Acoustic wave resonator, acoustic wave filter, electronic device module, electronic device, method for forming an acoustic wave resonator, and piezoelectric material

Abstract

To provide piezoelectric materials that may be utilized as substrates in acoustic wave devices, and acoustic wave filters including acoustic wave devices (FBARs), to enhance performance of an acoustic wave resonator.SOLUTION: An FBAR 100 is an acoustic wave resonator comprising a piezoelectric material 115, where the piezoelectric material is formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr) and sodium (Na) to enhance performance of the acoustic wave resonator. The acoustic wave resonator is used in an acoustic wave filter, an electronics module including the acoustic wave filter, and an electronic device including the electronics module.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under Section 119(e) of U.S. Provisional Patent Application No. 62 / 983,152, entitled "Aluminum Nitride Dopant Scheme for Bulk Acoustic Wave Filters," filed February 28, 2020, which is incorporated by reference in its entirety for all purposes.

[0002] Embodiments of the present disclosure relate to piezoelectric materials that can be utilized as substrates in acoustic wave devices, and to acoustic wave filters that include such acoustic wave devices. [Background technology]

[0003] Acoustic wave filters can filter radio frequency signals. Acoustic wave filters can include multiple resonators arranged to filter radio frequency signals. The resonators can be arranged as a ladder circuit. Examples of acoustic wave filters include surface acoustic wave (SAW) filters, bulk acoustic wave (BAW) filters, and Lamb wave resonator filters. A thin film bulk acoustic wave resonator (FBAR) filter is an example of a BAW filter. A solid mounted resonator (SMR) filter is another example of a BAW filter.

[0004] Acoustic wave filters can be implemented in radio frequency electronic systems. For example, the filter in the radio frequency front end of a mobile phone can include an acoustic wave filter. Two acoustic wave filters can be arranged as a duplexer. Summary of the Invention

[0005] According to one aspect, an elastic wave resonator including a piezoelectric material is provided. This piezoelectric material is formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), magnesium (Mg), zinc (Zn), calcium (Ca), strontium (Sr), lithium (Li), and sodium (Na) to enhance the performance of the elastic wave resonator.

[0006] In some embodiments, the one or more of Be, Mg, Zn, Ca, Sr, Li, and Na are charge-balanced with at least one of Si and Ge, and the material is Al 1-2x Ca x Si x N(0<x<1), Al 1-2x Ca x Ge x N(0<x<1), Al 1-2x Sr x Si x N(0<x<1), Al 1-2x Sr x Ge x N(0<x<1), Al 1-2x Be x Si x N(0<x<1), Al 1-2x Be x Ge x N(0<x<1), Al 1-2x Mg x Si x N(0<x<1), Al 1-2x Mg x Ge x N(0<x<1), Al 1-2x Zn x Si x N(0<x<1), Al 1-2x Zn x Ge x N(0<x<1), Al 1-3x Li x Si 2x N(0<x<1), Al 1-3x Li x Ge 2x N(0<x<1), Al 1-3x Na x Si 2x N(0<x<1), or Al 1-3x Nax Ge 2x It has a chemical formula from one of N(0 < x < 1).

[0007] In some embodiments, at least one of Si and Ge occupies an Al site within the crystal structure of doped AlN.

[0008] In some embodiments, AlN is doped with a compound exhibiting a wurtzite or distorted wurtzite crystal structure.

[0009] In some embodiments, AlN is doped with CaAlSiN3.

[0010] In some embodiments, the doped AlN is Al 1-2x Ca x Si x It has a chemical formula of N.

[0011] According to another aspect, an elastic wave filter including an elastic wave resonator is provided. This elastic wave resonator includes a piezoelectric material formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), magnesium (Mg), zinc (Zn), calcium (Ca), strontium (Sr), lithium (Li), and sodium (Na) to enhance the performance of the elastic wave resonator.

[0012] In some embodiments, the elastic wave filter includes a bulk acoustic wave (BAW) resonator including doped AlN.

[0013] In some embodiments, the BAW resonator is one of a thin film bulk acoustic wave resonator, a lamb wave resonator, or a surface mount resonator.

[0014] In some embodiments, the elastic wave filter includes a radio frequency filter.

[0015] In some embodiments, an electronic device module includes the elastic wave filter.

[0016] In some embodiments, the electronic device includes an electronics module.

[0017] According to another aspect, an acoustic wave resonator is provided that includes a piezoelectric material formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na) to enhance the performance of the acoustic wave resonator.

[0018] In some embodiments, the acoustic wave resonator is included in an acoustic wave filter.

[0019] In some embodiments, the acoustic wave filter includes a bulk acoustic wave (BAW) resonator comprising doped AlN.

[0020] In some embodiments, the BAW resonator is one of a thin film bulk acoustic wave resonator, a Lamb wave resonator, or a surface mount resonator.

[0021] In some embodiments, the acoustic wave filter comprises a radio frequency filter.

[0022] In some embodiments, the acoustic wave filter is included in an electronics module.

[0023] In some embodiments, the electronics module is included in an electronic device.

[0024] In some embodiments, one or more of Be, Sr, and Na are charge balanced with at least one of Si and Ge, and the substrate material is Al 1-2x Sr x Si x N(0 <x<1)、Al 1-2x Sr x Ge x N(0 <x<1)、Al 1-2x Be x Si x N(0 <x<1)、Al 1-2x Be x Ge xN(0 < x < 1), Al 1-3x Na x Si 2x N(0 < x < 1) or Al 1-3x Na x Ge 2x It has a chemical formula from one of N(0 < x < 1).

[0025] In some embodiments, the piezoelectric material has a wurtzite crystal structure.

[0026] According to another aspect, a method of forming an elastic wave resonator is provided. This method includes depositing electrodes on a piezoelectric film formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na).

[0027] In some embodiments, depositing electrodes on the piezoelectric film includes depositing a first electrode on the top surface of the piezoelectric film and depositing a second electrode on the bottom surface of the piezoelectric film.

[0028] In some embodiments, the elastic wave resonator is a thin film bulk acoustic wave resonator, and the method further includes defining a cavity under the lower surface of the piezoelectric film.

[0029] In some embodiments, the elastic wave resonator is a lamb wave resonator, and depositing a first electrode on the top surface of the piezoelectric film includes depositing interdigitated transducer electrodes on the top surface of the piezoelectric film.

[0030] In some embodiments, the elastic wave resonator is a solidly mounted resonator, and the method further includes forming a piezoelectric film on the top surface of a Bragg reflector.

[0031] According to another aspect, a piezoelectric material including aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na) is provided.

[0032] In some embodiments, one or more of Be, Sr, and Na are charge balanced with at least one of Si and Ge, and the piezoelectric material is Al 1-2x Sr x Si x N (0 < x < 1), Al 1-2x Sr x Ge x N (0 < x < 1), Al 1-2x Be x Si x N (0 < x < 1), Al 1-2x Be x Ge x N (0 < x < 1), Al 1-3x Na x Si 2x N (0 < x < 1) or Al 1-3x Na x Ge 2x has a chemical formula from one of N (0 < x < 1).

[0033] In some embodiments, the piezoelectric material has a wurtzite crystal structure.

Brief Description of the Drawings

[0034] Multiple embodiments of the present disclosure are described below through non-limiting examples referring to the accompanying drawings.

[0035] [Figure 1] It is a cross-sectional view of an example of a thin film bulk acoustic wave resonator. [Figure 2] It is a cross-sectional view of an example of a Lamb wave resonator. [Figure 3] It is a cross-sectional view of an example of a surface mount resonator. [Figure 4] It is a table of selected compounds that can be used to dope aluminum nitride to form a piezoelectric material for use in a bulk acoustic wave resonator. [Figure 5A]1 is a table of compounds that may be used as piezoelectric materials in bulk acoustic wave resonators or that may be utilized to dope aluminum nitride to form piezoelectric materials for use in bulk acoustic wave resonators. [Figure 5B] 1 is a table of compounds that may be used as piezoelectric materials in bulk acoustic wave resonators or that may be utilized to dope aluminum nitride to form piezoelectric materials for use in bulk acoustic wave resonators. [Figure 6A] 1 illustrates the crystal structure of a material that can be used as a piezoelectric material in a bulk acoustic wave resonator. [Figure 6B] 1 illustrates the crystal structure of a material that can be used as a piezoelectric material in a bulk acoustic wave resonator. [Figure 6C] 1 illustrates the crystal structure of a material that can be used as a piezoelectric material in a bulk acoustic wave resonator. [Figure 6D] 1 illustrates the crystal structure of a material that can be used as a piezoelectric material in a bulk acoustic wave resonator. [Figure 7] 1 shows an example of a radio frequency filter. [Figure 8] 1 illustrates one embodiment of an electronics module. [Figure 9] 1 illustrates an example of a front-end module that may be used in an electronic device. [Figure 10] 1 shows an example of an electronic device. [Figure 11] Simulation results for the Young's modulus of Ca- and Si-doped Al are shown in comparison with the Young's modulus of AlN and the Young's modulus of Sc-doped AlN. DETAILED DESCRIPTION OF THE INVENTION

[0036] The following description of certain embodiments represents various descriptions of particular embodiments. However, the innovations described herein may be embodied in many different forms, as defined and covered, for example, by the claims. In this description, reference is made to the drawings, in which like reference numbers may indicate identical or functionally similar elements. It is understood that the elements depicted in the drawings are not necessarily drawn to scale. It is further understood that a given embodiment may include more elements than shown in the drawings and / or may include a subset of the elements depicted in the drawings. Furthermore, some embodiments may incorporate any suitable combination of features from two or more drawings.

[0037] A thin-film bulk acoustic wave resonator (FBAR) is a form of bulk acoustic wave resonator that generally includes a membrane of piezoelectric material sandwiched between top and bottom electrodes, which is suspended over a cavity and allowed to vibrate. A signal applied between the top and bottom electrodes generates acoustic waves that travel through the membrane. FBARs exhibit a frequency response to the applied signal, with a resonant peak determined by the thickness of the membrane. Ideally, the only acoustic waves generated in an FBAR are dominant acoustic waves that travel through the piezoelectric material in a direction perpendicular to the layers of conductive material forming the top and bottom electrodes. However, the piezoelectric material of an FBAR typically has a non-zero Poisson's ratio. Compression and relaxation of the piezoelectric material associated with the passage of a dominant acoustic wave can cause compression and relaxation of the piezoelectric material in a direction perpendicular to the direction of propagation of the dominant acoustic wave. Compression and relaxation of the piezoelectric material in a direction perpendicular to the direction of propagation of the dominant acoustic wave can generate transverse acoustic waves through the piezoelectric material that are perpendicular to the dominant acoustic wave (parallel to the surfaces of the electrode membrane). As transverse acoustic waves are reflected back into the area where the main acoustic wave propagates, they can induce spurious acoustic waves traveling in the same direction as the main acoustic wave. These spurious acoustic waves are generally considered undesirable because they can degrade the frequency response of the FBAR from what is expected or intended.

[0038] FIG. 1 is a cross-sectional view of an example FBAR, generally designated 100. FBAR 100 is disposed on substrate 110. Substrate 110 may be, for example, a silicon substrate that may include a dielectric surface layer 110A, for example, of silicon dioxide. FBAR 100 includes a layer or film of piezoelectric material 115, for example, aluminum nitride (AlN). Top electrode 120 is disposed over a portion of the layer or film of piezoelectric material 115, and bottom electrode 125 is disposed below the portion of the layer or film of piezoelectric material 115. Top electrode 120 may be formed of, for example, ruthenium (Ru). Bottom electrode 125 may include a layer 125A of Ru disposed below and in contact with a portion of the layer or film of piezoelectric material 115, and a layer 125B of titanium (Ti) disposed below Ru layer 125A opposite one side of Ru layer 125A that is in contact with the portion of the layer or film of piezoelectric material 115. The top electrode 120 and the bottom electrode 125 may each be covered by a layer of dielectric material 130, such as silicon dioxide. A cavity 135 is defined below the layer of dielectric material 130 that covers the bottom electrode 125 and the surface layer 110A of the substrate 110. A bottom electrical contact 140, formed for example from copper, makes electrical connection with the bottom electrode 125, and a top electrical contact 145, formed for example from copper, makes electrical connection with the top electrode 120.

[0039] The FBAR 100 may include a central region 150 that includes a primary active domain in the layer or film of piezoelectric material 115 where primary acoustic waves are excited during operation. The central region may have a width of, for example, about 20 μm to about 100 μm. One or more recessed frame regions 155 may bound and define the lateral extents of the central region 150. The recessed frame region may have a width of, for example, about 1 μm. The recessed frame region 155 may be defined by an area over the top electrode 120 that has a thinner layer of dielectric material 130 than the central region 150. The dielectric material layer 130 in the recessed frame region 155 may be thinner by about 10 nm to about 100 nm than the dielectric material layer 130 in the central region 150. The difference in thickness of the dielectric material in the recessed frame region 155 versus the central region 150 can cause the resonant frequency of the device in the recessed frame region 155 to be about 5 MHz to about 50 MHz higher than the resonant frequency of the device in the central region 150. In some embodiments, the thickness of the dielectric material layer 130 in the central region 150 can be about 200 nm to about 300 nm, and the thickness of the dielectric material layer 130 in the recessed frame region 155 can be about 100 nm. The dielectric film 300 in the recessed frame region 155 is typically etched during fabrication to achieve the desired difference in sound velocity between the central region 150 and the recessed frame region 155. Therefore, the dielectric film 300 initially deposited in both the central region 150 and the recessed frame region 155 is deposited to a thickness sufficient to allow etching of the dielectric film 300 in the recessed frame region 155 sufficient to achieve the desired difference in thickness of the dielectric film 300 between the central region 150 and the recessed frame region 155. This allows the desired difference in sound speed between the regions to be achieved.

[0040] One or more raised frame regions 160 may be defined on the opposite side of the recessed frame region 155 from the central region 150 and directly abut the outer edge of the recessed frame region 155. The raised frame region 160 may have a width of, for example, about 1 μm. The raised frame region 160 may be defined by an area where the top electrode 120i is thicker than in the central region 150 and the recessed frame region 155. The top electrode 120 may have the same thickness in the central region 150 and the recessed frame region 155, but has a greater thickness in the raised frame region 160. The top electrode 120 may be thicker in the raised frame region 160 by about 50 nm to about 500 nm than in the central region 150 and / or the recessed frame region 155. In some embodiments, the thickness of the top electrode in the central region may be 50-500 nm.

[0041] The recessed frame region 155 and the raised frame region 160 may contribute to the dissipation or scattering of transverse acoustic waves generated in the FBAR 100 during operation and / or may reflect the propagating transverse acoustic waves outside the recessed frame region 155 and the raised frame region 160, preventing the transverse acoustic waves from penetrating into the central region and inducing spurious signals in the FBAR's main active domain region. Without being bound by theory, it is believed that the recessed frame region 155 exhibits a higher acoustic wave propagation velocity than the central region 150 due to the thinner layer of dielectric material 130 overlying the top electrode 120 in the recessed frame region 155. Conversely, the raised frame region 160 may exhibit a lower acoustic wave propagation velocity than the central region 150, and a lower acoustic wave propagation velocity than the recessed frame region 155, due to the increased thickness and mass of the top electrode 120 in the raised frame region 160. The discontinuity in acoustic wave velocity between the recessed frame regions 155 and the raised frame regions 160 provides a barrier that scatters, suppresses and / or reflects shear acoustic waves.

[0042] Another form of BAW resonator is the Lamb wave acoustic wave resonator. Lamb wave resonators can combine the features of surface acoustic wave (SAW) resonators with those of BAW resonators. Lamb wave resonators typically include interdigital transducer (IDT) electrodes similar to SAW resonators. Therefore, the frequency of the Lamb wave resonator can be defined by lithography. Lamb wave resonators can achieve a relatively high quality factor (Q) and a relatively high phase velocity, similar to BAW resonators (e.g., due to their suspension structure). Lamb wave resonators including AlN piezoelectric layers are relatively easy to integrate into other circuits. This is because, for example, AlN process technology can be compatible with metal-oxide-semiconductor (CMOS) process technology. AlN Lamb wave resonators can overcome the relatively low resonant frequency limitations and integration difficulties associated with SAW resonators, as well as the multi-frequency capability difficulties associated with BAW resonators. Some Lamb wave resonator topologies are based on acoustic reflection from a periodic reflection grating. Some other Lamb wave resonator topologies are based on acoustic reflection from the suspended free edge of a piezoelectric layer.

[0043] An example of a Lamb wave acoustic wave resonator is generally designated 200 in FIG. 2 . Lamb wave resonator 200 includes features of a SAW resonator and an FBAR. As shown, Lamb wave resonator 200 includes a piezoelectric layer 205, an interdigital transducer electrode (IDT) 210 on the piezoelectric layer 205, and a bottom electrode 215 disposed on the bottom surface of the piezoelectric layer 205. Piezoelectric layer 205 may be a thin film. Piezoelectric layer 205 may be an aluminum nitride layer. In other examples, piezoelectric layer 205 may be any suitable piezoelectric layer. The resonant frequency of the Lamb wave resonator may be based on the dimensions of IDT 210. Electrode 215 may be grounded in certain examples. In some examples, electrode 215 may be floating. An air cavity 220 is disposed between electrode 215 and substrate 225. Instead of air cavity 220, any suitable cavity, such as a vacuum cavity or a cavity filled with a different gas, may be implemented.

[0044] Another form of BAW resonator is the surface-mounted resonator (SMR). One example of an SMR is generally designated 300 in FIG. 3. As shown, the SMR 300 includes a piezoelectric layer 305, an upper electrode 310 on the piezoelectric layer 305, and a lower electrode 315 on the lower surface of the piezoelectric layer 305. The piezoelectric layer 305 may be an aluminum nitride layer. In other examples, the piezoelectric layer 305 may be any suitable piezoelectric layer. The lower electrode 315 may be grounded in certain examples. In some examples, the lower electrode 315 may be floating. A Bragg reflector 320 is disposed between the lower electrode 315 and a semiconductor substrate 325. The semiconductor substrate 325 may be a silicon substrate. Any suitable Bragg reflector may be implemented. For example, the Bragg reflector may be SiO2 / W.

[0045] In the BAW resonators described above, each of the piezoelectric layers can be formed from AlN. It has been discovered that the operating characteristics of the BAW resonators disclosed herein, such as the coupling coefficient and / or quality factor, can be improved by adding one or more dopant components to the AlN forming each of the piezoelectric layers. FIG. 4 includes a table of various compounds that can be used to dope AlN ("End Member" column) and the resulting chemical formulas of the doped materials that can be utilized as piezoelectric materials in BAW resonators ("Solid Solution Series" column). FIGS. 5A and 5B are tables of additional wurtzite-related nitride compounds that can be used as dopants for AlN to form piezoelectric materials for use in BAW resonators, or that can themselves be used as piezoelectric materials in BAW resonators. The tables in FIGS. 5A and 5B were taken from Ottinger's Doctoral Thesis (2004) Diss. ETH Nr. 15624.

[0046] Scandium nitride (ScN)-doped aluminum nitride, used as the piezoelectric material in BAW resonators, has been shown to improve the operating characteristics of the resonators compared to similar BAW resonators that utilize undoped AlN for the piezoelectric layer. Without being bound by theory, it is believed that the electropositive properties of Sc may contribute to the improved operating characteristics of BAW resonators that utilize Sc-doped AlN for the piezoelectric layer. Therefore, doping AlN with an element more electropositive than Sc can result in a superior piezoelectric material for use in BAW resonators than Sc-doped AlN. Charge compensation of the dopant in AlN with silica, instead of a substitute element such as zirconia, can result in a better fit into the tetrahedral sites of the AlN crystal structure, where Si can substitute for Al. This can result in a piezoelectric material that exhibits a higher quality factor in BAW resonators compared to Sc-doped AlN or Mg / Zr-codoped AlN. Dopant compounds with wurtzite or distorted wurtzite structure ("end-members") can exhibit a wider range of dopant concentrations that remain in solid solution in AlN than those achievable with rock-salt structure ScN.

[0047] The crystal structures of selected materials that can be advantageously used for the piezoelectric material in BAW resonators are shown in Figures 6A-6D. 0.99 EU 0.01 Figure 6B shows the crystal structure of AlSiN3. Figure 6B shows the Sr tetrahedron shown by the Al / Si centered nitrogen tetrahedron. 0.99 EU 0.01 Figure 6C is a projection representation of the crystal structure of AlSiN3. The Sr in the N2-centered Sr / Eu-Al / Si octahedron is shown. 0.99 EU 0.01 Figure 6D shows the crystal structure of CaAlSiN3 projected onto the ab plane and the Sr 0.99 EU 0.01 This is a comparison with the crystal structure of AlSiN3. Figures 6A to 6D are taken from Watanabe et al., J. Solid State Chem. 181, 1848 (2008).

[0048] It should be noted that the BAW resonators shown in these figures are shown in a highly simplified form. The relative dimensions of different features are not shown to scale. Furthermore, a typical BAW resonator may include additional features or layers that are not illustrated.

[0049] In some embodiments, multiple BAW resonators disclosed herein are combined into a filter, such as an RF ladder filter including multiple series resonators R1, R3, R5, R7, and R9 and multiple parallel (or shunt) resonators R2, R4, R6, and R8, as shown schematically in Figure 7. As shown, the multiple series resonators R1, R3, R5, R7, and R9 are connected in series between the input and output of the RF ladder filter, and the multiple parallel resonators R2, R4, R6, and R8 are each connected in a shunt configuration between a series resonator and ground. Other filter structures and other circuit structures known in the art that may include BAW devices or resonators, such as duplexers, baluns, etc., can also be formed to include multiple instances of the BAW resonators disclosed herein.

[0050] The acoustic wave devices described herein can be implemented in a variety of packaged modules. Some examples of packaged modules that can implement any suitable principles and advantages of the packaged acoustic wave devices described herein are described below. Figures 8, 9, and 10 are schematic block diagrams of exemplary packaged modules and devices according to certain embodiments.

[0051] As described above, embodiments of the disclosed BAW resonators can be configured as or in filters, for example. Similarly, BAW filters using one or more BAW elements can be incorporated into and packaged as modules for ultimate use in electronic devices, such as wireless communication devices. FIG. 8 is a block diagram illustrating an example of a module 400 including a BAW filter 410. The BAW filter 410 may be implemented on one or more dies 420 that include one or more connection pads 422. For example, the BAW filter 410 may include connection pads 422 corresponding to input contacts for the BAW filter and other connection pads 422 corresponding to output contacts for the BAW filter. The packaged module 400 includes a package substrate 430 configured to receive multiple components, including the die 420. Multiple connection pads 432 can be disposed on the package substrate 430, and various connection pads 422 of the BAW filter die 420 can be connected to the connection pads 432 on the package substrate 430 via electrical connectors 434. The electrical connectors 434 may be, for example, solder bumps or wire bonds to allow various signals to pass to and from the BAW filter 410. The module 400 may further optionally include other circuit dies 440, such as one or more additional filters, amplifiers, pre-filters, modulators, demodulators, downconverters, etc., as would be known to those skilled in the art of semiconductor fabrication in view of this disclosure. In some embodiments, the module 400 may also include one or more packaging structures, for example, to provide protection for and facilitate easy handling of the module 400. Such packaging structures may include an overmold formed over the package substrate 430 and dimensioned to substantially encapsulate the various circuits and components.

[0052] Various examples and embodiments of BAW filter 410 can be used in a wide variety of electronic devices. For example, BAW filter 410 can be used in antenna duplexers, which themselves can be incorporated into various electronic devices such as RF front-end modules and communication devices.

[0053] 9, there is illustrated a block diagram of an example front-end module 500 that can be used in an electronic device, such as a wireless communication device (e.g., a mobile phone). The front-end module 500 includes an antenna duplexer 510 having a common node 502, an input node 504, and an output node 506. An antenna 610 is connected to the common node 502.

[0054] The antenna duplexer 510 may include one or more transmit filters 512 connected between the input node 504 and a common node 502, and one or more receive filters 514 connected between the common node 502 and an output node 506. The passband of the transmit filters is different from the passband of the receive filters. Multiple instances of the BAW filter 410 may be used to form the transmit filters 512 and / or the receive filters 514. An inductor or other matching component 520 may be connected to the common node 502.

[0055] The front-end module 500 further includes a transmitter circuit 532 coupled to the input node 504 of the duplexer 510 and a receiver circuit 534 coupled to the output node 506 of the duplexer 510. The transmitter circuit 532 can generate signals for transmission via the antenna 610, and the receiver circuit 534 can receive signals via the antenna 610 and process the received signals. In some embodiments, the receiver circuit and the transmitter circuit are implemented as separate components as shown in FIG. 9, although in other embodiments, these components may be integrated into a common transceiver circuit or module. Those skilled in the art will appreciate that the front-end module 500 may include other components not illustrated in FIG. 9, including, but not limited to, switches, electromagnetic couplers, amplifiers, processors, etc.

[0056] FIG. 10 is a block diagram of an example wireless device 600 including the antenna duplexer 510 shown in FIG. 9 . The wireless device 600 may be a cellular phone, a smartphone, a tablet, a modem, a communications network, or any other portable or non-portable device configured for voice or data communications. The wireless device 600 can receive and transmit signals from an antenna 610. The wireless device includes an embodiment of a front-end module 500 similar to that described above with reference to FIG. 9 . The front-end module 500 includes the duplexer 510 described above. In the example shown in FIG. 10 , the front-end module 500 further includes an antenna switch 540. The antenna switch 540 can be configured to switch between different frequency bands or modes, such as a transmit mode and a receive mode. In the example shown in FIG. 10 , the antenna switch 540 is positioned between the duplexer 510 and the antenna 610; however, in other examples, the duplexer 510 may be positioned between the antenna switch 540 and the antenna 610. In another example, the antenna switch 540 and the duplexer 510 can be integrated into one component.

[0057] The front-end module 500 includes a transceiver 530 configured to generate a signal for transmission or to process a received signal. The transceiver 530 may include a transmitter circuit 532 that may be connected to an input node 504 of the duplexer 510 and a receiver circuit 534 that may be connected to an output node 506 of the duplexer 510, as shown in the example of FIG.

[0058] Signals generated for transmission by the transmitter circuitry 532 are received by a power amplifier (PA) module 550, which amplifies the generated signals from the transceiver 530. The power amplifier module 550 may include one or more power amplifiers. The power amplifier module 550 can be used to amplify transmit signals in a variety of RF or other frequency bands. For example, the power amplifier module 550 can receive an enable signal used to pulse the output of the power amplifier to facilitate the transmission of a wireless local area network (WLAN) signal or any other suitable pulsed signal. The power amplifier module 550 can be configured to amplify any of a variety of types of signals, including, for example, Global System for Mobile (GSM) signals, code division multiple access (CDMA) signals, W-CDMA signals, Long Term Evolution (LTE) signals, or EDGE signals. In certain embodiments, the power amplifier module 550 and associated components, including switches and the like, may be fabricated on a gallium arsenide (GaAs) substrate using, for example, high electron mobility transistors (pHEMTs) or insulated gate bipolar transistors (BiFETs), or on a silicon substrate using complementary metal oxide semiconductor (CMOS) field effect transistors.

[0059] 10, the front-end module 500 may further include a low-noise amplifier module 560, which amplifies the received signal from the antenna 610 and provides the amplified signal to the receiver circuitry 534 of the transceiver 530.

[0060] The wireless device 600 of FIG. 10 further includes a power management subsystem 620 coupled to the transceiver 530 to manage power for operation of the wireless device 600. The power management system 620 may also control operation of the baseband subsystem 630 and various other components of the wireless device 600. The power management system 620 may include or be coupled to a battery (not shown) that provides power for the various components of the wireless device 600. The power management system 620 may further include one or more processors or controllers that may, for example, control the transmission of signals. In one embodiment, the baseband subsystem 630 is coupled to a user interface 640 that facilitates various inputs and outputs of voice and / or data to or from a user. The baseband subsystem 630 may also be coupled to a memory 650 configured to store data and / or instructions that facilitate operation of the wireless device and / or provide information storage for the user. Any of the above-described embodiments may be implemented in connection with a mobile device, such as a cellular handset. The principles and advantages of the embodiments may be used by any system or apparatus, 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. Although the present disclosure includes several example embodiments, the teachings described herein can be applied to a variety of structures. Any of the principles and advantages described herein can be implemented in connection with RF circuits configured to process signals in the range of approximately 30 kHz to 300 GHz, such as the range of approximately 450 MHz to 6 GHz.

[0061] Aspects of the present disclosure can be implemented in various electronic devices. Examples of electronic devices include, but are not limited to, consumer electronic products, components of consumer electronic products such as packaged radio frequency modules, uplink wireless communication devices, wireless communication infrastructure, electronic test equipment, etc. Examples of electronic devices include, but are not limited to, mobile phones such as smartphones, wearable computing devices such as smart watches or earpieces, telephones, televisions, computer monitors, computers, modems, handheld computers, laptop computers, tablet computers, microwave ovens, refrigerators, in-vehicle electronic systems such as automotive electronic systems, stereo systems, digital music players, radios, cameras such as digital cameras, portable memory chips, washing machines, dryers, washer / dryer machines, copiers, facsimile machines, scanners, multifunction peripheral devices, watches, clocks, etc. Additionally, electronic devices may include unfinished products.

[0062] example

[0063] Formula Al 0.875 Ca 0.0625 Si 0.0625 The predicted Young's modulus of a material with N is calculated using the formula Al 0.875 Sc 0.125 Simulations were performed to determine the Young's modulus of the AlN-containing material and that of undoped AlN. The results of this simulation are shown in FIG. 11. As shown, 0.875 Ca 0.0625 Si 0.0625 The Young's modulus of the N material is smaller than that of undoped AlN, but Al 0.875 Sc 0.125 It is predicted to have a Young's modulus greater than that of N.

[0064] Throughout this specification and the claims, unless the context clearly requires otherwise, words such as "comprise," "comprise," "include," and the like, shall generally be interpreted in an inclusive sense, i.e., "including, but not limited to," as opposed to an exclusive or exhaustive sense. The word "coupled," as generally used herein, refers to two or more elements that may be either directly connected or connected via one or more intermediate elements. Similarly, the word "connected," as generally used herein, refers to two or more elements that may be either directly connected or connected via one or more intermediate elements. In addition, the words "here," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to any specific portion of this application. Where the context permits, terms in the above Detailed Description using the singular or plural number may also include the plural or singular number, respectively. The words "or" and "or," referring to a list of two or more items, cover all of the following interpretations of that word: any item in the list, all items in the list, and any combination of items in the list.

[0065] Furthermore, conditional language used herein, such as "can," "could," "may," "might," "for example," "such as," and the like, among others, is generally intended to convey that certain embodiments include certain features, elements, and / or conditions, while other embodiments do not, unless specifically stated otherwise or understood otherwise from the context of use. That is, such conditional language is not generally intended to imply that features, elements, and / or conditions are in any necessary manner for one or more embodiments, or that one or more embodiments necessarily include logic that determines, with or without author input or prompting, whether or not these features, elements, and / or conditions are included in or performed in any specific embodiment.

[0066] While certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Indeed, the novel methods, apparatuses, and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the present disclosure. For example, while several blocks are presented in a given arrangement, alternative embodiments may perform similar functions with different components and / or circuit topologies, and some blocks may be deleted, moved, added, subdivided, combined, and / or modified. Each of these blocks may be implemented in a variety of different ways. Any suitable combination of elements and steps of the various embodiments described above may be combined to provide further embodiments. The accompanying claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the present disclosure.

Claims

1. An acoustic wave resonator including a piezoelectric material, the piezoelectric material being formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na) to enhance performance of the acoustic wave resonator; one or more of Be, Sr, and Na are charge-balanced with at least one of Si and Ge; The piezoelectric material is Al １－２ｘ 3r ｘ ｳi ｘ (00011)、 Al １－２ｘ Be ｘ Si ｘ N(0<x<1)、 Al １－２ｘ Be ｘ Ge ｘ N(0<x<1)、 Al １－３ｘ Na ｘ Si ２ｘ N (0 < x < 1) or Al １－３ｘ Na ｘ Ge ２ｘ An acoustic wave resonator having a chemical formula from one of N (0<x<1).

2. An acoustic wave filter comprising the acoustic wave resonator of claim 1.

3. 3. The acoustic wave filter of claim 2, comprising a bulk acoustic wave resonator comprising said doped AlN.

4. The acoustic wave filter of claim 3 , wherein the bulk acoustic wave resonator is one of a thin film bulk acoustic wave resonator, a Lamb wave resonator, or a surface mount resonator.

5. 4. The acoustic wave filter of claim 3, comprising a radio frequency filter.

6. An electronic device module comprising the acoustic wave filter of claim 5.

7. An electronic device comprising the electronics module of claim 6.

8. The acoustic wave resonator of claim 1 , wherein the piezoelectric material has a wurtzite crystal structure.

9. 1. A method for forming an acoustic wave resonator, comprising depositing electrodes on a piezoelectric film formed from aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na); one or more of Be, Sr, and Na are charge-balanced with at least one of Si and Ge; The material of the piezoelectric film is Al １－２ｘ 3r ｘ ｳi ｘ (00011)、 Al １－２ｘ Be ｘ Si ｘ N(0<x<1)、 Al １－２ｘ Be ｘ Ge ｘ N(0<x<1)、 Al １－３ｘ Na ｘ Si ２ｘ N (0 < x < 1) or Al １－３ｘ Na ｘ Ge ２ｘ N (0<x<1)

10. 10. The method of claim 9, wherein depositing the electrodes on the piezoelectric film comprises depositing a first electrode on a top surface of the piezoelectric film and depositing a second electrode on a bottom surface of the piezoelectric film.

11. The method of claim 10 , wherein the acoustic wave resonator is a thin film bulk acoustic wave resonator, and the method further comprises defining a cavity below a lower surface of the piezoelectric film.

12. 11. The method of claim 10, wherein the acoustic wave resonator is a Lamb wave resonator, and depositing the first electrode on a top surface of the piezoelectric film includes depositing an interdigital transducer electrode on a top surface of the piezoelectric film.

13. The method of claim 10 , wherein the acoustic wave resonator is a solid-mounted resonator, and the method further comprises forming the piezoelectric film on a top surface of a Bragg reflector.

14. A piezoelectric material comprising aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na), one or more of Be, Sr, and Na are charge-balanced with at least one of Si and Ge; The piezoelectric material is Al １－２ｘ 3r ｘ ｳi ｘ (00011)、 Al １－２ｘ Be ｘ Si ｘ N(0<x<1)、 Al １－２ｘ Be ｘ Ge ｘ N(0<x<1)、 Al １－３ｘ Na ｘ Si ２ｘ N (0 < x < 1) or Al １－３ｘ Na ｘ Ge ２ｘ N (0<x<1)

15. 15. The piezoelectric material of claim 14 having a wurtzite crystal structure.

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