HK40070873A - Bulk acoustic wave device with raised frame structure - Google Patents

Description

Bulk acoustic wave device having a raised frame structure

CROSS-REFERENCE TO PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claim is identified in an application data sheet filed herein are hereby incorporated by reference in accordance with 37 c.f.r. § 1.57. Priority of U.S. provisional application No.63/080,530, entitled "BULK ACOUSTIC WAVE DEVICE WITH RAISED FRAME construction", filed on 18/9/2020, the disclosure of which is hereby incorporated by reference in its entirety.

Technical Field

Embodiments of the present application relate to acoustic wave devices, and more particularly, to bulk acoustic wave devices.

Background

The acoustic wave filter may be implemented in a radio frequency electronic system. For example, the filter in the radio frequency front end of a mobile phone may include one or more acoustic wave filters. The plurality of acoustic wave filters may be arranged as a multiplexer. For example, two acoustic wave filters may be arranged as one duplexer.

The acoustic wave filter may comprise a plurality of acoustic resonators arranged to filter the radio frequency signal. Example acoustic wave filters include Surface Acoustic Wave (SAW) filters and Bulk Acoustic Wave (BAW) filters. BAW filters include BAW resonators. Example BAW resonators include film bulk acoustic wave resonators (FBARs) and solid-State Mounted Resonators (SMRs). In BAW resonators, the acoustic wave propagates in the body (bulk) of the piezoelectric layer.

For BAW devices, it is often desirable to achieve a high quality factor (Q). However, the Q value of BAW devices may vary due to variations in the manufacturing process and/or other reasons.

Disclosure of Invention

The innovations described in the claims each have several aspects, no one of which is solely responsible for its desirable attributes. Without limiting the scope of the claims, some of the salient features of the present application will now be briefly described.

One aspect of the present application is a bulk acoustic wave device having a multi-gradient convex frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure configured to reduce lateral energy leakage from a primary acoustic activity (active) region of the bulk acoustic wave device. The multi-gradient convex frame structure is tapered (tapered) on opposite sides. The bulk acoustic wave device is configured to generate a bulk acoustic wave.

The multi-gradient raised frame structure may surround a main acoustically active region of the bulk acoustic wave device in plan view. The multi-gradient raised frame structure may have a non-gradient portion between two gradient portions. The multi-gradient raised frame structure may consist essentially of gradient sections.

The multi-gradient raised frame structure may comprise a plurality of raised frame layers. The plurality of raised frame layers may include a first raised frame layer and a second raised frame layer. The second raised frame layer may extend beyond the first raised frame layer on an opposite side. The first raised frame layer may have a lower acoustic impedance than the piezoelectric layer and/or the second raised frame layer. The first raised frame layer may be an oxide layer and the second raised frame layer may be metal-containing. The first raised frame layer may be a silicon dioxide layer and the second raised frame layer may be metal-containing. The first raised frame layer may be positioned between the first and second electrodes. In some cases, the second electrode may be positioned between the first and the second raised frame layers. The second raised frame layer may have a first taper angle (taper angle) on a first side and a second taper angle on a second side, wherein the first and second taper angles are in a range of 5 degrees to 45 degrees.

The multi-gradient bump frame structure may be a bump (convex) structure with respect to the piezoelectric layer.

The bulk acoustic wave device may be a thin film bulk acoustic resonator.

Another aspect of the present application is an acoustic wave filter having a multi-gradient convex-frame bulk acoustic wave device. The acoustic wave filter includes a bulk acoustic wave device and at least one additional acoustic wave device that are together arranged to filter a radio frequency signal. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure configured to reduce lateral energy leakage from a primary acoustic active region of the bulk acoustic wave device. The multi-gradient projection frame structure is tapered on opposite sides.

The at least one additional acoustic wave device can include a second bulk acoustic wave device including a second multi-gradient bump frame structure that is tapered on an opposite side.

The multi-gradient raised frame structure may include a first raised frame layer and a second raised frame layer. The first raised frame layer may include an oxide and the second raised frame layer may be metallic. The second raised frame layer may extend beyond the first raised frame layer on an opposite side.

Another aspect of the present application is a wireless communication device, comprising: an acoustic wave filter and an antenna operatively coupled to the acoustic wave filter. The acoustic wave filter includes a bulk acoustic wave device. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure configured to reduce lateral energy leakage from a primary acoustic active region of the bulk acoustic wave device. The multi-gradient projection frame structure is tapered on opposite sides.

The wireless communication device may be a mobile phone. The acoustic wave filter may be included in a multiplexer.

Another aspect of the present application is a bulk acoustic wave device having a multi-gradient convex frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient convex frame structure. The multi-gradient raised frame structure includes a first raised frame layer and a second raised frame layer. The second raised frame layer extends beyond the first raised frame layer. The second raised frame layer is tapered on the opposite side. The bulk acoustic wave device is configured to generate a bulk acoustic wave.

The second raised frame layer may extend beyond the first raised frame layer on opposing sides, wherein the opposing sides include a first side facing a primary acoustically active region of the bulk acoustic wave device and a second side facing away from the primary acoustically active region.

The first raised frame layer may have a lower acoustic impedance than the piezoelectric layer. The first raised frame layer may include an oxide and the second raised frame layer may include a metal. The second raised frame layer may comprise one or more of ruthenium, molybdenum, tungsten, platinum, or iridium.

The first raised frame layer may comprise a metal. The first raised frame layer may comprise a polymer.

The multi-gradient raised frame structure may have a non-gradient portion between two gradient portions. The multi-gradient raised frame structure may consist essentially of gradient sections.

The first raised frame layer may be positioned between the first electrode and the second electrode.

The second electrode may be positioned between the second raised frame layer and the first raised frame layer. The first raised frame layer may also be positioned between the piezoelectric layer and the second electrode.

The second raised frame layer may have a first taper angle on the first side and a second taper angle on the second side, and both the first and second taper angles may be greater than 5 degrees and less than 45 degrees.

The surface of the second raised frame layer opposite the piezoelectric layer may be a raised structure.

The multi-gradient raised frame structure may surround a main acoustically active region of the bulk acoustic wave device in plan view.

The bulk acoustic wave device may be a thin film bulk acoustic resonator.

Another aspect of the present application is an acoustic wave filter comprising a bulk acoustic wave device and at least one additional acoustic wave device, which together are arranged to filter a radio frequency signal. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure including a first raised frame layer and a second raised frame layer. The second raised frame layer extends beyond the first raised frame layer. The second raised frame layer is tapered on an opposite side.

The at least one additional acoustic wave device can include a second bulk acoustic wave device including a second multi-gradient bump frame structure that is tapered on an opposite side.

Another aspect of the present application is a packaged rf module including an acoustic wave filter configured to filter an rf signal, an rf circuit element, and a package structure packaging the acoustic wave filter and the rf circuit element. The acoustic wave filter includes a bulk acoustic wave device. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure including a first raised frame layer and a second raised frame layer. The second raised frame layer extends beyond the first raised frame layer. The second raised frame layer is tapered on an opposite side.

The radio frequency circuit element may be a radio frequency switch. The radio frequency circuit element may be a radio frequency amplifier.

Another aspect of the present application is a bulk acoustic wave device comprising a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-layer raised frame structure configured to reduce lateral energy leakage from a primary acoustically active region of the bulk acoustic wave device. The multi-layer raised frame structure includes a first raised frame layer embedded in the piezoelectric layer, and a second raised frame layer. The first raised frame layer has a lower acoustic impedance than the piezoelectric layer. The second raised frame layer at least partially overlaps the first raised frame layer in a raised frame region of the bulk acoustic wave device. The bulk acoustic wave device is configured to generate a bulk acoustic wave.

The second raised frame layer may be embedded in the piezoelectric layer.

The first raised frame layer may include an oxide, and the second raised frame layer may include a metal. The first raised frame layer may be a silicon dioxide layer and the second raised frame layer may be metal-containing. The second raised frame layer may be embedded in the piezoelectric layer.

The multi-layer raised frame structure may be a multi-gradient raised frame structure. The second raised frame layer may extend beyond the first raised frame layer on an opposite side of the multi-layer raised frame structure. The multi-gradient raised frame structure may have a non-gradient portion between two gradient portions. The second raised frame layer may have a first taper angle on the first side and a second taper angle on the second side, both the first and second taper angles may be greater than 5 degrees and less than 45 degrees.

The multi-layer raised frame structure may surround a main acoustically active region of the bulk acoustic wave device in plan view.

The bulk acoustic wave device may be a thin film bulk acoustic resonator.

Another aspect of the present application is an acoustic wave filter comprising a bulk acoustic wave device and at least one additional acoustic wave device, which together are arranged to filter a radio frequency signal. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-layer raised frame structure including a first raised frame layer and a second raised frame layer. The first raised frame layer is embedded in the piezoelectric layer, which has a lower acoustic impedance than the piezoelectric layer. The second raised frame layer at least partially overlaps the first raised frame layer.

The at least one additional acoustic wave device may include a second bulk acoustic wave device including a raised frame layer embedded in a piezoelectric layer of the second bulk acoustic wave device.

The multi-layer raised frame structure may be a multi-gradient raised frame structure. The second raised frame layer may have a first taper angle on a first side and a second taper angle on a second side, and the first and second taper angles may each be greater than 5 degrees and less than 45 degrees. The first raised frame layer may be an oxide and the second raised frame layer may be a metal. The first raised frame layer may be a silicon dioxide layer.

Another aspect of the present application is a packaged rf module that includes an acoustic wave filter, an rf circuit element, and a package structure that encapsulates the acoustic wave filter and the rf circuit element. The acoustic wave filter includes a bulk acoustic wave device. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-layer raised frame structure including a first raised frame layer and a second raised frame layer. The first raised frame layer is embedded in the piezoelectric layer, which has a lower acoustic impedance than the piezoelectric layer. The second raised frame layer at least partially overlaps the first raised frame layer.

The radio frequency circuit element may be a radio frequency switch. The radio frequency circuit element may be a radio frequency amplifier.

For purposes of summarizing the present application, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, the innovations may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Drawings

Embodiments of the present application will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

Fig. 1 is a schematic cross-sectional view of a Bulk Acoustic Wave (BAW) device having a dual gradient convex frame structure, according to an embodiment.

Fig. 2A is a plan view of an example BAW device having a frame region surrounding a primary acoustically active region.

Fig. 2B is a plan view of another BAW device having a frame region surrounding a primary acoustically active region.

Fig. 3A is a cross-sectional view of a BAW device having a dual gradient convex frame structure.

Fig. 3B is a simulation result of the BAW device of fig. 3A.

Fig. 4A is a cross-sectional view of a portion of a BAW device having a single-gradient convex frame structure.

Fig. 4B shows simulation results of the BAW device of fig. 4A.

Fig. 5A is a cross-sectional view of a BAW device having a dual gradient convex frame structure.

Fig. 5B shows simulation results of the BAW device of fig. 5A.

FIG. 6 is a cross-sectional view of a solid-assembled resonator (SMR) BAW device having a dual gradient raised frame structure, according to an embodiment.

Fig. 7 is a cross-sectional view of a BAW device having a multi-gradient raised frame structure, according to an embodiment.

Fig. 8 is a cross-sectional view of a BAW device according to another embodiment.

Fig. 9 is a cross-sectional view of a BAW device according to another embodiment.

Fig. 10 is a cross-sectional view of a BAW device having a single raised frame layer, according to an embodiment.

Fig. 11 is a cross-sectional view of a BAW device having a single raised frame layer according to another embodiment.

Fig. 12 is a cross-sectional view of a BAW device according to another embodiment.

Fig. 13 is a cross-sectional view of a BAW device having a multi-gradient convex frame structure between a piezoelectric layer and a lower electrode, according to an embodiment.

Fig. 14 is a cross-sectional view of a BAW device having a multi-gradient raised frame structure with raised frame layers on opposite sides of a piezoelectric layer, according to an embodiment.

Fig. 15 is a cross-sectional view of a BAW device having a multi-layer raised frame structure with raised frame layers on opposite sides of a piezoelectric layer, according to an embodiment.

Fig. 16 is a cross-sectional view of a BAW device having a multi-layer raised frame structure with raised frame layers embedded in a piezoelectric layer, according to an embodiment.

Fig. 17 is a schematic cross-sectional view of a BAW device having a multi-layer raised frame structure with multiple gradients, according to an embodiment.

Fig. 18 is a schematic cross-sectional view of a BAW device having a dual gradient raised frame structure with a raised frame layer embedded in a piezoelectric layer, according to an embodiment.

Fig. 19 is a schematic cross-sectional view of a BAW device having a dual gradient raised frame structure, according to an embodiment.

Fig. 20 illustrates a schematic cross-sectional view of a BAW device, according to an embodiment.

Fig. 21 illustrates a schematic cross-sectional view of a BAW device according to another embodiment.

Fig. 22 illustrates the taper angle of the gradient portion of the raised frame layer.

Fig. 23 illustrates an example gradient portion of a raised frame layer, where the gradient portion is non-linear.

Figure 24 is a schematic diagram of a ladder filter including bulk acoustic wave resonators, according to an embodiment.

Figure 25 is a schematic diagram of a lattice (lattice) filter including bulk acoustic wave resonators, according to an embodiment.

Figure 26 is a schematic diagram of a hybrid ladder lattice filter including bulk acoustic wave resonators, according to an embodiment.

Fig. 27A is a schematic diagram of an acoustic wave filter.

Figure 27B is a schematic diagram of a duplexer including an acoustic wave filter, according to an embodiment.

Fig. 27C is a schematic diagram of a multiplexer including an acoustic wave filter according to an embodiment.

FIG. 27D is a schematic diagram of a multiplexer including an acoustic wave filter, according to an embodiment.

Fig. 27E is a schematic diagram of a multiplexer including an acoustic wave filter according to an embodiment.

28, 29, 30, 31, and 32 are schematic block diagrams of illustrative packaging modules according to some embodiments.

FIG. 33 is a schematic diagram of an embodiment of a mobile device.

Fig. 34 is a schematic diagram of an example of a communication network.

Detailed Description

The following description of certain embodiments presents various descriptions of specific embodiments. The innovations described herein, however, may be implemented in a number of different ways, such as those defined and covered by the claims. In the description, reference is made to the drawings wherein like reference numerals may indicate identical or functionally similar elements. It will be understood that the elements illustrated in the figures are not necessarily drawn to scale. Moreover, it will be understood that certain embodiments may include more elements than the subset of elements illustrated in the figures and/or illustrated in the figures. Further, some embodiments may include any suitable combination of features from two or more of the figures.

The BAW device may include a raised frame structure. The raised frame structure may reduce lateral energy leakage from the primary acoustically active region of the bulk acoustic wave device.

Various aspects of the present disclosure relate to Bulk Acoustic Wave (BAW) devices having a multi-gradient convex frame structure. The multi-gradient bump frame structure disclosed herein can achieve high quality factor (Q) stability and reduce the Q sensitivity of bump frame technology. The Q value of the BAW device can be improved by a combination of a multi-layer bump frame structure and a gradient bump frame. This Q value may be the Qp of the BAW device, where Qp is the quality factor at anti-resonance. The dual gradient bump frame structure disclosed herein can improve the stability of the Q value and also reduce the sensitivity of the bump frame to the Q value. The dual gradient bump frame structure may compensate for energy reflections from leakage relative to the single gradient bump frame structure. Thus, in certain applications, a dual gradient bump frame structure may provide better performance than a single gradient bump frame structure.

Embodiments disclosed herein relate to BAW devices that include a multi-layer raised frame structure having multiple gradients. The multi-layer raised frame structure may include a first raised frame layer positioned between a lower electrode and an upper electrode of the BAW device. The multi-layer raised frame structure may further comprise a second raised frame layer positioned on the first raised frame layer. The second raised frame layer may extend beyond the first raised frame layer. The second raised frame layer may be tapered on an opposite side where the second raised frame layer extends beyond the first raised frame layer. The tapered portion of the second raised frame layer may have a taper angle of less than 90 degrees. For example, the taper angle may be less than 45 degrees. The multi-layer raised frame structure may have a raised structure relative to the surface of the piezoelectric layer and/or the electrode layer. The multi-layer raised frame structure may have a raised structure relative to an acoustic reflector, such as an air cavity. The multi-layer raised frame structure may form a dome-shaped structure. In plan view, the multi-layer raised frame structure may surround a primary acoustically active region of the BAW device.

The first raised-frame layer may have a lower acoustic impedance than the piezoelectric layer of the BAW device. The first raised frame layer may have a lower acoustic impedance than the lower and upper electrode layers of the BAW device. The first raised frame layer may reduce the coupling coefficient. The first raised frame layer may be an oxide. The first raised frame layer may be a metal. The first raised frame layer may be a polymer. The first raised frame layer may include one or more of an oxide, a metal, or a polymer. The first raised frame layer may comprise, for example, a silicon dioxide (SiO2) layer, a silicon nitride (SiN) layer, a silicon carbide (SiC) layer, or any other suitable low acoustic impedance material. Because silicon dioxide has been used for various bulk acoustic wave devices, the first raised frame layer of silicon dioxide can be relatively easily fabricated. Although the first raised frame layer may be referred to as an oxide in some cases, the first raised frame layer may comprise any material suitable for a particular application.

The second raised frame layer may be a relatively high acoustic impedance. For example, the second raised frame layer may comprise molybdenum (Mo), tungsten (W), ruthenium (Ru), platinum (Pt), iridium (Ir), or the like, or any suitable alloy thereof. The second raised frame layer may be a metal layer. Alternatively, the second raised frame layer may be a suitable non-metallic material having a relatively high acoustic impedance. The acoustic impedance of the second raised frame layer may be similar to or higher than the acoustic impedance of the electrode layer of the BAW device. In some cases, the second raised frame layer may be the same material as an electrode layer of the BAW device. The second raised frame layer may have a relatively high density. While the second raised frame layer may be referred to as a metal layer or a metal-containing layer in some cases, the second raised frame layer may comprise any material suitable for a particular application.

An example BAW device having a multi-gradient raised frame structure will now be discussed. Any suitable principles and advantages of these BAW devices may be implemented together with each other.

Fig. 1 is a schematic cross-sectional view of a BAW device 10 having a dual gradient convex frame structure, according to an embodiment. BAW device 10 can generate bulk acoustic waves. The BAW device 10 may be a BAW resonator. The illustrated BAW device 10 includes a primary acoustically active Region "primary Region" and frame regions on opposite sides of the primary acoustically active Region in the illustrated cross-sectional view. Both the primary acoustic active region "primary (Main)" and the frame region are included on the acoustic reflector in the BAW device 10. In the primary mode of the frame region, there is a significant (e.g., exponential) drop in acoustic energy in the piezoelectric layer relative to the primary acoustically active region. In the framework region, there are a first gradient region RaF1, a non-gradient region RaF2, and a second gradient region RaF 3. The first and second gradient zones RaF1 and RaF3, respectively, are included above the acoustic reflector. As shown in fig. 1, the first and second gradient regions RaF1 and RaF3 are above the air cavity 18, respectively. The primary acoustically active region may be significantly larger than the frame region. Fig. 2A and 2B may show the relative sizes of the primary acoustically active region and the framing region, more to scale than the cross-sectional view of fig. 1.

As shown, the BAW device 10 includes a piezoelectric layer 11, a first electrode 12, a second electrode 14, a first raised frame layer 15, a second raised frame layer 16, a support substrate 17, an acoustic reflector such as an air cavity 18, and a passivation layer 19.

The piezoelectric layer 11 is positioned between the first electrode 12 and the second electrode 14. The piezoelectric layer 11 may be an aluminum nitride (AlN) layer. The piezoelectric layer 11 may be any other suitable piezoelectric layer. In the primary acoustically active region "primary area", the piezoelectric layer 11 overlaps both the first electrode 12 and the second electrode 14 and is in physical contact therewith over the air cavity 18. The primary acoustically active region "primary region" is also independent of the first and second raised frame layers 15 and 16, respectively.

The first electrode 12 may have a relatively high acoustic impedance. For example, the first electrode 12 may include molybdenum (Mo), tungsten (W), ruthenium (Ru), chromium (Cr), iridium (Ir), platinum (Pt), Ir/Pt, or any suitable alloy and/or combination thereof. Similarly, the second electrode 14 may have a relatively high acoustic impedance. The second electrode 14 may include Mo, W, Ru, Ir, Cr, Pt, Ir/Pt, or any suitable alloy and/or combination thereof. In some cases, the second electrode 14 may be formed of the same material as the first electrode 14. The first electrode 12 may be referred to as a lower electrode. The second electrode 14 may be referred to as an upper electrode.

The first raised-frame layer 15 may have a lower acoustic impedance than the piezoelectric layer 11 of the BAW device 10. The first raised frame layer 15 may have a lower acoustic impedance than the first electrode 12 and the second electrode layer 14 of the BAW device 10. The first raised frame layer 15 may be an oxide, such as silicon oxide. Such a first raised frame layer 15 may be referred to as an oxide raised frame layer. The first raised frame layer 15 may be a dielectric layer. The first bump frame 15 layer may include metal. The first raised frame 15 layer may be a polymer. The first raised frame layer 15 may include one or more of an oxide, a metal, or a polymer. The first bump frame layer 15 may include, for example, SiO₂A layer, a SiN layer, a SiC layer, or any other suitable low acoustic impedance material. Because of SiO₂Has been used for various bulk acoustic wave devices, SiO₂The first raised frame layer 15 may be relatively easy to manufacture.

The second raised 16 frame layer may be a relatively high acoustic impedance material. For example, the second leadframe 16 layer may include Mo, W, Ru, Ir, Cr, Pt, etc., or any suitable alloy thereof. The second raised 16 frame layer may be a metal-containing layer. In such embodiments, the second raised frame layer 16 may be referred to as a metallic raised frame layer. Alternatively, the second raised frame layer 16 may be a suitable non-metallic material having a relatively high acoustic impedance. The acoustic impedance of the second raised frame layer 16 may be similar to or greater than the acoustic impedance of the electrodes 12 and/or 14 of the BAW device 10. In some cases, the second raised frame layer 16 may be the same material as the electrodes 12 and/or 14 of the BAW device 10. The second raised frame layer 16 may have a relatively high density. The density of the second raised frame layer 16 may be similar to or higher than the density of the electrodes 12 and/or 14 of the BAW device 10.

In some embodiments, the first raised frame layer 15 is an oxide layer (e.g., a silicon dioxide layer) and the second raised frame layer 16 is a metal-containing layer. In at least some such embodiments, the first raised frame layer 15 may be the same material as the passivation layer 19. In some such cases, the second raised frame layer 16 may be the same material as at least one of the electrodes 12 and 14.

In fig. 1, the first raised frame layer 15 and the second raised frame layer 16 are both substantially parallel to the piezoelectric layer 11 in the non-gradient area RaF2 of the frame area. The illustrated second raised frame layer 16 is tapered and extends beyond the first raised frame layer 15 in the first and second gradient regions of the frame region, RaF1 and RaF3, respectively. The first gradient zone RaF1 and the second gradient zone RaF3 are positioned on opposite sides of the raised frame structure. In the BAW device 10 shown in fig. 1, the opposite sides are the inside of the raised frame structure extending towards the "main region" of the main acoustically active region, and the outside away from the "main region" of the main acoustically active region. The outer side is at or near the edge of the air chamber 18 in fig. 1. The second raised frame layer 16 is a continuous layer extending from the first gradient region RaF1 to the second gradient region RaF3 in the BAW device 10. In fig. 1, the second convex frame layer 16 has a non-gradient portion in the non-gradient region RaF2, and gradient portions in the gradient regions RaF1 and RaF 3.

Although embodiments disclosed herein may include a dual gradient raised frame structure, any suitable principles and advantages disclosed herein may be implemented in BAW devices having three or more gradient regions. Although the frame region of fig. 1 includes two gradient regions RaF1 and RaF3 and a non-gradient region RaF2 between the gradient regions RaF1 and RaF3, some other multi-gradient raised frame structures (e.g., raised frame structures having a relatively narrow width) may include gradient regions without non-gradient regions. Thus, the multi-gradient projection frame structure may comprise or substantially comprise the gradient region. An example of such a BAW device is shown in figure 21.

Any suitable principles and advantages disclosed herein may be applied to a floating bump frame structure, where the bump frame structure is at a floating voltage level. The floating bump frame structure may be electrically insulated (e.g., by a dielectric material) from the electrodes of the BAW device.

In plan view, the frame region may surround a main acoustically active region of the BAW device. Fig. 2A shows an example of a frame region 22 surrounding the primary acoustically active region 21 in plan view. In some embodiments, the cross-sectional view in the drawings may be along the line A-A' in FIG. 2A. The BAW device 20A shown in fig. 2A has a semicircular or semi-elliptical shape in plan view. The frame region 22 shown in fig. 2A may include a gradient frame region and a non-gradient frame region shown in any of the cross-sectional views of the figures. The frame region 22 may also include one or more recessed frame regions. The recessed frame region may be located between the raised frame region and a central portion of the primary acoustically active region 21. In the depressed frame region, there may be less mass loading than in the primary acoustically active region 21.

BAW devices according to any suitable principles and advantages disclosed herein may alternatively have any other suitable shape in plan view, such as a quadrilateral, a quadrilateral with curved sides, a pentagon with curved sides, and the like. For example, fig. 2B shows another example of another BAW device 20B having a frame region 22 surrounding a primary acoustically active region 21 in plan view. The BAW device 20B shown in fig. 2B has a shape of a pentagon whose sides are circles in a plan view. In some embodiments, the cross-sectional view in the drawings may be along the line B-B' in FIG. 2B. The frame region 22 shown in fig. 2B may include a gradient frame region and a non-gradient frame region shown in any of the cross-sectional views of the figures. The frame region 22 of the BAW device 20B may also include one or more recessed frame regions located between the raised frame region and the central portion of the primary acoustically active region 21.

Fig. 3A shows a cross-sectional view of a BAW device 30 having a dual gradient convex frame structure. Fig. 3B shows simulation results of the BAW device 30 of fig. 3A, wherein a mirrored version of the circled dual gradient bump-frame structure is included on the opposite side of the cross-sectional view of the BAW device 30. The simulation results are for Q values that vary with the slope and thickness of the silicon dioxide first raised frame layer 15. Simulation results show a large area in which a high Q value is achieved. These simulation results show that stable Q values can be achieved under process variations and/or process variations. For example, simulation results show that the thickness of the first convex frame layer 15 of fig. 3A can be adjusted without significantly affecting the Q value.

Fig. 4A shows a cross-sectional view of a portion of a BAW device 40, in which a single gradient bump frame structure is circled. In the BAW device 40, the single gradient is inside the raised frame structure, extending to the main acoustically active region. The outside of the raised frame structure of the BAW device 40 near the edges of the air cavity 18 does not include a gradient. Fig. 4B shows simulation results of the BAW device 40 of fig. 4A, wherein a mirror image version of the circled single-gradient bump-frame structure is included on opposite sides of the cross-section of the BAW device 40. The simulation results are for Q values that vary with the slope and thickness of the silicon dioxide first raised frame layer 15. Simulation results show that the simulated BAW device 40 can achieve high Q values. These simulation results also show that the Q value is less stable with device parameters, such as the thickness variation of the first raised frame layer 15, compared to the BAW device 30 of fig. 3A.

Fig. 5A shows a cross-sectional view of a portion of a BAW device 50 having a raised frame structure in which no second raised frame layer 16 extends beyond the first raised frame layer 15 towards the circled primary acoustic active region. Fig. 5B shows simulation results of the BAW device 50 of fig. 5A, wherein a mirrored version of the circled raised frame structure is included on opposite sides of the cross-section of the BAW device 50. The simulation results are for Q values that vary with the slope and thickness of the silicon dioxide first raised frame layer 15. Simulation results show that the simulated BAW device 50 has less than ideal Q performance relative to BAW devices 30 and 40 corresponding to the simulation results in fig. 3B and 4B, respectively. It may be desirable to have the second raised frame layer 16 extend beyond the first raised frame layer on opposite sides of the raised frame structure.

The BAW device 10 of fig. 1 is a Film Bulk Acoustic Resonator (FBAR). The principles and advantages disclosed herein may be applied to other BAW devices. Fig. 6 illustrates a solid-assembled resonator (SMR) BAW device 60 having a dual gradient raised frame structure. The SMR BAW device 60 includes a solid acoustic mirror 62 as an acoustic reflector in place of the air cavity. The solid acoustic mirror 62 is an acoustic bragg reflector. The solid acoustic mirror 62 comprises alternating low acoustic impedance layers 63 and high acoustic impedance layers 64. As one example, the solid acoustic mirror 62 may include alternating layers of silicon dioxide as the low impedance layer 63 and tungsten as the high impedance layer 64. Any suitable principles and advantages disclosed herein may be applied to SMR BAW devices.

Fig. 7 to 21 are cross-sectional views of embodiments of BAW devices having a multi-gradient convex frame structure. In these figures, the support substrate under the acoustic reflector (e.g., air cavity) is not shown, although in these embodiments the support substrate is included under the acoustic reflector. Any suitable combination of features of these embodiments may be implemented with each other and/or with other embodiments disclosed herein.

Fig. 7 is a schematic cross-sectional view of a BAW device 70 having a multi-gradient raised frame structure, according to an embodiment. As shown in fig. 7, for the first portion 72 of the BAW device 70, the second raised frame layer 16 may extend beyond the first raised frame layer 15 on only one side of the first raised frame layer 15, and for the second portion 74 of the BAW device 70, the second raised frame layer 16 may extend beyond both sides of the first raised frame layer 15. As shown in fig. 7, the first portion 72 and the second portion 74 of the BAW device 70 may be on opposite sides of the primary acoustically active region.

Fig. 8 is a schematic cross-sectional view of a BAW device 80 having a multi-gradient raised frame structure, according to an embodiment. In fig. 8, a first raised frame layer 15 comprises one side of the BAW device in the schematic cross-sectional view shown. As shown, the multi-gradient raised frame structure of the BAW device 80 includes a multi-layer portion 85 and a single-layer portion 84. The BAW device 80 is one example of a multi-gradient convex-frame BAW device in which the convex-frame layer (i.e., the first convex-frame layer 15 of the BAW device 80) is included only along a portion of the main acoustic active region of the BAW device.

Fig. 9 is a schematic cross-sectional view of a BAW device 90 having a multi-gradient raised frame structure, according to an embodiment. In fig. 9, one side of the cross-sectional view includes a single raised frame layer in a first portion 92 of the BAW device 90, and a second side of the cross-sectional view includes a double raised frame layer in a second portion 94 of the BAW device 90, where the second layer extends beyond the first layer on one side. The raised frame structure of BAW device 90 includes a multi-layer portion 94 and a single-layer portion 92. In the multi-layer portion 94 of the multi-gradient raised frame structure, the second raised frame layer 16 extends beyond the first raised frame layer 15 on only one side. In the single-layer portion 92 of the multi-gradient raised frame structure, a portion of the second raised frame layer 16 is thicker than the multi-layer portion of the multi-gradient raised frame structure in the BAW device 90. In the non-gradient region of the single-layer portion 92, the second raised frame layer 16 is thicker than in the multi-layer portion 94.

Although some multi-gradient-bump-frame BAW devices disclosed herein include multiple bump-frame layers, a multi-gradient-bump-frame BAW device may include a single bump-frame layer. Fig. 10, 11 and 12 illustrate examples of these BAW devices.

Fig. 10 illustrates a schematic cross-sectional view of a BAW device 100 having a single-layer raised frame structure, according to an embodiment. In the illustrated view, the raised frame layer 16 is asymmetric about the center of the primary acoustically active region of the BAW device 100. The BAW device 100 includes a multi-gradient bump frame structure with a single bump frame layer. The single raised frame layer 16 corresponds to the second raised frame layer 16 of other BAW devices disclosed herein. The raised frame layer 16 may be considered to be a single layer even though it is formed from several layers of the same material. In certain embodiments, the raised frame layer 16 of the BAW device 100 may be the same material as the electrode 14. The raised frame layer 16 of the BAW device 100 may have a relatively high acoustic impedance.

Fig. 11 illustrates a schematic cross-sectional view of a BAW device 110 having a single-layer raised frame structure, according to an embodiment. In the BAW device 110, the convex frame layer 15 corresponds to the first convex frame layer 15 of the other embodiments. In certain embodiments, the single raised frame layer 15 of the BAW device 110 may be the same material as the passivation layer 19. The raised frame layer 15 of the BAW device 110 may have a relatively low acoustic impedance, which is lower than the acoustic impedance of the electrodes 12 and 14 and/or the piezoelectric layer 11. As shown, the raised frame layer 15 is positioned between the piezoelectric layer 11 and the electrode 14. In other embodiments, the raised frame layer 15 may alternatively or additionally be positioned between the piezoelectric layer 11 and the electrode 12.

Fig. 12 illustrates a schematic cross-sectional view of a BAW device 120, according to an embodiment. The BAW device 120 includes a dual-gradient convex frame structure, wherein the convex frame structure is positioned between the piezoelectric layer 11 and the lower electrode 12. In the BAW device 120, the bump frame structure includes a single bump frame layer 16. The raised frame layer 16 of the BAW device 120 corresponds to the second raised frame layer 16 of the BAW device of the other embodiments. As shown in fig. 12, a raised frame layer is positioned between electrodes 12 and 14.

Fig. 13 illustrates a schematic cross-sectional view of a BAW device 130, according to an embodiment. The BAW device 130 comprises a dual gradient raised frame structure, wherein the raised frame structure comprises two layers positioned between the piezoelectric layer 11 and the lower electrode 12. In the BAW device 130, a dual gradient raised frame structure is positioned between the electrodes 12 and 14. In the BAW device 130, the first raised frame layer 15 is positioned between the electrode 12 and the second raised frame structure 16. In the BAW device 130, the second convex frame layer 16 includes a portion between the first convex frame layer 15 and the piezoelectric layer. In fig. 13, the second raised frame layer 16 extends beyond the first raised frame layer 15 on opposite sides.

Fig. 14 illustrates a schematic cross-sectional view of a BAW device 140, according to an embodiment. The BAW device 140 comprises a dual gradient raised frame structure, wherein the raised frame structure comprises two layers positioned between electrodes 12 and 14 on opposite sides of the piezoelectric layer 11. In the BAW device 140, the piezoelectric layer 11 is positioned between the first convex frame layer 15 and the second convex frame layer 16, and both the first convex frame layer 15 and the second convex frame layer 16 are positioned between the electrodes 12 and 14. In the BAW device 140, the second convex frame layer 16 extends beyond the first convex frame layer 15 on opposite sides. In the BAW device 140, the second convex frame layer 16 is positioned between the piezoelectric layer 11 and the second electrode 14. In the BAW device 140, the first convex frame layer 15 is positioned between the piezoelectric layer 11 and the first electrode 12.

Fig. 15 illustrates a schematic cross-sectional view of a BAW device 150, according to an embodiment. The BAW device 150 comprises a dual gradient raised frame structure, wherein the raised frame structure comprises two layers positioned between electrodes 12 and 14 on opposite sides of the piezoelectric layer 11. In the BAW device 150, the second raised frame layer 16 extends beyond the first raised frame layer 15, inside the raised frame structure, towards the primary acoustically active region. In the BAW device 150, the second raised frame layer 16 does not extend beyond the first raised frame layer 15 on the outside of the raised frame structure opposite the primary acoustically active region. In the BAW device 150, the second raised frame layer 16 is positioned between the piezoelectric layer 11 and the first electrode 12 above the acoustic reflector. In the BAW device 150, the first convex frame layer 15 is positioned between the piezoelectric layer 11 and the second electrode 14.

Embodiments disclosed herein relate to a multi-layer raised frame structure configured to reduce lateral energy leakage from the primary acoustically active region of a bulk acoustic wave device, wherein one layer of the multi-layer raised frame structure is embedded in a piezoelectric layer. Example embodiments of raised frame layers with embedded piezoelectric layers will be discussed with reference to fig. 16, 18 and 20.

Fig. 16 illustrates a schematic cross-sectional view of a BAW device 160, according to an embodiment. The BAW device 160 includes a two-layer raised frame structure with a raised frame layer 15 embedded in the piezoelectric layer 11. In some applications, the piezoelectric layer 11 may comprise different materials on opposite sides of the embedded raised frame layer 15. For example, on one side of the embedded raised frame layer 15, the piezoelectric layer 11 may comprise AlN, and on the other side of the embedded raised frame layer 15, the piezoelectric layer 11 may comprise scandium-doped AlN. In some cases, the piezoelectric layer 11 comprises the same material on opposite sides of the embedded raised frame structure. In the BAW device 160, the second raised frame layer 16 extends beyond the first raised frame 15, inside the raised frame structure, towards the main acoustically active area of the BAW device 160. In the BAW device 160, the second raised frame layer 16 does not extend beyond the first raised frame layer 15 on the outside of the raised frame structure opposite the primary acoustically active region.

Fig. 17 illustrates a schematic cross-sectional view of a BAW device 170 having a gradient multi-layer raised frame structure, according to an embodiment. In the BAW device 170, the first raised frame layer 16 is embedded in the piezoelectric layer 11. The BAW device 170 is similar to the BAW device 160 of fig. 16, except that in the BAW device 170, the first raised frame layer 15 is positioned between the piezoelectric layer 11 and the first electrode 12 above the acoustic reflector.

Fig. 18 illustrates a schematic cross-sectional view of a BAW device 180 having a dual gradient raised frame structure with a raised frame layer 15 embedded in the piezoelectric layer 11, according to an embodiment. The BAW device 180 is similar to the BAW device 10 of fig. 1, except that in the BAW device 180, the first raised frame layer 15 is embedded in the piezoelectric layer 11.

Fig. 19 illustrates a schematic cross-sectional view of a BAW device 190 having a dual gradient raised frame structure, in accordance with an embodiment. The BAW device 190 is similar to the BAW device 10 of fig. 1, except that in the BAW device 190, the first raised frame layer 15 is positioned between the piezoelectric layer 11 and the first electrode 12. The BAW device 190 is similar to the BAW device 170 of fig. 17, except that in the BAW device 190, the second raised frame layer 16 extends beyond the first raised frame layer 15 both inside and outside the raised frame structure.

Fig. 20 illustrates a schematic cross-sectional view of a BAW device 200, according to an embodiment. In some applications, a multi-gradient raised frame structure may be embedded in the piezoelectric layer 11. The BAW device 200 comprises a dual gradient raised frame structure, wherein two layers 15 and 16 of the raised frame structure are embedded in the piezoelectric layer 11.

Fig. 21 illustrates a schematic cross-sectional view of a BAW device 210, according to an embodiment. BAW device 210 is an example of a BAW device having a multi-gradient bump-frame structure consisting of or consisting essentially of gradient regions RaF1 and RaF 3. In such BAW devices, the raised frame structure may have a relatively narrow width on the acoustic reflector.

In the illustrated schematic cross-sectional view, the gradient portion of the raised frame layer may have a taper angle α with respect to the horizontal direction. The taper angle a can be relative to an underlying layer (e.g., a piezoelectric layer and/or an electrode layer). Fig. 22 illustrates a taper angle a, which may be less than 45 °. In some applications, the taper angle may be less than 45 ° for the gradient portion of the raised frame layer in the first gradient region RaF 1. In such an application, the cone angle in the first gradient region RaF1 may also be greater than 5 °. In some cases, the taper angle may be in the range of about 5 ° to 45 ° for the gradient portion of the convex frame layer in the first gradient region RaF 1. In some applications, the taper angle may be less than 45 ° for the gradient portion of the raised frame layer in the second gradient region RaF3 in any of the embodiments disclosed herein. In such an application, the cone angle in the second gradient region RaF3 may also be greater than 5 °. In some cases, the taper angle may be in the range of about 5 ° to 45 ° for the gradient portion of the raised frame layer in the second gradient region RaF3 of any of the embodiments disclosed herein.

In certain applications, the taper angle may be in the range of about 10 ° to 40 ° for the gradient portion of the raised frame layer in the first gradient region RaF1 and/or the second gradient region RaF3 of any of the embodiments disclosed herein. In some applications, the taper angle may be in the range of about 10 ° to 30 ° for the gradient portion of the raised frame layer in the first gradient region RaF1 and/or the second gradient region RaF3 in any of the embodiments disclosed herein.

In some applications, the taper angles of the first and second gradient regions RaF1 and RaF3 may be approximately the same. In other applications, the taper angles of the first and second gradient regions RaF1 and RaF3 may be different. The taper angles discussed in this paragraph can be applied to any suitable BAW device disclosed herein.

Fig. 23 illustrates an example of an example gradient portion of a raised frame layer, where the gradient portion may be non-linear. The non-linear gradient portion may include a convex (constant) portion, a concave (constant) portion, or any combination thereof. Other variations of the gradient bump frame layer portion are possible.

The BAW devices disclosed herein may be implemented in acoustic wave filters as BAW resonators. Such a filter may be arranged to filter radio frequency signals. In some applications, the acoustic wave filter may be a band pass filter arranged to pass a radio frequency band and attenuate frequencies outside the radio frequency band. The acoustic wave filter may implement a band-stop filter. The bulk acoustic wave devices disclosed herein can implement a variety of different filter topologies. Example filter topologies include ladder filters, lattice filters, hybrid ladder lattice filters, and the like. The acoustic wave filter may comprise all BAW resonators or one or more BAW resonators and one or more other types of acoustic wave resonators, such as SAW resonators. BAW resonators as disclosed herein may be implemented in a filter comprising at least one BAW resonator and one non-acoustic inductor-capacitor component. Some example filter topologies will now be discussed with reference to fig. 24-26. Any suitable combination of features of the filter topologies of fig. 24-26 may be implemented together with each other and/or with other filter topologies.

Figure 24 is a schematic diagram of a ladder filter 240 that includes bulk acoustic wave resonators, according to an embodiment. Ladder filter 240 is an example topology that may implement a bandpass filter formed of acoustic wave resonators. In a bandpass filter with a ladder filter topology, parallel (shunt) resonators may be more common than series resonatorsThere is a lower resonant frequency. Ladder filter 240 may be arranged to filter radio frequency signals. As shown, the ladder filter 240 includes series acoustic wave resonators R1, R3, R5, and R7 and parallel acoustic wave resonators R2, R4, R6, and R8 coupled to the first input/output port I/O₁And a second input/output port I/O₂In the meantime. Any suitable number of series acoustic wave resonators may be included in the ladder filter. Any suitable number of parallel acoustic wave resonators may be included in the ladder filter. The first input/output port I/O1 may be a transmit port, and the second input/output port I/O₂May be an antenna port. Alternatively, the first input/output port I/O₁May be a receiving port, a second input/output port I/O₂May be an antenna port.

According to an embodiment, one or more of the acoustic wave resonators of the ladder filter 240 may comprise a bulk acoustic wave filter. For example, some or all of the parallel resonators R2, R4, R6, and R8 may be multi-gradient convex-frame BAW resonators in accordance with any suitable principles and advantages disclosed herein. When the ladder filter 240 is a band pass filter, the anti-resonance frequency of the parallel resonators of the ladder filter 240 may be set to the lower edge of the pass band. Using a multi-gradient convex-frame BAW parallel resonator, a high quality factor stability of the quality factor at the anti-resonance Qp can be advantageously achieved, for example, as shown in the graph of fig. 3B. Alternatively or additionally, one or more series resonators of the ladder filter 240 may be implemented in accordance with any suitable principles and advantages disclosed herein.

Figure 25 is a schematic diagram of a lattice filter 250 including bulk acoustic wave resonators, according to an embodiment. Lattice filter 250 is an example topology and may be formed as a band pass filter from acoustic wave resonators. The lattice filter 250 may be arranged to filter radio frequency signals. As shown, the lattice filter 250 includes acoustic wave resonators RL1, RL2, RL3, and RL 4. The acoustic wave resonators RL1 and RL2 are series resonators. The acoustic wave resonators RL3 and RL4 are parallel resonators. The illustrated lattice filter 250 has a balanced input and a balanced output. One or more of the illustrated acoustic wave resonators RL 1-RL 4 may be bulk acoustic wave resonators in accordance with any suitable principles and advantages disclosed herein.

Figure 26 is a schematic diagram of a hybrid ladder and lattice filter 260 including bulk acoustic wave resonators, according to an embodiment. The illustrated hybrid ladder and lattice filter 260 includes series acoustic wave resonators RL1, RL2, RH3 and RH4 and parallel acoustic wave resonators RL3, RL4, RH1 and RH 2. The hybrid ladder and lattice filter 260 includes one or more bulk acoustic wave resonators according to any suitable principles and advantages disclosed herein.

In some applications, the bulk acoustic wave resonator may be included in a filter that also includes one or more inductors and one or more capacitors.

The principles and advantages disclosed herein may be implemented in one or more of the filters in separate filters and/or in any suitable multiplexers. Such a filter may be any suitable topology discussed herein, such as any filter topology according to any suitable principles and advantages disclosed with reference to any of fig. 21. The filter may be a band pass filter arranged to filter a fourth generation (4G) Long Term Evolution (LTE) frequency band and/or a fifth generation (5G) New Radio (NR) frequency band. Examples of independent filters and multiplexers will be discussed with reference to fig. 27A through 27E. Any suitable principles and advantages of these filters and/or multiplexers may be implemented in conjunction with each other. In addition, the multi-gradient bump-on-frame bulk acoustic wave resonators disclosed herein may be included in a filter that also includes one or more inductors and one or more capacitors.

Fig. 27A is a schematic diagram of the acoustic wave filter 330. The acoustic wave filter 330 is a band pass filter. The acoustic wave filter 330 is arranged to filter radio frequency signals. The acoustic wave filter 330 includes a plurality of acoustic wave resonators coupled between the first input/output port RF _ IN and the second input/output port RF _ OUT. The acoustic wave filter 330 includes one or more BAW resonators having a multi-gradient bump-frame structure implemented in accordance with any suitable principles and advantages disclosed herein.

Fig. 27B is a schematic diagram of a duplexer 332 including an acoustic wave filter according to an embodiment. Duplexer 332 includes a first filter 330A and a second filter 330B coupled together at a common node COM. One of the filters of the duplexer 332 may be a transmit filter and the other of the filters of the duplexer 332 may be a receive filter. In some other cases, such as in diversity reception applications, duplexer 332 may include two receive filters. Alternatively, the duplexer 332 may include two transmit filters. The common node COM may be an antenna node.

The first filter 330A is an acoustic wave filter arranged to filter radio frequency signals. The first filter 330A includes an acoustic wave resonator coupled between a first radio frequency node RF1 and a common node COM. The first radio frequency node RF1 may be a transmitting node or a receiving node. The first filter 330A includes one or more BAW resonators having a multi-gradient convex frame structure implemented in accordance with any suitable principles and advantages disclosed herein.

The second filter 330B may be any suitable filter arranged to filter the second radio frequency signal. The second filter 330B may be, for example, an acoustic wave filter including one or more BAW resonators having a multi-gradient convex frame structure implemented in accordance with any suitable principles and advantages disclosed herein, an LC filter, a hybrid acoustic wave LC filter, or the like. The second filter 330B is coupled between the second radio frequency node RF2 and the common node. The second radio frequency node RF2 may be a transmitting node or a receiving node.

Although example embodiments may be discussed with filters or duplexers for purposes of illustration, any suitable principles and advantages disclosed herein may be implemented in a multiplexer including a plurality of filters coupled together at a common node. Examples of multiplexers include, but are not limited to, duplexers having two filters coupled together at a common node, triplexers having three filters coupled together at a common node, quadplexers having four filters coupled together at a common node, hexaplexers having six filters coupled together at a common node, octaplexers having eight filters coupled together at a common node, or the like. The multiplexer may comprise filters having different passbands. The multiplexer may include any suitable number of transmit filters and any suitable number of receive filters. For example, the multiplexer may include all receive filters, all transmit filters, or one or more transmit filters and one or more receive filters. The one or more filters of the multiplexer may include any suitable number of BAW resonators having a multi-gradient raised frame structure.

Fig. 27C is a schematic diagram of a multiplexer 334 including an acoustic wave filter according to an embodiment. Multiplexer 334 includes a plurality of filters 330A through 330N coupled together at a common node COM. The plurality of filters may include any suitable number of filters including, for example, 3 filters, 4 filters, 5 filters, 6 filters, 7 filters, 8 filters, or more filters. Some or all of the plurality of acoustic wave filters may be acoustic wave filters. As shown, filters 330A through 330N each have a fixed electrical connection to common node COM. This may be referred to as hard multiplexing or fixed multiplexing. In hard multiplexing applications, the filters have fixed electrical connections to a common node. Each of the filters 330A through 330N has a respective input/output node RF1 through RFN.

The first filter 330A is an acoustic wave filter arranged to filter radio frequency signals. The first filter 330A may include one or more acoustic wave devices coupled between the first radio frequency node RF1 and the common node COM. The first radio frequency node RF1 may be a transmitting node or a receiving node. The first filter 330A includes one or more BAW resonators having a multi-gradient convex frame structure according to any suitable principles and advantages disclosed herein. Other filters of multiplexer 334 may include one or more acoustic wave filters, one or more acoustic wave filters including one or more BAW resonators having a multi-gradient convex frame structure, one or more LC filters, one or more hybrid acoustic wave LC filters, or any suitable combination thereof.

Fig. 27D is a schematic diagram of a multiplexer 336 that includes an acoustic wave filter according to an embodiment. The multiplexer 336 is the same as the multiplexer 334 of fig. 27C, except that the multiplexer 336 implements on-off multiplexing. In switched multiplexing, the filters are coupled to a common node via a switch. In multiplexer 336, switches 337A through 337N may selectively electrically connect respective filters 330A through 330N to a common node COM. For example, switch 337A may selectively electrically connect first filter 330A to common node COM via switch 337A. Any suitable number of switches 337A to 337N may electrically connect the respective filters 330A to 330N to the common node COM in a given state. Similarly, any suitable number of switches 337A to 337N may electrically isolate the respective filters 330A to 330N from the common node COM in a given state. The functionality of switches 337A to 337N may support various carrier aggregations.

Fig. 27E is a schematic diagram of a multiplexer 338 that includes acoustic wave filters, according to an embodiment. Multiplexer 338 illustrates that the multiplexer may include any suitable combination of hard and switched multiplexing filters. One or more BAW resonators having a multi-gradient convex frame structure may be included in a filter that is hard multiplexed to a common node of a multiplexer. Alternatively or additionally one or more BAW resonators with a multi-gradient raised frame structure may be included in a filter multiplexed by a switch to a common node of a multiplexer.

The BAW resonators disclosed herein may be implemented in various packaged modules. Some example package modules will now be discussed in which any suitable principles and advantages of the BAW devices disclosed herein may be implemented. An example package module includes one or more acoustic wave filters, and one or more radio frequency amplifiers (e.g., one or more power amplifiers and/or one or more low noise amplifiers), and/or one or more radio frequency switches. An example package module may include a package that encloses the illustrated circuit elements. The illustrated circuit elements may be disposed on a common package substrate. The package substrate may be, for example, a laminate substrate. Fig. 28-32 are schematic block diagrams of illustrative packaging modules according to some embodiments. Any suitable combination of the features of these packaged modules may be implemented with each other. Although duplexers are illustrated in the example package modules of fig. 29-32, any other suitable multiplexer including multiple filters coupled to a common node may be implemented in place of one or more duplexers. For example, a quadplexer may be implemented in certain applications. Alternatively or additionally, one or more filters of the encapsulation module may be arranged as a transmit filter or a receive filter, which are not comprised in the multiplexer.

Fig. 28 is a schematic diagram of a radio frequency module 340 including an acoustic member 342, according to an embodiment. The illustrated radio frequency module 340 includes an acoustic component 342 and other circuitry 343. The acoustic wave component 342 may include one or more BAW resonators having a multi-gradient convex frame structure in accordance with any suitable combination of features disclosed herein. The acoustic wave component 342 may include a BAW chip (die) that includes a BAW resonator.

The acoustic wave component 342 shown in fig. 28 includes a filter 344 and terminals 345A and 345B. The filter 344 includes one or more BAW resonators implemented in accordance with any suitable principles and advantages disclosed herein. Terminals 345A and 344B may serve as input and output contacts, for example. In fig. 28, acoustic wave element 342 and other circuitry 343 are on a common package substrate 346. The package substrate 346 may be a laminate substrate. Terminals 345A and 345B may be electrically connected to contacts 347A and 347B on package substrate 346 by electrical connectors 348A and 348B, respectively. The electrical connectors 348A and 348B may be, for example, bumps (bumps) or wire bonds (wire bonds).

Other circuitry 343 may include any suitable additional circuitry. For example, the other circuitry may include one or more radio frequency amplifiers (e.g., one or more power amplifiers, and/or one or more low noise amplifiers), one or more power amplifiers, one or more radio frequency switches, one or more additional filters, one or more low noise amplifiers, one or more RF couplers, one or more delay lines, one or more phase shifters, the like, or any suitable combination thereof. Other circuitry 343 may be electrically connected to the filter 344. Rf module 340 may include one or more packaging structures, for example, to provide protection and/or facilitate easier handling (handling) of rf module 340. Such a package structure may include a clad structure formed on the package substrate 340. The encasing structure may encapsulate some or all of the components of the rf module 340.

Fig. 29 is a schematic block diagram of a module 350 that includes duplexers 351A to 351N and an antenna switch 352. One or more filters in the duplexers 351A-351N may include one or more BAW resonators having a multi-gradient convex frame structure in accordance with any suitable principles and advantages discussed herein. Any suitable number of duplexers 351A to 351N may be implemented. The antenna switch 352 may have a throw number corresponding to the number of duplexers 351A to 351N. The antenna switch 352 may include one or more additional throws coupled to one or more filters external to the module 350 and/or coupled to other circuitry. An antenna switch 352 may electrically couple the selected duplexer to an antenna port of the module 350.

Fig. 30 is a schematic block diagram of a module 354, the module 354 including a power amplifier 355, a radio frequency switch 356, and multiplexers 351A-351N in accordance with one or more embodiments. The power amplifier 355 may amplify a radio frequency signal. The rf switch 356 may be a multi-throw rf switch. The radio frequency switch 356 may electrically couple the output of the power amplifier 355 to the selected transmit filter of the multiplexers 351A-351N. One or more of the filters in multiplexers 351A-351N may include any suitable number of BAW resonators having a multi-gradient convex frame structure in accordance with any suitable principles and advantages discussed herein. Any suitable number of multiplexers 351A-351N may be implemented.

Figure 31 is a schematic block diagram of a module 357 comprising multiplexers 351A ' through 351N ', a radio frequency switch 358 ', and a low noise amplifier 359, according to an embodiment. One or more filters of multiplexers 351A 'through 351N' may include any suitable number of BAW resonators having a multi-gradient convex frame structure in accordance with any suitable principles and advantages disclosed herein. Any suitable number of multiplexers 351A 'through 351N' may be implemented. The radio frequency switch 358 may be a multi-throw radio frequency switch. The radio frequency switch 358 may electrically couple the output of the selected filter of the multiplexers 351A 'through 351N' to the low noise amplifier 359. In some embodiments (not shown), multiple low noise amplifiers may be implemented. In some applications, module 357 may include diversity reception features.

Fig. 32 is a schematic diagram of a radio frequency module 380 including an acoustic wave filter according to an embodiment. As shown, the radio frequency module 380 includes duplexers 382A to 382N including respective transmit filters 383a1 to 383N1 and respective receive filters 383a2 to 383N2, a power amplifier 384, a select switch 385, and an antenna switch 386. The rf module 380 may include an enclosure that encloses the illustrated components. The illustrated components may be disposed on a common package substrate 387. For example, the package substrate 387 may be a laminate substrate. A radio frequency module including a power amplifier may be referred to as a power amplifier module. The radio frequency module may include a subset of the elements illustrated in fig. 32 and/or additional elements. The rf module 380 may include one or more BAW resonators having a multi-gradient convex frame structure in accordance with any suitable principles and advantages disclosed herein.

Each of the duplexers 382A to 382N may include two acoustic wave filters coupled to a common node. For example, the two acoustic wave filters may be a transmit filter and a receive filter. As shown, the transmit filter and the receive filter may each be a band pass filter arranged to filter the radio frequency signal. The one or more transmit filters 383a 1-383N 1 may include one or more BAW resonators having a multi-gradient convex frame structure in accordance with any suitable principles and advantages disclosed herein. Similarly, the one or more receive filters 383a 2-383N 2 may include one or more BAW resonators having a multi-gradient convex frame structure in accordance with any suitable principles and advantages disclosed herein. Although fig. 32 illustrates a duplexer, any suitable principles and advantages disclosed herein may be implemented in other multiplexers (e.g., quadplexers, hexagons, octagons, etc.) and/or switch-mode multiplexers.

The power amplifier 384 may amplify the radio frequency signal. The illustrated switch 385 is a multi-throw radio frequency switch. The switch 385 may electrically couple the output of the power amplifier 384 to a selected one of the transmit filters 383a1 through 383N 1. In some cases, switch 385 may electrically connect the output of power amplifier 384 to more than one of transmit filters 383a1 through 383N 1. The antenna switch 386 may selectively couple signals from one or more of the duplexers 382A through 382N to the antenna port ANT. The duplexers 382A-382N may be associated with different frequency bands and/or different operating modes (e.g., different power modes, different signaling modes, etc.).

BAW devices having multi-gradient raised frame structures as disclosed herein may be implemented in various wireless communication devices, such as mobile devices. One or more filters having any suitable number of BAW devices implemented in accordance with any suitable principles and advantages disclosed herein may be included in various wireless communication devices, such as mobile phones. The BAW device may be included in a filter in a radio frequency front end. FIG. 33 is a schematic diagram of an embodiment of a mobile device 390. The mobile device 390 includes a baseband system 391, a transceiver 392, a front-end system 393, an antenna 394, a power management system 395, a memory 396, a user interface 397, and a battery 398.

The mobile device 390 may communicate using various communication technologies including, but not limited to, second generation (2G), third generation (3G), fourth generation (4G) including LTE, LTE Advanced, and LTE Advanced Pro, fifth generation (5G) New Radio (NR), Wireless Local Area Network (WLAN) (e.g., WiFi), Wireless Personal Area Network (WPAN) (e.g., bluetooth and ZigBee), WMAN (wireless personal area network) (e.g., WiMax), Global Positioning System (GPS) technologies, or any suitable combination thereof.

Transceiver 39 generates RF signals for transmission and processes incoming RF signals received from antenna 394. It should be appreciated that various functions associated with the transmission and reception of RF signals may be performed by one or more components, shown generally in fig. 33 as transceiver 392. In an example, different components (e.g., different circuits or chips) may be provided for processing a particular type of RF signal.

Front-end system 393 facilitates conditioning signals transmitted to and/or received from antenna 394. In the illustrated embodiment, the front-end system 393 includes an antenna tuning circuit 400, a Power Amplifier (PA) 401, a Low Noise Amplifier (LNA) 402, a filter 403, a switch 404, and a signal splitting/combining circuit 405. However, other implementations are possible. One or more of the filters 403 may be implemented in accordance with any suitable principles and advantages disclosed herein. For example, one or more of the filters 403 may include at least one BAW resonator having a multi-gradient convex frame structure in accordance with any suitable principles and advantages disclosed herein.

For example, head-end system 393 may provide functions including, but not limited to, amplifying a signal for transmission, amplifying a received signal, filtering a signal, switching between different frequency bands, switching between different power modes, switching between transmit and receive modes, duplexing of signals, multiplexing of signals (e.g., diplexing or triplexing), or any suitable combination thereof.

In certain embodiments, the mobile device 390 supports carrier aggregation, thereby providing flexibility to increase peak data rates. Carrier aggregation may be used for Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD), and may be used to aggregate multiple carriers or channels. Carrier aggregation includes contiguous aggregation in which contiguous carriers having the same operating frequency band are aggregated. Carrier aggregation may also be non-contiguous and may include carriers separated in frequency in a common frequency band or different frequency bands.

The antenna 394 may include an antenna for various types of communication. For example, the antenna 394 can include an antenna for transmitting and/or receiving signals associated with a wide variety of frequencies and communication standards.

In certain embodiments, the antenna 394 supports MIMO communications and/or switched diversity communications. For example, MIMO communication uses multiple antennas to communicate multiple data streams via a single radio frequency channel. MIMO communications benefit from higher signal-to-noise ratios, improved coding, and/or reduced signal interference due to spatial multiplexing differences in the radio environment. Switched diversity refers to communication in which a particular antenna is selected to operate at a particular time. For example, a switch may be used to select a particular antenna from a group of antennas based on various factors, such as an observed bit error rate and/or a signal strength indicator.

The mobile device 390 may operate with beamforming in some embodiments. For example, front-end system 393 may include an amplifier with controllable gain and a phase shifter with controllable phase. In addition, the phase shifters are controlled to provide beamforming as well as diversity for transmission and/or reception of signals using antenna 394. For example, in the case of signal transmission, the amplitude and phase of the transmit signal provided to the antenna 394 are controlled such that the radiated signals from the antenna 394 are combined using constructive and destructive interference to generate an aggregate transmit signal that exhibits beamlike quality with more signal strength propagation in a given direction. In the case of signal reception, the amplitude and phase are controlled so that more signal energy is received when the signal reaches the antenna 394 from a particular direction. In some embodiments, antenna 394 includes an array of one or more antenna elements to enhance beamforming.

The baseband system 391 is coupled to a user interface 397 to facilitate handling of various user inputs and outputs (I/O), such as voice and data. Baseband system 391 provides transceiver 392 with a digital representation of the transmitted signal, which transceiver 392 processes to generate an RF signal for transmission. Baseband system 391 also processes the digital representation of the received signal provided by transceiver 392. As shown in fig. 33, the baseband system 391 is coupled to the memory 396 to facilitate operation of the mobile device 390.

Memory 396 may be used for a variety of purposes such as, for example, storing data and/or instructions to facilitate operation of mobile device 390 and/or providing storage of user information.

The power management system 395 provides many of the power management functions of the mobile device 390. In certain embodiments, the power system 395 includes a PA power supply control circuit that controls the supply voltage of the power amplifier 401. For example, the power management system 395 may be configured to vary a supply voltage provided to one or more of the power amplifiers 401 to improve efficiency, such as Power Added Efficiency (PAE).

As shown in fig. 33, the power management system 395 receives battery voltage from the battery 398. The battery 398 may be any suitable battery for use in the mobile device 390, including, for example, a lithium ion battery.

The techniques disclosed herein may be implemented in acoustic wave filters in 5G applications. The 5G technology is also referred to herein as 5G New Radio (NR). The 5G NR supports and/or plans to support various features such as communications over the millimeter wave spectrum, beamforming capability, high spectral efficiency waveforms, low latency communications, multi-radio digital and/or non-orthogonal multiple access (NOMA). While such radio frequency functionality provides flexibility to the network and increases user data rates, supporting these functions presents several technical challenges.

The teachings herein are applicable to a variety of communication systems, including but not limited to communication systems using Advanced cellular technology, such as LTE-Advanced, LTE-Advanced Pro, and/or 5G NR. An acoustic wave device comprising any suitable combination of the features disclosed herein is included in a filter arranged to filter radio frequency signals of the 5G NR operating band within frequency range 1(FR 1). The filter arranged to filter radio frequency signals in the 5G NR operating band may comprise one or more BAW devices as disclosed herein. FR1 may be from 410MHz to 7.125GHz, for example, as specified in the current 5G NR specification. One or more BAW devices according to any suitable principles and advantages disclosed herein may be included in a filter arranged to filter radio frequency signals in fourth generation (4G) Long Term Evolution (LTE). One or more BAW devices according to any suitable principles and advantages disclosed herein may be included in a filter having a pass band that includes a 4G LTE operating band and a 5G NR operating band. Such a filter may be implemented in Dual Connectivity applications, such as E-UTRAN New air-Dual Connectivity (endec) applications.

BAW devices disclosed herein can provide high Q values and/or high Q stability in the presence of manufacturing variations. This feature may be advantageous in 5G NR applications. For example, the Q stability of BAW devices may be important in meeting 5G performance specifications at the filter stage and/or system level.

Fig. 34 is a schematic diagram of one example of a communication network 410. The communication network 410 includes various examples of macro cellular base stations 411, small cellular base stations 413, and User Equipment (UE), including a first mobile device 412a, a wirelessly connected car 412b, a laptop computer 412c, a stationary wireless device 412d, a wirelessly connected train 412e, a second mobile device 412f, and a third mobile device 412 g. The UE is a wireless communication device. One or more of the macrocell base station 411, the small cell base station 413, or the UE illustrated in fig. 34 may implement one or more acoustic wave filters according to any suitable principles and advantages disclosed herein. For example, one or more of the UEs shown in fig. 34 may include one or more acoustic wave filters including any suitable number of BAW resonators having a multi-gradient convex frame structure.

Although specific examples of base stations and user equipment are illustrated in fig. 34, the communication network may include a wide variety of types and/or numbers of base stations and user equipment. For example, in the example shown, the communication network 410 includes a macro cell base station 411 and a small cell base station 413. The small cell base station 413 may operate at a relatively lower power, shorter range, and/or fewer concurrent users than the macro cell base station 411. The small cell base station 413 may also be referred to as a femtocell (femtocell), a picocell (picocell), or a microcell (microcell). Although communication network 410 is illustrated as including two base stations, communication network 410 may be implemented to include more or fewer base stations and/or other types of base stations.

Although various examples of user devices are shown, the teachings herein are applicable to a wide variety of user devices, including but not limited to mobile phones, tablets, laptops, Internet of things (IoT) devices, wearable electronic devices, Customer Premises Equipment (CPE), wirelessly connected vehicles, wireless relays, and/or a wide variety of other communication devices. Further, the user equipment includes not only currently available communication devices operating in a cellular network, but also subsequently developed communication devices that will be readily implemented with the inventive systems, processes, methods and apparatus described and claimed herein.

The illustrated communication network 410 of fig. 34 supports communication using a variety of cellular technologies, including, for example, 4G LTE and 5G NR. In some embodiments, the communication network 410 is further adapted to provide a Wireless Local Area Network (WLAN), such as WiFi. Although examples of various communication technologies have been provided, the communication network 410 may be adapted to support a variety of communication technologies.

Various communication links of the communication network 410 have been depicted in fig. 34. The communication links may be duplexed in a variety of ways including, for example, using frequency-division duplexing (FDD) and/or time-division duplexing (TDD). FDD is a type of radio frequency communication that uses different frequencies for transmitting and receiving signals. FDD may provide many advantages, such as high data rates and low latency. In contrast, TDD is a type of radio frequency communication that uses approximately the same frequency to transmit and receive signals, and where the transmit and receive communications are switched in time. TDD can provide many advantages, such as efficient use of spectrum and variable allocation of throughput between transmit and receive directions.

In some embodiments, the user equipment may communicate with the base station using one or more of 4G LTE, 5G NR, and WiFi technologies. In some embodiments, enhanced licensed assisted access (eLAA) is used to aggregate one or more licensed frequency carriers (e.g., licensed 4G LTE and/or 5G NR frequencies) with one or more unlicensed carriers (e.g., unlicensed WiFi frequencies).

As shown in fig. 34, the communication link includes not only a communication link between the UE and the base station, but also UE-to-UE communication and base station-to-base station communication. For example, the communication network 410 may be implemented to support self-fronthaul (self-fronthaul) and/or self-backhaul (self-backhaul) (e.g., between the mobile device 412g and the mobile device 412 f).

The communication link may operate on a variety of frequencies. In certain embodiments, communications are supported using 5G NR techniques over one or more frequency bands less than 6 gigahertz (GHz) and/or over one or more frequency bands greater than 6 GHz. According to certain embodiments, the communication link may serve frequency range 1(FR1), frequency range 2(FR2), or a combination thereof. An acoustic wave filter according to any suitable principles and advantages disclosed herein may filter radio frequency signals within FR 1. In an embodiment, one or more of the mobile devices support HPUE power class specifications.

In some embodiments, the base station and/or the user equipment communicate using beamforming. For example, beamforming may be used to focus signal strength to overcome path loss, such as high loss associated with communication at high signal frequencies. In some embodiments, user equipment, such as one or more mobile phones, communicate using beamforming at millimeter wave frequency bands in the range of 30GHz to 300GHz and/or centimeter wave frequencies in the range of 6GHz to 30GHz, or more specifically 24GHz to 30 GHz.

Different users of the communication network 410 may share available network resources, such as available spectrum, in a variety of ways. In one example, Frequency Division Multiple Access (FDMA) is used to divide a frequency band into multiple frequency carriers. Further, one or more carriers are allocated to a particular user. Examples of FDMA include, but are not limited to, single-carrier FDMA (SC-FDMA) and orthogonal FDMA (orthogonal FDMA). OFDMA is a multi-carrier technique that subdivides the available bandwidth into multiple mutually orthogonal narrowband subcarriers, which may be allocated to different users, respectively.

Other examples of shared access include, but are not limited to: time Division Multiple Access (TDMA), in which users are allocated to use a specific time slot of a frequency resource; code Division Multiple Access (CDMA), in which frequency resources are shared among different users by assigning a unique code to each user; space-division multiple access (SDMA), in which beamforming is used to provide shared access through spatial division; and non-orthogonal multiple access (NOMA), in which the power domain is used for multiple access. For example, NOMA may be used to serve multiple users at the same frequency, time, and/or code, but at different power levels.

Enhanced mobile broadband (eMBB) refers to a technology for increasing system capacity of an LTE network. For example, the eMBB may refer to communications with peak data rates of at least 10Gbps and a minimum of 100Mbps per user. Ultra-reliable low latency communication (urlllc) refers to a communication technology with very low latency, e.g., less than 3 milliseconds. urrllc may be used for mission critical communications such as autopilot and/or telesurgical applications. Massive machine-type communication (mtc) refers to low-cost and low data rate communication associated with wireless connection of everyday objects, such as communication associated with internet of things (IoT) applications.

The communication network 410 of fig. 34 may be used to support a wide variety of advanced communication features including, but not limited to, eMBB, urrllc, and/or mtc.

Any of the embodiments described above may be implemented with a mobile device such as a cellular handset. The principles and advantages of various embodiments may be applied to any system or device, such as any uplink wireless communication device, that may benefit from any of the embodiments described herein. The teachings herein are applicable to a variety of systems. While this disclosure includes some example embodiments, the teachings herein are applicable to a variety of configurations. Any of the principles and advantages discussed herein may be implemented with RF circuitry configured to process signals having frequencies ranging from about 30kHz to 300GHz (such as frequencies ranging from about 450MHz to 5GHz, frequencies ranging from about 450MHz to 8.5GHz, or frequencies ranging from about 450MHz to 10 GHz).

Aspects of the present application may be implemented in various electronic devices. Examples of electronic devices may include, but are not limited to, consumer electronics, components of consumer electronics such as packaged RF modules, upstream wireless communication devices, wireless communication infrastructure, electronic test equipment, and the like. Examples of electronic devices may include, but are not limited to, mobile phones such as smart phones, wearable computing devices such as smart watches or earpieces, telephones, televisions, computer displays, computers, modems, handheld computers, notebook computers, tablet computers, microwave ovens, refrigerators, vehicular electronic systems such as automotive electronic systems, stereos, digital music players, radios, cameras such as digital cameras, portable memory chips, washing machines, dryers, washing/drying machines, copiers, facsimile machines, scanners, multifunction peripherals, watches, clocks, and so forth. Further, these electronic devices may include unfinished products.

Throughout the specification and claims, unless the context requires otherwise, the words "comprise," "comprising," "include," "including," and the like are to be construed in an inclusive sense as opposed to an exclusive or exclusive sense; that is, in the sense of "including, but not limited to". Unless stated otherwise or used as understood within the context, conditional language such as, where "may", "might", "may", "right", "may", "example", "such" and similar language, as used herein, is generally intended to convey that certain embodiments include but other embodiments do not include certain features, elements and/or states. As generally used herein, the word "coupled" means that two or more elements may be connected directly or through one or more intermediate elements. Similarly, the word "connected," as generally used herein, means that two or more elements may be connected directly or through one or more intermediate elements. Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words of the above detailed description in the singular or plural number may also include the singular or plural number respectively.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the application. Indeed, the novel resonators described herein may also be implemented in a variety of other applications. Furthermore, various omissions, substitutions and changes in the form of the resonators described herein may be made without departing from the spirit of the application. Any suitable combination of the elements and/or acts of the various embodiments described above can be combined to provide further embodiments. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims (40)

1. A bulk acoustic wave device having a multi-gradient convex frame, the bulk acoustic wave device comprising:

a first electrode;

a second electrode;

a piezoelectric layer positioned between the first electrode and the second electrode; and

a multi-gradient raised frame structure configured to reduce lateral energy leakage from a primary acoustically active region of the bulk acoustic wave device, the multi-gradient raised frame structure being tapered on opposite sides and the bulk acoustic wave device being configured to generate a bulk acoustic wave.

2. The bulk acoustic wave device of claim 1, wherein the multi-gradient convex frame structure surrounds a primary acoustically active region of the bulk acoustic wave device in plan view.

3. The bulk acoustic wave device of claim 1, wherein the multi-gradient raised frame structure has one non-gradient portion between two gradient portions.

4. The bulk acoustic wave device of claim 1, wherein the multi-gradient raised frame structure consists essentially of gradient portions.

5. The bulk acoustic wave device of claim 1, wherein the bulk acoustic wave device is a thin film bulk acoustic resonator.

6. The bulk acoustic wave device of claim 1, wherein the multi-gradient raised frame structure comprises a plurality of raised frame layers.

7. The bulk acoustic wave device of claim 6 wherein the plurality of raised frame layers includes a first raised frame layer and a second raised frame layer, the second raised frame layer extending beyond the first raised frame layer on an opposite side.

8. The bulk acoustic wave device of claim 7 wherein the first raised frame layer has a lower acoustic impedance than at least one of the piezoelectric layer or the second raised frame layer.

9. The bulk acoustic wave device of claim 7, wherein the first raised frame layer is an oxide layer and the second raised frame layer is metal.

10. The bulk acoustic wave device of claim 7, wherein the first raised frame layer is a silicon dioxide layer and the second raised frame layer is metal containing.

11. The bulk acoustic wave device of claim 7, wherein the first raised frame layer is positioned between the first and second electrodes.

12. The bulk acoustic wave device of claim 11, wherein the second electrode is positioned between the first and second raised frame layers.

13. The bulk acoustic wave device of claim 7, wherein the second raised frame layer has a first taper angle on a first side and a second taper angle on a second side, and the first and second taper angles are in a range of 5 degrees to 45 degrees.

14. The bulk acoustic wave device of claim 1, wherein the multi-gradient raised frame structure is a raised structure relative to the piezoelectric layer.

15. An acoustic wave filter having a multi-gradient raised-frame acoustic wave device, the acoustic wave filter comprising:

a bulk acoustic wave device comprising a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient convex frame structure configured to reduce lateral energy leakage from a primary acoustic active region of the bulk acoustic wave device, the multi-gradient convex frame structure being tapered on opposing sides; and

at least one additional acoustic wave device, the bulk acoustic wave device and the at least one additional acoustic wave device together arranged to filter a radio frequency signal.

16. The acoustic wave filter according to claim 15 wherein said at least one additional acoustic wave device comprises a second bulk acoustic wave device comprising a second multi-gradient bump frame structure, said second multi-gradient bump frame structure being tapered on opposite sides.

17. The acoustic wave filter according to claim 15 wherein the multi-gradient raised frame structure comprises a first raised frame layer comprising an oxide and a second raised frame layer comprising a metal, the second raised frame layer extending beyond the first raised frame layer on opposite sides.

18. A wireless communication device, comprising:

an acoustic wave filter comprising a bulk acoustic wave device comprising a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient convex frame structure configured to reduce lateral energy leakage from a primary acoustic active region of the bulk acoustic wave device, the multi-gradient convex frame structure being tapered on opposing sides; and

an antenna operatively coupled to the acoustic wave filter.

19. The wireless communication device of claim 18, wherein the wireless communication device is a mobile phone.

20. The wireless communication device of claim 18, wherein the acoustic wave filter is included in a multiplexer.

21. A bulk acoustic wave device having a multi-gradient convex frame, the bulk acoustic wave device comprising:

a first electrode;

a second electrode;

a piezoelectric layer positioned between the first electrode and the second electrode; and

a multi-gradient raised frame structure comprising a first raised frame layer and a second raised frame layer extending beyond the first raised frame layer, the second raised frame layer being tapered on opposite sides, the bulk acoustic wave device being configured to generate bulk acoustic waves.

22. The bulk acoustic wave device of claim 21, wherein the second raised frame layer extends beyond the first raised frame layer on opposing sides, the opposing sides including a first side toward a primary acoustically active region of the bulk acoustic wave device and a second side away from the primary acoustically active region.

23. The bulk acoustic wave device of claim 21 wherein the first raised frame layer has a lower acoustic impedance than the piezoelectric layer.

24. The bulk acoustic wave device of claim 21, wherein the first raised frame layer comprises an oxide and the second raised frame layer comprises a metal.

25. The bulk acoustic wave device of claim 24, wherein the second raised frame layer comprises one or more of ruthenium, molybdenum, tungsten, platinum, or iridium.

26. The bulk acoustic wave device of claim 21, wherein the first raised frame layer comprises a metal.

27. The bulk acoustic wave device of claim 21, wherein the first raised frame layer comprises a polymer.

28. The bulk acoustic wave device of claim 21, wherein the multi-gradient raised frame structure has one non-gradient portion between two gradient portions.

29. The bulk acoustic wave device of claim 21, wherein the first raised frame layer is positioned between the first electrode and the second electrode.

30. The bulk acoustic wave device of claim 21, wherein the second electrode is positioned between the second raised frame layer and the first raised frame layer.

31. The bulk acoustic wave device of claim 30 wherein the first raised frame layer is positioned between the piezoelectric layer and the second electrode.

32. The bulk acoustic wave device of claim 21 wherein the second raised frame layer has a first taper angle on a first side and a second taper angle on a second side, and the first and second taper angles are each greater than 5 degrees and less than 45 degrees.

33. The bulk acoustic wave device of claim 21 wherein the second raised frame layer is a raised structure relative to a surface of the piezoelectric layer.

34. The bulk acoustic wave device of claim 21, wherein the multi-gradient raised frame structure surrounds a primary acoustically active region of the bulk acoustic wave device in plan view.

35. The bulk acoustic wave device of claim 21, wherein the bulk acoustic wave device is a thin film bulk acoustic resonator.

36. An acoustic wave filter comprising:

a bulk acoustic wave device comprising a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure comprising a first raised frame layer and a second raised frame layer, the second raised frame layer extending beyond the first raised frame layer, the second raised frame layer being tapered on opposing sides; and

at least one additional acoustic wave device, the bulk acoustic wave device and the at least one additional acoustic wave device together arranged to filter a radio frequency signal.

37. The acoustic wave filter according to claim 36 wherein said at least one additional acoustic wave device comprises a second bulk acoustic wave device comprising a second multi-gradient bump frame structure, said second multi-gradient bump frame structure being tapered on opposite sides.

38. A packaged radio frequency module, comprising:

an acoustic wave filter comprising a bulk acoustic wave device including a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure including a first raised frame layer and a second raised frame layer, the second raised frame layer extending beyond the first raised frame layer, the second raised frame layer being tapered on opposing sides, the acoustic wave filter configured to filter a radio frequency signal;

a radio frequency circuit element; and

a package structure encapsulating the acoustic wave filter and the radio frequency circuit element.

39. The packaged rf module of claim 38, wherein the rf circuit element is an rf switch.

40. The packaged rf module of claim 38, wherein the rf circuit element is an rf amplifier.