Surface acoustic wave (SAW) devices with high dielectric constant materials

Abstract

Certain aspects of the present disclosure relate to a SAW device (100). The SAW device can include a piezoelectric layer (102), an interdigital transducer (IDT) (104) disposed above the piezoelectric layer and including first electrode fingers (404a) and second electrode fingers (404b), and a first high dielectric constant (high-k) (410) material disposed between the first electrode fingers and the second electrode fingers, where a height of the first high-k material above the piezoelectric layer is greater than 60% of a height of the first electrode fingers or the second electrode fingers above the piezoelectric layer.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Patent Application No. 18 / 631,850, filed April 10, 2024, which is incorporated herein by reference. Technical Field

[0002] Certain aspects of this disclosure relate generally to electronic components, and more specifically to surface acoustic wave (SAW) devices. Background Technology

[0003] Electronic devices include traditional computing devices such as desktop computers, laptops, tablets, smartphones, wearable devices such as smartwatches, and internet servers. These diverse electronic devices provide human users with information, entertainment, social interaction, security, safety, productivity, transportation, manufacturing, and other services. Many of the functions of these diverse electronic devices rely on wireless communication. Wireless communication systems and devices are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems (e.g., Long Term Evolution (LTE) systems or New Radio (NR) systems).

[0004] The wireless communication transceivers used in these electronic devices typically include multiple radio frequency (RF) filters for filtering signals at specific frequencies or frequency ranges. Electroacoustic devices (e.g., "acoustic filters") are used in many applications to filter high-frequency (e.g., typically greater than 100 MHz) signals. Using piezoelectric materials as the vibrating medium, acoustic resonators operate by converting electrical signal waves propagating along an electrical conductor into sound waves propagating via the piezoelectric material. Sound waves propagate at speeds significantly smaller than those of electromagnetic waves. Generally, the speed of wave propagation is proportional to the wavelength of the wave. Therefore, after converting an electrical signal into an acoustic signal, the wavelength of the acoustic signal wave is significantly smaller than the wavelength of the electrical signal wave. The resulting smaller wavelength of the acoustic signal allows for the use of smaller filter devices to perform filtering. This permits the use of acoustic resonators in electronic devices with size constraints, such as those listed above (e.g., specifically portable electronic devices such as cellular phones).

[0005] Today, surface acoustic wave (SAW) or bulk acoustic wave (BAW) components are used in wireless communication devices, such as for implementing RF filters. In SAW technology, acoustic waves propagate laterally across the surface of a piezoelectric substrate (or, in an example, a piezoelectric layer with an additional layer beneath it), where the movement of the piezoelectric material is generated by interdigitated metal transducers (IDTs) on the surface. The wavelength of the acoustic wave can be defined by the pitch of the IDTs (e.g., the spacing between the fingers, which can be defined as the width of the metal fingers and the gap from one edge of a finger to the corresponding edge on an adjacent finger). In BAW technology, acoustic waves propagate vertically through a three-dimensional structure, where an electric field is applied through electrodes above and below the piezoelectric material. In this case, the wavelength is defined by the thickness of the piezoelectric material.

[0006] In some types of SAW devices, surface acoustic waves are generated by the input IDT and detected by the output IDT. In other types of SAW devices, reflectors on either side of the IDT can be used to confine the acoustic energy. A planar resonant cavity created between two mirrors consisting of reflective metal strips can also be used to capture acoustic energy.

[0007] As the number of frequency bands used in wireless communication increases and as the desired bandwidth of filters widens, the performance of acoustic filters becomes increasingly important in reducing losses and improving the overall performance of electronic devices. Acoustic filters with improved performance, particularly those with reduced mechanical losses and self-heating, are therefore highly sought after. Summary of the Invention

[0008] The systems, methods, and apparatuses of this disclosure each have several aspects, none of which are solely responsible for their desired properties. Without limiting the scope of this disclosure as set forth in the following claims, some features will now be briefly discussed. Upon consideration of this discussion, and especially after reading the section entitled “Detailed Description,” it will be understood how the features of this disclosure provide advantages including reducing the size of surface acoustic wave (SAW) devices.

[0009] Certain aspects of this disclosure relate to a SAW device. The SAW device may include: a piezoelectric layer; an interdigital transducer (IDT) disposed above the piezoelectric layer and including a first electrode and a second electrode; and a first high dielectric constant (high κ) material disposed between the first electrode and the second electrode, wherein the height of the first high κ material above the piezoelectric layer is greater than 60% of the height of the first electrode or the second electrode above the piezoelectric layer.

[0010] Certain aspects of this disclosure relate to a method of manufacturing a SAW device. The method generally includes: forming an IDT disposed over a piezoelectric layer, wherein forming the IDT includes forming a first electrode and a second electrode; and forming a first high-κ material such that the first high-κ material is located between the first electrode and the second electrode, wherein the height of the first high-κ material over the piezoelectric layer is greater than 60% of the height of the first electrode or the second electrode over the piezoelectric layer.

[0011] Certain aspects of this disclosure relate to a wireless device. The wireless device typically includes radio frequency (RF) circuitry and a SAW filter coupled to the RF circuitry. The SAW filter includes: a piezoelectric layer; an individual dielectric layer (IDT) disposed above the piezoelectric layer and including a first electrode and a second electrode; and a high-kb material disposed between the first and second electrodes, wherein the height of the high-kb material above the piezoelectric layer is greater than 60% of the height of the first or second electrode above the piezoelectric layer.

[0012] To achieve the foregoing and related objectives, one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and drawings illustrate certain exemplary features of these one or more aspects in detail. However, these features indicate only a few of the various ways in which the principles of the various aspects may be employed. Attached Figure Description

[0013] To gain a more detailed understanding of the foregoing features of this disclosure, a more specific description, some of which is illustrated in the accompanying drawings, may be obtained by referring to various aspects. However, it should be noted that the drawings illustrate only certain aspects of this disclosure and should therefore not be considered as limiting its scope, as the description may allow for other equivalent aspects.

[0014] Figure 1A This is a perspective view of an example electroacoustic device in which certain aspects of this disclosure can be practiced.

[0015] Figure 1B yes Figure 1A A cross-sectional view of an example electroacoustic device.

[0016] Figure 2A This is a top view of an example electrode structure for an electroacoustic device, in which certain aspects of this disclosure can be practiced.

[0017] Figure 2B This is a top view of another example electrode structure of an electroacoustic device, in which some aspects of this disclosure can be practiced.

[0018] Figure 3 This is a cross-sectional view of an example electroacoustic device having a continuous thin layer of dielectric material deposited on a piezoelectric layer prior to electrode deposition.

[0019] Figure 4 A cross-sectional view of a surface acoustic wave (SAW) device having an interdigital transducer (IDT) and having a high-κ material disposed between electrodes of the IDT is illustrated according to certain aspects of this disclosure.

[0020] Figure 5 A cross-sectional view of a SAW device having a high-κ material manufactured with a sacrificial layer, according to certain aspects of this disclosure, is illustrated.

[0021] Figure 6 This is a block diagram illustrating example operations for manufacturing SAW equipment according to certain aspects of this disclosure.

[0022] Figure 7 This is a schematic diagram of an electroacoustic filter circuit.

[0023] Figure 8 This is one of the options that can be adopted. Figure 7 The example of a filter circuit simplifies the functional block diagram of at least a portion of a wireless transceiver circuit.

[0024] Figure 9 This is a diagram of an environment including electronic devices, such as wireless transceivers, etc. Figure 8 The transceiver circuit.

[0025] For ease of understanding, the same reference numerals have been used where possible to denote common elements in the figures. It is conceivable that elements disclosed in one aspect may be usefully applied to other aspects without specific description. Detailed Implementation

[0026] Certain aspects of this disclosure generally relate to a surface acoustic wave (SAW) device having an interdigital transducer (IDT) implemented between electrodes using a high dielectric constant (high κ) material (e.g., also referred to as a high permittivity material) to increase the static capacitance of the IDT. For example, the static capacitance of the IDT in a SAW filter can be increased by filling the entire space (or at least most of the space) between the electrodes of the IDT with a high κ material. The height of the high κ material can be at least 60% of the electrode height. By increasing the static capacitance of the IDT, the static capacitance of the SAW device is increased, thus enabling a reduction in the size of the SAW device by reducing the number of fingers in the IDT.

[0027] The specific embodiments described below with reference to the accompanying drawings are intended as exemplary embodiments and are not intended to represent the only embodiments in which the invention may be practiced. The term "exemplary" as used throughout this specification means "serving as an example, instance, or illustration" and should not be construed as superior to or better than other exemplary embodiments. The specific embodiments include particular details for the purpose of providing a thorough understanding of the exemplary embodiments. In some instances, some devices are shown in block diagram form. Drawing elements common in the following drawings may be identified using the same reference numerals. Example electroacoustic equipment

[0028] Figure 1A This is a perspective view of an example electroacoustic device 100. Electroacoustic device 100 may be configured as or part of a SAW resonator. In some descriptions herein, electroacoustic device 100 may be referred to as a SAW resonator. However, other types of electroacoustic devices may exist that can be constructed based on the principles described herein.

[0029] Electroacoustic device 100 includes an electrode structure 104, which may be referred to as an interdigital transducer (IDT), located on the surface of a piezoelectric material 102. The electrode structure 104 typically includes a first comb-shaped electrode structure and a second comb-shaped electrode structure (conductive and typically metallic), wherein electrode fingers extend from two busbars toward each other and are arranged in an interlocking manner between the two busbars (e.g., in an interdigital arrangement). An electrical signal excited (e.g., by applying an AC voltage) in the electrode structure 104 is converted into an acoustic wave 106, which propagates in a specific direction via the piezoelectric material 102. The acoustic wave 106 is converted back into an electrical signal and provided as an output. In many applications, the piezoelectric material 102 has a specific crystal orientation such that when the electrode structure 104 is arranged relative to the crystal orientation of the piezoelectric material 102, the acoustic wave propagates primarily in a direction perpendicular to the fingers (e.g., parallel to the busbars).

[0030] Figure 1B It is along Figure 1A The line segment 108 shown is cut from Figure 1AA cross-sectional view of an electroacoustic device 100. The electroacoustic device 100 is exemplified by a simplified layer stack comprising a piezoelectric material 102, wherein an electrode structure 104 is disposed on the piezoelectric material 102. The electrode structure 104 is conductive and is typically formed of a metallic material. The electrode structure 104 may alternatively be formed of a conductive but non-metallic material (e.g., graphene). The piezoelectric material 102 may be formed of various materials, such as quartz, lithium tantalate (LiTaO3), lithium niobate (LiNbO3), doped variants of these, other piezoelectric materials, or other crystals. The piezoelectric material 102 may be referred to as a "piezoelectric substrate," but may also be referred to as a "piezoelectric layer," as in examples where an additional layer exists beneath the piezoelectric material 102. It should be understood that more complex layer stacks comprising layers of various materials are possible within this stack. For example, optionally, a temperature compensation layer 110, indicated by dashed lines, may be disposed above the electrode structure 104. In another example, a layer (e.g., a substrate or other layer) may exist beneath the piezoelectric material 102. The piezoelectric material 102 can be extended with multiple interconnected electrode structures disposed thereon to form a multi-resonator filter or provide multiple filters. Although not illustrated, when disposed as an integrated circuit component, a capping layer may be disposed over the electrode structure 104. The capping layer is applied such that a cavity is formed between the electrode structure 104 and the lower surface of the capping layer. Electrical vias or bumps may also be included to allow the component to be electrically connected to connectors on the substrate (e.g., via flip chips or other techniques).

[0031] Figure 2A This is a top view of an example electrode structure 204a for an electroacoustic device. Electrode structure 204a has an IDT 205, which includes a first busbar 222 (e.g., a first conductive segment or conductive trunk) electrically connected to a first terminal 220 and a second busbar 224 (e.g., a second conductive segment or conductive trunk) spaced apart from the first busbar 222 and connected to a second terminal 230. A plurality of conductive fingers 226 are interdigitatedly connected to the first busbar 222 or the second busbar 224. The fingers 226 connected to the first busbar 222 extend toward the second busbar 224 but are not connected to the second busbar 224, such that a small gap exists between the ends of these fingers 226 and the second busbar 224. Similarly, the fingers 226 connected to the second busbar 224 extend toward the first busbar 222 but are not connected to the first busbar 222, such that a small gap exists between the ends of these fingers 226 and the first busbar 222. Similarly, small gaps can also be formed between the finger 226 and any structure (e.g., a truncated finger) extending from the first busbar 222 or the second busbar 224.

[0032] Between the busbars, there exists an overlapping region comprising a central region where a portion of one finger overlaps with a portion of an adjacent finger, as illustrated by central region 225. This central region 225, including the overlap, may be referred to as an aperture, track, or active region, in which an electric field is generated between the fingers 226 to allow acoustic waves to propagate in this region of the piezoelectric material 102. The periodicity of the fingers 226 is referred to as the pitch of the IDT. The pitch can be indicated in various ways. For example, in some aspects, the pitch may correspond to a magnitude of the distance between the fingers in central region 225. This distance may be defined, for example, as the distance between the center points of each of these fingers (and when the fingers have a uniform width, it is typically measured between the right (or left) edge of one finger and the right (or left) edge of an adjacent finger). In some aspects, the average distance between adjacent fingers can be used as the pitch. The frequency of the piezoelectric material's vibration is the dominant resonant frequency of the electrode structure 204a. The frequency is determined at least in part by the pitch of the IDT 205 and other characteristics of the electroacoustic device 100.

[0033] An IDT 205 is arranged between two reflectors 228 that reflect sound waves toward the IDT 205 so that the sound waves are converted into electrical signals via the IDT 205 in the illustrated configuration, and loss is prevented (e.g., the sound waves are confined and prevented from escaping). Each reflector 228 has two buses and a grating structure of conductive fingers, each connected to one of the two buses. The pitch of the reflectors may be similar to or the same as the pitch of the IDT 205 to reflect sound waves within the resonant frequency range. However, many configurations are possible.

[0034] When converted back to an electrical signal, the converted electrical signal can be provided as an output, such as one of the first terminal 220 or the second terminal 230, while the other terminal can be used as an input.

[0035] Multiple electrode structures are possible. Figure 2A A single-port configuration can be broadly illustrated. Other configurations (e.g., dual-port configurations) are also possible. For example, electrode structure 204a may have an input IDT 205, where each terminal 220 and 230 serves as an input terminal. In this case, an adjacent output IDT (not shown) positioned between reflectors 228 and adjacent to the input IDT 205 can be provided to convert the acoustic waves propagating in the piezoelectric material 102 into electrical signals to be provided at the output terminals of the output IDTs.

[0036] Figure 2BThis is a top view of another example electrode structure 204b for an electroacoustic device. In this case, a dual-mode SAW (DMS) electrode structure 204b is illustrated; a DMS structure is capable of inducing multiple resonances. Electrode structure 204b includes multiple IDTs arranged between reflectors 228 and connected as shown. Electrode structure 204b is provided to illustrate various electrode structures to which the principles described herein are applicable, including... Figure 2A Electrode structure 204a and Figure 2B Electrode structure 204b.

[0037] It should be understood that although a certain number of fingers 226 are illustrated, the actual number of fingers, as well as the length and width of the fingers 226 and the bus, may differ in actual implementations. These parameters depend on the specific application and desired filter characteristics. Furthermore, the SAW filter may include multiple interconnect electrode structures, each including multiple IDTs to achieve a desired passband (e.g., multiple interconnect resonators or IDTs to form the desired filter transfer function).

[0038] Figure 3 This is a cross-sectional view of an example electroacoustic device 300. The electroacoustic device 300 includes an IDT (Integrated Device Transducer), which includes a first electrode having a first plurality of fingers 304a and 304c, and a second electrode having a second plurality of fingers 304b and 304d intersecting the first plurality of fingers 304a and 304c of the first electrode. As shown, the plurality of fingers 304a and 304c of the first electrode have a polarity opposite to that of the plurality of fingers 304b and 304d of the second electrode. The plurality of fingers 304a to 304d of the IDT have a height 310, which can be, for example, between 80 nm and 500 nm. Although... Figure 3 Only four fingers 304a to 304d are shown to illustrate the concept, but it should be understood that the IDT may include more or fewer than four fingers.

[0039] Material 302 may be disposed above and between the fingers 304a to 304d of the IDT. For example, when the electroacoustic device 300 is a standard SAW device, material 302 may be air. Alternatively, if the electroacoustic device 300 is a temperature-compensated surface acoustic wave (TCSAW) device, material 302 may be a dielectric material such as silicon dioxide (SiO2). Material 302 may have a low relative permittivity (e.g., ε for air). r =1, and for SiO2, ε r =3.9).

[0040] Electroacoustic device 300 (e.g., it may be configured as a SAW resonator or part thereof) is similar to Figure 1AThe electroacoustic device 100 has a different layer stack. Specifically, the electroacoustic device 300 includes a continuous thin dielectric layer 308 disposed on (or at least above) a piezoelectric layer 306 having a height of 312. In other aspects, the dielectric layer 308 may be absent. For example, the piezoelectric layer 306 may comprise lithium tantalate (LiTaO3), lithium niobate (LiNbO3), some doped variant thereof, or any other suitable material. The piezoelectric layer 306 may also include other layers, such as a substrate material or other layers below the piezoelectric layer 306.

[0041] like Figure 3 As shown, dielectric layer 308 has a height 314, which can also be referred to as thickness. It may be desirable to deposit dielectric layer 308 as a very thin layer to avoid coupling losses between piezoelectric layer 306 and the electrode fingers 304a to 304d. For example, the height 314 of the continuous dielectric layer 308 could be 2.5 nm. Generally, piezoelectric layer 306 can be substantially thicker than dielectric layer 308 (e.g., as an example, it could be about 20,000 to 200,000 times thicker, or more). Additionally, IDT electrode fingers 304a to 304d can be substantially thicker than dielectric layer 308 (e.g., as an example, it could be up to about 250 times thicker). In other words, heights 310 and 312 can be substantially at least an order of magnitude larger than height 314.

[0042] According to certain aspects of this disclosure, the electroacoustic device 300 may be implemented in a filter or duplexer of a radio frequency (RF) circuit used in a wireless communication device. Figures 7 to 9 The description further details this type of wireless communication device. High between electrodes κ Examples of materials SAW equipment

[0043] Certain aspects of this disclosure relate to passive frequency-selective temperature-compensated (TC) surface acoustic wave (SAW) devices for wireless communication applications. The radio frequency (RF) performance of a TCSAW filter can be closely related to the static capacitance of each acoustic track. The capacitance of the acoustic structure can be affected by the number of interdigital transducer (IDT) fingers and / or track aperture. In some cases, the acoustic active components (acoustic structure) of a TCSAW filter can have a minimum size specification to meet the filter's RF specifications. Therefore, further miniaturization of TCSAW devices is challenging due to this minimum size specification of the acoustic structure.

[0044] In some cases, the static capacitance of an IDT can be increased by introducing a dielectric material with a high relative permittivity (a high dielectric constant (high κ) material) into regions with high electric field strength (e.g., between the electrode fingers of the IDT). Examples of usable high κ materials include those with a dielectric constant greater than that of silicon dioxide (SiO2), while examples of usable low κ materials include those with a dielectric constant equal to or less than that of SiO2. Further examples are described below. By increasing the static capacitance of the acoustic structure, the minimum size specification of the acoustic active components of an RF filter can be reduced, thereby reducing chip size and cost.

[0045] Figure 4 A cross-sectional view of a SAW device 400 having an IDT and a high-κ material disposed between electrode fingers according to certain aspects of the present disclosure is illustrated. As shown, the SAW device 400 includes a piezoelectric layer 306, over which electrode fingers 404a, 404b, and 404c (e.g., corresponding to...) are disposed. Figure 3 The fingers 304a, 304b, and 304c. High-κ materials 408, 410, and 412 can be disposed between the electrode fingers of the IDT. For example, high-κ material 410 can be disposed between electrode fingers 404b and 404c, as shown in the figure.

[0046] Any suitable high-κ material can be used. For example, high-κ materials can be aluminum nitride (AlN), hafnium dioxide (HfO2), titanium dioxide (TiO2), zirconium dioxide (ZrO2), aluminum oxide (Al2O3), hafnium silicon oxide (HfSiO2), tantalum pentoxide (Ta2O5), niobium oxide (Nb2O5), scandium oxide (Sc2O3), or strontium titanate (SrTiO3).

[0047] In some aspects, the height of the high-κ material (e.g., high-κ material 410) from the piezoelectric layer can be 60% or more of the height of the electrode fingers (e.g., electrode fingers 404b or 404c). In some aspects, the height of the high-κ material (e.g., high-κ material 410) from the piezoelectric layer can be 50% or more of the height of the electrode fingers (e.g., electrode fingers 404b or 404c). In some aspects, the height of the high-κ material can be the same as the height of the electrode fingers. If the height difference between the high-κ material and the electrode does not exceed 30 nm (e.g., the height of the high-κ material is 30 nm greater than the height of the electrode), then the height of the high-κ material can be considered to be the same as the height of the electrode fingers.

[0048] In some aspects, a low-κ material, such as a temperature compensation layer 414 (e.g., silicon dioxide (SiO2), which may be doped with fluorine) and a passivation layer 416 (e.g., silicon nitride (Si3N4)), lies above the electrodes and the high-κ material. In SAW devices, some materials become softer (less stiff) as temperature increases. With the decrease in stiffness at higher temperatures, the frequency response of the SAW device changes. The temperature compensation layer is used to stabilize the frequency response of the SAW device at different temperatures. The temperature compensation layer becomes stiffer as temperature increases and compensates for the effect of other materials in the SAW device becoming softer with increasing temperature, thus providing a more stable frequency response relative to temperature changes.

[0049] By including a high-κ material between the IDT electrodes, the size of the IDT can be reduced by decreasing the number of fingers in the IDT. In some cases, porosity (e.g., Figure 2A The central region 225 (representing the electrode overlap of the IDT) shown can also be reduced.

[0050] In some cases, a metal chemical mechanical planarization (CMP) process can be used. For example, the facility can first deposit and construct a high-κ material. Then, the facility can deposit a metal for the electrode and remove a portion of the metal via CMP. Depending on the interaction between the high-κ material and the CMP process, the height of the high-κ material can be 100% of the electrode height.

[0051] In some cases, oxide CMP processes can be used to fabricate SAW devices. In this case, the fabrication facility can first deposit metal and construct the electrodes of the IDT. Afterward, the facility can deposit a high-κ material. Then, the facility can use CMP to remove a portion of the high-κ material, which can produce a high-κ material film of approximately 20 nm to 30 nm on top of the electrodes. Therefore, the height of the high-κ material between the electrodes can (e.g., depending on the deposition method) reach 100% (or higher) of the electrode height. In some cases, oxide CMP processes with a SiO2 sacrificial layer can be used, as discussed regarding... Figure 5 A more detailed description.

[0052] Figure 5 An example is illustrated of a SAW device 500 with a high-κ material manufactured using an oxide CMP process with a sacrificial layer, according to certain aspects of this disclosure. In this case, a sacrificial layer 502 (e.g., a sacrificial layer of SiO2) can be formed on top of the structured electrode, as shown. As shown, removing the high-κ material with CMP can produce a 20 nm to 30 nm thick layer of SiO2 on top of the electrode. In this case, the height of the high-κ material can be 20 nm to 30 nm higher than the height of the electrode fingers, as shown. Used for manufacturing SAW Example operation of the device

[0053] Figure 6 This is a block diagram of an example operation 600 for manufacturing a surface acoustic wave (SAW) device such as SAW device 400 or 500 (e.g., a TCSAW device). Operation 600 can be performed by a manufacturing facility.

[0054] At frame 602, the facility may form an interdigital transducer (IDT) (e.g., IDT 205) disposed above a piezoelectric layer (e.g., piezoelectric layer 306). Forming the IDT may include forming a first electrode finger (e.g., electrode finger 404a) and a second electrode finger (e.g., electrode finger 404b).

[0055] At frame 604, the facility may form a first high dielectric constant (high κ) material (e.g., high κ material 408) such that the first high κ material is located between the first electrode finger and the second electrode finger. The height of the first high κ material above the piezoelectric layer is greater than 60% of the height of the first or second electrode above the piezoelectric layer. In some aspects, the height of the first high κ material may be the same as the height of the first or second electrode finger. The first high κ material may include aluminum nitride (AlN), hafnium dioxide (HfO2), titanium dioxide (TiO2), zirconium dioxide (ZrO2), aluminum oxide (Al2O3), hafnium silicon oxide (HfSiO2), tantalum pentoxide (Ta2O5), niobium oxide (Nb2O5), scandium oxide (Sc2O3), or strontium titanate (SrTiO3).

[0056] In some cases, the first electrode fingers and the second electrode fingers may be formed before the first high-k material. In other cases, the first electrode fingers and the second electrode fingers are formed after the first high-k material.

[0057] In some aspects, the IDT also includes a third electrode finger (e.g., electrode finger 404c). The SAW device may also include a second high-κ material (e.g., high-κ material 410) disposed between the second and third electrode fingers. The height of the second high-κ material above the piezoelectric layer may be greater than 60% of the height of the second or third electrode fingers above the piezoelectric layer.

[0058] In some aspects, the facility forms a low-κ material over the first electrode finger, the second electrode finger, and the first high-κ material. For example, the facility may form a temperature compensation layer (e.g., temperature compensation layer 414) over the IDT. The facility may form a passivation layer (e.g., passivation layer 416) over the temperature compensation layer. Examples of integration into filters and wireless communication devices

[0059] Figure 7 Yes, it can include Figures 3 to 5A schematic diagram of an electroacoustic filter circuit 700 for one or more of electroacoustic devices 300, 400, and 500 is provided. The filter circuit 700 provides an example of a SAW device that can be used. The filter circuit 700 includes an input terminal 702 and an output terminal 714. A ladder network of SAW resonators is provided between the input terminal 702 and the output terminal 714. The filter circuit 700 includes a first SAW resonator 704, a second SAW resonator 706, and a third SAW resonator 708, all electrically connected in series between the input terminal 702 and the output terminal 714. A fourth SAW resonator 710 (e.g., a parallel resonator) has a first terminal connected to a node between the first SAW resonator 704 and the second SAW resonator 706, and a second terminal connected to a reference potential node (e.g., electrically grounded) of the filter circuit 700. The fifth SAW resonator 712 (e.g., a parallel resonator) has a first terminal connected to the node between the second SAW resonator 706 and the third SAW resonator 708, and a second terminal connected to the node at a reference potential. The electroacoustic filter circuit 700 may be, for example, a bandpass filter circuit with a selected frequency range (e.g., between 500 MHz and 6 GHz).

[0060] Figure 8 This is one of the options that can be adopted. Figure 7 The example of filter circuit 700 simplifies the functional block diagram of at least a portion of wireless transceiver circuit 800. Transceiver circuit 800 is configured to receive a signal / information (shown as in-phase (I) and quadrature (Q) values) for transmission provided to one or more baseband (BB) filters 812. The filtered output is provided to one or more mixers 814 for upconversion to a radio frequency (RF) signal. The output from one or more mixers 814 can be provided to a driver amplifier (DA) 816, the output of which can be provided to a power amplifier (PA) 818 to generate an amplified signal for transmission. The amplified signal is output to antenna 822 through one or more filters 820 (e.g., a duplexer (if used as a frequency division duplex transceiver) or other filters). The one or more filters 820 may include... Figure 7 The filter circuit 700.

[0061] Antenna 822 can be used for both wirelessly transmitting and receiving data. Transceiver circuitry 800 includes the following receiving path: before the signal is further processed (e.g., provided to an analog-to-digital converter (ADC) and subsequently demodulated or otherwise processed in the digital domain), it passes through one or more filters 820 to be supplied to a low-noise amplifier (LNA) 824 and an additional filter 826, and then down-converts from the received frequency to a baseband frequency via one or more mixer circuits 828. It is possible to have... Figure 7 The filter circuit 700 is used to implement a separate filter for the receiving circuit (e.g., the receiving circuit may have a separate antenna or a separate receiving filter).

[0062] Figure 9 This is a diagram of an environment 900 including electronic device 902, in which various aspects of the present disclosure can be practiced. In environment 900, electronic device 902 communicates with base station 904 (e.g., gNB) via wireless link 906. As shown, electronic device 902 is depicted as a smartphone. However, electronic device 902 can be implemented as any suitable computing device or other electronic device, such as a cellular base station, broadband router, access point, cellular or mobile phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, server computer, network attached storage (NAS) device, smart appliance, vehicle-based communication system, Internet of Things (IoT) device, wearable device, sensor or security device, asset tracker, etc.

[0063] Base station 904 communicates with electronic device 902 via wireless link 906, which can be implemented as any suitable type of wireless link. Although depicted as a base station tower of a cellular radio network, base station 904 can represent or be implemented as another device, such as a satellite, terrestrial broadcast tower, access point, peer-to-peer device, mesh network node, fiber optic line, or another electronic device generally described above. Therefore, electronic device 902 can communicate with base station 904 or another device via wired connection, wireless connection, or a combination thereof. Wireless link 906 can include a downlink transmitting data or control information from base station 904 to electronic device 902, and an uplink transmitting other data or control information from electronic device 902 to base station 904. Any suitable communication protocol or standard can be used, such as 3GPP LTE, 3GPP NR 5G, IEEE 802.11, IEEE 802.16, Bluetooth, etc. ™ To achieve wireless link 906.

[0064] Electronic device 902 includes a processor 980 and a memory 982. The memory 982 may be part of or form part of a computer-readable storage medium. The processor 980 may include any type of processor configured to execute processor-executable instructions (e.g., code) stored in the memory 982, such as an application processor or a multi-core processor. The memory 982 may include any suitable type of data storage medium, such as volatile memory (e.g., random access memory (RAM)), non-volatile memory (e.g., flash memory), optical media, magnetic media (e.g., magnetic disk or magnetic tape), etc. In the context of this disclosure, the memory 982 is implemented to store instructions 984, data 986, and other information of the electronic device 902, and therefore, when configured as or part of a computer-readable storage medium, the memory 982 does not include transient propagation signals or carrier waves.

[0065] Electronic device 902 may also include input / output port 990. I / O port 990 enables data exchange or interaction with other devices, networks, users, or components of the device.

[0066] Electronic device 902 may also include a signal processor (SP) 992 (e.g., such as a digital signal processor (DSP)). The signal processor 992 may function similarly to a processor and may be able to execute instructions and / or process information in conjunction with memory 982.

[0067] For communication purposes, electronic device 902 also includes a modem 994, a wireless transceiver 996, and an antenna (not shown). The wireless transceiver 996 uses radio frequency (RF) wireless signals to provide connectivity to a corresponding network and other electronic devices connected to those networks, and may include... Figure 8 The transceiver circuit 800. The wireless transceiver 996 can facilitate communication on any suitable type of wireless network, such as wireless local area network (WLAN), peer-to-peer (P2P) network, mesh network, cellular network, wireless wide area network (WWAN), navigation network (e.g., North American Global Positioning System (GPS) or another Global Navigation Satellite System (GNSS)) and / or wireless personal area network (WPAN). Example

[0068] In addition to the various aspects described above, specific combinations of these aspects are also within the scope of this disclosure, some of which are detailed in the following provisions:

[0069] Aspect 1: A surface acoustic wave (SAW) device, the SAW device comprising: a piezoelectric layer; an interdigital transducer (IDT) disposed above the piezoelectric layer and including a first electrode finger and a second electrode finger; and a first high dielectric constant (high κ) material disposed between the first electrode finger and the second electrode finger, wherein the height of the first high κ material above the piezoelectric layer is greater than 60% of the height of the first electrode finger or the second electrode finger above the piezoelectric layer.

[0070] Aspect 2: The SAW device according to aspect 1, wherein the dielectric constant of the first high-k material is greater than that of silicon dioxide.

[0071] Aspect 3: The SAW device according to aspect 1 or 2, wherein the height of the first high-k material is at least as high as the height of the first electrode finger or the second electrode finger.

[0072] Aspect 4: The SAW device according to any one of Aspects 1 to 3, wherein: the IDT further includes a third electrode finger; the SAW device further includes a second high-k material disposed between the second electrode finger and the third electrode finger; and the height of the second high-k material above the piezoelectric layer is greater than 60% of the height of the second electrode finger or the third electrode finger above the piezoelectric layer.

[0073] Aspect 5: The SAW device according to any one of Aspects 1 to 4, the SAW device further includes a temperature compensation layer disposed above the IDT.

[0074] Aspect 6: The SAW device according to aspect 5 further includes a passivation layer disposed above the temperature compensation layer.

[0075] Aspect 7: The SAW device according to any one of Aspects 1 to 6, wherein the SAW device includes a temperature-compensated (TC) SAW device.

[0076] Aspect 8: The SAW device according to any one of Aspects 1 to 7, the SAW device further comprising a low-κ material disposed above the first electrode finger, the second electrode finger and the first high-κ material.

[0077] Aspect 9: The SAW device according to aspect 8, wherein the low-κ material comprises silicon dioxide.

[0078] Aspect 10: The SAW apparatus according to any one of Aspects 1 to 9, wherein the first high-k material comprises aluminum nitride (AlN), hafnium dioxide (HfO2), titanium dioxide (TiO2), zirconium dioxide (ZrO2), aluminum oxide (Al2O3), hafnium silicon oxide (HfSiO2), tantalum pentoxide (Ta2O5), niobium oxide (Nb2O5), scandium oxide (Sc2O3), or strontium titanate (SrTiO3).

[0079] Aspect 11: A method of manufacturing a surface acoustic wave (SAW) device, the method comprising: forming an interdigitated transducer (IDT) disposed above a piezoelectric layer, wherein forming the IDT includes forming a first electrode finger and a second electrode finger; and forming a first high dielectric constant (high κ) material such that the first high κ material is located between the first electrode finger and the second electrode finger, wherein the height of the first high κ material above the piezoelectric layer is greater than 60% of the height of the first electrode finger or the second electrode finger above the piezoelectric layer.

[0080] Aspect 12: According to the method of aspect 11, wherein the first electrode finger and the second electrode finger are formed before the first high-κ material.

[0081] Aspect 13: The method according to aspect 11 or 12, wherein the first electrode finger and the second electrode finger are formed after the first high-κ material.

[0082] Aspect 14: The method according to any one of aspects 11 to 13, wherein the height of the first high-k material is the same as the height of the first electrode finger or the second electrode finger.

[0083] Aspect 15: The method according to any one of Aspects 11 to 14, wherein: the IDT further includes a third electrode finger; the SAW device further includes a second high-k material disposed between the second electrode finger and the third electrode finger; and the height of the second high-k material above the piezoelectric layer is greater than 60% of the height of the second electrode finger or the third electrode finger above the piezoelectric layer.

[0084] Aspect 16: The method according to any one of aspects 11 to 15, the method further comprising: forming a temperature compensation layer over the IDT.

[0085] Aspect 17: The method according to aspect 16 further includes: forming a passivation layer over the temperature compensation layer.

[0086] Aspect 18: The method according to any one of Aspects 9 to 17, the method further comprising: forming a low-κ material over the first electrode finger, the second electrode finger and the first high-κ material.

[0087] Aspect 19: A wireless device comprising: a radio frequency (RF) circuit; and a surface acoustic wave (SAW) filter coupled to the RF circuit, the SAW filter comprising: a piezoelectric layer; an interdigital transducer (IDT) disposed above the piezoelectric layer and including a first electrode finger and a second electrode finger; and a high dielectric constant (high κ) material disposed between the first electrode finger and the second electrode finger, wherein the height of the high κ material above the piezoelectric layer is greater than 60% of the height of either the first electrode finger or the second electrode finger above the piezoelectric layer.

[0088] Aspect 20: The wireless device according to aspect 19, wherein the height of the high-k material is the same as the height of the first electrode finger or the second electrode finger. Additional Notes

[0089] The various operations of the methods described above can be performed by any suitable component capable of performing the corresponding function. This component may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors.

[0090] By way of example, the elements described herein, or any portion thereof, or any combination thereof, may be implemented as a “processing system” including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. One or more processors in the processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, software should be broadly interpreted as meaning instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc.

[0091] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" can include calculation, operation, processing, deduction, investigation, lookup (e.g., searching in a table, database, or other data structure), assertion, etc. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), etc. Additionally, "determine" can include parsing, selecting, picking, building, etc.

[0092] Within this disclosure, the term "exemplary" is used to mean "serving as an example, instance, or illustration." Any specific implementation or aspect described herein as "exemplary" is not necessarily to be construed as superior to or better than other aspects of this disclosure. Similarly, the term "aspect" does not require that all aspects of this disclosure include the features, advantages, or modes of operation discussed. The term "coupled" is used herein to refer to direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, objects A and C can still be considered coupled to each other, even if objects A and C are not in direct physical contact. For example, a first object can be coupled to a second object, even if the first object never has direct physical contact with the second object. The term "circuit" is used broadly and is intended to include hardware implementations of electronic devices and conductors that, when connected and configured, enable the performance of the functions described in this disclosure, without limitation on the type of electronic circuit.

[0093] The apparatus and methods described in the detailed description are illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively, "elements"). These elements may be implemented, for example, in hardware.

[0094] One or more of the components, steps, features, and / or functions illustrated herein may be rearranged and / or combined into a single component, step, feature, or function, or embodied in several components, steps, or functions. Additional elements, components, steps, and / or functions may also be added without departing from the features disclosed herein. The apparatus, devices, and / or components illustrated herein may be configured to perform one or more of the methods, features, or steps described herein.

[0095] It should be understood that the specific order or hierarchy of steps in the disclosed methods is an example of an exemplary process. It should be understood that the specific order or hierarchy of steps in these methods may be rearranged based on design preferences. The appended method claims present the elements of various steps in a sample order, but are not intended to be limited to the specific order or hierarchy presented, unless specifically stated herein.

[0096] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the text of the claims, wherein references to elements in the singular form are not intended to mean “one and only one,” but rather “one or more.” Unless otherwise specifically stated, the term “some” refers to one or more. The phrase “at least one of” referring to a list of items means any combination of those items, including individual members. For example, “at least one of the following: a , b or c "Aims to cover at least: a , b , c , ab , ac , bc and ab- c and any combination with multiples of the same element (e.g., a - a , a - a - a , a - a - b , a - a - c , a - b - b , a - c - c , b - b , b - b - b , b - b - c , c - c and c - c - c or a , b and c(any other order). All structural and functional equivalents of the elements throughout the various aspects described herein that are known to a person of ordinary skill in the art or will later be known are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is explicitly recited in the claims. No claim element should be construed in accordance with 35 USC § 112(f) unless the element is expressly recited using the phrase “component for…” or, in the case of a method claim, the phrase “step for…”.

[0097] It should be understood that the claims are not limited to the precise configurations and components illustrated above. Various modifications, variations, and alterations may be made to the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A surface acoustic wave (SAW) device, the surface acoustic wave (SAW) device comprising: piezoelectric layer; An interdigital transducer (IDT) is disposed above the piezoelectric layer and includes a first electrode finger and a second electrode finger. and A first high dielectric constant (high κ) material is disposed between the first electrode finger and the second electrode finger, wherein the height of the first high κ material above the piezoelectric layer is greater than 60% of the height of the first electrode finger or the second electrode finger above the piezoelectric layer.

2. The SAW device according to claim 1, wherein the dielectric constant of the first high-k material is greater than the dielectric constant of silicon dioxide.

3. The SAW device of claim 1, wherein the height of the first high-k material is at least as high as the height of the first electrode finger or the second electrode finger.

4. The SAW device according to claim 1, wherein: The IDT also includes a third electrode finger; The SAW device further includes a second high-kb material disposed between the second electrode finger and the third electrode finger; and The height of the second high-k material above the piezoelectric layer is greater than 60% of the height of the second electrode finger or the third electrode finger above the piezoelectric layer.

5. The SAW device according to claim 1, wherein the SAW device further comprises a temperature compensation layer disposed above the IDT.

6. The SAW device according to claim 5, wherein the SAW device further comprises a passivation layer disposed above the temperature compensation layer.

7. The SAW device of claim 1, wherein the SAW device includes a temperature-compensated (TC) SAW device.

8. The SAW device according to claim 1, wherein the SAW device further comprises a low-κ material disposed above the first electrode finger, the second electrode finger and the first high-κ material.

9. The SAW device of claim 8, wherein the low-κ material comprises silicon dioxide.

10. The SAW device according to claim 1, wherein the first high-k material comprises aluminum nitride (AlN), hafnium dioxide (HfO2), titanium dioxide (TiO2), zirconium dioxide (ZrO2), aluminum oxide (Al2O3), hafnium silicon oxide (HfSiO2), tantalum pentoxide (Ta2O5), niobium oxide (Nb2O5), scandium oxide (Sc2O3), or strontium titanate (SrTiO3).

11. A method for manufacturing a surface acoustic wave (SAW) device, the method comprising: An interdigitated transducer (IDT) is formed above a piezoelectric layer, wherein forming the IDT includes forming a first electrode finger and a second electrode finger; as well as A first high dielectric constant (high κ) material is formed such that the first high κ material is located between the first electrode finger and the second electrode finger, wherein the height of the first high κ material above the piezoelectric layer is greater than 60% of the height of the first electrode finger or the second electrode finger above the piezoelectric layer.

12. The method of claim 11, wherein the first electrode finger and the second electrode finger are formed prior to the first high-k material.

13. The method of claim 11, wherein the first electrode finger and the second electrode finger are formed after the first high-k material.

14. The method of claim 11, wherein the height of the first high-k material is the same as the height of the first electrode finger or the second electrode finger.

15. The method according to claim 11, wherein: The IDT also includes a third electrode finger; The SAW device further includes a second high-kb material disposed between the second electrode finger and the third electrode finger; and The height of the second high-k material above the piezoelectric layer is greater than 60% of the height of the second electrode finger or the third electrode finger above the piezoelectric layer.

16. The method according to claim 11, further comprising: A temperature compensation layer is formed on top of the IDT.

17. The method according to claim 16, further comprising: A passivation layer is formed on top of the temperature compensation layer.

18. The method according to claim 11, further comprising: A low-κ material is formed over the first electrode finger, the second electrode finger, and the first high-κ material.

19. A wireless device, the wireless device comprising: Radio frequency (RF) circuits; and A surface acoustic wave (SAW) filter, said SAW filter being coupled to said RF circuit, said SAW filter comprising: piezoelectric layer; An interdigitated transducer (IDT), the interdigitated transducer (IDT) being disposed above the piezoelectric layer and including a first electrode finger and a second electrode finger; and A high dielectric constant (high κ) material is disposed between the first electrode finger and the second electrode finger, wherein the height of the high κ material above the piezoelectric layer is greater than 60% of the height of the first electrode finger or the second electrode finger above the piezoelectric layer.

20. The wireless device of claim 19, wherein the height of the high-k material is the same as the height of the first electrode finger or the second electrode finger.

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