CN214256258U

CN214256258U - Resonator device and filter

Info

Publication number: CN214256258U
Application number: CN202120382749.2U
Authority: CN
Inventors: 龚颂斌; 杨岩松
Original assignee: Baichuang Shenzhen Technology Co ltd
Current assignee: Baichuang Shenzhen Technology Co ltd
Priority date: 2021-02-20
Filing date: 2021-02-20
Publication date: 2021-09-21
Anticipated expiration: 2031-02-20

Abstract

The embodiment of the utility model discloses resonance device and wave filter. The resonance device comprises a wafer substrate, a piezoelectric layer and an interdigital electrode layer; the piezoelectric layer comprises a piezoelectric single crystal material; the main positioning edge of the wafer substrate is positioned in a first direction, and the piezoelectric single crystal material comprises a first crystal axis, a second crystal axis and a third crystal axis; the first crystal axis is vertical to the wafer substrate, or the first crystal axis is parallel to the wafer substrate, and the included angle between the first crystal axis and the first direction is less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees; the second crystal axis is parallel to the wafer substrate and the included angle between the second crystal axis and the first direction is less than or equal to 60 degrees, or the included angle between the second crystal axis and the direction perpendicular to the wafer substrate is greater than or equal to 120 degrees and less than or equal to 135 degrees. According to the scheme, the performance and the working frequency of the resonance device are improved while the low-cost advantage of the resonance device is ensured, and the performance of the band-pass filter containing the resonance device is improved so as to meet the requirement of the 5G communication standard.

Description

Resonator device and filter

Technical Field

The embodiment of the utility model provides a relate to wireless communication technical field, especially, relate to a resonance device and wave filter.

Background

The radio frequency filter is used as an important component of a wireless communication front end and has the functions of frequency selection and interference signal suppression. The radio frequency filter with better performance can not only improve the sensitivity of the transmitter and reduce the frequency spectrum occupation space of the transmitter, but also improve the signal-to-noise ratio of the transceiver and reduce the power consumption of the mobile equipment in a communication link.

The rf filter device is composed of a resonator device, which generally includes a Surface Acoustic Wave (SAW) resonator device and a Bulk Acoustic Wave (BAW) resonator device, and the SAW resonator device and the BAW resonator device have technical and cost advantages in different frequency ranges, respectively. At present, in order to meet the requirements of mobile broadband and high data rate wireless applications, modern communication standards are continuously developing towards higher frequencies and wider bandwidths, and the SAW resonator device and the BAW resonator device in the prior art cannot meet the standards.

For example, the SAW resonator device has the advantage of low cost, but the operating frequency of the SAW resonator device is low, and if the operating frequency of the SAW resonator device is to be increased, the electrode width of the resonator device needs to be adjusted, so that the design of the SAW resonator device cannot simultaneously consider the power threshold, the insertion loss and the manufacturing cost of the device, and further, the SAW resonator device with a high operating frequency is either too high in cost or insufficient in performance. Although BAW resonator devices have advantages in performance and high frequency, the manufacturing process of BAW resonator devices is complicated, increasing the manufacturing cost of BAW resonator devices, and it is difficult to meet the demand of consumer electronics market.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a resonance device and wave filter to improve resonance device's performance and operating frequency.

In a first aspect, an embodiment of the present invention provides a resonant device, including:

a wafer substrate;

a piezoelectric layer on one side of the wafer substrate, the piezoelectric layer comprising a piezoelectric single crystal material;

the interdigital electrode layer is positioned on one side of the piezoelectric layer far away from the substrate;

the main positioning edge of the wafer substrate is positioned in a first direction, and the piezoelectric single crystal material comprises a first crystal axis, a second crystal axis and a third crystal axis which are perpendicular to each other; the first crystal axis is perpendicular to the wafer substrate, or the first crystal axis is parallel to the wafer substrate, and an included angle between the first crystal axis and the first direction is less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees; the second crystal axis is parallel to the wafer substrate, and an included angle between the second crystal axis and the first direction is smaller than or equal to 60 degrees, or an included angle between the second crystal axis and a direction perpendicular to the wafer substrate is larger than or equal to 120 degrees and smaller than or equal to 135 degrees.

Optionally, the first crystal axis is perpendicular to the wafer substrate, and an included angle between the first direction and the second crystal axis is greater than or equal to 0 degree and less than or equal to 60 degrees in a clockwise direction.

Optionally, the first crystal axis is parallel to the wafer substrate, an included angle between the second crystal axis and a direction perpendicular to the wafer substrate is greater than or equal to 120 degrees and less than or equal to 135 degrees, and along a clockwise direction, an included angle between the first direction and the first crystal axis is greater than or equal to 60 degrees and less than or equal to 120 degrees.

Optionally, the first crystal axis is parallel to the wafer substrate, an included angle between the second crystal axis and a direction perpendicular to the wafer substrate is greater than or equal to 30 degrees and less than or equal to 50 degrees, and along a clockwise direction, an included angle between the first direction and the first crystal axis is greater than or equal to-30 degrees and less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees.

Optionally, the interdigital electrode layer comprises a plurality of first interdigital electrodes and a plurality of second interdigital electrodes;

a plurality of the first interdigital electrodes are each connected to a bus bar located on a first side of the interdigital electrode layer, and the first interdigital electrodes each extend from the first side of the interdigital electrode layer toward a second side of the interdigital electrode layer located opposite to the first side in a second direction;

a plurality of the second interdigital electrodes are each connected to a bus bar located on a second side of the interdigital electrode layer, and the second interdigital electrodes are each extended toward the first side along the second direction from the second side;

the vertical projections of the first interdigital electrode and the second interdigital electrode on the piezoelectric layer are alternated, and the first interdigital electrode and the second interdigital electrode are insulated from each other.

Optionally, an included angle between the first direction and a third direction is greater than or equal to-30 degrees and less than or equal to 30 degrees, and the third direction is parallel to the wafer substrate and perpendicular to the second direction.

Optionally, the interdigital electrode layer further comprises a plurality of first dummy interdigital electrodes and a plurality of second dummy interdigital electrodes;

the first dummy interdigital electrode is located between adjacent first interdigital electrodes and connected to the bus bar of the first side, the first dummy interdigital electrode extending from the first side to the second side along the second direction;

the second dummy interdigital electrode is located between adjacent second interdigital electrodes and connected to a bus bar of the second side, the second dummy interdigital electrode extending from the second side to the first side along the second direction;

the first dummy interdigital electrode, the second dummy interdigital electrode, the first interdigital electrode, and the second interdigital electrode are insulated from each other.

Optionally, the wafer substrate further comprises an acoustic reflection grating, the acoustic reflection grating is located on one side of the piezoelectric layer away from the wafer substrate, and the acoustic reflection grating is arranged on two sides of the interdigital electrode layer along the second direction and is insulated from the interdigital electrode layer;

each of the acoustic reflection gratings includes a plurality of metal strips extending in the second direction, and a width of the metal strips in a third direction is greater than 0.25 times a width of the first and second interdigital electrodes in the third direction and less than 10 times the width of the first and second interdigital electrodes in the third direction; wherein the third direction is parallel to the wafer substrate and perpendicular to the second direction;

the distance between the interdigital electrode layer and the adjacent metal strip is greater than 0.2 times the width of the first interdigital electrode and the second interdigital electrode in the third direction, and less than 10 times the width of the first interdigital electrode and the second interdigital electrode in the third direction.

Optionally, the wafer substrate further comprises a metal layer, the metal layer is located on a side of the interdigital electrode layer away from the wafer substrate, and the metal layer covers at least a partial region of the bus bar on the first side of the interdigital electrode layer and covers at least a partial region of the bus bar on the second side of the interdigital electrode layer.

In a second aspect, the present invention provides a filter, including the resonator device of the first aspect.

The embodiment of the utility model provides a resonance device includes wafer substrate, piezoelectric layer and interdigital electrode layer; the piezoelectric layer comprises a piezoelectric single crystal material; the main positioning edge of the wafer substrate is positioned in a first direction, and the piezoelectric single crystal material comprises a first crystal axis, a second crystal axis and a third crystal axis which are mutually vertical; the first crystal axis is vertical to the wafer substrate, or the first crystal axis is parallel to the wafer substrate, and the included angle between the first crystal axis and the first direction is less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees; the second crystal axis is parallel to the wafer substrate and the included angle between the second crystal axis and the first direction is less than or equal to 60 degrees, or the included angle between the second crystal axis and the direction perpendicular to the wafer substrate is greater than or equal to 120 degrees and less than or equal to 135 degrees. The utility model discloses technical scheme has realized arousing the longitudinal polarization surface acoustic wave through resonance device, through the specific direction that sets up the crystal axis, realized setting up the specific direction of the piezoelectricity single crystal material in the piezoelectric layer, with inside geometry and the structure of adjustment resonance device, because piezoelectricity single crystal material has anisotropic characteristics, with piezoelectricity single crystal material with above-mentioned specific direction and wafer substrate carry out the bonding, help strengthening the piezoelectric effect that the piezoelectric layer produced, thereby promote the electromechanical coupling coefficient of resonance device, and strengthen the performance of resonance device. The utility model discloses technical scheme has alleviated surface acoustic wave resonator device among the prior art and can't compromise high performance and low-cost problem, is favorable to when guaranteeing the low-cost advantage of resonator device, improves the performance and the operating frequency of resonator device, and then improves the performance of the band pass filter who contains this resonator device to satisfy 5G communication standard's demand.

Drawings

Fig. 1 is a schematic structural diagram of a resonator device according to an embodiment of the present invention;

fig. 2 is a top view of a resonator device according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of a resonator device according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a piezoelectric single crystal material provided by an embodiment of the present invention;

fig. 5 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 6 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 7 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention;

fig. 8 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 9 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 10 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention;

fig. 11 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention;

fig. 12 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention;

fig. 13 is a top view of another resonator device provided by embodiments of the present invention;

fig. 14 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 15 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 16 is a top view of another resonator device provided by embodiments of the present invention;

fig. 17 is a cross-sectional view of another resonator device provided by an embodiment of the present invention;

fig. 18 is a schematic diagram of stress distribution of a resonator device according to an embodiment of the present invention;

fig. 19 is a schematic diagram of displacement distribution of a resonator device according to an embodiment of the present invention;

fig. 20 is an admittance characteristic curve of the resonator device according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

The embodiment of the present invention provides a resonant device, fig. 1 is a schematic structural diagram of a resonant device provided by the embodiment of the present invention, specifically a side view of a wafer level resonant device, wherein fig. 1 only schematically shows a wafer substrate 10 and a piezoelectric layer 20 of the wafer level resonant device, the wafer level resonant device may include a plurality of resonant devices, and fig. 1 shows one of the resonant devices 100; fig. 2 is a top view of a resonator device provided in an embodiment of the present invention, and may be a top view of the resonator device 100 in fig. 1; fig. 3 is a cross-sectional view of a resonator device provided in an embodiment of the present invention, which may be a cross-sectional view obtained by cutting the resonator device shown in fig. 2 along a section line AA'; fig. 4 is a schematic structural diagram of a piezoelectric single crystal material according to an embodiment of the present invention.

With reference to fig. 1 to 4, a resonant device 100 provided by the embodiment of the present invention includes: a wafer substrate 10, a piezoelectric layer 20 and an interdigital electrode layer 30; the piezoelectric layer 20 is located on one side of the wafer substrate 10, the piezoelectric layer 20 comprising a piezoelectric single crystal material; an interdigital electrode layer 30 located on a side of the piezoelectric layer 20 away from the substrate; the main positioning edge 11 of the wafer substrate 10 is located in a first direction N1, and the piezoelectric single crystal material comprises a first crystal axis X, a second crystal axis Y and a third crystal axis Z which are perpendicular to each other; wherein the first crystal axis X is perpendicular to the wafer substrate 10, or the first crystal axis X is parallel to the wafer substrate 10, and an included angle between the first crystal axis X and the first direction N1 is less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees; the second crystal axis Y is parallel to the wafer substrate 10 and the included angle between the second crystal axis Y and the first direction N1 is less than or equal to 60 degrees, or the included angle between the second crystal axis Y and the direction perpendicular to the wafer substrate 10 is greater than or equal to 120 degrees and less than or equal to 135 degrees.

In particular, the wafer substrate 10 can provide buffering, protection or support for the resonant device, and the material of the wafer substrate 10 may be sapphire. The various layers of the resonator device may be sequentially formed over the wafer substrate 10 to form a wafer-level resonator device comprising a plurality of resonator devices, which may be diced after formation of the wafer-level resonator device to yield the resonator device 100. The piezoelectric layer 20 may be formed on the wafer substrate 10 by bonding, and the piezoelectric layer 20 may be formed by a plurality of piezoelectric single crystal materials arranged according to a certain rule, where the piezoelectric single crystal material is a single crystal material with piezoelectric effect, and under the action of an electric field, a mechanical stress may be generated in the piezoelectric single crystal material and a corresponding deformation may occur.

The interdigitated electrode layer 30 may include two sets of interdigitated electrodes extending along the second direction N2 that form a pattern of metal electrodes on the piezoelectric layer 20 that are interdigitated similar to the fingers of two hands. When the two sets of interdigital electrodes in the resonator device 100 input electrical signals to apply an electric field in a third direction N3 (the third direction N3 is a direction parallel to the wafer substrate 10 and perpendicular to the extending direction of the interdigital electrodes) to the piezoelectric layer 20, so that an electric field in the third direction N3 is generated in the entire thickness direction of the piezoelectric layer 20 (the direction perpendicular to the wafer substrate 10), the interdigital electrodes can excite a surface acoustic wave (i.e., a longitudinally polarized acoustic wave) propagating in the third direction N3 in the piezoelectric layer 20, and convert the surface acoustic wave into a corresponding electrical signal for outputting, so as to implement filtering.

Because the crystal structures have three-dimensional periodicity in spatial arrangement, each type of crystal structure has a corresponding crystal axis coordinate system comprising three crystal axes. In this embodiment, the crystal structure of the trigonal piezoelectric single crystal material shown in fig. 4 is only taken as an example for illustrative purposes, and the kind of the crystal structure of the piezoelectric single crystal material is not limited. Illustratively, the piezoelectric single crystal material shown in fig. 4 may be any one of lithium niobate and lithium tantalate, and the crystal structure of the piezoelectric single crystal material may be such that the third crystal axis Z is located on a diagonal line of the crystal, and a midpoint of the diagonal line of the crystal may be a coordinate origin, and a plane perpendicular to the third crystal axis Z is taken, so that planes in which the first crystal axis X and the second crystal axis Y are located may be obtained. When the crystal axis direction of the piezoelectric single crystal material in the piezoelectric layer 20 is determined, the arrangement direction of the piezoelectric single crystal material with respect to the wafer substrate 10 and the interdigital electrode layer 30 is also determined.

Fig. 1 schematically shows a case where the first crystal axis X is perpendicular to the wafer substrate 10, that is, a plane formed by the second crystal axis Y and the third crystal axis Z is parallel to the wafer substrate 10, and an included angle a1 between the second crystal axis Y and the main positioning edge 11 of the wafer substrate 10 is less than or equal to 60 degrees. The first direction N1 in which the main locating edge 11 of the wafer substrate 10 is located may also be the device direction. Because the piezoelectric single crystal material has the characteristic of anisotropy, in the embodiment, the first crystal axis X is perpendicular to the wafer substrate 10, the plane formed by the second crystal axis Y and the third crystal axis Z is parallel to the wafer substrate 10, and the included angle a1 between the second crystal axis Y and the main positioning edge 11 of the wafer substrate 10 is less than or equal to 60 degrees, so that when the resonance device applies an electric field to the piezoelectric single crystal material through the interdigital electrode, the piezoelectric effect generated by the piezoelectric layer can be enhanced, the electromechanical coupling coefficient of the resonance device is increased, the performance of the resonance device is enhanced, and the working frequency of the resonance device is increased.

In other embodiments of the present invention, the first crystal axis X may be parallel to the wafer substrate 10, and the included angle between the first crystal axis X and the main positioning edge 11 of the wafer substrate 10 may be less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees. The second crystal axis Y may also be parallel to the wafer substrate 10, and an included angle between the second crystal axis Y and the main positioning edge 11 of the wafer substrate 10 may be less than or equal to 60 degrees, or an included angle between the second crystal axis Y and a direction perpendicular to the wafer substrate 10 is greater than or equal to 120 degrees and less than or equal to 135 degrees. The specific direction of the piezoelectric single crystal material in the piezoelectric layer is set through the specific direction of the crystal axis, and the piezoelectric single crystal material has the characteristic of anisotropy, so that the piezoelectric layer is bonded with the wafer substrate in the specific direction, the piezoelectric effect generated by the piezoelectric layer is enhanced, the electromechanical coupling coefficient of the resonance device is improved, the performance of the resonance device is enhanced, and the working frequency of the resonance device is improved.

The utility model discloses technical scheme has realized arousing the longitudinal polarization surface acoustic wave through resonance device, through the specific direction that sets up the crystal axis, realized setting up the specific direction of the piezoelectricity single crystal material in the piezoelectric layer, with inside geometry and the structure of adjustment resonance device, because piezoelectricity single crystal material has anisotropic characteristics, with piezoelectricity single crystal material with above-mentioned specific direction and wafer substrate carry out the bonding, help strengthening the piezoelectric effect that the piezoelectric layer produced, thereby promote the electromechanical coupling coefficient of resonance device, and strengthen the performance of resonance device. The utility model discloses technical scheme has alleviated surface acoustic wave resonator device among the prior art and can't compromise high performance and low-cost problem, is favorable to when guaranteeing the low-cost advantage of resonator device, improves the performance and the operating frequency of resonator device, and then improves the performance of the band pass filter who contains this resonator device to satisfy 5G communication standard's demand.

With reference to fig. 1 to 4, on the basis of the above embodiment, optionally, the first crystal axis X is perpendicular to the wafer substrate 10, and an included angle a1 between the first direction N1 and the second crystal axis Y along the clockwise direction is greater than or equal to 0 degree and less than or equal to 60 degrees.

Illustratively, the first crystal axis X is perpendicular to the wafer substrate 10, and a positive half axis of the first crystal axis X points in a direction in which the piezoelectric layer 20 is away from the wafer substrate 10, a negative half axis (-X) of the first crystal axis X points in a direction in which the piezoelectric layer 20 is close to the wafer substrate 10, or a positive half axis of the first crystal axis X points in a direction in which the piezoelectric layer 20 is close to the wafer substrate 10, and a negative half axis of the first crystal axis X points in a direction in which the piezoelectric layer 20 is away from the wafer substrate 10. In the clockwise direction, the included angle between the first direction N1 and the second crystal axis Y is greater than or equal to 0 degrees and less than or equal to 60 degrees, which means that the positive half axis or the negative half axis (-Y) of the second crystal axis Y can rotate clockwise from the positioning edge 11 of the wafer substrate 10 to any position between 0 degrees and 60 degrees. The specific direction of the piezoelectric single crystal material in the piezoelectric layer is set through the specific direction of the crystal axis, and the piezoelectric single crystal material has the characteristic of anisotropy, so that the piezoelectric layer is bonded with the wafer substrate in the specific direction, the piezoelectric effect generated by the piezoelectric layer is enhanced, the electromechanical coupling coefficient of the resonance device is improved, the performance of the resonance device is enhanced, and the working frequency of the resonance device is improved. Experiments prove that the electromechanical coupling coefficient of the resonance device provided by the embodiment is as high as about 15%.

Fig. 5 is a cross-sectional view of another resonator device provided in an embodiment of the present invention, which may be specifically another cross-sectional view obtained by cutting the resonator device shown in fig. 2 along a cross-sectional line AA', wherein fig. 5 only shows the wafer substrate 10 and the piezoelectric layer 20 of the resonator device; fig. 6 is a cross-sectional view of another resonator device provided in an embodiment of the present invention, which may be specifically another cross-sectional view obtained by cutting the resonator device shown in fig. 2 along a cross-sectional line AA', wherein fig. 6 only shows the wafer substrate 10 and the piezoelectric layer 20 of the resonator device; fig. 7 is a schematic structural diagram of another resonator device according to an embodiment of the present invention, specifically, a side view of another wafer-level resonator device, where fig. 7 only shows the wafer substrate 10 and the piezoelectric layer 20 of the wafer-level resonator device.

With reference to fig. 4 to 7, optionally, the first crystal axis X is disposed parallel to the wafer substrate 10, an included angle a2 between the second crystal axis Y and a direction perpendicular to the wafer substrate 10 is greater than or equal to 120 degrees and less than or equal to 135 degrees, and an included angle a3 between the first direction N1 and the first crystal axis X is greater than or equal to 60 degrees and less than or equal to 120 degrees in the clockwise direction.

Illustratively, the included angle between the first direction N1 and the first crystal axis X is greater than or equal to 60 degrees and less than or equal to 120 degrees in the clockwise direction, which means that the first crystal axis X can be located at any position rotated clockwise from the positioning edge 11 of the wafer substrate 10 to 60 degrees and 120 degrees. The direction perpendicular to the wafer substrate 10 may be the direction of the dashed line L shown in fig. 5 and 6, and accordingly, the included angle a2 between the second crystal axis Y and the direction perpendicular to the wafer substrate 10 is greater than or equal to 120 degrees and less than or equal to 135 degrees, which means that the second crystal axis Y may be located at any position rotated clockwise from the dashed line L to 120 degrees to 135 degrees, and the positive half axis of the second crystal axis Y is directed to the side of the piezoelectric layer 20 close to the wafer substrate 10 (as shown in fig. 5), or the positive half axis of the second crystal axis Y is directed to the side of the piezoelectric layer 20 far from the wafer substrate 10 (as shown in fig. 6). The specific direction of the piezoelectric single crystal material in the piezoelectric layer is set through the specific direction of the crystal axis, and the piezoelectric single crystal material has the characteristic of anisotropy, so that the piezoelectric layer is bonded with the wafer substrate in the specific direction, the piezoelectric effect generated by the piezoelectric layer is enhanced, the electromechanical coupling coefficient of the resonance device is improved, the performance of the resonance device is enhanced, and the working frequency of the resonance device is improved. Experiments prove that the electromechanical coupling coefficient of the resonance device provided by the embodiment is as high as about 10%.

Fig. 8 is a cross-sectional view of another resonator device provided in an embodiment of the present invention, which may be specifically another cross-sectional view obtained by cutting the resonator device shown in fig. 2 along a cross-sectional line AA', wherein fig. 8 only shows the wafer substrate 10 and the piezoelectric layer 20 of the resonator device; fig. 9 is a cross-sectional view of another resonator device provided in an embodiment of the present invention, which may be specifically another cross-sectional view obtained by cutting the resonator device shown in fig. 2 along a cross-sectional line AA', wherein fig. 9 only shows the wafer substrate 10 and the piezoelectric layer 20 of the resonator device; fig. 10 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention, and is a side view of another wafer-level resonator device, where fig. 10 only shows the wafer substrate 10 and the piezoelectric layer 20 of the wafer-level resonator device.

With reference to fig. 4 and 8 to 10, optionally, the first crystal axis X is disposed parallel to the wafer substrate 10, an included angle a4 between the second crystal axis Y and a direction perpendicular to the wafer substrate 10 is greater than or equal to 30 degrees and less than or equal to 50 degrees, and an included angle a5 between the first direction N1 and the first crystal axis X along the clockwise direction is greater than or equal to-30 degrees and less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees.

Illustratively, in the clockwise direction, the included angle a5 from the first direction N1 to the first crystal axis X is greater than or equal to-30 degrees and less than or equal to 30 degrees, or greater than or equal to 60 degrees and less than or equal to 120 degrees, which means that the first crystal axis X can be located at any position from the positioning edge 11 of the wafer substrate 10 to the clockwise direction of-30 degrees and 120 degrees, or from the positioning edge 11 of the wafer substrate 10 to the clockwise direction of 60 degrees and 120 degrees. The direction perpendicular to the wafer substrate 10 may be the direction of the dashed line L shown in fig. 8 and 9, and accordingly, the included angle a4 between the second crystal axis Y and the direction perpendicular to the wafer substrate 10 is greater than or equal to 30 degrees and less than or equal to 50 degrees, which means that the second crystal axis Y may be located at any position rotated clockwise from the dashed line L to 30 degrees to 50 degrees, and the positive half axis of the second crystal axis Y is directed to the side of the piezoelectric layer 20 away from the wafer substrate 10 (as shown in fig. 8), or the positive half axis of the second crystal axis Y is directed to the side of the piezoelectric layer 20 close to the wafer substrate 10 (as shown in fig. 9). The specific direction of the piezoelectric single crystal material in the piezoelectric layer is set through the specific direction of the crystal axis, and the piezoelectric single crystal material has the characteristic of anisotropy, so that the piezoelectric layer is bonded with the wafer substrate in the specific direction, the piezoelectric effect generated by the piezoelectric layer is enhanced, the electromechanical coupling coefficient of the resonance device is improved, the performance of the resonance device is enhanced, and the working frequency of the resonance device is improved. Experiments prove that the electromechanical coupling coefficient of the resonance device provided by the embodiment is as high as about 10%.

Referring to fig. 2 and 3, optionally, providing interdigitated electrode layer 30 includes a plurality of first interdigitated electrodes 310 and a plurality of second interdigitated electrodes 320; the plurality of first interdigital electrodes 310 are each connected to bus bars 311 located on the first side of the interdigital electrode layer 30, and the first interdigital electrodes 310 each extend from the first side of the interdigital electrode layer 30 toward the second side of the interdigital electrode layer 30, which is located opposite to the first side, along the second direction N2; the plurality of second interdigital electrodes 320 are each connected to the bus bar 321 located on the second side of the interdigital electrode layer 30, and the second interdigital electrodes 320 each extend from the second side toward the first side in the second direction N2; the vertical projections of the first interdigital electrode 310 and the second interdigital electrode 320 on the piezoelectric layer 20 are alternated, and the first interdigital electrode 310 and the second interdigital electrode 320 are insulated from each other.

Specifically, the first interdigital electrode 310 and the second interdigital electrode 320 are both metal electrodes, the material of the first interdigital electrode 310 and the second interdigital electrode 320 may include any one of titanium (Ti), silver (Ag), aluminum (Al), copper (Cu), copper aluminum alloy (AlCu), chromium (Cr), ruthenium (Ru), molybdenum (Moly), and tungsten (W), or the material of the first interdigital electrode 310 and the second interdigital electrode 320 may be a combination of the above materials. Each first interdigital electrode 310 is connected to a common electrode, i.e., a bus bar 311; each of the second interdigital electrodes 320 is connected to a common electrode, i.e., the bus bar 321. The widths of the respective first interdigital electrodes 310 may be the same or different, and the widths of the respective second interdigital electrodes 320 may also be the same or different. When the resonator device works, the first interdigital electrode 310 inputs a power supply signal Vin through the bus bar 311, and the second interdigital electrode 320 inputs a ground signal GND through the bus bar 321, so that the interdigital electrode layer 30 can apply an electric field in a direction perpendicular to the first interdigital electrode 310 and the second interdigital electrode 320 in the piezoelectric layer 20, that is, an electric field in the third direction N3, so that an electric field in the third direction N3 is generated in the whole thickness direction of the piezoelectric layer 20, and further, a surface acoustic wave propagating along the third direction N3, that is, a longitudinally polarized acoustic wave is excited, and the surface acoustic wave is converted into a corresponding electric signal to be output, so as to implement filtering.

Fig. 11 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention, specifically, a side view of another wafer-level resonator device, where fig. 11 only shows the wafer substrate 10 and the piezoelectric layer 20 of the wafer-level resonator device; fig. 12 is a schematic structural diagram of another resonator device provided in an embodiment of the present invention, specifically, a side view of another wafer-level resonator device, where fig. 12 only shows the wafer substrate 10 and the piezoelectric layer 20 of the wafer-level resonator device. With reference to fig. 1 to 4 and fig. 11 and 12, optionally, an included angle a1 between the first direction N1 and the third direction N3 is greater than or equal to-30 degrees and less than or equal to 30 degrees, and the third direction N3 is parallel to the wafer substrate 10 and perpendicular to the second direction N2.

Illustratively, the angle between the first direction N1 and the third direction N3 is greater than or equal to-30 degrees and less than or equal to 30 degrees, which means the angle between the direction perpendicular to the extending direction of the first interdigital electrode 310 and the second interdigital electrode 320 (i.e., the second direction N2) (i.e., the third direction N3) and the main positioning edge 11 of the wafer substrate 10 is-30 ≦ a1 ≦ 30 degrees, in other words, the angle between the propagation direction of the surface acoustic wave excited by the resonator device 100 (the third direction N3) and the main positioning edge 11 of the wafer substrate 10 is-30 ≦ a1 ≦ 30 degrees. Fig. 1 schematically shows a case where an angle a1 between the first direction N1 and the third direction N3 is 0 °, fig. 11 schematically shows a case where an angle a1 between the first direction N1 and the third direction N3 is 30 °, and fig. 12 schematically shows a case where an angle a1 between the first direction N1 and the third direction N3 is-30 °. Because the piezoelectric layer 20 generates mechanical stress and generates corresponding deformation under the action of the electric field applied by the interdigital electrode, further, the surface acoustic wave propagating along the third direction N3 is excited in the piezoelectric layer 20, and considering that the piezoelectric single crystal material in the piezoelectric layer 20 has the characteristic of anisotropy, in this embodiment, by setting the included angle between the first direction N1 and the third direction N3 to-30 ° or more and a1 or less and 30 ° or less, the adjustment of the relative position relationship between the direction of the interdigital electrode and the crystal structure orientation of the piezoelectric single crystal material is realized, which is beneficial to enhancing the piezoelectric effect generated by the piezoelectric layer while exciting the surface acoustic wave propagating along the third direction N3, thereby enhancing the electromechanical coupling coefficient of the resonator, so as to enhance the performance of the resonator and improve the working frequency of the resonator.

Fig. 13 is a top view of another resonator device provided in the embodiments of the present invention, and may be another top view of the resonator device 100 in fig. 1. As shown in fig. 13, the interdigital electrode layer 30 is optionally provided to further include a plurality of first dummy interdigital electrodes 312 and a plurality of second dummy interdigital electrodes 322; first dummy interdigital electrodes 312 are located between adjacent first interdigital electrodes 310 and connected to the bus bars 311 on the first side, the first dummy interdigital electrodes 312 extending from the first side to the second side in the second direction N2; second dummy interdigital electrodes 322 are located between adjacent second interdigital electrodes 320 and connected to the bus bar 321 of the second side, the second dummy interdigital electrodes 322 extending from the second side toward the first side along the second direction N2; the first dummy interdigital electrode 312, the second dummy interdigital electrode 322, the first interdigital electrode 310, and the second interdigital electrode 320 are insulated from each other. The material of the first dummy interdigital electrode 312 and the second dummy interdigital electrode 322 may be the same as the material of the first interdigital electrode 310 and the second interdigital electrode 320, and in the present embodiment, a virtual short finger disconnected from the interdigital electrodes is formed by disposing the first dummy interdigital electrode 312 and the second dummy interdigital electrode 322 (for example, the first dummy interdigital electrode 312 forms a virtual short finger disconnected from the corresponding second interdigital electrode 320, and the second dummy interdigital electrode 322 forms a virtual short finger disconnected from the corresponding first interdigital electrode 310), so that the surface acoustic wave excited by the resonator device is reflected when propagating to the first dummy interdigital electrode 312 and the second dummy interdigital electrode 322, thereby confining the surface acoustic wave inside the resonator device in the second direction N2, further improving the energy reflectance of the resonator device and suppressing an unwanted spurious response.

Fig. 14 is a cross-sectional view of another resonator device provided in an embodiment of the present invention, and may be a cross-sectional view obtained by cutting the resonator device shown in fig. 13 along a section line bb'. With reference to fig. 2, 13 and 14, optionally, the resonator device 100 further includes an acoustic reflection grating 330, the acoustic reflection grating 330 is located on a side of the piezoelectric layer 20 away from the wafer substrate 10, the acoustic reflection grating 330 is disposed on two sides of the interdigitated electrode layer 30 along the second direction N2, and is insulated from the interdigitated electrode layer 30; each acoustic reflection grating 330 includes a plurality of metal strips 331 extending in the second direction N2, the width Wr of the metal strips 331 in the third direction N3 being greater than 0.2 times the width We of the first and second

interdigital electrodes

310 and 320 in the third direction N3 and less than 10 times the width We of the first and second

interdigital electrodes

310 and 320 in the third direction N3; wherein the third direction N3 is parallel to the wafer substrate 10 and perpendicular to the second direction N2; the pitch Wg of the interdigital electrode layer 30 from the adjacent metal strip 331 is greater than 0.2 times the width We of the first and second

interdigital electrodes

310 and 320 in the third direction N3, and less than 10 times the width We of the first and second

interdigital electrodes

310 and 320 in the third direction N3.

Specifically, the material of acoustic reflection grating 330 may be the same as or different from the material of first interdigital electrode 310 and second interdigital electrode 320. The two ends of the metal strip 331 in the acoustic reflection grating 330 are connected to the bus bars, namely the bus bar 332 and the bus bar 333, respectively. The bus bars connecting the first interdigital electrode 310 and the second interdigital electrode 320 may or may not be connected to the bus bars connected to the metal bars 331 in the acoustic reflection grating 330, and fig. 2 and 13 each show a case where the bus bars connecting the interdigital electrodes are not connected to the bus bars connected to the metal bars in the acoustic reflection grating. In the embodiment, the acoustic reflection grids 330 are arranged on the two sides of the interdigital electrode layer, so that the surface acoustic waves transmitted to the outside of the acoustic reflection grids 330 on the two sides from the resonator device can be reduced based on the diffraction principle of the acoustic waves, the surface acoustic waves are limited in the resonator device along the third direction N3, and the energy conversion efficiency between the electric energy and the mechanical energy of the resonator device is improved.

The distance Wg between the interdigital electrode layer 30 and the adjacent metal strip 331 is the distance between the metal strip 331 closest to the interdigital electrode in the acoustic reflection grating and the first interdigital electrode 310 or the second interdigital electrode 320 closest to the acoustic reflection grating in the interdigital electrode layer. Fig. 14 schematically shows a case where the widths We of the first interdigital electrode 310 and the second interdigital electrode 320 in the third direction N3 are both, and this embodiment helps to reduce the diffraction of the acoustic wave generated by the resonant device through the acoustic reflection grating by providing the width 0.25We < Wr < 10We of the metal strip 331 in the third direction N3 and the distance 0.2We < Wg < 10We between the interdigital electrode layer 30 and the adjacent metal strip 331, thereby further reducing the surface acoustic wave propagating to the outside of the acoustic reflection grating 330 on both sides of the resonant device, and helping to confine the surface acoustic wave inside the resonant device in the third direction N3, thereby improving the energy conversion efficiency between the electrical energy and the mechanical energy of the resonant device.

Fig. 15 is a cross-sectional view of another resonator device provided in an embodiment of the present invention, and may be another cross-sectional view obtained by cutting the resonator device shown in fig. 13 along a section line bb'. As shown in fig. 3, fig. 14 and fig. 15, the resonator device optionally further includes a passivation layer 50 on the side of the interdigital electrode layer 30 away from the wafer substrate 10, and the passivation layer 50 covers the interdigital electrode layer 30.

Specifically, the passivation layer 50 may be silicon dioxide (SiO2) or silicon nitride (SiNx), and in the embodiment, the passivation layer 50 is disposed to cover the interdigital electrode layer 30 to isolate water and oxygen, so as to protect the interdigital electrode layer 30. When the passivation layer 50 is formed on the side of the interdigital electrode layer 30 away from the wafer substrate 10, the upper surface of the passivation layer 50 on the side away from the wafer substrate 10 can be made flat, or the undulation of the upper surface of the passivation layer 50 can be made to conform to the topography of the upper surface of the interdigital electrode layer.

Fig. 16 is a top view of another resonator device provided by an embodiment of the present invention, which may be specifically another top view of the resonator device 100 in fig. 1; fig. 17 is a cross-sectional view of another resonator device according to an embodiment of the present invention, and may be another cross-sectional view obtained by cutting the resonator device shown in fig. 16 along a section line CC'. With reference to fig. 16 and 17, optionally, the resonator device further includes a metal layer 60, the metal layer 60 is located on a side of the interdigital electrode layer 30 away from the wafer substrate 10, and the metal layer 60 covers at least a partial region of the bus bar 311 on a first side of the interdigital electrode layer 30 and at least a partial region of the bus bar 321 on a second side of the interdigital electrode layer 30.

Specifically, the material of the metal layer 60 may include any one of titanium (Ti), silver (Ag), aluminum (Al), copper (Cu), copper aluminum alloy (AlCu), chromium (Cr), ruthenium (Ru), molybdenum (Moly), and tungsten (W), or may also be a combination of the above materials. The metal layer 60 is arranged to cover at least a partial region of the bus bar 311 and at least a partial region of the bus bar 321, so as to help the surface acoustic wave excited by the resonator device to reflect when propagating to the metal layer 60, thereby confining the surface acoustic wave inside the resonator device along the second direction N2, and at the same time, the metal layer 60 can be exposed on the surface of the packaged resonator device 100, so that the interdigital electrode can access an electrical signal through the metal layer and the bus bar covered thereby.

On the basis of the above embodiments, optionally, one or more dielectric layers may be further disposed between the piezoelectric layer and the wafer substrate to adjust the electromechanical coupling coefficient of the resonant device, so as to improve the performance of the resonant device.

With reference to fig. 13 and 14, on the basis of the above embodiments, the widths 250nm < We < 1 μm of the first interdigital electrode 310 and the second interdigital electrode 320 in the third direction N3 are optionally set, so as to adjust the electromechanical coupling coefficient of the resonator device by adjusting the widths of the interdigital electrodes, thereby enhancing the performance of the resonator device and increasing the operating frequency of the resonator device.

With reference to fig. 13 and 14, optionally, the total number of the first interdigital electrode 310 and the second interdigital electrode 320 is set to be greater than 50, so as to adjust the electromechanical coupling coefficient of the resonator device by adjusting the number of the interdigital electrodes, thereby enhancing the performance of the resonator device and increasing the operating frequency of the resonator device. Optionally, the total number of the metal strips 331 in the acoustic reflection grating 330 is set to be greater than 50, so as to reduce the surface acoustic wave propagating from the resonator device to the outside of the acoustic reflection grating 330 on both sides, which is helpful to limit the surface acoustic wave inside the resonator device along the third direction N3, and further improve the energy conversion efficiency between the electrical energy and the mechanical energy of the resonator device.

With reference to fig. 13 and 14, alternatively, the length of the overlap of the first interdigital electrode 310 and the second interdigital electrode 320 along the second direction N2 is 15 μm < La < 200 μm, and the distance between the second interdigital electrode 320 and the bus bar 311 (i.e., the distance between the first interdigital electrode 310 and the bus bar 321) is 250 μm < Lg < 5 μm, so as to adjust the electromechanical coupling coefficient of the resonator device, thereby enhancing the performance of the resonator device and increasing the operating frequency of the resonator device.

With reference to fig. 13 and 14, alternatively, the distance 500nm < Wpi < 2 μm between the adjacent first interdigital electrode 310 and second interdigital electrode 320 in the interdigital electrode 30 is set, and the distance between the adjacent first interdigital electrode 310 and second interdigital electrode 320 may specifically be the distance between the center of the first interdigital electrode 310 along the third direction N3 and the center of the adjacent second interdigital electrode 320 along the third direction N3. Since f is v/(2 × Wpi), where f is the operating frequency of the resonator device and v is the wave velocity of the surface acoustic wave propagating in the resonator device, the smaller the distance Wpi between the first interdigital electrode 310 and the second interdigital electrode 320 is, the operating frequency of the resonator device is, and the distance between the first interdigital electrode 310 and the second interdigital electrode 320 is, while the wave velocity is unchanged, the present embodiment increases the operating frequency of the resonator device by setting the distance between the first interdigital electrode 310 and the second interdigital electrode 320.

With reference to fig. 13 and 14, optionally, the thickness of the first interdigital electrode 310 and the second interdigital electrode 320 in the direction perpendicular to the wafer substrate 10 is 500nm < Te < 200nm, the thickness of the passivation layer 50 between the surface of the piezoelectric layer 20 on the side away from the wafer substrate 10 and the surface of the passivation layer 50 on the side close to the piezoelectric layer 20 is 100nm < Tp1 < 600nm, and the thickness of the piezoelectric layer 20 in the direction perpendicular to the wafer substrate 10 is 300nm < Tp2 < 1 μm, so as to adjust the electromechanical coupling coefficient of the resonator device by adjusting the thickness of the interdigital electrodes, the thickness of the passivation layer, and the thickness of the piezoelectric layer, thereby enhancing the performance of the resonator device and increasing the operating frequency of the resonator device.

Fig. 18 is a schematic diagram of stress distribution of the resonator device according to an embodiment of the present invention, and fig. 18 schematically shows stress distribution of each film layer of the resonator device shown in fig. 14 under the action of an electric field. In conjunction with fig. 14 and 18, under the action of the electric field, the mechanical stress generated by the resonant device is mainly present in the piezoelectric layer 20, the interdigital electrode layer and the passivation layer 50, and only a small amount of stress is present in the wafer substrate 10. And since the first interdigital electrode 310 inputs a power supply signal Vin and the second interdigital electrode 320 inputs a ground signal GND, the second interdigital electrode 320 can generate electric fields E1 and E2 opposite to each other with the first interdigital electrodes 310 on both sides in the whole thickness direction of the piezoelectric layer 20, accordingly, the stress generated by the resonator device in the piezoelectric layer 20 reaches an extreme value, for example, the electric field E1 applied by the second interdigital electrode 320 and the first interdigital electrode 310 on the left side in the piezoelectric layer 20 makes the stress generated by the corresponding position of the piezoelectric layer 20 reach a maximum value (close to Max), and the electric field E2 applied by the second interdigital electrode 320 and the first interdigital electrode 310 on the right side in the piezoelectric layer 20 makes the stress generated by the corresponding position of the piezoelectric layer 20 reach a minimum value (close to-Max).

Fig. 19 is a schematic diagram of displacement distribution of the resonator device according to the embodiment of the present invention, and fig. 19 schematically illustrates the displacement distribution of each film layer of the resonator device shown in fig. 14 under the action of an electric field. Referring to fig. 14 and 19, the displacements caused by the standing waves generated in the acoustic wave propagation in the resonant device are mainly in the piezoelectric layer 20, the interdigital electrode layer and the passivation layer 50, and there is only a small displacement in the wafer substrate 10.

Fig. 20 is an admittance characteristic curve of the resonator device according to an embodiment of the present invention, which may be obtained by performing a simulation experiment on the resonator device shown in fig. 13 and 14. As shown in fig. 20, the resonant frequency of the resonant device provided by the embodiment of the present invention is 2.62GHz, and the electromechanical coupling coefficient K_t ²Up to 12%, it can be seen that the solution of this embodiment helps to increase the electromechanical coupling coefficient and frequency of the resonator device, and helps to determine the preferred structure and size of the resonator device according to the thickness and width of each film layer of the resonator device, the size and position of the interdigital electrode, and the size and position of the acoustic reflection grating relative to the interdigital electrode corresponding to the solution.

The embodiment of the utility model provides a still provide a wave filter, this wave filter includes the utility model discloses resonance device in the above-mentioned arbitrary embodiment. The embodiment of the utility model provides a wave filter includes the utility model discloses the resonance device that the above-mentioned arbitrary embodiment provided consequently possesses corresponding functional module and beneficial effect of resonance device, no longer gives unnecessary details.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims

1. A resonant device, comprising:

a wafer substrate;

2. The resonator device according to claim 1, wherein the first crystal axis is perpendicular to the wafer substrate, and an angle between the first direction and the second crystal axis is greater than or equal to 0 degrees and less than or equal to 60 degrees in a clockwise direction.

3. The resonator device according to claim 1, wherein the first crystal axis is parallel to the wafer substrate, the second crystal axis forms an angle of 120 degrees or more and 135 degrees or less with respect to a direction perpendicular to the wafer substrate, and the angle from the first direction to the first crystal axis is 60 degrees or more and 120 degrees or less in a clockwise direction.

4. The resonator device according to claim 1, wherein the first crystal axis is parallel to the wafer substrate, the second crystal axis forms an angle of greater than or equal to 30 degrees and less than or equal to 50 degrees with a direction perpendicular to the wafer substrate, and an angle between the first direction and the first crystal axis is greater than or equal to-30 degrees and less than or equal to 30 degrees or greater than or equal to 60 degrees and less than or equal to 120 degrees in a clockwise direction.

5. The resonator device according to claim 1, wherein said interdigital electrode layer comprises a plurality of first interdigital electrodes and a plurality of second interdigital electrodes;

6. The resonator device according to claim 5, wherein the first direction is at an angle greater than or equal to-30 degrees and less than or equal to 30 degrees to a third direction, the third direction being parallel to the wafer substrate and perpendicular to the second direction.

7. The resonator device according to claim 5, wherein said interdigital electrode layer further comprises a plurality of first dummy interdigital electrodes and a plurality of second dummy interdigital electrodes;

8. The resonator device according to claim 5, further comprising an acoustic reflection grating on a side of the piezoelectric layer away from the wafer substrate, the acoustic reflection grating being disposed on both sides of the interdigital electrode layer in the second direction and insulated from the interdigital electrode layer;

9. The resonator device according to claim 5, further comprising a metal layer on a side of said interdigitated electrode layer remote from said wafer substrate, said metal layer covering at least part of the area of the bus bars on a first side of said interdigitated electrode layer and covering at least part of the area of the bus bars on a second side of said interdigitated electrode layer.

10. A filter comprising a resonator device according to any of claims 1-9.