group and a second resonant group, the first electrode regions corresponding to the resonant rings of the first resonant group are all positive driving electrodes, and the second electrode regions corresponding to the resonant rings of the first resonant group are all positive sensing electrodes; The first electrode regions corresponding to the resonant rings of the second resonant group are all negative driving electrodes, and the second electrode regions corresponding to the resonant rings of the second resonant group are all negative sensing electrodes.

3. The MEMS resonator according to claim 1, wherein: The positive electrode includes a positive driving electrode and a positive sensing electrode, and the negative electrode includes a negative driving electrode and a negative sensing electrode. The positive driving electrode and the negative driving electrode have the same capacitance area relative to the base substrate, and the positive sensing electrode and the negative sensing electrode have the same capacitance area relative to the base substrate.

4. The MEMS resonator according to claim 1, wherein: The anchoring area includes a central connecting portion and a plurality of reinforcing portions arranged around the connecting portion, wherein adjacent reinforcing portions are spaced apart from each other and are respectively connected to the connecting portion; A plurality of resonant rings surround the outer circumference of the reinforcement portion, and a connecting beam corresponding to each resonant ring passes through the adjacent reinforcement portion to connect the corresponding resonant ring with the connecting portion.

5. The MEMS resonator according to claim 4, characterized in that An opening is provided on one side of the second electrode region close to the reinforcing portion, the connecting beam passes through the opening, and planes are provided on both sides of the opening in the second electrode region that are parallel to and spaced from the edge of the reinforcing portion.

6. The MEMS resonator according to claim 1, wherein: The MEMS resonator includes a base substrate, a device layer spaced apart from the base substrate, and a separation layer located between the base substrate and the device layer. The anchor region and the electrode region are respectively fixedly connected to the base substrate through the separation layer.

7. The MEMS resonator according to claim 1, wherein: The positive driving electrode and the negative driving electrode are located on the same side of the resonant ring, and the capacitance area of any one of the positive driving electrodes is the same as the capacitance area of the negative driving electrode; and / or, The positive sensing electrode and the negative sensing electrode are located on the other side of the resonant ring, and the capacitance area of any one of the positive sensing electrodes is the same as the capacitance area of the negative sensing electrode.

8. The MEMS resonator according to claim 7, wherein: The positive driving electrode and the negative driving electrode have the same shape and size; and / or, The positive sensing electrode and the negative sensing electrode have the same shape and size.

9. The MEMS resonator according to any one of claims 1 to 8, wherein: The resonant ring forms a widened area and a narrowed area alternately arranged along the circumference thereof between the inner edge and the outer edge.

10. The MESM resonator according to claim 9, characterized in that The inner edge is a circle, an irregular circle, a polygon or a polygon with rounded corners, and the outer edge is a circle, an irregular circle, a polygon or a polygon with rounded corners.

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