A coupled resonator and a method for preparing the same

Abstract

The present invention belongs to the field of microelectronic technology, and discloses a coupled resonator and a preparation method thereof. The coupled resonator includes at least two resonant oscillators, among which at least one resonant oscillator has a positive frequency temperature coefficient, and at least one resonant oscillator has a negative frequency temperature coefficient. Different types of resonant oscillators have different vibration modes. When multiple resonant oscillators are coupled and resonated, the frequency-temperature characteristics of the multiple resonant oscillators compensate each other. The coupled resonator designed by the present invention has good temperature stability.

Description

Technical Field

[0001] The present invention belongs to the field of microelectronic technology, and more specifically, relates to a coupled resonator and a preparation method thereof. Background Art

[0002] One of the main disadvantages of silicon-based MEMS resonators is that they have a high temperature coefficient of frequency (TCF). Temperature changes will cause a large frequency shift, which cannot meet the actual application requirements of industry. i (i represents the order) is determined by the temperature sensitivity of the resonator dimensions and several material properties such as elastic modulus, Poisson's ratio, and mass density. The first-order temperature coefficient of frequency can be determined by the temperature coefficient of elasticity (TCE) and thermal expansion coefficient (α) of the resonator material:

[0003]

[0004] In the above formula, the temperature elastic coefficient of silicon is usually about -60ppm / ℃, and the thermal expansion coefficient is about 2.6ppm / ℃. Therefore, the resonant frequency of the silicon resonator decreases with the increase of temperature, showing a TCF of about -30ppm / ℃. In the industrial temperature range of -40℃ to 85℃, the resonant frequency of the silicon resonator will produce an offset of more than 3500ppm. Therefore, temperature compensation is required to reduce the TCF of the micromechanical resonator. The most commonly used temperature compensation schemes are mainly divided into passive compensation and active compensation. Unlike the additional power consumption or complex circuit system required by active compensation, passive compensation reduces its inherent dependence on temperature by adopting a compensation scheme when designing or manufacturing the resonator, thereby improving the temperature stability of the resonator. Summary of the invention

[0005] The present invention solves the problems of high frequency temperature coefficient and poor temperature stability of the resonator in the prior art by providing a coupled resonator and a preparation method thereof.

[0006] The present invention provides a coupled resonator, comprising: at least two resonant oscillators; among the at least two resonant oscillators, at least one resonant oscillator has a positive frequency temperature coefficient, and at least one resonant oscillator has a negative frequency temperature coefficient; different types of resonant oscillators have different vibration modes, and when multiple resonant oscillators are coupled and resonated, the frequency-temperature characteristics of the multiple resonant oscillators compensate each other.

[0007] Preferably, if the coupled resonator includes two resonant oscillators, the resonant oscillator 2 is symmetrically fixed around the resonant oscillator 1;

[0008] If the coupled resonator includes n types of resonant oscillators, and n is greater than or equal to 3, then resonant oscillator 2 is symmetrically fixed around resonant oscillator 1, resonant oscillator 3 is symmetrically fixed around resonant oscillator 2, and so on, and finally resonant oscillator n is symmetrically fixed around resonant oscillator n-1;

[0009] The number of the resonant vibrator 1 is 1, and the number of other types of resonant vibrators is an even number.

[0010] Preferably, the vibration mode of the resonant oscillator with a positive frequency temperature coefficient is one of length extension LE, width extension WE, Lamé, and surface shear FS; the vibration mode of the resonant oscillator with a negative frequency temperature coefficient is one of wine glass WG and square plate extension SE.

[0011] Preferably, the shape of the resonant oscillator is one of a beam, a plate or a disk; under the condition of satisfying resonance, the size, crystal orientation or doping region volume of the resonant oscillator can be adjusted.

[0012] Preferably, the driving and detection mode of the resonant oscillator is one of electrostatic driving-capacitive detection, electrostatic driving-piezoresistive detection or piezoelectric driving-piezoelectric detection.

[0013] Preferably, when the driving and detection mode of the resonant oscillator is the electrostatic driving-capacitive detection or the electrostatic driving-piezoresistive detection, the resonant oscillator is composed of a device layer;

[0014] When the driving and detecting mode of the resonant oscillator is the piezoelectric driving-piezoelectric detecting mode, the resonant oscillator is composed of a device layer and a piezoelectric stack located above the device layer.

[0015] Preferably, the material of the device layer is N-type heavily doped single crystal silicon, the doping element is one of phosphorus, arsenic and antimony, and the doping concentration is greater than 10 19 / cm 3 ;

[0016] The piezoelectric stack is composed of a lower electrode, a piezoelectric film and an upper electrode stack; the piezoelectric film is one of aluminum nitride, scandium-doped aluminum nitride, lead zirconate titanate, lithium niobate, lithium tantalate, polyvinylidene fluoride or zinc oxide.

[0017] Preferably, the silicon wafer used for the device layer is a (100) or (110) plane, and the coupled resonator is along <100> and <110> between, <100> , <110> Any crystal orientation arrangement in .

[0018] The present invention provides a method for preparing the coupled resonator as described above, comprising the following steps:

[0019] Step 1, preparing a silicon-on-insulator substrate CSOI with a cavity, wherein the CSOI includes a substrate layer, an oxide layer and a device layer;

[0020] Step 2, etching the device layer to prepare a coupled resonator structure;

[0021] The driving and detection method of the resonant oscillator in the coupled resonator is the electrostatic drive-capacitance detection or the electrostatic drive-piezoresistive detection.

[0022] The present invention provides a method for preparing the coupled resonator as described above, comprising the following steps:

[0023] Step 1, preparing a silicon-on-insulator substrate CSOI with a cavity, wherein the CSOI includes a substrate layer, an oxide layer and a device layer;

[0024] Step 2, sequentially growing a lower electrode, a piezoelectric film and an upper electrode on the device layer, and etching to obtain a piezoelectric stack;

[0025] Step 3, etching the device layer and the piezoelectric stack to prepare a coupled resonator structure;

[0026] The driving and detecting method of the resonant oscillator in the coupled resonator is the piezoelectric driving-piezoelectric detecting method.

[0027] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0028] In the invention, a new coupled resonator is designed by utilizing the characteristic that the frequency temperature coefficient of a resonant oscillator can be either positive or negative in different vibration modes. The coupled resonator specifically includes at least two resonant oscillators, among which at least one resonant oscillator has a positive frequency temperature coefficient and at least one resonant oscillator has a negative frequency temperature coefficient. Different types of resonant oscillators have different vibration modes. When multiple resonant oscillators are coupled and resonated, the frequency-temperature characteristics of the multiple resonant oscillators compensate for each other. The present invention enables multiple resonant oscillators with different frequency-temperature characteristics to compensate for each other when they are coupled and resonated, thereby passively improving the frequency-temperature stability of the resonator based on the resonator structure design itself. The coupled resonator obtained by the present invention has good temperature stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a coupled resonator provided in Embodiment 1 of the present invention;

[0030] Figure 2 A schematic diagram of the structure of a coupled resonator provided in Embodiment 2 of the present invention;

[0031] Figure 3A schematic diagram of the structure of a coupled resonator provided in Embodiment 3 of the present invention;

[0032] Figure 4 A schematic diagram of the structure of a coupled resonator provided in Embodiment 4 of the present invention;

[0033] Figure 5 A schematic diagram of the structure of a coupled resonator provided in Embodiment 5 of the present invention;

[0034] Figure 6 A schematic diagram of the structure of a coupled resonator provided in Embodiment 6 of the present invention;

[0035] Figure 7-1 to Figure 7-2 A process flow for preparing a coupled resonator provided in Example 7;

[0036] Figure 7-1 : Preparing a silicon-on-insulator substrate CSOI with a cavity;

[0037] Figure 7-2 : The resonant oscillator structure is patterned in the device layer region by photolithography, and then the single crystal silicon of the CSOI device layer is etched by deep reactive ion etching to prepare a coupled resonator structure;

[0038] Figure 8-1 to Figure 8-3 A process flow for preparing a coupled resonator provided in Example 8;

[0039] Figure 8-1 : Preparing a silicon-on-insulator substrate CSOI with a cavity;

[0040] Figure 8-2 :Growing the electrode / AlN / electrode piezoelectric stack on the device layer by sputtering process, and etching the patterned structure as the piezoelectric stack by patterned photolithography and etching technology;

[0041] Figure 8-3 :The resonant oscillator structure is patterned in the device area by photolithography, and then the device layer and the piezoelectric stack are etched by deep reactive ion etching to prepare a coupled resonator structure;

[0042] Fig. 9 To perform finite element analysis Figure 1 The coupled resonator structure shown in the figure shows the curve of the coupled resonator frequency shift as the length extension mode (LE) width size changes within the industrial temperature range;

[0043] Fig.10 To perform finite element analysis Figure 1 The coupled resonator structure shown in the figure shows the curve of the coupled resonator frequency shift as the crystal orientation changes within the industrial temperature range.

[0044] Among them, 11 is a first resonant oscillator, 12 is a second resonant oscillator, and 13 is a third resonant oscillator;

[0045] 1-substrate layer, 2-oxide layer, 3-device layer, 4-piezoelectric stack. DETAILED DESCRIPTION

[0046] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0047] In the first aspect, the present invention provides a coupled resonator, comprising: at least two resonant oscillators; among the at least two resonant oscillators, at least one resonant oscillator has a positive frequency temperature coefficient, and at least one resonant oscillator has a negative frequency temperature coefficient; different types of resonant oscillators have different vibration modes, and when multiple resonant oscillators are coupled and resonated, the frequency-temperature characteristics of the multiple resonant oscillators compensate each other.

[0048] Wherein, if the coupled resonator includes two types of resonant oscillators, then the resonant oscillator 2 is symmetrically fixed around the resonant oscillator 1. If the coupled resonator includes n types of resonant oscillators, and n is greater than or equal to 3, then the resonant oscillator 2 is symmetrically fixed around the resonant oscillator 1 (on both sides or all around), and the resonant oscillator 3 is symmetrically fixed around the resonant oscillator 2 (on both sides or all around), and so on, and finally the resonant oscillator n is symmetrically fixed around the resonant oscillator n-1 (on both sides or all around). The number of the resonant oscillator 1 is 1, and the number of other types of resonant oscillators is an even number. The number of other types of resonant oscillators except the resonant oscillator 1 may be different, and the other types of resonant oscillators are also symmetrically arranged about the resonant oscillator 1.

[0049] The vibration mode of the resonant oscillator with a positive frequency temperature coefficient is one of length extension LE (Length extensional), width extension WE (Width extensional), Lamé, and face shear FS (Face shear); the vibration mode of the resonant oscillator with a negative frequency temperature coefficient is one of wine glass WG (Wine-glass) and square extension SE (Squareextensional).

[0050] The shape of the resonant oscillator is one of a beam, a plate or a disk; under the condition of satisfying resonance, the size, crystal orientation or doping region volume of the resonant oscillator can be adjusted.

[0051] The driving and detection mode of the resonant oscillator is one of electrostatic driving-capacitive detection, electrostatic driving-piezoresistive detection or piezoelectric driving-piezoelectric detection.

[0052] When the driving and detection mode of the resonant oscillator is the electrostatic drive-capacitive detection or the electrostatic drive-piezoresistive detection, the resonant oscillator is composed of a device layer; when the driving and detection mode of the resonant oscillator is the piezoelectric drive-piezoelectric detection, the resonant oscillator is composed of a device layer and a piezoelectric stack located above the device layer.

[0053] The material of the device layer is N-type heavily doped single crystal silicon, the doping element is one of phosphorus, arsenic and antimony, and the doping concentration is greater than 10 19 / cm 3 ; The piezoelectric stack is composed of a lower electrode, a piezoelectric film and an upper electrode stack; the piezoelectric film is one of aluminum nitride, scandium-doped aluminum nitride, lead zirconate titanate, lithium niobate, lithium tantalate, polyvinylidene fluoride or zinc oxide.

[0054] The piezoelectric coupled resonator can be driven or detected by any single resonant vibrator, or by any combination of multiple resonant vibrators.

[0055] The silicon wafer used in the device layer is a (100) or (110) surface, and the coupling resonator is along <100> and <110> between, <100> , <110> Any crystal orientation arrangement in .

[0056] The overall TCF of the coupled resonators is within 10-1000 ppm in the range of -40°C to 85°C.

[0057] The present invention proposes a coupled resonator with good temperature stability by coupling resonance of multiple resonant oscillators with opposite frequency variation trends with temperature. The present invention mainly utilizes the frequency-temperature characteristics of a resonator with N-type heavily doped single crystal silicon as the main material, which can be positive or negative in different resonant modes, so that when multiple resonant oscillators with different frequency-temperature characteristics are coupled and resonated, their frequency-temperature characteristics compensate each other, thereby passively improving the frequency-temperature stability of the resonator based on the resonator structure design itself.

[0058] Several specific embodiments are given below in conjunction with the accompanying drawings to provide a better understanding of the present invention.

[0059] Embodiment 1:

[0060] See also Figure 1 The coupled resonator provided in Example 1 includes two resonant oscillators (respectively referred to as a first resonant oscillator 11 and a second resonant oscillator 12). The vibration mode of the first resonant oscillator 11 is LE, the vibration mode of the second resonant oscillator 12 is SE, and the two second resonant oscillators 12 are fixed on both sides of the first resonant oscillator 11, respectively.

[0061] The frequency temperature coefficient of the first resonant oscillator 11 is positive, and the frequency temperature coefficient of the second resonant oscillator 12 is negative. The frequency-temperature characteristics of these two resonant oscillators compensate each other.

[0062] Embodiment 2:

[0063] See also Figure 2 The coupled resonator provided in Example 2 includes two resonant oscillators (respectively denoted as a first resonant oscillator 11 and a second resonant oscillator 12). The vibration mode of the first resonant oscillator 11 is Lamé, the vibration mode of the second resonant oscillator 12 is SE, and the two second resonant oscillators 12 are fixed on both sides of the first resonant oscillator 11, respectively.

[0064] The frequency temperature coefficient of the first resonant oscillator 11 is positive, and the frequency temperature coefficient of the second resonant oscillator 12 is negative. The frequency-temperature characteristics of these two resonant oscillators compensate each other.

[0065] Embodiment 3:

[0066] See also Figure 3 The coupled resonator provided in Example 3 includes two resonant oscillators (respectively referred to as a first resonant oscillator 11 and a second resonant oscillator 12). The vibration mode of the first resonant oscillator 11 is FS, the vibration mode of the second resonant oscillator 12 is SE, and the two second resonant oscillators 12 are fixed on both sides of the first resonant oscillator 11, respectively.

[0067] The frequency temperature coefficient of the first resonant oscillator 11 is positive, and the frequency temperature coefficient of the second resonant oscillator 12 is negative. The frequency-temperature characteristics of these two resonant oscillators compensate each other.

[0068] Embodiment 4:

[0069] See also Figure 4 The coupled resonator provided in Example 4 includes three resonant oscillators (respectively denoted as the first resonant oscillator 11, the second resonant oscillator 12, and the third resonant oscillator 13). The vibration mode of the first resonant oscillator 11 is LE, the vibration mode of the second resonant oscillator 12 is SE, and the vibration mode of the third resonant oscillator 13 is Lamé. The two second resonant oscillators 12 are respectively fixed on both sides of the first resonant oscillator 11, one third resonant oscillator 13 is fixed on the outside of one second resonant oscillator 12, and the other third resonant oscillator 13 is fixed on the outside of the other second resonant oscillator 12, that is, the two third resonant oscillators 13 are also symmetrically arranged about the first resonant oscillator 11.

[0070] The frequency temperature coefficient of the first resonant oscillator 11 is positive, the frequency temperature coefficient of the second resonant oscillator 12 is negative, and the frequency temperature coefficient of the third resonant oscillator 13 is positive. The frequency-temperature characteristics of these three resonant oscillators compensate each other.

[0071] Embodiment 5:

[0072] See also Figure 5 The coupled resonator provided in Example 5 includes three resonant oscillators (respectively denoted as the first resonant oscillator 11, the second resonant oscillator 12, and the third resonant oscillator 13). The vibration mode of the first resonant oscillator 11 is Lamé, the vibration mode of the second resonant oscillator 12 is SE, and the vibration mode of the third resonant oscillator 13 is LE. The two second resonant oscillators 12 are respectively fixed on both sides of the first resonant oscillator 11, one third resonant oscillator 13 is fixed on the outside of one second resonant oscillator 12, and the other third resonant oscillator 13 is fixed on the outside of the other second resonant oscillator 12, that is, the two third resonant oscillators 13 are also symmetrically arranged about the first resonant oscillator 11.

[0073] The frequency temperature coefficient of the first resonant oscillator 11 is positive, the frequency temperature coefficient of the second resonant oscillator 12 is negative, and the frequency temperature coefficient of the third resonant oscillator 13 is positive. The frequency-temperature characteristics of these three resonant oscillators compensate each other.

[0074] Embodiment 6:

[0075] See also Figure 6 The coupled resonator provided in Example 6 includes three resonant oscillators (respectively recorded as the first resonant oscillator 11, the second resonant oscillator 12, and the third resonant oscillator 13). The vibration mode of the first resonant oscillator 11 is FS, the vibration mode of the second resonant oscillator 12 is SE, and the vibration mode of the third resonant oscillator 13 is LE. The two second resonant oscillators 12 are respectively fixed on both sides of the first resonant oscillator 11, one third resonant oscillator 13 is fixed on the outside of one second resonant oscillator 12, and the other third resonant oscillator 13 is fixed on the outside of the other second resonant oscillator 12, that is, the two third resonant oscillators 13 are also symmetrically arranged about the first resonant oscillator 11.

[0076] The frequency temperature coefficient of the first resonant oscillator 11 is positive, the frequency temperature coefficient of the second resonant oscillator 12 is negative, and the frequency temperature coefficient of the third resonant oscillator 13 is positive. The frequency-temperature characteristics of these three resonant oscillators compensate each other.

[0077] In addition to the solutions provided in Examples 1 and 6, other combinations of multiple resonant oscillators may be provided as needed. The coupled resonator includes a combination of multiple resonant oscillators with positive and negative frequency temperature coefficients, which can achieve mutual compensation of frequency-temperature characteristics.

[0078] In a second aspect, the present invention provides a method for preparing a coupled resonator, comprising the following steps:

[0079] Step 1, preparing a silicon-on-insulator substrate CSOI with a cavity, wherein the CSOI includes a substrate layer, an oxide layer and a device layer;

[0080] Step 2, etching the device layer to prepare a coupled resonator structure;

[0081] The driving and detection method of the resonant oscillator in the coupled resonator is the electrostatic drive-capacitance detection or the electrostatic drive-piezoresistive detection.

[0082] An embodiment is given below in conjunction with the accompanying drawings.

[0083] Embodiment 7:

[0084] The drive and detection method for the resonant oscillator is an electrostatic drive-capacitive detection coupled resonator, which is manufactured using micromachining technology. The entire processing process includes:

[0085] 1) Prepare a silicon-on-insulator substrate CSOI with a cavity, see Figure 7-1 , CSOI includes substrate layer 1, oxide layer 2, and device layer 3 from bottom to top, wherein the device layer 3 is N-type heavily doped single crystal silicon with a doping concentration of >10 19 / cm 3 ;

[0086] 2) Patterning the resonant oscillator structure in the device layer region by photolithography, and then etching the single crystal silicon of the CSOI device layer 3 by deep reactive ion etching to prepare a coupled resonator structure, see Figure 7-2 .

[0087] In a third aspect, the present invention provides a method for preparing a coupled resonator, comprising the following steps:

[0088] Step 1, preparing a silicon-on-insulator substrate CSOI with a cavity, wherein the CSOI includes a substrate layer, an oxide layer and a device layer;

[0089] Step 2, sequentially growing a lower electrode, a piezoelectric film and an upper electrode on the device layer, and etching to obtain a piezoelectric stack;

[0090] Step 3, etching the device layer and the piezoelectric stack to prepare a coupled resonator structure;

[0091] The driving and detecting method of the resonant oscillator in the coupled resonator is the piezoelectric driving-piezoelectric detecting method.

[0092] An embodiment is given below in conjunction with the accompanying drawings.

[0093] Embodiment 8:

[0094] The coupled resonator with piezoelectric drive and piezoelectric detection as the resonant oscillator drive and detection method is made using micromachining technology. The entire processing process includes:

[0095] 1) Prepare a silicon-on-insulator substrate CSOI with a cavity, see Figure 8-1 , CSOI includes substrate layer 1, oxide layer 2, and device layer 3 from bottom to top, wherein the device layer 3 is N-type heavily doped single crystal silicon with a doping concentration of >10 19 / cm 3 ;

[0096] 2) growing an electrode / AlN / electrode piezoelectric stack on the device layer 3 by a sputtering process, and etching a patterned structure by patterned photolithography and etching technology to form a piezoelectric stack 4, see Figure 8-2 ;

[0097] 3) Patterning the resonant oscillator structure in the device layer region by photolithography, and then etching the device layer 3 and the piezoelectric stack 4 by deep reactive ion etching to prepare a coupled resonator structure, see Figure 8-3 .

[0098] Under the condition of satisfying resonance, the size (volume) of the resonant oscillator can be adjusted. For example, for the resonant coupler structure provided in Example 1, Fig. 9 For example, through finite element analysis Figure 1 The coupled resonator structure shown in the figure shows the curve of the coupled resonator frequency shift as the length extension mode (LE) width changes within the industrial temperature range. Among them, LE5-SE means the LE width is 5μm, LE10-SE means the LE width is 10μm, and so on (the length and width of SE are fixed at 86μm); LE-0 means LE <100> Crystal orientation, SE-45 means SE <110> It can be seen that changing the width of the LE mode can change the degree of mutual compensation, thereby adjusting the overall frequency shift of the coupled resonator.

[0099] Under the condition of satisfying resonance, the crystal orientation of the resonant oscillator can be adjusted. For example, for the resonant coupler structure provided in Example 1, Fig.10 For example, through finite element analysis Figure 1The coupled resonator structure shown in the figure shows that the frequency shift of the coupled resonator in the industrial temperature range varies with the crystal orientation (the silicon wafer is (100) plane. LE 0° is <100> Crystal direction, SE is 45° <110> Crystal direction, 5° means from <100> Crystal Yearning <110> It can be seen that changing the crystal orientation of the coupled resonator can change the degree of mutual compensation, thereby adjusting the overall frequency offset of the coupled resonator.

[0100] A coupled resonator and a method for manufacturing the same provided by an embodiment of the present invention include at least the following technical effects:

[0101] The present invention mainly utilizes the frequency-temperature characteristics of a resonator made of N-type heavily doped single crystal silicon as the main material, which can be positive or negative in different resonant modes, so that when multiple resonators with different frequency-temperature characteristics are coupled and resonated, their frequency-temperature characteristics compensate each other, thereby improving the frequency-temperature stability of the resonator from the resonator structure design itself. This is equivalent to providing a new resonator structure and a new method for improving the frequency-temperature stability of the resonator, that is, proposing a method for passively improving the frequency-temperature stability of the resonator by coupling and resonating multiple resonators with opposite frequency-temperature variation trends.

[0102] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A coupled resonator, characterized in that: include: At least two resonant oscillators; Among at least two resonant oscillators, at least one resonant oscillator has a positive frequency temperature coefficient, and at least one resonant oscillator has a negative frequency temperature coefficient; different types of resonant oscillators have different vibration modes, and when multiple resonant oscillators are coupled and resonated, the frequency-temperature characteristics of the multiple resonant oscillators compensate each other; If the coupled resonator includes two resonant oscillators, the resonant oscillator 2 is symmetrically fixed around the resonant oscillator 1; If the coupled resonator includes n types of resonant oscillators, and n is greater than or equal to 3, then resonant oscillator 2 is symmetrically fixed around resonant oscillator 1, resonant oscillator 3 is symmetrically fixed around resonant oscillator 2, and so on, and finally resonant oscillator n is symmetrically fixed around resonant oscillator n-1; The number of the resonant oscillator 1 is 1, and the number of other types of resonant oscillators is an even number; The vibration mode of the resonant oscillator with a positive frequency temperature coefficient is one of length extension LE, width extension WE, Lamé, and surface shear FS; the vibration mode of the resonant oscillator with a negative frequency temperature coefficient is one of wine glass WG and square plate extension SE.

2. The coupled resonator according to claim 1, characterized in that The shape of the resonant oscillator is one of a beam, a plate or a disk; under the condition of satisfying resonance, the size, crystal orientation or doping region volume of the resonant oscillator can be adjusted.

3. The coupled resonator according to claim 1, characterized in that The driving and detection mode of the resonant oscillator is one of electrostatic driving-capacitive detection, electrostatic driving-piezoresistive detection or piezoelectric driving-piezoelectric detection.

4. The coupled resonator according to claim 3, characterized in that When the driving and detection mode of the resonant oscillator is the electrostatic driving-capacitive detection or the electrostatic driving-piezoresistive detection, the resonant oscillator is composed of a device layer; When the driving and detecting mode of the resonant oscillator is the piezoelectric driving-piezoelectric detecting mode, the resonant oscillator is composed of a device layer and a piezoelectric stack located above the device layer.

5. The coupled resonator according to claim 4, characterized in that The material of the device layer is N-type heavily doped single crystal silicon, the doping element is one of phosphorus, arsenic and antimony, and the doping concentration is greater than 10 19 / cm 3 ; The piezoelectric stack is composed of a lower electrode, a piezoelectric film and an upper electrode stack; the piezoelectric film is one of aluminum nitride, scandium-doped aluminum nitride, lead zirconate titanate, lithium niobate, lithium tantalate, polyvinylidene fluoride or zinc oxide.

6. The coupled resonator according to claim 4, characterized in that The silicon wafer used in the device layer is a (100) or (110) surface, and the coupling resonator is along <100> and <110> between, <100> , <110> Any crystal orientation arrangement in .

7. A method for preparing a coupled resonator according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, preparing a silicon-on-insulator substrate CSOI with a cavity, wherein the CSOI includes a substrate layer, an oxide layer and a device layer; Step 2, etching the device layer to prepare a coupled resonator structure; The driving and detection mode of the resonant oscillator in the coupled resonator is electrostatic driving-capacitive detection or electrostatic driving-piezoresistive detection.

8. A method for preparing a coupled resonator according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, preparing a silicon-on-insulator substrate CSOI with a cavity, wherein the CSOI includes a substrate layer, an oxide layer and a device layer; Step 2, sequentially growing a lower electrode, a piezoelectric film and an upper electrode on the device layer, and etching to obtain a piezoelectric stack; Step 3, etching the device layer and the piezoelectric stack to prepare a coupled resonator structure; The driving and detecting mode of the resonant oscillator in the coupled resonator is piezoelectric driving-piezoelectric detecting.

Images