CN220653348U

CN220653348U - Single-port MEMS resonator

Info

Publication number: CN220653348U
Application number: CN202322391641.1U
Authority: CN
Inventors: 雷永庆; 金怡; 王宏宇
Original assignee: Mestar Microelectronics Shenzhen Co ltd
Current assignee: Mestar Microelectronics Shenzhen Co ltd
Priority date: 2023-09-01
Filing date: 2023-09-01
Publication date: 2024-03-22
Anticipated expiration: 2033-09-01

Abstract

The utility model provides a single-port MEMS resonator, which comprises a resonator body, resonator body anchor points, driving electrodes and detection electrodes, wherein the driving electrodes are connected with each other by leads to enable only one input port of driving voltage, and the detection electrodes are connected with each other by leads to enable only one output port of detection signals, so that the input ports and the output ports are reduced, the driving area and the detection area are further increased, the signal strength is enhanced, the impedance of the MEMS resonator is reduced, in addition, the lead connection is also carried out among the resonator body anchor points, the wiring modes among the anchor points, among the detection electrodes and among the driving electrodes are simple, the parasitic capacitance of the MEMS resonator is better reduced, and the complexity of a back-end circuit can be reduced when the MEMS resonator is combined with other back-end circuits due to only one input port and one output port, and the power consumption of the whole device is reduced.

Description

Single-port MEMS resonator

Technical Field

The utility model relates to the technical field of micro-electromechanical systems, in particular to a single-port MEMS resonator.

Background

Microelectromechanical systems (MEMS, micro-Electro-Mechanical System) are a high-tech field based on microelectronics and micromachining technologies. MEMS devices have the advantages of being small, intelligent, executable, integrated, good in process compatibility, low in cost and the like. The development of MEMS technology opens up a brand new technical field and industry, and micro sensors, micro actuators, micro components, micro mechanical optical devices, vacuum microelectronic devices, power electronic devices and the like manufactured by utilizing the MEMS technology have very wide application prospects in the fields of aviation, aerospace, automobiles, biomedicine, environmental monitoring, military, internet of things and the like.

Impedance is an important parameter of MEMS resonators, and has an extremely important impact on the performance of MEMS resonators. The impedance can determine the response speed of the MEMS resonator to external excitation, and the lower impedance can improve the sensitivity of the MEMS resonator, so that the MEMS resonator can respond to external signals more easily, and the MEMS resonator can be applied to a sensor and a vibration energy collector; the impedance also affects the power consumption of the MEMS resonator, and the lower impedance generally corresponds to the lower power consumption of the MEMS resonator, so that the energy efficiency can be improved, and the application of the MEMS resonator on portable and low-power-consumption equipment is expanded; the impedance also affects the phase response of the MEMS resonator, and different impedance characteristics may lead to different phase shifts, a property of which is important for the use of the MEMS resonator in timing and signal processing.

However, in the existing MEMS resonator, a plurality of driving ports or detection ports are generally disposed, so that the impedance of the MEMS resonator is too high, which severely limits the application of the MEMS resonator in the above fields.

It should be noted that the foregoing description of the background art is only for the purpose of facilitating a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background section of the present application.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present utility model is to provide a single-port MEMS resonator, which is used for solving the problem that in the prior art, the impedance is too high due to the MEMS resonator being provided with a plurality of driving ports or detection ports, and limiting the application of the MEMS resonator in the fields of time sequence, signal processing portability, low power consumption equipment and the like.

To achieve the above and other related objects, the present utility model provides a single-port MEMS resonator comprising:

the number of the resonance bodies is at least two, and the resonance bodies are positioned at two ends of the connecting beam and are used for generating resonance;

the electrode comprises a driving electrode and a detecting electrode, wherein the driving electrode and the detecting electrode are provided with only one electrical interface, the driving electrode is used for providing alternating voltage and inducing the resonance body to generate resonance, and the detecting electrode is used for detecting the resonance generated by the resonance body;

the resonant body anchor points are connected with two adjacent connecting beams and are used for supporting the resonant body and the connecting beams on a substrate, and the resonant body anchor points are electrically connected.

Optionally, the number of the resonators may be even or odd, and the resonators are uniformly distributed around the intersection point of the connection beams.

Optionally, the shape of the resonator body comprises one or more of a circular ring, square, triangle or other polygon.

Optionally, the number of the driving electrodes and the number of the detecting electrodes are equal and are one, so that only one driving voltage input port and only one detecting signal output port are provided.

Optionally, the number of the driving electrodes is equal to the number of the detecting electrodes, the driving electrodes are connected in series by wires, and the detecting electrodes are connected in series by connecting wires, so that only one driving voltage input port and one detecting signal output port are provided.

Optionally, the number of the resonant body anchor points is less than or equal to the number of the resonant bodies, and the anchor points are symmetrically distributed about the intersection point of the connecting beam.

Optionally, the number of the resonators is four, at this time, the number of the connection beams is two, and the four resonators are arranged in a cross shape with the intersection point of the connection beams as the center.

Optionally, the connection beam comprises one of a straight beam structure, a soft spring structure or an S-shaped structure.

Optionally, the connection beam is a flexible connection beam.

Optionally, a driving capacitance is formed between the driving electrode and the resonator body, and a detection capacitance is formed between the detection electrode and the resonator body.

As described above, the single-port MEMS resonator of the present utility model has the following advantageous effects: compared with the MEMS resonator in the prior art, the single-port MEMS resonator has the advantages that the driving electrodes are connected through the leads, so that the input ports of driving voltages are only one, the detecting electrodes are connected through the leads, so that the output ports of detecting signals are only one, the input ports and the output ports are reduced, the driving area and the detecting area are further increased, the signal intensity is enhanced, the impedance is reduced, in addition, the lead connection is also carried out among the resonator anchor points, the wiring modes among the resonator anchor points, among the detecting electrodes and among the driving electrodes are simple, the parasitic capacitance of the MEMS resonator is better reduced, and the complexity of a back-end circuit can be reduced when the MEMS resonator is combined with other back-end circuits due to the fact that only one input port and one output port are arranged.

Drawings

Fig. 1 shows a schematic top view of a single-port MEMS resonator of the present utility model.

Fig. 2 shows an equivalent circuit schematic of a single-port MEMS resonator of the present utility model.

Description of element reference numerals

101. A resonator body; 102. a driving electrode; 103. a detection electrode; 104. a resonator anchor; 105. a connecting beam; 106. and connecting wires.

Detailed Description

Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model.

As described in detail in the embodiments of the present utility model, the schematic drawings showing the structure of the apparatus are not partially enlarged to general scale, and the schematic drawings are merely examples, which should not limit the scope of the present utility model. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.

For ease of description, spatially relative terms such as "under", "below", "beneath", "above", "upper" and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures.

In the context of this application, a structure described as a first feature being "on" a second feature may include embodiments where the first and second features are formed in direct contact, as well as embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

Referring to fig. 1 to 2, it should be noted that the illustrations provided in the present embodiment are only schematic illustrations of the basic concept of the present utility model, and only the components related to the present utility model are shown in the illustrations, rather than being drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

As shown in fig. 1, the present utility model provides a single-port MEMS resonator including a resonator body 101, the number of the resonator bodies 101 being at least two and being located at both ends of a connection beam 105 for generating resonance; the electrode comprises a driving electrode 102 and a detecting electrode 103, wherein the driving electrode 102 and the detecting electrode 103 are provided with only one electrical interface, the driving electrode 102 provides alternating voltage for inducing the resonance of the resonance body 101, and the detecting electrode 103 is used for detecting the resonance generated by the resonance body 101; and the resonator anchor points 104, wherein the resonator anchor points 104 are connected with two adjacent connecting beams 105, and are used for supporting the resonator 101 and the connecting beams 105 on a substrate, and the resonator anchor points 104 are electrically connected.

The single-port MEMS resonator in this application is secured to a substrate, including but not limited to a silicon doped substrate, which is a generally planar structure, by the resonator body anchor 104.

The resonator body 101, the driving electrode 102, the detecting electrode 103, the resonator body anchor 104, and other structures that constitute the single port MEMS resonator may be made of semiconductor materials. For example, materials in column IV of the periodic table include, but are not limited to, silicon, germanium, carbon, and adaptive compositions or compounds thereof, such as silicon germanium or silicon carbide; for another example, a composition or compound of materials in columns III-V of the periodic Table of elements, including but not limited to gallium phosphide, aluminum gallium phosphide; also for example, a composition or compound of materials in columns III, IV, V or VI of the periodic Table of elements, including but not limited to at least one of silicon nitride, silicon oxide, aluminum carbide, aluminum nitride and aluminum oxide; of course, at least one of metal silicide, germanide and carbide may also be included, including but not limited to at least one of nickel silicide, cobalt silicide, tungsten carbide and platinum germanium silicide; doping variants including, but not limited to, phosphorus, arsenic, antimony, boron or aluminum doped silicon or germanium, carbon or germanium combinations, such as silicon germanium; materials having various crystalline structures and suitable combinations thereof (either doped or undoped materials) include, but are not limited to, at least one of monocrystalline, polycrystalline, nanocrystalline, and amorphous crystals.

In some embodiments, the number of the resonators 101 may be even or odd, and the resonators 101 are uniformly distributed around the intersection of the connection beams 105.

Specifically, the number of the resonators 101 is at least two, and the number of the resonators 101 may be even or odd, and in addition, the resonators 101 are uniformly distributed around the intersection of the connection beams 105, regardless of whether the number of the resonators 101 is odd or even, for example, when the number of the resonators 101 is two, the resonators 101 are located at two ends of the connection beams 105, and when the number of the resonators 101 is three, the adjacent resonators 101 are distributed at an angle of 120 degrees. In this embodiment, as shown in fig. 1, the number of the resonators 101 is four, and the four resonators 101 are uniformly distributed around the intersection of the connection beams 105, and the adjacent resonators 101 are distributed at an angle of 90 degrees, so that the quality factor (Q value) of the single-port MEME resonator caused by the photolithography error can be reduced by the symmetrical structure design of the resonators 101.

In some embodiments, the shape of the resonator body 101 includes one or more of a circular ring, square, triangle, or other polygon.

Specifically, the resonator body 101 may also be referred to as a resonator for generating vibrations of a desired frequency, i.e., generating resonance of a preset resonance frequency. In practical applications, the shape of the resonator body 101 includes one or more of a circular ring shape, a square shape, or a triangle shape. In this embodiment, the resonator body 101 has a circular ring shape, and its cross-sectional shape is shown in fig. 1, however, in other embodiments, the cross-sectional shape may be square, triangular or other polygonal shape, and in addition, the resonator body 101 may be a closed connection structure or a non-closed connection structure, which is not limited herein.

In some embodiments, the connecting beam 105 comprises one of a straight beam structure, a soft spring structure, or an S-shaped structure.

Specifically, as shown in fig. 1, in the present embodiment, a connection beam 105 is disposed in the MEMS resonator, two ends of the connection beam 105 are respectively connected to the resonator bodies 101, and the connection beam 105 may enable communication between the plurality of resonator bodies 101, so as to transfer vibration between the respective resonator bodies 101. In the present embodiment, the connection beams 105 between the resonators 101 are provided in a straight beam structure, and by the provided straight beam structure, the path of vibration transmission between the respective resonators 101 can be shortened, the vibration transmission loss can be reduced, and finally the accuracy of the resonator can be improved. Of course, in other embodiments, the shape of the connecting beam 105 may also be a soft spring structure or an S-shaped structure, without limitation.

In some embodiments, the connection beam 105 is a flexible connection beam.

Specifically, in this embodiment, the connection beams 105 are all flexible connection beams, and the flexible connection beams have good elasticity, and by the arrangement of the flexible connection beams, energy transmission loss between the resonator body 101 and the resonator body anchor point 104 can be reduced, so that the Q value of the MEMS resonator is improved.

In some embodiments, the number of the driving electrodes 102 and the detecting electrodes 103 is equal and one, so that there is only one input port of the driving voltage and one output port of the detecting signal.

Specifically, the driving electrode 102 provides an ac voltage for inducing the resonance of the resonator body 101, the detecting electrode 103 is used for detecting the resonance generated by the resonator body 101 and transmitting it to the IC circuit, in this embodiment, the number of the driving electrode 102 and the detecting electrode 103 is set to one, so as to ensure that only one voltage input port on the driving electrode 102 and only one output port of the detecting signal on the detecting electrode 103 are provided, and according to the equivalent circuit schematic diagram of electrostatic driving and electrostatic detection of the single-port MEMS resonator in the present utility model shown in fig. 2, the impedance of the single-port MEMS resonator satisfies the following formula:

wherein R is _m The impedance of the MEMS resonator, d is the electrode gap (the gap between the drive electrode 102 and the resonator body 101, the gap between the detection electrode 103 and the resonator body 101, and the two are equal), k is the effective stiffness of the resonator body 101, Q is the quality factor of the resonator, ω _n The resonant frequency of the resonator 101, ε is the dielectric constant, A is the facing area of the resonator 101 and the electrode, V _Bias For the bias voltage applied to the resonator body 101.

In practical use, let us assume a bias voltage V _Bias The gap between the electrodes remains unchanged, the effective rigidity and quality factor of the resonator body 101 and the resonant frequency are fixed values, and the impedance R of the single-port MEMS resonator relative to the multi-port MEMS resonator is caused by the change of the facing area A of the resonator body 101 and the electrodes _m And (3) reducing. For example, since the facing area between the resonator body 101 and the electrodes of the two-port MEMS resonator (e.g., differential resonator) is 0.5 times that of the single-port MEMS resonator, substituting the above formula to calculate can result in that the impedance thereof is 4 times that of the single-port MEMS resonator, if the single-port MEMS resonator is used instead of the MEMS resonator having two ports, the impedance of the resonator can be reduced by 4 times, thereby improving the application of the MEMS resonator in the fields of time series, signal processing portability, low power consumption devices, and the like.

In some embodiments, the number of the driving electrodes 102 and the number of the detecting electrodes 103 are equal and are multiple, and the driving electrodes 102 are connected in series by wires, and the detecting electrodes 103 are connected in series by wires, so that only one input port of the driving voltage and only one output port of the detecting signal are provided.

Specifically, as shown in fig. 1, in this embodiment, the number of the driving electrodes 102 and the number of the detecting electrodes 103 may be multiple, and the multiple driving electrodes 102 are connected in series by using a connection wire 106, so as to ensure that only one input port of a driving voltage is provided, and the multiple detecting electrodes 103 are connected in series by using the connection wire 106 so that only one output port of a detecting signal is provided, thereby ensuring that the single-port MEMS resonator in the present application can perform single-port driving and single-port detection, and further reducing the impedance of the MEMS resonator, and further improving the application of the MEMS resonator in the fields of time sequence, signal processing portability, low power consumption equipment, and the like.

For those skilled in the art, the driving electrode 102 and the detecting electrode 103 in this embodiment may be of a type well known in the conventional art, and will not be described here.

In some embodiments, a driving capacitance is formed between the driving electrode 102 and the resonator body 101, and a detection capacitance is formed between the detection electrode 103 and the resonator body 101.

Specifically, an external contact may be disposed in the MEMS resonator, so as to be connected with an interface of the IC circuit correspondingly, for example, for wire bonding, or flip-chip bonding, so as to ensure normal operation of the MEMS resonator. For a plurality of electrodes in the MEMS resonator, the electrodes need to be electrically connected with the external contact so as to facilitate signal transmission, and at this time, a connection wire 106 may be disposed between the various types of electrodes, where the connection wire 106 is used to connect the external contact with the corresponding electrode, and also is used to electrically connect the plurality of electrodes. The port number of the MEMS resonator is reduced, so that the internal structure of the resonator is greatly simplified, the structural optimization of the resonator is facilitated, the parasitic capacitance and electrode stress of the resonator can be reduced, the performance yield of the resonator is improved, and the design and processing cost can be saved.

In some embodiments, the number of resonator body anchors 104 is less than or equal to the number of resonator bodies 101, and the resonator body anchors 104 are symmetrically distributed about the intersection of the connection beams 105.

Specifically, as shown in fig. 1, the resonator anchor points 104 are located between two adjacent connection beams 105 and are connected with two adjacent connection beams 105, so that the resonator 101 and the connection beams 105 are supported on the substrate by the resonator anchor points 104, the number of the resonator anchor points 104 can be equal to that of the resonator 101, at this time, the number of the resonator anchor points 104 can be smaller than that of the resonator 101, at this time, the resonator anchor points 104 are symmetrically distributed with respect to the crossing points of the connection beams 105, and no matter how many of the resonator anchor points 104 are arranged, metal leads are needed to make the resonator anchor points 104 electrically connected, that is, only one electrical interface is arranged between the resonator anchor points 104.

In summary, the single-port MEMS resonator of the present utility model uses the lead wire to interconnect the driving electrodes to make only one input port of the driving voltage, and uses the lead wire to interconnect the detecting electrodes to make only one output port of the detecting signal, thereby reducing the input port and the output port, further increasing the driving area and the detecting area, enhancing the signal strength, and reducing the impedance of the MEMS resonator. Therefore, the utility model effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. A single-port MEMS resonator, the single-port MEMS resonator comprising:

2. The single port MEMS resonator of claim 1 wherein: the number of the resonators can be even or odd, and the resonators are uniformly distributed around the intersection point of the connecting beams.

3. The single port MEMS resonator of claim 1 wherein: the shape of the resonator body includes one or more of a circular ring, square, triangle, or other polygon.

4. The single port MEMS resonator of claim 1 wherein: the number of the driving electrodes and the number of the detecting electrodes are equal and are one, so that only one driving voltage input port and one detecting signal output port are arranged.

5. The single port MEMS resonator of claim 1 wherein: the number of the driving electrodes is equal to that of the detecting electrodes, the driving electrodes are connected in series by connecting wires, and the detecting electrodes are connected in series by wires, so that the input port of the driving voltage and the output port of the detecting signal are only one.

6. The single port MEMS resonator of claim 1 wherein: the number of the anchor points of the resonant bodies is smaller than or equal to that of the resonant bodies, and the anchor points are symmetrically distributed about the crossing points of the connecting beams.

7. The single port MEMS resonator of claim 1 wherein: the number of the resonant bodies is four, at this time, the number of the connecting beams is two, and the four resonant bodies are distributed in a cross shape by taking the crossing point of the connecting beams as the center.

8. The single port MEMS resonator of claim 1 wherein: the connecting beam comprises one of a straight beam structure, a soft spring structure or an S-shaped structure.

9. The single-port MEMS resonator of claim 8 wherein: the connecting beam is a flexible connecting beam.

10. The single port MEMS resonator of claim 1 wherein: a driving capacitor is formed between the driving electrode and the resonance body, and a detection capacitor is formed between the detection electrode and the resonance body.