阅读说明：本技术 声波谐振器及无线通信设备 (Acoustic wave resonator and wireless communication device ) 是由 董树荣 冯志宏 于 2020-04-29 设计创作，主要内容包括：本申请提供了一种声波谐振器,应用于无线通信设备、终端设备中,该声波谐振器,包括：第一电极,由导电材料制成；第二电极,由导电材料制成；压电层,由压电材料制成,配置在所述第一电极和所述第二电极之间；其中,所述第一电极包括：第一区域,所述第一区域的材料具有第一密度；第二区域,形成为包围所述第一区域的环状区域,与所述第一区域电气连通,所述第二区域的材料具有第二密度,所述第二密度小于所述第一密度,通过使该第二区域的密度小于该第一区域的密度,能够形成边界条件,从而能够抑制寄生模式,提高功率容量,并且不会对器件的有效面积和结构稳定性等造成影响。(The application provides an acoustic wave resonator, is applied to in wireless communication equipment, terminal equipment, and this acoustic wave resonator includes: a first electrode made of a conductive material; a second electrode made of a conductive material; a piezoelectric layer made of a piezoelectric material and disposed between the first electrode and the second electrode; wherein the first electrode comprises: a first region of a material having a first density; and a second region formed in an annular region surrounding the first region and electrically connected to the first region, wherein a material of the second region has a second density lower than the first density, and the second region has a density lower than that of the first region, so that a boundary condition can be formed, a parasitic mode can be suppressed, power capacity can be improved, and an effective area and structural stability of the device are not affected.)

1. An acoustic wave resonator, comprising:

a first electrode made of a conductive material;

a second electrode made of a conductive material;

a piezoelectric layer made of a piezoelectric material and disposed between the first electrode and the second electrode;

wherein the first electrode comprises:

a first region of a material having a first density;

a second region formed as an annular region surrounding the first region and in electrical communication with the first region, the second region being of a material having a second density different from the first density.

2. The acoustic resonator according to claim 1, wherein the first region and the second region have the same height in a first direction perpendicular to a plane in which the first electrode is arranged.

3. The acoustic resonator according to claim 1, wherein a height in the first direction of a region having a large density is larger than a height in the first direction of a region having a small density, of the first region and the second region.

4. The acoustic resonator according to claim 3, wherein a difference in height between the first region and the second region in a first direction perpendicular to a plane in which the first electrode is arranged is greater than or equal to 5 nm and less than or equal to 100 nm.

5. The acoustic resonator according to any one of claims 1 to 4, wherein a width between an outer edge and an inner edge of the second region is greater than or equal to 0.5 micrometers and less than or equal to 10 micrometers.

6. The acoustic resonator according to any one of claims 1 to 5, wherein the material of the first region has a first thermal conductivity and the material of the second region has a second thermal conductivity, the first thermal conductivity being greater than the second thermal conductivity.

7. The acoustic resonator according to any one of claims 1 to 6, wherein, of the first density and the second density, the larger density is 3 times the smaller density, or the larger density is 7 times the smaller density.

8. The acoustic resonator according to any one of claims 1 to 7, wherein the material of the first region is tungsten, and the material of the second region is aluminum; or

The first region is made of aluminum, and the second region is made of tungsten.

9. The acoustic resonator according to any one of claims 1 to 8, wherein the second density is smaller than the first density, and

the first electrode further comprises:

a third region formed as an annular region surrounding the second region, in electrical communication with the second region, the third region having a material having a third density, the second density being less than the third density.

10. The acoustic resonator according to claim 9, wherein the first region, the second region, and the third region have the same height in a first direction perpendicular to a plane in which the first electrode is arranged.

11. The acoustic resonator according to claim 9, wherein a height of the first region in a first direction is larger than a height of the second region in the first direction, and a difference in height between the first region and the second region is greater than or equal to 5 nm and less than or equal to 100 nm,

the height of the third region in the first direction is greater than that of the second region in the first direction, the height difference between the second region and the third region is greater than or equal to 5 nanometers and less than or equal to 100 nanometers, and the first direction is perpendicular to the arrangement plane of the first electrodes.

12. The acoustic resonator according to any one of claims 9 to 11, wherein a width between an outer edge and an inner edge of the third region is greater than or equal to 0.5 micrometers and less than or equal to 10 micrometers.

13. The acoustic resonator according to any one of claims 9 to 12, wherein the first density is smaller than the third density.

14. The acoustic resonator according to any one of claims 9 to 13, wherein the material of the third region has a third thermal conductivity, the first thermal conductivity being greater than the third thermal conductivity.

15. The acoustic resonator of claim 9, wherein the first electrode further comprises:

a fourth region formed as an annular region surrounding the third region, in electrical communication with the third region, the fourth region being of a material having a fourth density, the third density being less than the fourth density.

16. The acoustic resonator according to claim 15, wherein the first region, the second region, the third region, and the fourth region have the same height in a first direction perpendicular to a plane in which the first electrode is arranged.

17. The acoustic resonator according to claim 15, wherein a height of the first region in a first direction is larger than a height of the second region in the first direction, and a difference in height between the first region and the second region is greater than or equal to 5 nm and less than or equal to 100 nm,

the height of the third region in the first direction is greater than the height of the second region in the first direction, and the difference in height between the second region and the third region is greater than or equal to 5 nm and less than or equal to 100 nm,

the height of the fourth region in the first direction is greater than that of the third region, the height difference between the third region and the fourth region is greater than or equal to 5 nanometers and less than or equal to 100 nanometers, and the first direction is perpendicular to the arrangement plane of the first electrodes.

18. The acoustic resonator according to any one of claims 15 to 17, wherein a width between an outer edge and an inner edge of the third region is greater than or equal to 0.1 micrometers and less than or equal to 2 micrometers,

a width between an outer edge and an inner edge of the fourth region is greater than or equal to 0.5 micrometers and less than or equal to 10 micrometers.

19. The acoustic resonator according to any one of claims 15 to 18, wherein the first density is the same as the third density; and/or

The first density is less than the fourth density.

20. The acoustic resonator according to any one of claims 15 to 19, wherein the material of the fourth region has a fourth thermal conductivity, the first thermal conductivity being greater than the fourth thermal conductivity.

21. The acoustic resonator according to any one of claims 1 to 20, further comprising:

a substrate, wherein a lower electrode is provided on the substrate, the lower electrode being one of the first electrode or the second electrode;

an acoustic isolation layer between the lower electrode and the substrate;

wherein a projection of an upper electrode on an arrangement plane of the first electrode is located inside a projection of the acoustic isolation layer on the arrangement plane of the first electrode, the upper electrode being the other of the first electrode or the second electrode.

22. A filter, comprising:

the acoustic wave resonator of any one of claims 1 to 21.

23. A wireless communication device, comprising:

a receiver comprising the filter of claim 22; and/or

A transmitter comprising a filter according to claim 22.

24. A terminal device, comprising:

a transceiver for receiving or transmitting a signal, the transceiver comprising a filter according to claim 22 for filtering the signal;

and the processor is used for carrying out signal processing on the signals.

Technical Field

The present invention relates to the field of communications, and more particularly, to an acoustic wave resonator, a filter, and a wireless communication device in the field of communications.

Background

Film Bulk Acoustic Resonator (FBAR) filters have become the dominant rf frequency device in the field of wireless communications. The FBAR has an ultra-high Q value, so that a filter composed of the FBAR has very good roll-off characteristics, out-of-band rejection, and in-band insertion loss.

As shown in fig. 1, the FBAR has the following structure: the piezoelectric film is clamped between the upper layer of metal electrode and the lower layer of metal electrode to form a sandwich structure, an alternating radio frequency voltage is applied between the two electrodes to form an alternating electric field in the piezoelectric film, and longitudinal sound waves propagating along the z axis can be excited under specific frequency to form standing wave oscillation.

Most acoustic waves in FBAR resonators propagate vertically (along the z-axis), but the presence of various boundary conditions can result in the propagation of lateral (horizontal) acoustic waves, known as lateral standing waves. The lateral standing waves cause in-band ripples, which lower the Q value. In particular, as the development of communication technology appears, the operating frequency of the FBAR is increased, the thickness (specifically, the thickness in the z-axis direction) is reduced, the size of the integrated device is reduced, and the ratio of the thickness to the width is increased, so that the influence of the lateral vibration characteristic of the piezoelectric layer is more remarkable. How to suppress the lateral standing wave is a key technology for improving the filtering characteristic of the FBAR filter.

As FBAR operating frequencies increase device thickness and become thinner, the increase in integration requires a reduction in the lateral dimensions of the device. And an increase in the thickness-to-width ratio results in a more significant effect on the lateral vibration characteristics of the piezoelectric layer. In particular, when both sides of the electrodes of the FBAR are parallel to each other, lateral modes generated on one pair of sides are reflected by the other side and are superimposed on each other. Transverse modes with very small amplitudes can also affect the transverse vibration characteristics if they are superimposed and amplified, adversely affecting device performance. It is common to use only irregular electrode shapes to reduce the effect of the lateral standing waves, but this design does not have significant suppression of higher frequency spurious waves.

Disclosure of Invention

The application provides an acoustic wave resonator, a filter, a receiver, a transmitter and a wireless communication device, which can restrain transverse standing waves and improve the restraining effect on higher-frequency parasitic waves.

In a first aspect, there is provided an acoustic wave resonator comprising: a first electrode made of a conductive material; a second electrode made of a conductive material; a piezoelectric layer made of a piezoelectric material and disposed between the first electrode and the second electrode; wherein the first electrode comprises: a first region of a material having a first density; a second region formed as an annular region surrounding the first region in electrical (or electrical) communication with the first region, the second region having a material with a second density that is different from the first density.

According to the acoustic wave resonator provided by the present application, the first electrode includes the first region located at the center and the second region surrounding the first region, and both the first region and the second region are made of a conductive material, and the density of the second region is different from that of the first region, so that a boundary condition is formed, a parasitic mode can be suppressed, power capacity can be improved, and an effective area, structural stability, and the like of a device are not affected.

In the present application, the first electrode is formed in a sheet or plate shape.

The first electrode and the second electrode are arranged in parallel.

By way of example and not limitation, the material of the first region may include, but is not limited to, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

Additionally, the material of the second region may include, but is not limited to, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials of the first region and the second region listed above are merely exemplary, and the present application is not limited thereto, and for example, the material of the first region or the second region may also be a material such as an alloy.

Optionally, the first region and the second region have the same height in a first direction, and the first direction is perpendicular to the arrangement plane of the first electrode.

Alternatively, the first region and the second region have different heights in the first direction.

For example, the height of the first region in the first direction may be greater than the height of the second region in the first direction.

It should be understood that the above-listed relationship of the heights of the first region and the second region in the first direction is merely an example, and the present application is not particularly limited, and for example, the height of the first region in the first direction may be smaller than the height of the second region.

Optionally, a width d2 between an outer edge and an inner edge of the second region is greater than or equal to 0.5 microns and less than or equal to 10 microns.

Therefore, the filtering requirements of signals with different frequencies can be flexibly met.

In the present application, the term "outer edge" may be understood as an outer ring edge of the annular region (or a projection of the annular region on the configuration plane), and the term "inner edge" may be understood as an inner ring edge of the annular region (or a projection of the annular region on the configuration plane).

Optionally, the material of the first region has a first thermal conductivity and the material of the second region has a second thermal conductivity, the first thermal conductivity being greater than the second thermal conductivity.

Because the central area of the electrode has larger heat productivity, the heat conductivity of the material of the first area positioned in the center is larger than that of the second area positioned at the edge, so that the heat dissipation of the acoustic wave resonator can be facilitated, and the performance of the acoustic wave resonator is further improved.

Optionally, in the first region and the second region, a height of a region with a large density in the first direction is greater than a height of a region with a small density in the first direction.

Therefore, the effect of the boundary condition between the first region and the second region can be significantly improved, the parasitic mode can be further suppressed, and the performance of the acoustic wave resonator of the present application can be improved.

Optionally, a height difference between the first region and the second region in a first direction is greater than or equal to 5 nm and less than or equal to 100 nm, and the first direction is perpendicular to a configuration plane of the first electrode.

Therefore, filtering of signals in different frequency ranges can be flexibly handled while forming a boundary condition between the first region and the second region.

Optionally, of the first density and the second density, the larger one is 3 times the smaller one, or the larger one is 7 times the smaller one.

By increasing the density difference between the first region and the second region, the effect of the boundary condition between the first region and the second region can be significantly improved, the parasitic mode can be further suppressed, and the performance of the acoustic wave resonator of the present application can be improved.

Optionally, the material of the first region is tungsten, and the material of the second region is aluminum; or

The first region is made of aluminum, and the second region is made of tungsten.

By selecting the materials, the density difference between the first region and the second region can be easily increased, and the practicability of the acoustic wave resonator is further improved.

Optionally, when the second density is less than the first density, the first electrode further comprises: a third region formed as an annular region surrounding the second region, in electrical communication with the second region, the third region having a material having a third density, the second density being less than the third density.

The density of the third region is different from the density of the second region, so that a boundary condition can be formed between the second region and the third region, and a parasitic mode can be further suppressed.

By way of example and not limitation, the material of the third region may include, but is not limited to, tungsten, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials of the third region listed above are merely exemplary, and the present application is not limited thereto, and for example, the materials of the third region may also be materials such as alloys.

Optionally, the heights of the first region, the second region, and the third region in a first direction are the same, and the first direction is perpendicular to the arrangement plane of the first electrode.

Alternatively, the first, second, and third regions may have different heights in a first direction, for example, the third region may have a height in the first direction greater than that of the first region, and the first region may have a height in the first direction greater than that of the second region.

By making the height of the region with a high density larger than the height of the region with a low density, the effect of the boundary condition can be further improved, and the parasitic mode can be further suppressed.

Optionally, a width d3 between an outer edge and an inner edge of the third region is greater than or equal to 0.5 microns and less than or equal to 10 microns.

Optionally, the first density is less than the third density.

Optionally, the material of the third region has a third thermal conductivity, the first thermal conductivity being greater than the third thermal conductivity.

Optionally, the first electrode further comprises: a fourth region formed as an annular region surrounding the third region, in electrical communication with the third region, the fourth region being of a material having a fourth density, the third density being less than the fourth density.

The density of the fourth region is different from the density of the third region, so that a boundary condition can be formed between the fourth region and the third region, and a parasitic mode can be further suppressed.

By way of example and not limitation, the material of the fourth region may include, but is not limited to, tungsten, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials of the fourth region listed above are merely exemplary, and the present application is not limited thereto, and for example, the materials of the fourth region may also be materials such as alloys.

Optionally, the first region, the second region, the third region, and the fourth region have the same height in a first direction, and the first direction is perpendicular to a configuration plane of the first electrode.

Alternatively, the first, second, third, and fourth regions may have different heights in a first direction, for example, the height of the fourth region in the first direction may be greater than the height of the first region in the first direction, and the height of the first region in the first direction may be greater than the height of the second region in the first direction. Also, for another example, the height of the third region in the first direction may be greater than the height of the first region in the first direction. For example, the third region may have the same height as the first region in the first direction.

By making the height of the region with a high density larger than the height of the region with a low density, the effect of the boundary condition can be further improved, and the parasitic mode can be further suppressed.

Optionally, a width d3 between an outer edge and an inner edge of the third region is greater than or equal to 0.1 microns and less than or equal to 2 microns, and a width d4 between an outer edge and an inner edge of the fourth region is greater than or equal to 0.5 microns and less than or equal to 10 microns.

Therefore, the filtering of signals in different frequency ranges can be flexibly handled while improving the boundary condition between the first region and the second region.

Optionally, the first density is the same as the third density.

For example, the material of the first and third regions may be the same.

Optionally, the material of the fourth region has a fourth thermal conductivity, the first thermal conductivity being greater than the fourth thermal conductivity.

Optionally, the acoustic wave resonator further includes: a substrate, wherein a lower electrode is provided on the substrate, the lower electrode being one of the first electrode or the second electrode; an acoustic isolation layer between the lower electrode and the substrate; wherein a projection of an upper electrode on an arrangement plane of the first electrode is located inside a projection of the acoustic isolation layer on the arrangement plane of the first electrode, the upper electrode being the other of the first electrode or the second electrode.

In a second aspect, there is provided a filter comprising an acoustic wave resonator, the acoustic wave resonator comprising: a first electrode made of a conductive material; a second electrode made of a conductive material; a piezoelectric layer made of a piezoelectric material and disposed between the first electrode and the second electrode; wherein the first electrode comprises: a first region of a material having a first density; a second region formed as an annular region surrounding the first region and in electrical communication with the first region, the second region being formed of a material having a second density different from the first density.

According to the acoustic wave resonator provided by the present application, the first electrode includes the first region located at the center and the second region surrounding the first region, and both the first region and the second region are made of a conductive material, and the density of the second region is different from that of the first region, so that a boundary condition is formed, a parasitic mode can be suppressed, power capacity can be improved, and an effective area, structural stability, and the like of a device are not affected.

In the present application, the first electrode is formed in a sheet or plate shape.

The first electrode and the second electrode are arranged in parallel.

By way of example and not limitation, the material of the first region may include, but is not limited to, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

Additionally, the material of the second region may include, but is not limited to, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials of the first region and the second region listed above are merely exemplary, and the present application is not limited thereto, and for example, the material of the first region or the second region may also be a material such as an alloy.

Optionally, the first region and the second region have the same height in a first direction, and the first direction is perpendicular to the arrangement plane of the first electrode.

Alternatively, the first region and the second region have different heights in the first direction.

For example, the height of the first region in the first direction may be greater than the height of the second region in the first direction.

It should be understood that the above-listed relationship of the heights of the first region and the second region in the first direction is merely an example, and the present application is not particularly limited, and for example, the height of the first region in the first direction may be smaller than the height of the second region.

Optionally, a width d2 between an outer edge and an inner edge of the second region is greater than or equal to 0.5 microns and less than or equal to 10 microns.

In the present application, the term "outer edge" may be understood as an outer ring edge of the annular region (or a projection of the annular region on the configuration plane), and the term "inner edge" may be understood as an inner ring edge of the annular region (or a projection of the annular region on the configuration plane).

Optionally, the material of the first region has a first thermal conductivity and the material of the second region has a second thermal conductivity, the first thermal conductivity being greater than the second thermal conductivity.

Optionally, in the first region and the second region, a height in the first direction of a side having a larger density is larger than a height in the first direction of a side having a smaller density.

Optionally, a height difference between the first region and the second region in a first direction is greater than or equal to 5 nm and less than or equal to 100 nm, and the first direction is perpendicular to a configuration plane of the first electrode.

Optionally, of the first density and the second density, the larger one is 3 times the smaller one, or the larger one is 7 times the smaller one.

Optionally, the material of the first region is tungsten, and the material of the second region is aluminum; or

The first region is made of aluminum, and the second region is made of tungsten.

Optionally, when the second density is less than the first density, the first electrode further comprises: a third region formed as an annular region surrounding the second region, in electrical communication with the second region, the third region having a material having a third density, the second density being less than the third density.

By way of example and not limitation, the material of the third region may include, but is not limited to, tungsten, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials of the third region listed above are merely exemplary, and the present application is not limited thereto, and for example, the materials of the third region may also be materials such as alloys.

Optionally, the heights of the first region, the second region, and the third region in a first direction are the same, and the first direction is perpendicular to the arrangement plane of the first electrode.

Alternatively, the first, second, and third regions may have different heights in a first direction, for example, the third region may have a height in the first direction greater than that of the first region, and the first region may have a height in the first direction greater than that of the second region.

Optionally, a width d3 between an outer edge and an inner edge of the third region is greater than or equal to 0.5 microns and less than or equal to 10 microns.

Optionally, the first density is less than the third density.

Optionally, the material of the third region has a third thermal conductivity, the first thermal conductivity being greater than the third thermal conductivity.

Optionally, the first electrode further comprises: a fourth region formed as an annular region surrounding the third region, in electrical communication with the third region, the fourth region being of a material having a fourth density, the third density being less than the fourth density.

By way of example and not limitation, the material of the fourth region may include, but is not limited to, tungsten, molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials of the fourth region listed above are merely exemplary, and the present application is not limited thereto, and for example, the materials of the fourth region may also be materials such as alloys.

Optionally, the first region, the second region, the third region, and the fourth region have the same height in a first direction, and the first direction is perpendicular to a configuration plane of the first electrode.

Alternatively, the first, second, third, and fourth regions may have different heights in a first direction, for example, the height of the fourth region in the first direction may be greater than the height of the first region in the first direction, and the height of the first region in the first direction may be greater than the height of the second region in the first direction. Also, for another example, the height of the third region in the first direction may be greater than the height of the first region in the first direction. For example, the third region may have the same height as the first region in the first direction.

Optionally, a width d3 between an outer edge and an inner edge of the third region is greater than or equal to 0.1 microns and less than or equal to 2 microns, and a width d4 between an outer edge and an inner edge of the fourth region is greater than or equal to 0.5 microns and less than or equal to 10 microns.

Optionally, the first density is the same as the third density.

For example, the material of the first and third regions may be the same.

Optionally, the material of the fourth region has a fourth thermal conductivity, the first thermal conductivity being greater than the fourth thermal conductivity.

Optionally, the acoustic wave resonator further includes: a substrate, wherein a lower electrode is provided on the substrate, the lower electrode being one of the first electrode or the second electrode; an acoustic isolation layer between the lower electrode and the substrate; wherein a projection of an upper electrode on an arrangement plane of the first electrode is located inside a projection of the acoustic isolation layer on the arrangement plane of the first electrode, the upper electrode being the other of the first electrode or the second electrode.

In a third aspect, a wireless communication device is provided, which includes a receiver and/or a transmitter, and at least one of the receiver or the transmitter includes the filter of the second aspect or any one of the possible implementations of the second aspect.

In a fourth aspect, a terminal device is provided, which includes a transceiver configured to receive a downlink signal or send an uplink signal, where the transceiver includes a filter in any one of the second aspect and the second aspect, where the filter is configured to filter the uplink signal to be sent before sending the uplink signal, or filter the received downlink signal after receiving the downlink signal; the processor is configured to perform signal processing on the signal, for example, perform coding modulation on data to be transmitted to generate an uplink signal, or perform demodulation or decoding on a received downlink signal.

In a fifth aspect, a base station is provided, which includes a transceiver configured to receive an uplink signal or send a downlink signal, where the transceiver includes a filter in any one of the second aspect and the second aspect, where the filter is configured to filter the downlink signal to be sent before sending the downlink signal, or filter the received uplink signal after receiving the uplink signal; the processor is configured to perform signal processing on the signal, for example, perform coding modulation on data to be transmitted to generate a downlink signal, or perform demodulation or decoding on a received uplink signal.

Drawings

Fig. 1 is a schematic structural view of an acoustic wave resonator.

Fig. 2 is a front sectional view of an example of the acoustic wave resonator of the present application.

Fig. 3 is a top view of the upper electrode of the acoustic wave resonator depicted in fig. 2.

Fig. 4 is a front sectional view of another example of the acoustic wave resonator of the present application.

Fig. 5 is a front sectional view of still another example of the acoustic wave resonator of the present application.

Fig. 6 is a front sectional view of still another example of the acoustic wave resonator of the present application.

Fig. 7 is a top view of the upper electrode of the acoustic wave resonator depicted in fig. 6.

Fig. 8 is a front sectional view of another example of the acoustic wave resonator of the present application.

Fig. 9 is a front sectional view of still another example of the acoustic wave resonator of the present application.

Fig. 10 is a front sectional view of still another example of the acoustic wave resonator of the present application.

Fig. 11 is a top view of the upper electrode of the acoustic wave resonator depicted in fig. 10.

Fig. 12 is a front sectional view of another example of the acoustic wave resonator of the present application.

Fig. 13 is a front sectional view of still another example of the acoustic wave resonator of the present application.

Fig. 14 is a schematic diagram of an example of the filter of the present application.

Fig. 15 is a schematic diagram of another example of the filter of the present application.

Fig. 16 is a schematic diagram of a radio frequency module of the wireless communication device of the present application.

Fig. 17 is a schematic diagram of a terminal device of the present application.

Fig. 18 is a schematic diagram of a base station of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

Fig. 2 is a schematic structural view showing an example of the acoustic wave resonator of the present application.

As shown in fig. 2, the acoustic wave resonator (or, film bulk acoustic resonator) includes:

a substrate;

a lower electrode (i.e., an example of the second electrode) disposed above the substrate;

a piezoelectric layer disposed over the lower electrode;

the upper electrode (i.e., an example of the first electrode) is disposed above the piezoelectric layer.

It should be understood that the above-listed structures of the acoustic wave resonators are merely illustrative and the present application is not particularly limited.

For example, an acoustic isolation layer (or acoustic isolator) may be formed between the lower electrode and the substrate.

The above-described portions will be described in detail below.

A. Substrate

By way of example, and not limitation, the substrate may be formed as a cuboid or a cube.

The lower electrode of the present application is disposed on the upper surface of the substrate.

Hereinafter, for convenience of understanding and explanation, a plane formed in the x-axis direction and the y-axis direction of the three-dimensional coordinate system will be referred to as a plane # a (i.e., an example of an arrangement plane). The upper surface of the substrate is parallel or approximately parallel to the plane # a.

The substrate may be a semiconductor material, such as silicon or the like.

It should be noted that the acoustic wave resonator of the present application may not include a substrate according to configuration needs.

B. Acoustic isolation layer

The acoustic isolation layer may be located inside the substrate for reflecting acoustic waves.

For example, as shown in fig. 2, the acoustic isolation layer may be an air cavity formed within the substrate.

Alternatively, the acoustic isolation layer may be an acoustic mirror.

It should be noted that the acoustic wave resonator of the present application may not include the acoustic isolation layer according to configuration requirements.

C. Lower electrode

As shown in fig. 2, the lower electrode is located above the acoustic isolation layer (specifically, above in the z-axis direction of the three-dimensional coordinate system).

Alternatively, the lower electrode is disposed on the upper surface of the substrate.

By way of example and not limitation, as shown in fig. 2, the boundary (or edge) of the lower electrode is located outside the boundary of the acoustic isolation layer. Alternatively, the projection of the acoustic isolation layer onto plane # a is located inside the projection of the lower electrode onto plane # a.

In the present application, the lower electrode may be made of a conductive material.

By way of example and not limitation, the lower electrode material may include, but is not limited to, molybdenum, titanium, platinum, aluminum, copper, gold, and the like.

In the present application, the lower electrode may be formed in a sheet or plate shape extending in the plane # a direction.

By way of example and not limitation, the shape of the lower electrode (specifically, the shape of the projection of the lower electrode in the direction of the plane # a) may include, but is not limited to, a polygonal or irregular geometric figure such as a square or rectangle, and the present application is not particularly limited thereto.

D. A piezoelectric layer (or, a thin film bulk piezoelectric layer),

as shown in fig. 2, the piezoelectric layer is located above the lower electrode (specifically, above in the z-axis direction of the three-dimensional coordinate system).

In the present application, the upper electrode may be formed as a film package extending in the plane # A direction

In the present application, the piezoelectric layer is capable of producing a piezoelectric effect or an inverse piezoelectric effect.

Wherein, the piezoelectric effect means: when some dielectrics are deformed by an external force in a certain direction, polarization occurs in the dielectrics, and opposite charges of positive and negative polarities occur on two opposite surfaces of the dielectrics. When the external force is removed, it returns to an uncharged state, and this phenomenon is called the positive piezoelectric effect. When the direction of the force changes, the polarity of the charge changes. Conversely, when an electric field is applied in the polarization direction of the dielectrics, these dielectrics also deform, and after the electric field is removed, the deformation of the dielectrics disappears, which is called the inverse piezoelectric effect.

The principle of the piezoelectric effect is that if a pressure is applied to a piezoelectric material, it generates a potential difference (called a positive piezoelectric effect), whereas if a voltage is applied, a mechanical stress (called an inverse piezoelectric effect) is generated. If the pressure is a high frequency vibration, a high frequency current is generated. When a high-frequency electric signal is applied to the piezoelectric ceramic, a high-frequency acoustic signal (mechanical vibration) is generated.

By way of example and not limitation, the material of the piezoelectric layer may include, but is not limited to, aluminum nitride (AlN), aluminum scandium nitride (AlScN), lead zirconate titanate (PZT), lithium niobate (LiNbO)₃) And the like.

E. Upper electrode

As shown in fig. 2, the upper electrode is located above the piezoelectric layer (specifically, above in the z-axis direction of the three-dimensional coordinate system).

By way of example and not limitation, as shown in fig. 2, the boundary (or edge) of the upper electrode is located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the upper electrode on plane # a is located inside the projection of the acoustic isolation layer on plane # a.

In the present application, the upper electrode may be made of a conductive material.

In the present application, the upper electrode may be formed in a sheet or plate shape extending in the plane # a direction.

By way of example and not limitation, the shape of the upper electrode (specifically, the shape of the projection of the lower electrode in the direction of the plane # a) may include, but is not limited to, a polygon (e.g., an irregular polygon) or an irregular geometric figure, and the present application is not particularly limited. For example, as shown in fig. 3, the upper electrode may be formed in a trapezoidal shape.

As shown in fig. 2 or 3, in the present application, the upper electrode may include a region #1 (i.e., an example of the first region) and a region #2 (i.e., an example of the second region).

Here, the region #2 is formed as an annular region surrounding the region # 1.

Also, the region #2 is in electrical communication with the region #1, and the region #2 in electrical communication with the region #1 may be generated by, for example, vapor deposition or the like around the region # 1.

By way of example and not limitation, the boundary (or, alternatively, the edge) of region #1 is located inside the acoustic isolation layer boundary. Alternatively, the projection of the area #1 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

And, the height of this region #1 (specifically, the height in the z-axis direction) is 0.05 micrometers (μm) or more and 0.6 μm or less.

The region #1 is made of a conductive material, for example, the material of the region #1 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #1 are merely exemplary illustrations and the present application is not limited thereto.

The following describes the parameters of the region #2 in detail

1. Size of region #2

The boundary of region #2 may be located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the area #2 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

2. Width of region #2

By way of example and not limitation, the width d2 of the outer and inner annular edges of the region #2 (or the annular width of the projection of the region #2 on the plane # a, or the thickness of the region # 2) is greater than or equal to 0.5 μm and less than or equal to 10 μm.

It should be understood that the above-mentioned size of the width d2 of the region #2 is merely an exemplary illustration, the present application is not particularly limited, and the size of the width d2 of the region #2 may be arbitrarily adjusted according to parameters such as the range of the region #1, the range of the acoustic isolation layer, and the like.

3. Height of region #2

The height of the region #2 (specifically, the height in the z-axis direction) may be greater than or equal to 0.05 micrometer (μm), and less than or equal to 0.6 μm.

For example, as shown in fig. 2, the height of the region #2 may be the same as the height of the region # 1.

Alternatively, the height h2 of the region #2 may be different from the height h1 of the region # 1. For example, of the region #1 and the region #2, the region with the higher density has a larger height than the region with the lower density, and for example, as shown in fig. 4, if the density ρ 1 of the region #1 is larger than the density ρ 2 of the region #2, h1 is larger than h 2.

4. Material of region #2

The region #2 is made of a conductive material, for example, the material of the region #2 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #2 are merely exemplary illustrations and the present application is not limited thereto.

5. Density of region #2 (specifically, relationship between density of region #2 and density of region # 1)

In the present application, the density ρ 2 of the region #2 is different from the density ρ 1 of the region #1, so that an acoustic reflection boundary condition is formed, thereby suppressing a lateral parasitic mode.

For example, in the present application, the density of the region #2 may be made smaller than that of the region #1 by the selection of the material.

For another example, in the present application, the density of the region #2 may be made greater than the density of the region #1 by the selection of the material.

By way of example and not limitation, ρ 1 may be achieved to be 3 times or more than 3 times ρ 2, for example, by selection of materials.

For another example, ρ 2 may be 3 times or more than 3 times ρ 1 by selecting a material.

By way of example and not limitation, for example, ρ 1 may be 7 times or more than 7 times ρ 2 by choice of materials, e.g., tungsten is used as the material of region #1 and aluminum is used as the material of region # 2.

For another example, ρ 2 may be 3 times or more larger than ρ 1 by selecting a material, for example, aluminum is used as the material of the region #1, and molybdenum is used as the material of the region # 2.

6. Thermal conductivity of region #2 (specifically, relationship between thermal conductivity of region #2 and thermal conductivity of region # 1)

In the present application, the thermal conductivity k2 of region #2 is less than the thermal conductivity k1 of region # 1.

Specifically, the FBAR utilizes the piezoelectric effect to generate the resonant operation of the radio frequency band, and has dielectric loss and electromechanical loss caused by the mechanical vibration of the piezoelectric body compared with the conventional dielectric device, so that the FBAR can generate obvious temperature rise or thermal stress during operation, the temperature rise or thermal stress inevitably causes the drift of the performance of the FBAR, and when the drift exceeds the design index, the device cannot be used, which is the reason of low power capacity of the FBAR. Due to the mechanical resonance, the resonance amplitude is at a maximum in the middle of the resonance region, since the electrode mass load generates the most heat. Because the heat dissipation of the part of the suspension structure is the most difficult, the heating problem of the device is the most obvious in the area, the generated adverse effect is the most serious, and the key position of the maximum power capacity of the device is limited.

According to the present invention, by making the thermal conductivity k2 of the region #2 smaller than the thermal conductivity k1 of the region #1, the heat dissipation effect of the region #1 located at the middle of the resonance region can be improved, and the power capacity of the FBAR can be improved.

For example, in the present application, a thermal conductivity k2 of region #2 that is less than the thermal conductivity k1 of region #1 may be achieved through the selection of materials.

Next, a method for manufacturing the acoustic wave resonator will be described.

(a) And depositing a sacrificial layer material on the silicon substrate, wherein the sacrificial layer material can be a dielectric material such as silicon dioxide, phosphorosilicate glass and the like. Making the pattern of the sacrificial layer material into the pattern of a preset acoustic isolation layer by photoetching and etching processes to form a sacrificial layer of the acoustic isolation layer;

(b) silicon or germanium is epitaxially grown on the surface of the silicon substrate without the sacrificial layer material by using an epitaxial process, the epitaxial height is more than or equal to the height of the sacrificial layer, and the sacrificial layer and the substrate are processed into flat surfaces by using a chemical mechanical polishing process so as to be beneficial to the subsequent deposition and patterning process of an electrode and a piezoelectric layer;

(c) depositing a lower electrode material above the sacrificial layer and the substrate by using a physical vapor deposition process or other processes, wherein the lower electrode material can be a metal material such as molybdenum, platinum, tungsten, aluminum and the like, and forming a lower electrode by using a photoetching and etching process;

(d) depositing a piezoelectric layer over the lower electrode in a physical vapor deposition process;

(e) depositing the electrode material of the area #1 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #1 electrode by using a photoetching and etching process;

(f) depositing the electrode material of the area #2 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #2 electrode by using a photoetching and etching process;

(h) the sacrificial layer material is removed using an etching solution or gas to form an acoustic isolation layer.

Fig. 5 is a front sectional view of still another example of the acoustic wave resonator of the present application. The difference from the acoustic wave resonator shown in fig. 2 is that the lower electrode of the acoustic wave resonator shown in fig. 5 includes two regions, and the parameters of the two regions are similar to those of the two regions of the upper electrode of the acoustic wave resonator shown in fig. 2, and here, detailed description is omitted in order to avoid redundancy.

Further, in order to improve the performance of the piezoelectric layer, in the acoustic wave resonator shown in fig. 5, the heights of the two regions of the lower electrode (specifically, the heights in the z-axis direction) are the same, and the flatness of the upper surfaces of the two regions of the lower electrode (i.e., the surfaces in contact with the piezoelectric layer) is the same.

Fig. 6 and 7 show still another example of the acoustic wave resonator of the present application. The difference from the acoustic wave resonator shown in fig. 2 is that the upper electrode of the acoustic wave resonator shown in fig. 6 and 7 includes three regions. In order to avoid redundancy, the following description will mainly describe three regions of the upper electrode in detail.

As shown in fig. 6 or 7, in the present application, the upper electrode may include a region #1 (i.e., an example of the first region), a region #2 (i.e., an example of the second region), and a region #3 (i.e., an example of the third region).

Here, the region #2 is formed as an annular region surrounding the region # 1.

Also, the region #2 is in electrical communication with the region #1, and the region #2 in electrical communication with the region #1 may be generated by, for example, vapor deposition or the like around the region # 1.

The region #3 is formed as an annular region surrounding the region # 2.

Also, the region #3 is in electrical communication with the region #2, and the region #3 in electrical communication with the region #2 may be generated, for example, by vapor deposition or the like around the region # 2.

By way of example and not limitation, the boundary (or, alternatively, the edge) of region #1 is located inside the acoustic isolation layer boundary. Alternatively, the projection of the area #1 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

And, the height of this region #1 (specifically, the height in the z-axis direction) is 0.05 micrometers (μm) or more and 0.6 μm or less.

The region #1 is made of a conductive material, for example, the material of the region #1 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #1 are merely exemplary illustrations and the present application is not limited thereto.

The following describes the parameters of the region #2 in detail

1. Size of region #2

The boundary of region #2 may be located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the area #2 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

2. Width of region #2

By way of example and not limitation, the width d2 of the outer and inner annular edges of the region #2 (or the annular width of the projection of the region #2 on the plane # a, or the thickness of the region # 2) is greater than or equal to 0.5 μm and less than or equal to 10 μm.

It should be understood that the above-mentioned size of the width d2 of the region #2 is merely an exemplary illustration, the present application is not particularly limited, and the size of the width d2 of the region #2 may be arbitrarily adjusted according to parameters such as the range of the region #1, the range of the acoustic isolation layer, and the like.

3. Height of region #2

The height of the region #2 (specifically, the height in the z-axis direction) may be greater than or equal to 0.05 micrometer (μm), and less than or equal to 0.6 μm.

For example, as shown in fig. 2, the height of the region #2 may be the same as the height of the region # 1.

Alternatively, the height h2 of the region #2 may be different from the height h1 of the region # 1. For example, as shown in FIG. 4, h1 is greater than h 2.

4. Material of region #2

The region #2 is made of a conductive material, for example, the material of the region #2 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #2 are merely exemplary illustrations and the present application is not limited thereto.

5. Density of region #2 (specifically, relationship between density of region #2 and density of region # 1)

In the present application, the density ρ 2 of the region #2 is smaller than the density ρ 1 of the region #1, so that an acoustic reflection boundary condition is formed, thereby suppressing the lateral parasitic mode.

For example, in the present application, the density of the region #2 may be made smaller than that of the region #1 by the selection of the material.

6. Thermal conductivity of region #2 (specifically, relationship between thermal conductivity of region #2 and thermal conductivity of region # 1)

In the present application, the thermal conductivity k2 of region #2 is less than the thermal conductivity k1 of region # 1.

For example, in the present application, a thermal conductivity k2 of region #2 that is less than the thermal conductivity k1 of region #1 may be achieved through the selection of materials.

The following describes the parameters of the region #3 in detail

a. Size of region #3

The boundary of region #3 may be located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the area #3 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

b. Width of region #3

By way of example and not limitation, the width d3 of the outer and inner annular edges of the region #3 (or the annular width of the projection of the region #3 on the plane # a, or the thickness of the region # 3) is greater than or equal to 0.5 μm and less than or equal to 10 μm.

It should be understood that the above-mentioned size of the width d3 of the region #3 is merely an exemplary illustration, the present application is not particularly limited, and the size of the width d3 of the region #3 may be arbitrarily adjusted according to the parameters of the region #1, the region #2, the acoustic isolation layer, and the like.

c. Height of region #3

The height of the region #3 (specifically, the height in the z-axis direction) may be greater than or equal to 0.05 micrometer (μm), and less than or equal to 0.6 μm.

For example, as shown in fig. 6, the height of the region #3 is the same as the height of the region #1 and/or the region # 2.

Alternatively, the height h3 of the region #3 may be different from the height h1 of the region # 1. For example, as shown in FIG. 8, h3 is greater than h 1. The height h3 of the region #3 may be different from the height h2 of the region # 2. For example, as shown in FIG. 8, h3 is greater than h 2.

For example, h 1-h 2-h 3.

As another example, h3 > h1 > h 2.

d. Material of region #3

The region #3 is made of a conductive material, for example, the material of the region #3 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #3 are merely exemplary illustrations and the present application is not limited thereto.

e. The density of region #3 (specifically, the relationship between the density of region #3, the density of region #1, and the density of region # 2)

In the present application, the density ρ 3 of the region #3 is greater than the density ρ 1 of the region #1, and the density ρ 3 of the region #3 is greater than the density ρ 2 of the region # 2. So as to form acoustic reflection boundary conditions and further suppress transverse parasitic modes

For example, ρ 3 > ρ 1 > ρ 2.

In the present application, the density of the region #3 can be made greater than the density of the region #1 and the density of the region #2 by the selection of the material.

f. Thermal conductivity of region #3 (specifically, relationship between thermal conductivity of region #3 and thermal conductivity of region #1 and/or thermal conductivity of region # 2)

In the present application, the thermal conductivity k3 of region #3 is less than the thermal conductivity k1 of region # 1.

For example, in the present application, a thermal conductivity k3 of region #3 that is less than the thermal conductivity k1 of region #1 may be achieved through the selection of materials.

In the present application, the relationship between the thermal conductivity k3 of the region #3 and the thermal conductivity k2 of the region #2 is not particularly limited.

Next, a method for manufacturing the acoustic wave resonator will be described.

(a) And depositing a sacrificial layer material on the silicon substrate, wherein the sacrificial layer material can be a dielectric material such as silicon dioxide, phosphorosilicate glass and the like. Making the pattern of the sacrificial layer material into the pattern of a preset acoustic isolation layer by photoetching and etching processes to form a sacrificial layer of the acoustic isolation layer;

(b) silicon or germanium is epitaxially grown on the surface of the silicon substrate without the sacrificial layer material by using an epitaxial process, the epitaxial height is more than or equal to the height of the sacrificial layer, and the sacrificial layer and the substrate are processed into flat surfaces by using a chemical mechanical polishing process so as to be beneficial to the subsequent deposition and patterning process of an electrode and a piezoelectric layer;

(c) depositing a lower electrode material above the sacrificial layer and the substrate by using a physical vapor deposition process or other processes, wherein the lower electrode material can be a metal material such as molybdenum, platinum, tungsten, aluminum and the like, and forming a lower electrode by using a photoetching and etching process;

(d) depositing a piezoelectric layer over the lower electrode in a physical vapor deposition process;

(e) depositing the electrode material of the area #1 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #1 electrode by using a photoetching and etching process;

(f) depositing the electrode material of the area #2 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #2 electrode by using a photoetching and etching process;

(g) depositing the electrode material of the area #3 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #3 electrode by using a photoetching and etching process;

(h) the sacrificial layer material is removed using an etching solution or gas to form an acoustic isolation layer.

Fig. 9 is a front sectional view of still another example of the acoustic wave resonator of the present application. The difference from the acoustic wave resonator shown in fig. 6 is that the lower electrode of the acoustic wave resonator shown in fig. 9 includes three regions, and the parameters of the three regions are similar to those of the three regions of the upper electrode of the acoustic wave resonator shown in fig. 6, and here, detailed description is omitted in order to avoid redundancy.

Further, in order to improve the performance of the piezoelectric layer, in the acoustic wave resonator shown in fig. 9, the heights of the three regions of the lower electrode (specifically, the heights in the z-axis direction) are the same, and the flatness of the upper surfaces of the three regions of the lower electrode (i.e., the surfaces in contact with the piezoelectric layer) is the same.

Fig. 10 and 11 show still another example of the acoustic wave resonator of the present application. The difference from the acoustic wave resonator shown in fig. 2 is that the upper electrode of the acoustic wave resonator shown in fig. 10 and 11 includes four regions. In order to avoid redundancy, the following description mainly describes four regions of the upper electrode in detail.

As shown in fig. 10 or 11, in the present application, the upper electrode may include a region #1 (i.e., an example of the first region), a region #2 (i.e., an example of the second region), a region # 3' (i.e., an example of the third region), and a region #4 (i.e., an example of the third region).

Here, the region #2 is formed as an annular region surrounding the region # 1.

Also, the region #2 is in electrical communication with the region #1, and the region #2 in electrical communication with the region #1 may be generated by, for example, vapor deposition or the like around the region # 1.

The region #3 is formed as an annular region surrounding the region # 2.

Also, the region #3 'is in electrical communication with the region #2, and the region # 3' in electrical communication with the region #2 may be generated, for example, by vapor deposition or the like around the region # 2.

Also, the region #4 is in electrical communication with the region #3 ', and the region #4 in electrical communication with the region #3 ' may be created, for example, by vapor deposition or the like around the region #3 '.

By way of example and not limitation, the boundary (or, alternatively, the edge) of region #1 is located inside the acoustic isolation layer boundary. Alternatively, the projection of the area #1 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

And, the height of this region #1 (specifically, the height in the z-axis direction) is 0.05 micrometers (μm) or more and 0.6 μm or less.

The region #1 is made of a conductive material, for example, the material of the region #1 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #1 are merely exemplary illustrations and the present application is not limited thereto.

The following describes the parameters of the region #2 in detail

1. Size of region #2

The boundary of region #2 may be located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the area #2 onto the plane # a is located inside the projection of the acoustic isolation layer onto the plane # a.

2. Width of region #2

By way of example and not limitation, the width d2 of the outer and inner annular edges of the region #2 (or the annular width of the projection of the region #2 on the plane # a, or the thickness of the region # 2) is greater than or equal to 0.5 μm and less than or equal to 10 μm.

It should be understood that the above-mentioned size of the width d2 of the region #2 is merely an exemplary illustration, the present application is not particularly limited, and the size of the width d2 of the region #2 may be arbitrarily adjusted according to parameters such as the range of the region #1, the range of the acoustic isolation layer, and the like.

3. Height of region #2

The height of the region #2 (specifically, the height in the z-axis direction) may be greater than or equal to 0.05 micrometer (μm), and less than or equal to 0.6 μm.

For example, as shown in fig. 2, the height of the region #2 may be the same as the height of the region # 1.

Alternatively, the height h2 of the region #2 may be different from the height h1 of the region # 1. For example, as shown in FIG. 4, h1 is greater than h 2.

4. Material of region #2

The region #2 is made of a conductive material, for example, the material of the region #2 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #2 are merely exemplary illustrations and the present application is not limited thereto.

5. Density of region #2 (specifically, relationship between density of region #2 and density of region # 1)

In the present application, the density ρ 2 of the region #2 is smaller than the density ρ 1 of the region #1, so that an acoustic reflection boundary condition is formed, thereby suppressing the lateral parasitic mode.

For example, in the present application, the density of the region #2 may be made smaller than that of the region #1 by the selection of the material.

6. Thermal conductivity of region #2 (specifically, relationship between thermal conductivity of region #2 and thermal conductivity of region # 1)

In the present application, the thermal conductivity k2 of region #2 is less than the thermal conductivity k1 of region # 1.

For example, in the present application, a thermal conductivity k2 of region #2 that is less than the thermal conductivity k1 of region #1 may be achieved through the selection of materials.

The following describes the parameters of the region #3 in detail

a. Size of region #3

The boundary of region # 3' may be located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the region # 3' on the plane # a is located inside the projection of the acoustic isolation layer on the plane # a.

b. Width of region #3

By way of example and not limitation, the width d3 '(or the annular width of the projection of the region # 3' on the plane # a, or the thickness of the region #3 ') of the outer and inner annular edges of the region # 3' is greater than or equal to 0.1 μm and less than or equal to 2 μm.

It should be understood that the above-mentioned size of the width d3 'of the region # 3' is merely an exemplary illustration, the present application is not particularly limited, and the size of the width d3 'of the region # 3' may be arbitrarily adjusted according to parameters such as the range of the region #1, the range of the region #2, the range of the region #4, the range of the acoustic isolation layer, and the like.

c. Height of region #3

The height of the region # 3' (specifically, the height in the z-axis direction) may be greater than or equal to 0.05 micrometers (μm), and less than or equal to 0.6 μm.

For example, as shown in fig. 10, the height of the region # 3' is the same as the height of the region #1 and/or the region # 2.

Alternatively, the height h3 'of the region # 3' may be different from the height h2 of the region # 2. For example, as shown in FIG. 12, h 3' is greater than h 2.

In addition, the relationship between the height of the region # 3' and the height of the region #1 is not particularly limited in the present application.

For example, h 1-h 2-h 3.

For another example, h3 ═ h1 > h 2.

d. Material of region #3

The region #3 'is made of a conductive material, for example, the material of the region # 3' is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region # 3' are merely exemplary and the present application is not limited thereto.

By way of example and not limitation, region # 3' may be the same material as region # 1.

e. The density of the region #3 '(specifically, the relationship between the density of the region # 3' and the density of the region #1 and the density of the region # 2)

By way of example and not limitation, in the present application, the density ρ 3 'of region # 3' is greater than the density ρ 2 of region # 2. The density ρ 3 'of the region # 3' is equal to the density ρ 1 of the region # 1.

That is, ρ 3' ═ ρ 1 > ρ 2.

In the present application, the above density relationship may be achieved by the selection of materials.

f. Thermal conductivity of region #3 '(specifically, relationship between thermal conductivity of region # 3' and thermal conductivity of region #1 and/or thermal conductivity of region # 2)

In the present application, the thermal conductivity k3 'of region # 3' is equal to the thermal conductivity k1 of region # 1.

In the present application, the relationship between the thermal conductivity k3 'of the region # 3' and the thermal conductivity k2 of the region #2 is not particularly limited.

The following describes the parameters of the region #4 in detail

Size of region #4

The boundary of region #4 may be located inside the boundary of the acoustic isolation layer. Alternatively, the projection of the area #4 on the plane # a is located inside the projection of the acoustic isolation layer on the plane # a.

Width of region #4

By way of example and not limitation, the width d4 of the outer and inner annular edges of the region #4 (or the annular width of the projection of the region #4 on the plane # a, or the thickness of the region # 4) is greater than or equal to 0.5 μm and less than or equal to 10 μm.

It should be understood that the above-mentioned size of the width d4 of the region #4 is merely an exemplary illustration, the present application is not particularly limited, and the size of the width d4 of the region #4 may be arbitrarily adjusted according to parameters such as the range of the region #1, the range of the region #2, the range of the region # 3', and the range of the acoustic isolation layer.

Height of zone #4

The height of the region #4 (specifically, the height in the z-axis direction) may be greater than or equal to 0.05 micrometer (μm), and less than or equal to 0.6 μm.

For example, as shown in fig. 10, the height of the region #4 is the same as the height of the region #1, the region #2, and/or the region 3'.

Alternatively, the height h4 of the region #4 may be different from the height h2 of the region # 2. For example, as shown in FIG. 12, h4 is greater than h 2. The height h4 of the region #4 may be different from the height h1 of the region # 1. For example, as shown in FIG. 12, h4 is greater than h 1.

For example, h1 ═ h2 ═ h3 ═ h 4.

For another example, h4 > h3 ═ h1 > h 2.

IV material of zone #4

The region #4 is made of a conductive material, for example, the material of the region #4 is molybdenum, titanium, platinum, aluminum, copper, gold, or the like.

It should be understood that the materials listed above for this region #4 are merely exemplary illustrations and the present application is not limited thereto.

V. Density of region #4 (more specifically, relationship between Density of region #4, Density of region #1, Density of region #2, and Density of region # 3)

By way of example and not limitation, in the present application, the density ρ 4 of the region #4 is greater than the density ρ 2 of the region # 2. The density ρ 4 of the region #4 is greater than the density ρ 1 of the region # 1.

That is, ρ 4 > ρ 3 ═ ρ 1 > ρ 2.

In the present application, the above density relationship may be achieved by the selection of materials. Thereby forming an acoustically reflective boundary condition that suppresses the parasitic modes of the resonator.

VI thermal conductivity of region #4 (specifically, relationship between thermal conductivity of region #4 and thermal conductivity of region # 1)

In the present application, the thermal conductivity k4 of region #4 is less than the thermal conductivity k1 of region # 1.

In the present application, the relationship between the thermal conductivity k4 of the region #4 and the thermal conductivity k2 of the region #2 is not particularly limited.

Next, a method for manufacturing the acoustic wave resonator will be described.

(a) And depositing a sacrificial layer material on the silicon substrate, wherein the sacrificial layer material can be a dielectric material such as silicon dioxide, phosphorosilicate glass and the like. Making the pattern of the sacrificial layer material into the pattern of a preset acoustic isolation layer by photoetching and etching processes to form a sacrificial layer of the acoustic isolation layer;

(b) silicon or germanium is epitaxially grown on the surface of the silicon substrate without the sacrificial layer material by using an epitaxial process, the epitaxial height is more than or equal to the height of the sacrificial layer, and the sacrificial layer and the substrate are processed into flat surfaces by using a chemical mechanical polishing process so as to be beneficial to the subsequent deposition and patterning process of an electrode and a piezoelectric layer;

(c) depositing a lower electrode material above the sacrificial layer and the substrate by using a physical vapor deposition process or other processes, wherein the lower electrode material can be a metal material such as molybdenum, platinum, tungsten, aluminum and the like, and forming a lower electrode by using a photoetching and etching process;

(d) depositing a piezoelectric layer over the lower electrode in a physical vapor deposition process;

(e) depositing the electrode material of the area #1 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #1 electrode by using a photoetching and etching process;

(f) depositing the electrode material of the area #2 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #2 electrode by using a photoetching and etching process;

(g) depositing the electrode material of the area #3 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #3 electrode by using a photoetching and etching process;

(h) depositing the electrode material of the area #4 above the piezoelectric layer by using a physical vapor deposition process, and forming an area #4 electrode by using a photoetching and etching process;

(i) the sacrificial layer material is removed using an etching solution or gas to form an acoustic isolation layer.

Fig. 13 is a front sectional view of still another example of the acoustic wave resonator of the present application. The difference from the acoustic wave resonator shown in fig. 10 is that the lower electrode of the acoustic wave resonator shown in fig. 13 includes four regions, and the parameters of the four regions are similar to those of the four regions of the upper electrode of the acoustic wave resonator shown in fig. 10, and here, detailed description is omitted in order to avoid redundancy.

Further, in order to improve the performance of the piezoelectric layer, in the acoustic wave resonator shown in fig. 13, the heights of the four regions of the lower electrode (specifically, the heights in the z-axis direction) are the same, and the flatness of the upper surfaces of the four regions of the lower electrode (i.e., the surfaces in contact with the piezoelectric layer) is the same.

Fig. 14 is a schematic diagram showing an example of a filter according to the present application, and as shown in fig. 14, the filter includes a plurality of acoustic wave resonators, wherein at least one of the plurality of acoustic wave resonators has the structure of the acoustic wave resonator as shown in any one of fig. 2 to 13. Here, detailed description thereof is omitted in order to avoid redundancy. The two acoustic wave resonators connected in parallel may have the same or different structures, and the present application is not particularly limited. And a lattice type filter can be formed according to the connection manner of the acoustic wave resonators shown in fig. 14.

Fig. 15 is a schematic diagram showing another example of the filter of the present application, and as shown in fig. 15, the filter includes a plurality of acoustic wave resonators, wherein at least one of the plurality of acoustic wave resonators has the structure of the acoustic wave resonator as shown in any one of fig. 2 to 13 described above. Here, detailed description thereof is omitted in order to avoid redundancy. The two acoustic wave resonators connected in parallel may have the same or different structures, and the present application is not particularly limited. And a ladder type filter can be formed according to the connection manner of the acoustic wave resonators shown in fig. 15.

Fig. 16 shows a block diagram of a wireless communication device of the present application, specifically a radio frequency front end of the wireless communication device, which includes two communication links of receive (Rx) and transmit (Tx) as shown in fig. 16. On one hand, a weak Rx signal is received by an antenna, and is picked out from a wide electromagnetic spectrum by an Rx Filter #1, such as a Band Pass Filter (BPF), amplified by a Low Noise Amplifier (LNA), and transmitted to a mixer through an Rx Filter #2, such as a BPF; on the other hand, the Tx signal transmitted from the modulator passes through a Tx filter #2, such as a BPF, to filter out the spectrum except the Tx signal, then passes through a Power Amplifier (PA) to amplify the Tx signal to be transmitted, and then passes through a Tx filter #1, such as a BPF, to transmit the Tx signal via the same antenna.

At least one of the Rx filters #1, #2, Tx filters #1, and #2 has the structure of the acoustic wave resonator as shown in any one of fig. 2 to 13. Here, detailed description thereof is omitted in order to avoid redundancy.

Fig. 17 shows a simplified schematic diagram of a terminal device. For easy understanding and convenience of illustration, in fig. 17, the terminal device is exemplified by a mobile phone. As shown in fig. 17, the terminal device includes a processor, a memory, a radio frequency circuit, an antenna, and an input-output device. The processor is mainly used for processing communication protocols and communication data, controlling the terminal equipment, executing software programs, processing data of the software programs and the like. The memory is used primarily for storing software programs and data. The radio frequency circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are used primarily for receiving data input by a user and for outputting data to the user. It should be noted that some kinds of terminal devices may not have input/output devices. In the present application, the radio frequency circuit may include a plurality of filters, at least one of the plurality of filters having a structure of the acoustic wave resonator as shown in any one of fig. 2 to 13 described above.

When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs baseband signals to the radio frequency circuit, and the radio frequency circuit performs radio frequency processing on the baseband signals and sends the radio frequency signals to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal equipment, the radio frequency circuit receives radio frequency signals through the antenna, converts the radio frequency signals into baseband signals and outputs the baseband signals to the processor, and the processor converts the baseband signals into the data and processes the data. For ease of illustration, only one memory and processor are shown in FIG. 17, and one or more processors and one or more memories may be present in an actual end device product. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be provided independently of the processor, or may be integrated with the processor, which is not limited in this embodiment.

In the embodiment of the present application, the antenna and the radio frequency circuit having the transceiving function may be regarded as a transceiving unit of the terminal device, and the processor having the processing function may be regarded as a processing unit of the terminal device.

Fig. 18 shows a simplified base station structure. The base station includes a transceiver and a processor. The transceiver is mainly used for receiving and transmitting radio frequency signals and converting the radio frequency signals and baseband signals; the processor part is mainly used for baseband processing, base station control and the like. A transceiver may be generally referred to as a transceiver unit, transceiver, transceiving circuitry, etc. The processor is typically the control center of the base station and may be generally referred to as a processing unit.

The transceiver includes an antenna and a radio frequency circuit, wherein the radio frequency circuit is primarily for radio frequency processing. Alternatively, a device for implementing a receiving function in the transceiver may be regarded as a receiving unit, and a device for implementing a transmitting function may be regarded as a transmitting unit, that is, the transceiver includes a receiving unit and a transmitting unit. A receiving unit may also be referred to as a receiver, a receiving circuit, or the like, and a transmitting unit may be referred to as a transmitter, a transmitting circuit, or the like.

The processor may include one or more boards, each of which may include one or more processors and one or more memories. The processor is used to read and execute programs in the memory to implement baseband processing functions and control of the base station. If a plurality of single boards exist, the single boards can be interconnected to enhance the processing capacity. As an alternative implementation, multiple boards may share one or more processors, multiple boards may share one or more memories, or multiple boards may share one or more processors at the same time.

In the present application, a transceiver (e.g., a radio frequency circuit in a transceiver) may include a plurality of filters, at least one of which has a structure of an acoustic wave resonator as shown in any one of fig. 2 to 13 described above.

Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system and apparatus may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.