Cantilever resonator
By setting and etching the crystal assembly in the root area of the cantilever beam resonator, the problem of increasing the device size in the prior art is solved, and the combination of high quality factor and small size is achieved, and the scope of use is expanded.
Patent Information
- Application Number
- CN202411989331.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-03-25
AI Technical Summary
Existing cantilever beam resonators improve quality factor by increasing the length of the cantilever beam, but this results in increased device size and limited use.
By setting a crystal assembly at the root area of the cantilever beam and etching it on the cantilever beam, the crystal assembly is integrated with the cantilever beam. When the cantilever beam vibrates, energy is reflected through the crystal assembly, reducing energy loss, thereby improving the quality factor while reducing the stiffness of the cantilever beam for smaller length and low frequency operation.
It achieves the combination of high quality factor and small size at low frequency operation, and expands the scope of use of cantilever beam resonators.
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Figure CN119696539A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of resonators, and in particular to a cantilever beam resonator. Background Art
[0002] With the development of wireless communication technology, the performance requirements of clock devices are getting higher and higher. Traditional quartz crystal resonators have a high quality factor, but their size is large and it is difficult to meet the needs of miniaturization of electronic components. With the development of Micro-Electro-Mechanical System Resonators (MEMS resonators), MEMS resonators have replaced quartz crystal resonators with the advantages of miniaturization and integration, but the quality factor of MEMS resonators is low, which limits their market application.
[0003] In the prior art, in order to improve the quality factor of a device, such as a cantilever beam resonator, the stiffness of the device itself will affect its quality factor. For a low-frequency cantilever beam device, a lower stiffness can excite a lower frequency mode, that is, by increasing the length of the cantilever beam, the stiffness can be reduced, thereby improving the quality factor.
[0004] However, by increasing the length of the cantilever beam, the device size and power consumption are increased, and its use is relatively limited. Summary of the invention
[0005] The present application provides a cantilever beam resonator, which is used to solve the problem in the prior art that increasing the length of the cantilever beam increases the size of the device and limits its use.
[0006] In order to achieve the above purpose, the technical solution of this application is as follows:
[0007] The present application provides a cantilever beam resonator, comprising: a cantilever beam component and a crystal component; the cantilever beam component comprises a fixing member and a cantilever beam, one end of the cantilever beam is connected to the fixing member, the cantilever beam has a root area, and the root area is adjacent to the fixing member; the crystal component is arranged in the root area.
[0008] In some possible implementations, the cantilever beam resonator provided in the embodiments of the present application, the crystal assembly includes a plurality of unit cells, each unit cell is arranged on a root region at intervals along a first direction and a second direction, and the first direction and the second direction are perpendicular to each other.
[0009] In some possible implementations, the cantilever beam resonator provided in the embodiments of the present application, the unit cell includes a main body and at least two supporting beams, each supporting beam is respectively arranged on a different side of the main body, and a hole-shaped structure is arranged on the main body.
[0010] In some possible implementations, in the cantilever beam resonator provided in the embodiments of the present application, the hole-shaped structure includes a first through hole and a plurality of second through holes, and the second through holes are arranged around the circumference of the first through hole at intervals.
[0011] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the first through hole is a circular hole, and the second through hole is a trapezoidal hole.
[0012] In some possible implementations, the cantilever beam resonator provided in the embodiment of the present application has a body having a length of 15um to 25um and a width of 15um to 25um.
[0013] In some possible implementations, the cantilever beam resonator provided in the embodiment of the present application has a support beam with a length of 1 um to 3 um and a width of 0.5 um to 1.5 um.
[0014] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the radius of the first through hole is 2.5 um to 2.7 um.
[0015] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the upper bottom length of the second through hole is 3.8um to 4.0um, the lower bottom length is 5.2um to 5.4um, and the height is 3.3um to 3.5um.
[0016] In some possible implementations, the cantilever beam resonator provided in the embodiments of the present application comprises a substrate, a bottom molybdenum electrode, an aluminum nitride piezoelectric layer and a top molybdenum electrode arranged in sequence from bottom to top, a third through hole is etched on the aluminum nitride piezoelectric layer for electrically connecting to the bottom molybdenum electrode to output signals to the substrate, and the top molybdenum electrode is used to externally connect to a conductive plate to input signals; the fixing part comprises a bottom silicon layer, a silicon dioxide sacrificial layer, a substrate, a bottom molybdenum electrode, an aluminum nitride piezoelectric layer and a top molybdenum electrode arranged in sequence from bottom to top.
[0017] The cantilever beam resonator provided by the present application is provided with a cantilever beam component and a crystal component; the cantilever beam component includes a fixing part and a cantilever beam, one end of the cantilever beam is connected to the fixing part, the cantilever beam has a root area, and the root area is adjacent to the fixing part; the crystal component is arranged in the root area. The crystal component is arranged on the cantilever beam, and the crystal component is etched in the root area on the cantilever beam, so that the crystal component and the cantilever beam are integrated into one. When the cantilever beam vibrates, the energy lost through the tracing point can be reflected back through the crystal component, reducing energy loss, thereby improving the quality factor of the cantilever beam resonator. Moreover, the crystal component is etched in the root area, so that the stiffness of the cantilever beam is reduced, so that it can achieve low-frequency operation with a smaller length and reduce the size of the cantilever beam. Therefore, the cantilever beam resonator in the embodiment of the present application has the characteristics of high quality factor and small size under low-frequency operation, and has a wide range of uses. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0019] Figure 1 A schematic diagram of the structure of a cantilever beam resonator provided in an embodiment of the present application;
[0020] Figure 2 for Figure 1 Sectional view of AA in the middle;
[0021] Figure 3 for Figure 1 Cross-sectional view of the middle BB;
[0022] Figure 4 for Figure 1 Schematic diagram of the structure of the unit cell.
[0023] Description of reference numerals:
[0024] 100-cantilever beam assembly;
[0025] 110-fixing parts;
[0026] 120-cantilever beam; 121-root area;
[0027] 130-substrate;
[0028] 140- bottom molybdenum electrode;
[0029] 150-aluminum nitride piezoelectric layer;
[0030] 160-top molybdenum electrode;
[0031] 170- silicon dioxide sacrificial layer;
[0032] 180-bottom silicon;
[0033] 200-Crystal assembly;
[0034] 210 - unit cell; 211 - main body; 212 - hole-like structure; 213 - support beam; 214 - first through hole; 215 - second through hole.
[0035] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION
[0036] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.
[0037] It should be noted that in the description of the embodiments of the present application, terms such as "upper", "lower", "inside" and "outside" indicating orientation or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of description, and do not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the embodiments of the present application.
[0038] In addition, it should be noted that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined.
[0039] In this application, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. First, the relevant concepts or nouns involved in this application are explained.
[0040] MEMS resonator: The full name is micro-electromechanical system resonator. It is a resonator manufactured using micro-electromechanical system (MEMS) technology. It is a device that generates resonant frequency based on micro-electromechanical system technology. It is a basic component of MEMS oscillators and clock generators, and is widely used in various electronic products involving frequency transmission and reception. It has the characteristics of small size, light weight, compatibility with integrated circuit manufacturing processes, and strong stability. The main performance parameters of MEMS resonators include resonant frequency and quality factor. The quality factor is expressed by Q value, which is the main performance parameter of MEMS resonators. A high Q value can reduce the dynamic impedance of the resonator, reduce the phase noise of the system, and improve the frequency stability of the oscillator.
[0041] Anchor point loss: It is the energy loss caused by the mechanical vibration energy not being completely reflected back at the boundary of the resonator, such as the elastic wave or acoustic wave transmitted from the resonator to the substrate through the support beam. The dissipation of the acoustic wave through the support beam will reduce the energy stored in the resonator, thereby reducing the quality factor of the resonator.
[0042] The rapid development of modern wireless communication technology has placed increasingly higher requirements on the performance and size of clock devices. Traditional quartz crystal resonators have a high quality factor, but due to their large size, it is increasingly difficult to meet the needs of miniaturization of electronic components. With the rapid development of MEMS resonators in recent years, their miniaturization and integration advantages have made them gradually become a substitute for quartz crystal oscillators, but compared with quartz crystal oscillators, MEMS resonators have a lower quality factor, which has become a factor limiting their market application.
[0043] In order to improve the quality factor of the MEMS resonator, the prior art adopts a method of optimizing the anchor points. For example, by setting multiple anchor points and placing the anchor tethers at the zero displacement position of the high-order lateral thin film silicon piezoelectric thin film resonator to minimize the anchor loss, compared with a structure in which the anchor points are evenly distributed at the edge of the resonator, the load quality factor of the resonator is increased by 65%.
[0044] However, in low-frequency devices, such as cantilever beam resonators, there is usually only one anchor point, and other methods are needed to improve its quality factor. In addition, cantilever beam resonators operate in low-frequency modes, and in order to obtain lower stiffness, their beam length is large, which increases the size of the device. Usually, the length is reduced by increasing its width, but this approach increases the connection area between the anchor point and the substrate, thereby increasing the anchor point loss.
[0045] In the prior art, in order to improve the quality factor of the cantilever beam resonator, the stiffness of the device itself will affect its quality factor. For low-frequency cantilever beam devices, lower stiffness can excite lower frequency modes, that is, by increasing the length of the cantilever beam, the stiffness can be reduced, thereby improving the quality factor. However, by increasing the length of the cantilever beam, the size of the device is increased, and its use is relatively limited.
[0046] In view of this, the cantilever beam resonator provided in the embodiment of the present application includes: a cantilever beam component and a crystal component; the cantilever beam component includes a fixing part and a cantilever beam, one end of the cantilever beam is connected to the fixing part, the cantilever beam has a root area, and the root area is adjacent to the fixing part; the crystal component is arranged in the root area. By setting the crystal component on the cantilever beam, the crystal component is etched in the root area on the cantilever beam, so that the crystal component and the cantilever beam are integrated into one. When the cantilever beam vibrates, the energy lost through the tracing point can be reflected back through the crystal component, reducing energy loss, thereby improving the quality factor of the cantilever beam resonator. Moreover, the crystal component is etched in the root area, so that the stiffness of the cantilever beam is reduced, so that it can achieve low-frequency operation with a smaller length and reduce the size of the cantilever beam. Therefore, the cantilever beam resonator in the embodiment of the present application has the characteristics of high quality factor and small size under low-frequency operation.
[0047] Combine the following Figures 1 to 4 The present application is described in detail with reference to the accompanying drawings and specific embodiments. Figure 1 A schematic diagram of the structure of a cantilever beam resonator provided in an embodiment of the present application; Figure 2 for Figure 1 Sectional view of AA in the middle; Figure 3 for Figure 1 Cross-sectional view of the middle BB; Figure 4 for Figure 1 Schematic diagram of the structure of the unit cell.
[0048] The present application provides a cantilever beam resonator, comprising: a cantilever beam component 100 and a crystal component 200; the cantilever beam component 100 comprises a fixing member 110 and a cantilever beam 120, one end of the cantilever beam 120 is connected to the fixing member 110, the cantilever beam 120 has a root area 121, and the root area 121 is adjacent to the fixing member 110; the crystal component 200 is arranged in the root area 121.
[0049] The cantilever beam 120 has a first end and a second end, the first end of the cantilever beam 120 is arranged away from the fixing member 110, and the second end of the cantilever beam 120 faces the fixing member 110 and is connected to the fixing member 110. It should be noted that the substrate 130 of the cantilever beam 120 is connected to the substrate 130 of the fixing member 110, and the root area 121 of the cantilever beam 120 is arranged toward the fixing member 110, for example, the root area 121 of the cantilever beam 120 is located at the second end of the cantilever beam 120. In some embodiments, the cantilever beam 120 is in the shape of an elongated strip.
[0050] The crystal assembly 200 includes a phononic crystal, which is etched in the root region 121 of the cantilever beam 120, so that the phononic crystal array is integrated with the cantilever beam 120, and the root region 121 of the cantilever beam 120 is connected to the substrate 130 of the fixing member 110, so that the resonant body sound wave is transmitted to the substrate 130, and it is the only path, so that the length of the cantilever beam 120 can be reduced without increasing the width of the cantilever beam 120, while ensuring the low-frequency characteristics. By etching the crystal assembly 200 in the root region 121 of the cantilever beam 120, the cantilever beam 120 is integrated with the crystal assembly 200, the stiffness of the cantilever beam 120 itself is reduced, and it is easy to excite a lower frequency mode, and the crystal assembly 200 can reflect energy, reduce energy loss, and improve the quality factor of the cantilever beam resonator.
[0051] It should be noted that phononic crystals are usually composed of two or more elastic materials with different elastic coefficients and have specific acoustic band gap characteristics. The acoustic band gap characteristics can block sound waves in a specific frequency band from passing through the phononic crystal, thereby reducing the loss of the anchor point.
[0052] The phononic crystal is a two-dimensional phononic crystal. By changing the shape, size and arrangement of the phononic crystal, sound waves in a specific frequency band can be blocked from passing through the phononic crystal. Through the reflection effect of the phononic crystal, the energy lost when the cantilever beam 120 vibrates is reflected back, thereby reducing the loss of the anchor point and improving the quality factor of the cantilever beam resonator.
[0053] In some embodiments, the fixing member 110 is in a U-shape, and the cantilever beam 120 is located in the middle of the fixing member 110 .
[0054] It is understandable that for the cantilever beam 120, the eigenfrequency of the structure is affected by its stiffness, and the stiffness depends not only on the material properties but also on the size of the structure. If a low-frequency cantilever beam 120 device is to be realized, it is inevitable to reduce its stiffness by increasing the length of the cantilever beam 120. Doing so will not only increase the volume of the low-frequency device, but the increase in the device load and surface area will also increase energy loss and reduce the quality factor.
[0055] The cantilever beam resonator in the embodiment of the present application is arranged on the cantilever beam 120 through the crystal component 200, and the crystal component 200 is etched in the root area 121 on the cantilever beam 120, so that the crystal component 200 and the cantilever beam 120 are integrated into one body. When the cantilever beam vibrates, the energy lost through the plotting point can be reflected back through the crystal component 200, reducing energy loss, thereby improving the quality factor of the cantilever beam resonator. In addition, the crystal component 200 is etched in the root area 121, so that the stiffness of the cantilever beam 120 is reduced, so that it can achieve low-frequency operation with a smaller length, and reduce the size of the cantilever beam 120. Therefore, the cantilever beam resonator in the embodiment of the present application has the characteristics of high quality factor and small size under low-frequency operation.
[0056] In some possible implementations, the cantilever beam resonator provided in the embodiment of the present application, the crystal assembly 200 includes a plurality of unit cells 210, each unit cell 210 is arranged on the root region 121 in an interval arrangement along a first direction and a second direction, and the first direction and the second direction are perpendicular to each other.
[0057] The crystal assembly 200 includes a two-dimensional phononic crystal array formed by a plurality of unit cells 210, each unit cell 210 is periodically arranged in a first direction and a second direction on the root region 121, and the first direction and the second direction are perpendicular to each other. The first direction is the same as the length direction of the cantilever beam 120, and the second direction is the same as the width direction of the cantilever beam 120.
[0058] In some embodiments, the present application does not specifically limit the structure and size of the unit cell 210. Exemplarily, the unit cell 210 is a rectangular unit cell 210, which is composed of a plurality of rectangular unit cells 210 arranged periodically, the body 211 structure of the rectangular unit cell 210 is rectangular, the body 211 structure of the unit cell 210 is etched with columnar holes 214 and trapezoidal holes 215, and support beams 213 are respectively arranged in the middle of the four sides of the body 211 structure of the unit cell 210. In some other embodiments, the unit cell 210 can also be a square unit cell 210.
[0059] In some embodiments, the crystal assembly 200 covers the entire root region 121 , and the range of the root region 121 can be determined according to requirements. For example, the root region 121 is one sixth of the cantilever beam 120 , or the root region 121 is one seventh of the cantilever beam 120 .
[0060] In some possible implementations, the cantilever beam resonator provided in the embodiments of the present application, the unit cell 210 includes a main body 211 and at least two support beams 213 , each support beam 213 is respectively arranged on different sides of the main body 211 , and a hole structure 212 is provided on the main body 211 .
[0061] In a specific implementation, the number of the support beams 213 is two, and each support beam 213 can be arranged on two adjacent sides of the main body 211, or on two opposite sides of the main body 211, and the embodiment of the present application does not limit this.
[0062] In some embodiments, the number of the support beams 213 is four, and the support beams 213 are arranged at intervals on the circumference of the body 211 .
[0063] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the hole structure 212 includes a first through hole 214 and a plurality of second through holes 215 , and the second through holes 215 are arranged around the circumference of the first through hole 214 at intervals.
[0064] In a specific implementation, the first through hole 214 is located in the middle of the body 211, and the second through holes 215 are arranged around the first through hole 214. For example, there is one first through hole 214 and four second through holes 215, and each second through hole 215 corresponds to the circumference of the body 211 one by one.
[0065] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the first through hole 214 is a circular hole, and the second through hole 215 is a trapezoidal hole.
[0066] In a specific implementation, the first through hole 214 is a circular hole, and its size and dimension can be set according to actual conditions, and the present application does not impose any limitation on this.
[0067] The present application does not limit the number and shape of the trapezoidal holes. For example, the number of the trapezoidal holes 215 is four, the upper base of the trapezoidal hole 215 is arranged toward the cylindrical hole 214, the lower base of the trapezoidal hole 215 is arranged away from the cylindrical hole 214, the upper base of the trapezoidal hole 215 is less than or equal to the lower base of the trapezoidal hole 215, and each trapezoidal hole 215 is arranged corresponding to the peripheral side of the structure of the unit cell 210 body 211, that is, each side corresponds to a trapezoidal hole 215.
[0068] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the length of the body 211 is 15um to 25um, and the width is 15um to 25um.
[0069] In some embodiments, the overall dimensions of the unit cell 210 are 20um in length and 20um in width, wherein the support beam 213 is 2um in length and 1um in width, the radius of the cylindrical hole 214 is 2.5um to 2.7um, the upper base length of the trapezoidal hole 215 is 3.8um to 4.0um, the lower base length is 5.2um to 5.4um, and the height is 3.3um to 3.5um.
[0070] It should be noted that the unit cell 210 can achieve isolation of sound waves of different frequency bands by changing the sizes of the body 211 , the cylindrical hole 214 and the four trapezoidal holes 215 .
[0071] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the length of the support beam 213 is 1 um to 3 um, and the width is 0.5 um to 1.5 um.
[0072] Exemplarily, the length of the support beam 213 is 2um and the width is 1um, and the length of each support beam 213 is 2um and the width is 1um. Alternatively, the sizes of each support beam 213 may be different, for example, the length of one support beam 213 is 2um and the width is 1um, and the length of another support beam is 1um and the width is 0.5um.
[0073] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the radius of the first through hole 214 is 2.5 um to 2.7 um.
[0074] For example, the radius of the first through hole 214 may be 2.5 um, 2.6 um or 2.7 um.
[0075] In some possible implementations, in the cantilever beam resonator provided in the embodiment of the present application, the second through hole 215 has an upper bottom length of 3.8um to 4.0um, a lower bottom length of 5.2um to 5.4um, and a height of 3.3um to 3.5um.
[0076] Exemplarily, the second through hole 215 is a trapezoidal hole, with an upper bottom length of 3.8um, a lower bottom length of 5.2um, and a height of 3.3um. Alternatively, the upper bottom length of the trapezoidal hole is 3.9um, the lower bottom length is 5.3um, and the height is 3.4um. Alternatively, the upper bottom length of the trapezoidal hole is 4.0um, the lower bottom length is 5.4um, and the height is 3.5um. The sizes of the various trapezoidal holes can be the same or different, and can be set according to actual conditions, and the embodiments of the present application are not limited to this.
[0077] In some possible implementations, the cantilever beam resonator provided in the embodiment of the present application, the cantilever beam 120 includes a substrate 130, a bottom molybdenum electrode 140, an aluminum nitride piezoelectric layer 150 and a top molybdenum electrode 160 arranged in sequence from bottom to top, a third through hole is etched on the aluminum nitride piezoelectric layer 150, which is used to electrically connect with the bottom molybdenum electrode 140 to output signals to the substrate 130, and the top molybdenum electrode 160 is used to externally connect to a conductive plate to input signals; the fixing member 110 includes a bottom silicon 180, a silicon dioxide sacrificial layer, a substrate 130, a bottom molybdenum electrode 140, an aluminum nitride piezoelectric layer 150 and a top molybdenum electrode 160 arranged in sequence from bottom to top.
[0078] The cantilever beam 120 includes a substrate 130, a bottom molybdenum electrode 140, an aluminum nitride piezoelectric layer 150 and a top molybdenum electrode 160 which are arranged in sequence from bottom to top. The substrate 130 is used to etch a two-dimensional phononic crystal array. A through hole is etched on the aluminum nitride piezoelectric layer 150, and the through hole is used to electrically connect to the bottom molybdenum electrode 140 to output signals to the substrate 130. The top molybdenum electrode 160 is used to externally connect to a conductive plate to input signals.
[0079] Specifically, the top molybdenum electrode 160 is covered with an aluminum nitride piezoelectric layer 150, and the aluminum nitride piezoelectric layer 150 is covered with a bottom molybdenum electrode 140. A through hole is etched on the aluminum nitride piezoelectric layer 150, and the lower edge of the through hole is electrically connected to the bottom molybdenum electrode 140. The above structure is composed of a metal electrode, an aluminum nitride piezoelectric layer 150 and a metal electrode, and uses the piezoelectric properties of the material itself, such as the metal electrode to the aluminum nitride piezoelectric layer 150, to convert electrical energy into sound energy, and the sound wave is reflected at the interface between the medium and the air, and then converted into electrical energy through the inverse piezoelectric effect, such as the aluminum nitride piezoelectric layer 150 to the metal electrode, so as to achieve the passage of waves of a specific frequency, with good quality and a large width.
[0080] A substrate 130 is disposed under the bottom molybdenum electrode 140, and a
[0081] In some embodiments, the aluminum nitride piezoelectric layer 150 can be deposited on the surface of the molybdenum electrode by a thin film process, a photolithography process, and a wet etching process.
[0082] In addition to the above four-layer structure, the fixing part 110 also includes a silicon oxide sacrificial layer and an underlying silicon 180, that is, from bottom to top, they are respectively the underlying silicon 180, the silicon oxide sacrificial layer, the substrate 130, the bottom molybdenum electrode 140, the aluminum nitride piezoelectric layer 150 and the top molybdenum electrode 160, wherein the substrate 130, the silicon dioxide sacrificial layer 170 and the underlying silicon 180 together constitute a silicon wafer, which is used as a wafer for making a resonator.
[0083] Compared with the traditional device that etches the two-dimensional phononic crystal in the substrate 130 area, the cantilever beam resonator with an integrated crystal component 200 proposed in this application etches the crystal component 200 in the root area 121 of the cantilever beam 120, so that the crystal component 200 and the cantilever beam 120 are integrated into one body, and the energy lost through the anchor point when the cantilever beam 120 vibrates can be reflected back by the two-dimensional phononic crystal array, thereby improving the quality factor of the cantilever beam resonator. For low-frequency cantilever beam devices, lower stiffness can excite lower-frequency modes, so this application etches the crystal component 200 in the root area 121 of the cantilever beam 120 to reduce stiffness and facilitate the excitation of lower-frequency modes.
[0084] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the disclosure herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.
[0085] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.
Claims
1. A cantilever beam resonator, characterized in that: include: A cantilever beam assembly (100) and a crystal assembly (200); The cantilever beam assembly (100) comprises a fixing member (110) and a cantilever beam (120), one end of the cantilever beam (120) is connected to the fixing member (110), and the cantilever beam (120) has a root region (121), and the root region (121) is adjacent to the fixing member (110); The crystal assembly (200) is disposed in the root region (121).
2. The cantilever beam resonator according to claim 1, characterized in that The crystal assembly (200) comprises a plurality of unit cells (210), each unit cell (210) being arranged on the root region (121) at intervals along a first direction and a second direction, wherein the first direction and the second direction are perpendicular to each other.
3. The cantilever beam resonator according to claim 2, characterized in that: The unit cell (210) comprises a body (211) and at least two support beams (213), each of the support beams (213) being arranged on different sides of the body (211), and a hole-shaped structure (212) is arranged on the body (211).
4. The cantilever beam resonator according to claim 3, characterized in that The hole-like structure (212) comprises a first through hole (214) and a plurality of second through holes (215), wherein the second through holes (215) are arranged at intervals around the circumference of the first through hole (214).
5. The cantilever beam resonator according to claim 4, characterized in that The first through hole (214) is a circular hole, and the second through hole (215) is a trapezoidal hole.
6. The cantilever beam resonator according to any one of claims 3 to 5, characterized in that: The body (211) has a length of 15um to 25um and a width of 15um to 25um.
7. The cantilever beam resonator according to any one of claims 3 to 5, characterized in that: The support beam (213) has a length of 1 um to 3 um and a width of 0.5 um to 1.5 um.
8. The cantilever beam resonator according to claim 4, characterized in that The radius of the first through hole (214) is 2.5um-2.7um.
9. The cantilever beam resonator according to any one of claims 3 to 5, characterized in that: The second through hole (215) has an upper bottom length of 3.8um to 4.0um, a lower bottom length of 5.2um to 5.4um, and a height of 3.3um to 3.5um.
10. The cantilever beam resonator according to any one of claims 1 to 5, characterized in that: The cantilever beam (120) comprises a substrate (130), a bottom molybdenum electrode (140), an aluminum nitride piezoelectric layer (150) and a top molybdenum electrode (160) which are arranged in sequence from bottom to top, the aluminum nitride piezoelectric layer (150) being etched with a through hole for electrically connecting to the bottom molybdenum electrode (140) to output a signal to the substrate (130), and the top molybdenum electrode (160) being used to be externally connected to a conductive plate to input a signal; The fixing member (110) comprises a bottom silicon layer (180), a silicon dioxide sacrificial layer, a substrate (130), a bottom molybdenum electrode (140), an aluminum nitride piezoelectric layer (150) and a top molybdenum electrode (160) which are arranged in sequence from bottom to top.