Surface acoustic wave sensor assembly

Abstract

To provide a sensor device having a surface acoustic wave (SAW) sensor assembly for measuring an environmental state of an environment.SOLUTION: A sensor device is provided that comprises an integrated sensor assembly having a surface acoustic wave (SAW) sensor arranged on a piezoelectric substrate. The SAW sensor is adapted to measure an environmental condition of an environment in response to receiving an RF signal. The SAW sensor includes an interdigital transducer (IDT) arranged on a substrate having at least one layer of piezoelectric material. The SAW sensor includes one or more SAW reflectors, or a second IDT formed on the piezoelectric material. The SAW sensor further includes an RF antenna formed on the piezoelectric material. The SAW sensor and the RF antenna are integrated with each other on the piezoelectric material.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Some embodiments of the present disclosure generally relate to sensor devices having surface acoustic wave (SAW) sensor assemblies for measuring environmental conditions of an environment.

Background Art

[0002] Surface acoustic wave (SAW) is an acoustic wave that travels parallel to the surface of an elastic material. Although the general mathematical consideration of SAW was first reported by Lord Rayleigh in 1855, its application in electronic devices was not utilized until 1965 when White and Voltmer et al. utilized interdigital transducers on piezoelectric materials. SAW is used in electronic devices, particularly RF / IF filters. The conversion from electrical energy to mechanical energy (in the form of SAW) is realized through the use of piezoelectric materials. Piezoelectric materials are materials that have the ability to generate internal charges from mechanical stress or generate internal mechanical strain in response to the application of an electric field. SAW transducers are often used on the surface of piezoelectric materials and not only convert electrical energy into mechanical energy (e.g., SAW), but also convert SAW into electrical energy. SAW devices use SAW within electronic components to provide several different functions including delay lines, filters, resonators, correlators, converters, sensors, etc. SAW devices can be placed on a wafer to perform their respective functions.

Summary of the Invention

[0003] Some embodiments described herein are directed to sensor devices comprising an integrated sensor assembly having a surface acoustic wave (SAW) sensor disposed on a substrate having at least one layer of piezoelectric material. The SAW sensor can be adapted to measure an environmental condition based on detection of SAW characteristics in response to receiving an incoming radio frequency (RF) signal. The SAW sensor can include an interdigital transducer (IDT) formed on the piezoelectric material. The IDT can generate a SAW based on the environmental condition in response to receiving the incoming RF signal. The SAW sensor can include one or more SAW reflectors that communicate with the IDT. The SAW sensor can include another IDT for receiving the SAW wave and generating an outgoing RF signal. The SAW sensor assembly can further include an RF antenna and a matching circuit. The matching circuit can be connected to the RF antenna and the IDT. The SAW sensor, the RF antenna, and the matching circuit can be integrated with each other on the piezoelectric material.

[0004] In a further embodiment, the sensor assembly can include a second IDT that receives a SAW from the first IDT and generates a vibration potential associated with the acoustic frequency of the received SAW. This vibration potential can include information associated with the measured environmental condition across a region of the surface of the piezoelectric substrate or piezoelectric layer. The sensor assembly can include a second RF antenna and a second matching circuit for outputting an outgoing RF signal associated with the vibration potential.

[0005] In an exemplary embodiment, a method for fabricating a sensor device is disclosed. The method can include fabricating an integrated sensor assembly by depositing a first conductive structure on a substrate having at least one layer of piezoelectric material, wherein the first conductive structure forms a radio frequency (RF) antenna. The method can further include depositing a second conductive structure on the piezoelectric material, wherein the second conductive structure forms a matching circuit connected to the RF antenna. The method can further include depositing a third conductive structure on the piezoelectric material, wherein the third conductive structure forms an interdigital transducer (IDT) connected to the RF antenna, and the IDT is a component of a surface acoustic wave (SAW) sensor. The method can further include depositing a fourth conductive structure on the piezoelectric material, wherein the fourth conductive structure forms at least one of a) one or more SAW reflectors or b) a second IDT. In some embodiments, the first conductive structure, the second conductive structure, the third conductive structure, and / or the fourth conductive structure can be formed together in a single deposition step.

[0006] In some embodiments, the sensor assembly can include a SAW sensor adapted to measure an environmental condition in response to receiving an incoming RF signal. The SAW sensor can include at least one layer of piezoelectric material disposed on a base substrate. The SAW sensor can further include a first IDT formed on the piezoelectric substrate, and the first IDT operates at a base resonance frequency. The SAW sensor can include a dielectric coating having a thickness or material associated with a shift in the base resonance frequency, and the first IDT including the dielectric coating has an adjusted resonance frequency.

[0007] In an exemplary embodiment, a method for fabricating a sensor assembly is disclosed. The method begins by fabricating a SAW sensor by depositing a conductive layer on a piezoelectric substrate, where the conductive layer forms an interdigital transducer (IDT) of the SAW sensor. The IDT has a base resonance frequency, for example, based on the pitch between fingers in the IDT. The method continues by adjusting the resonance frequency of the IDT by depositing a dielectric coating having a thickness of a material on the conductive layer, where at least the thickness or the material is associated with a shift in the base resonance frequency, and the IDT including the dielectric coating has an adjusted resonance frequency.

[0008] In other embodiments, a sensor assembly can include one or more SAW sensors adapted to measure an environmental condition in response to receiving an incoming RF signal. The first SAW sensor can include a substrate having at least one layer of piezoelectric material and a first IDT formed on the piezoelectric material. The first IDT includes two comb-shaped electrodes including meshing conductive fingers in a first arrangement. The meshing conductive fingers in the first arrangement generate a signal modulation of a signal received by the first IDT. The signal modulation identifies the SAW sensor.

[0009] In other embodiments, a sensor assembly can include a SAW sensor disposed on a substrate having at least one layer of piezoelectric material. The SAW can be adapted to measure an environmental condition of the environment in response to receiving an incoming RF signal. The SAW sensor can include an IDT formed on the piezoelectric material. The IDT generates a SAW based on the environmental condition in response to receiving an incoming RF signal. The SAW sensor can further include a set of SAW reflectors, the set of SAW reflectors having a spatial arrangement such that a SAW reflected from the SAW reflector and propagating back from the SAW reflector to the IDT has a signal modulation that identifies the SAW sensor.

[0010] The present disclosure is shown in the accompanying drawings by way of example and not limitation, in which like reference numerals refer to like elements. References to "an" or "one" embodiment in the present disclosure are not necessarily to the same embodiment, and it should be noted that such references mean at least one.

Brief Description of the Drawings

[0011]

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DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiments of the present disclosure provide a sensor device including a SAW sensor assembly and related methods for fabricating the SAW sensor assembly. The SAW sensor assembly can include conductive elements such as antennas, circuits, and / or interdigital transducers (IDTs) disposed on a substrate having at least one layer of piezoelectric material. The SAW sensor assembly can be formed on, for example, a piezoelectric substrate or other types of substrates such as a semiconductor substrate with a piezoelectric layer thereon. The SAW sensor receives an incoming RF signal and generates SAWs for measuring environmental conditions such as pressure and temperature of an environment (e.g., the surface of the piezoelectric substrate or piezoelectric layer). The various disclosed embodiments provide ways to passively measure environmental conditions (e.g., without active devices such as a power supply), ways to perform measurements across the surface area of the piezoelectric substrate or piezoelectric layer, ways to finely tune the SAW sensor, and / or ways to distinguish between various SAW sensors of the sensor assembly.

[0013] Various embodiments include a SAW sensor disposed on a substrate having at least one layer of piezoelectric material (e.g., a piezoelectric substrate or a piezoelectric layer disposed on a substrate), and a device having a sensor assembly adapted to measure an environmental condition of an environment in response to receiving an incoming RF signal, or the device can be utilized. The SAW sensor can include an antenna, a matching circuit, and an interdigital transducer (IDT) disposed on the surface of the piezoelectric material. The SAW sensor can generate SAWs to measure the environmental condition without using an active circuit (e.g., a CMOS device driven by a battery). The antenna, the matching circuit, and the interdigital transducer can be integrated with each other on the piezoelectric material.

[0014] In one example, a sensor device includes an integrated sensor assembly having a SAW sensor disposed on a piezoelectric substrate. The SAW sensor can be adapted to measure an environmental condition of an environment in response to receiving an incoming high-frequency (RF) signal. The SAW sensor can include an IDT formed on the piezoelectric substrate. The IDT can generate SAWs based on an environmental condition (e.g., having at least one of amplitude, frequency, time delay, phase, or wavelength depending on the environmental condition) in response to receiving the incoming RF signal. The SAW sensor can include one or more SAW reflectors that reflect the SAWs back to the IDT. The IDT can then generate a new outgoing RF signal based on the received reflected SAWs. For example, the IDT can generate a vibration potential associated with the acoustic frequency of the reflected SAWs. This vibration potential can include information associated with the measured environmental condition across a region of the surface of the piezoelectric material. The SAW sensor assembly can further include an RF antenna and a matching circuit attached to the first IDF. The matching circuit can be connected to the RF antenna and the first IDT. The SAW sensor, the RF antenna, and the matching circuit can be integrated with each other on the piezoelectric material.

[0015] In some embodiments, the sensor assembly can include a SAW sensor having two IDTs separated by the surface of a piezoelectric substrate or a piezoelectric layer on a substrate. The first IDT can receive an incoming RF signal and be used to generate a SAW, which is passed along the surface of the piezoelectric substrate or piezoelectric layer to the other IDT. The other IDT can receive the SAW and generate a vibration potential associated with the acoustic frequency of the SAW. This vibration potential can include information associated with the measured environmental conditions (e.g., temperature, pressure, etc.), where the environment includes the region between the IDTs. Each IDT can be connected to an RF antenna via a matching circuit.

[0016] In one example, in addition to or instead of including one or more reflectors, the SAW sensor can include two IDTs (one to generate a SAW and the other to receive the SAW and then generate a new outgoing RF signal). The additional IDT can generate a vibration potential associated with the acoustic frequency of the received SAW. This vibration potential can include information associated with the environmental conditions measured across the surface region of the piezoelectric material (e.g., piezoelectric substrate or piezoelectric layer). In embodiments including a second IDT, the SAW sensor assembly can further include a second RF antenna that outputs a new outgoing RF signal, and a second matching circuit connected to the second RF antenna and the additional IDT. The second RF antenna and the second matching circuit can be integrated with each other and with the SAW sensor, RF antenna, and matching circuit on the piezoelectric material.

[0017] In an exemplary embodiment, a method for fabricating a sensor device is disclosed. The method can include fabricating an integrated sensor assembly by depositing a first conductive structure on a substrate having at least one layer of piezoelectric material, where the first conductive structure forms a radio frequency (RF) antenna. The method can further include depositing a second conductive structure on the piezoelectric material, where the second conductive structure forms a matching circuit connected to the RF antenna. The method can further include depositing a third conductive structure on the piezoelectric material, where the third conductive structure forms an interdigital transducer (IDT) connected to the RF antenna, where the IDT is a component of a surface acoustic wave (SAW) sensor. The method can further include depositing a fourth conductive structure on the piezoelectric material, where the fourth conductive structure forms a) one or more SAW reflectors, or b) at least one second IDT. In some embodiments, the first conductive structure, the second conductive structure, the third conductive structure, and / or the fourth conductive structure are formed together in a single deposition step. Alternatively, multiple deposition steps can be performed, with each deposition step forming one or more of the first conductive structure, the second conductive structure, the third conductive structure, and the fourth conductive structure. These conductive structures can, in embodiments, each be planar conductors. Fabricating a sensor device having all of the above elements in a single integrated device enables the use of a more compact sensor device, thereby reducing manufacturing costs and time and reducing the number of manufacturing steps required.

[0018] In an embodiment, the sensor assembly includes a SAW sensor having a first IDT disposed on a piezoelectric material and operating at a base resonance frequency. The first IDT can include a dielectric coating including a thickness and / or material associated with a shift in the base resonance frequency, and the first IDT including the dielectric coating has an adjusted resonance frequency. In a further embodiment, the sensor assembly can include various SAW sensors, each SAW sensor having an IDT including a dielectric coating of a different thickness and / or material, such that each respective IDT has a different adjusted resonance frequency. By each respective unique frequency, a reader can receive transmitted RF signals generated by different SAW sensors and can distinguish between the transmitted RF signals. Thereby, it becomes possible to manufacture a sensor wafer on which a plurality (e.g., 5 to 20 or more) of SAW sensors are disposed on the same sensor wafer. Signals generated by each SAW sensor on the sensor wafer can be received by a reading device. Thereafter, a reader (or a controller connected thereto) can determine which SAW sensor generated each particular transmitted RF signal based on the frequency of the transmitted RF signal. Thereby, a detector and / or a controller can determine various environmental conditions at various positions of the sensor wafer.

[0019] In an exemplary embodiment, a method for fabricating a sensor assembly is disclosed. The method can begin by fabricating a SAW sensor by depositing a conductive layer on a piezoelectric substrate, where the conductive layer forms an interdigital transducer (IDT) of the SAW sensor. The IDT has a base resonance frequency, for example, based on a pitch between fingers in the IDT. The method continues by adjusting the resonance frequency of the IDT by depositing a dielectric coating having a thickness of a material on the conductive layer, where at least the thickness or the material is associated with a shift in the base resonance frequency and the IDT including the dielectric coating has an adjusted resonance frequency.

[0020] In some embodiments, the sensor assembly has a SAW sensor that includes an IDT, which has two comb electrodes that include a configured set of meshing conductive fingers. The configured set of meshing conductive fingers can cause signal modulation of a signal passing through the IDT. This signal modulation can identify the SAW sensor. Additionally or alternatively, the sensor assembly can have a SAW sensor that includes an IDT and a set of SAW reflectors, where the set of SAW reflectors has a spatial arrangement such that a SAW reflected by the SAW sensor has a signal modulation that identifies the SAW sensor.

[0021] In one example, the sensor assembly can include a plurality of SAW sensors adapted to measure environmental conditions in response to receiving an incoming RF signal. A first SAW sensor can include a piezoelectric substrate and a first IDT formed on the piezoelectric substrate. The first IDT can include two comb electrodes that include a first configured set of meshing conductive fingers. The first configured set of meshing conductive fingers causes signal modulation of a signal received by the first IDT. The signal modulation identifies the SAW sensor. A second SAW sensor can include a second IDT formed on the piezoelectric substrate (or a different piezoelectric substrate). The second IDT can include two comb electrodes that include a second configured set of meshing conductive fingers. The second configured set of meshing conductive fingers causes signal modulation of a signal received by the second IDT. The second signal modulation identifies the second SAW sensor. Thus, the RF signals output by the first SAW sensor and the second SAW sensor can be identified based on their associated signal modulations. This enables the manufacture of a sensor wafer on which a plurality (e.g., 5 to 20 or more) of SAW sensors are disposed on the same sensor wafer. The signals generated by each SAW sensor on the sensor wafer can be received by a reader device. Thereafter, a reader (or a controller connected thereto) can determine, based on the frequency of the RF signal, which SAW sensor generated each particular RF signal. This enables a detector and / or a controller to determine various environmental conditions at various locations on the sensor wafer.

[0022] Any of the previously disclosed embodiments can be combined. For example, a sensor wafer can include a first SAW sensor having a first dielectric coating, IDT fingers in a first arrangement, and / or a reflector in a first arrangement, and a second SAW sensor having a second dielectric coating, IDT fingers in a second arrangement, and / or a reflector in a second arrangement. The first SAW sensor and the second SAW sensor can each optionally be part of an integrated sensor assembly that includes their respective antennas and matching networks. In some embodiments, an integrated sensor assembly of a plurality of SAW sensors is included on a shared piezoelectric substrate or on another substrate on which a piezoelectric layer is disposed.

[0023] The above embodiments and similar embodiments provide several advantages and improvements in the fields of manufacturing and signal processing of sensor assemblies, such as SAW sensors and sensor wafers including one or more SAW sensors disposed on a sensor wafer. Such advantages include improvements in SAW sensor assemblies, for example, improvements in the performance of SAW sensors, wide applications of SAW sensors, improvements in differentiating signals between SAW sensors, and reduction of manufacturing costs and manufacturing complexity of SAW sensors.

[0024] The performance of the sensor can be improved, for example, by a sensor assembly using a passive circuit (e.g., a SAW sensor). The passive circuit enables measurement of more severe levels of environment (such as high temperature and high pressure) without being restricted by the specification limitations of active devices. For example, by using an IDT connected to a unique antenna, a wider range of applications of the SAW sensor becomes possible. The IDT connected to the unique antenna can be used to measure environmental conditions over a wider environment by sending SAWs between IDTs arranged over a wide area of the piezoelectric substrate. Improvement in differentiation of signals between SAW sensors can be achieved, for example, by fabricating a sensor assembly including SAW sensors adjusted to operate at various frequencies by laying a dielectric coating of a unique thickness and material. Alternatively or additionally, the SAW sensor can generate a unique signal modulation for the signal passing through each respective SAW sensor. The signal modulation can be generated by utilizing the arrangement of the meshing conductive fingers of the IDT electrodes and / or the spatial arrangement of the SAW reflectors.

[0025] FIG. 1 shows a simplified top view of an exemplary processing system 100 according to an aspect of the present disclosure. The processing system 100 includes a factory interface 91 that can couple a plurality of substrate cassettes 102 (e.g., front opening unified pods (FOUPs) and side storage pods (SSPs)) for transferring a substrate (e.g., a wafer such as a silicon wafer) within the processing system 100. As used herein, FOUPs, SSPs, and other substrate cassettes may be collectively referred to as storage locations. In some embodiments, one or more of the substrate cassettes 102 include one or more sensor wafers 110 in which SAW sensor assemblies are disposed or incorporated in addition to or instead of the wafers to be processed. The SAW sensor assemblies of the sensor wafers 110 can be used to measure environmental conditions (e.g., temperature, pressure, etc.) of the environment. For example, the sensor wafers 110 can be used to measure the environmental conditions inside one or more processing chambers 107 and other compartments and chambers as described hereinafter. The factory interface 91 can also transfer the sensor wafers 110 into and out of the processing system 100 using the same functionality for transferring the wafers to be processed and / or the processed wafers, which will be described hereinafter.

[0026] The processing system 100 can also include first vacuum ports 103a, 103b, and the first vacuum ports 103a, 103b can couple the factory interface 91 to respective stations 104a, 104b that can be, for example, a degassing chamber and / or a load lock. Second vacuum ports 105a, 105b are coupled to the respective stations 104a, 104b and are disposed between the stations 104a, 104b and the transfer chamber 106, and can facilitate the transfer of substrates into the transfer chamber 106. The transfer chamber 106 includes a plurality of processing chambers 107 (also referred to as process chambers) disposed around and coupled to the transfer chamber 106. The processing chambers 107 are coupled to the transfer chamber 106 via respective ports 108 such as slit valves.

[0027] The processing chamber 107 can include one or more of an etching chamber, a deposition chamber (including an atomic layer deposition chamber, a chemical vapor deposition chamber, a physical vapor deposition chamber, or a plasma enhanced version thereof), and / or an annealing chamber. The processing chamber 107 can include chamber components such as, for example, a showerhead or a chuck (e.g., an electrostatic chuck).

[0028] In various embodiments, the factory interface 91 includes a factory interface robot 111. The factory interface robot 111 can include a robotic arm, which can be a SCARA (selective compliance assembly robot arm) robot such as a 2-link SCARA robot, a 3-link SCARA robot, a 4-link SCARA robot, etc., or can include the SACRA robot. The factory interface robot 111 can include an end effector at the end of the robotic arm. The end effector can be configured to grasp and handle a specific object such as a wafer. The factory interface robot 111 can be configured to transfer objects between a substrate cassette 102 (e.g., FOUP and / or SSP) and stations 104a, 104b (which can be load locks, for example).

[0029] The transfer chamber 106 includes a transfer chamber robot 112. The transfer chamber robot 112 can include an end effector at the end of the robotic arm. The end effector can be configured to handle specific objects such as wafers, edge rings, ring kits, and / or sensor wafers 110. The transfer chamber robot 112 can be a SCARA robot, although in some embodiments it can have fewer links and / or lower degrees of freedom than the factory interface robot 111.

[0030] The processing system can include one or more RF antennas 129 within the processing chamber 107. In an embodiment, the RF antenna 129 can be placed on the wall of the processing chamber 107 or disposed inside the wall. The RF antenna can be disposed within a component of the chamber in some embodiments. For example, the RF antenna 129 can be disposed within a chuck (e.g., an electrostatic chuck) of the processing chamber or within a showerhead. Additionally or alternatively, one or more RF antennas 129 can be disposed within the transfer chamber 106, within a load lock (e.g., load locks 104a, 104b), within the FI 101, and / or within the cassette 102.

[0031] The RF antenna 129 can be communicatively connected to the SAW sensor assembly on the sensor wafer 110. For example, an RF signal can be transmitted from the RF antenna 129 to the SAW sensor assembly on the sensor wafer 110, and a return signal can be generated by the SAW sensor assembly and received by the same RF antenna or another RF antenna 129. The return signal can include information indicating a measured value of the environmental state of the environment inside (e.g., on the surface of the SAW sensor assembly) such as a processing chamber, a load lock, a transfer chamber, etc. The RF antenna can be connected to a transceiver that generates and / or receives RF signals. In some embodiments, one or more RF antennas associated with the processing chamber are connected to an RF transmitter, and one or more RF antennas associated with the processing chamber are connected to an RF receiver. The sensor wafer may not include any power components (e.g., any battery), and instead, may be powered by the received RF signal generated by the RF antenna 129. Thus, the sensor wafer can be a passive device.

[0032] The controller 109 can control various aspects of the processing system 100 and can be communicatively connected to the RF antenna 129. The controller 109 may be and / or may include a computing device such as a personal computer, a server computer, a programmable logic controller (PLC), a microcontroller, etc. The controller 109 may include one or more processing devices such as a microprocessor or a central processing unit. More specifically, the processing device may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing another instruction set, or a processor implementing a combination of instruction sets. The processing device may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), or a network processor, etc.

[0033] Although not shown, the controller 109 may include a data storage device (e.g., one or more disk drives and / or solid state drives), main memory, static memory, a network interface, and / or other components. The controller 109 can execute instructions for performing any one or more of the methods and / or embodiments described herein. The instructions may be stored on a computer-readable storage medium, which may include main memory, static memory, secondary storage, and / or a processing device (during execution of the instructions). For example, the controller 109 can execute instructions to activate one or more RF antennas 129, a factory interface 91, load locks or stations 104a, 104b, a transfer chamber 106, and / or any processing chamber 107 located in different storage locations. Thereafter, the controller 109 can receive a return RF signal generated by a SAW sensor assembly on the sensor wafer 110 and analyze the received RF signal. Each of the SAW sensor assemblies can be configured to measure a specific environmental characteristic, such as pressure, temperature, plasma output, and output an RF signal indicative of the measured value of the specific environmental characteristic. Additionally, a plurality of different SAW sensor assemblies on the sensor wafer can be configured to measure different environmental characteristics. The controller 109 can receive the RF signal and determine a measured value (e.g., of amplitude, phase, frequency, and / or time delay) for the measured environmental characteristic based on the received RF signal.

[0034] In some embodiments, a single sensor wafer 110 includes a plurality of SAW sensor assemblies tuned to different frequencies and / or configured to perform different signal modulations (e.g., by performing a phase shift). Each SAW sensor can be associated with a particular modulation and / or frequency. The different frequencies and / or modulations of the various received RF signals can be used by the controller 109 to uniquely identify the particular SAW sensor that generated each RF signal. Thus, the sensor wafer can include many different SAW sensors, and the controller 109 can uniquely determine which SAW sensor generated each received RF signal based on the unique fingerprint of that RF signal. Thereby, the controller 109 can determine an environmental profile of the entire sensor wafer 110 (e.g., the local pressure and / or temperature of the sensor wafer 110).

[0035] FIG. 2 is a top perspective view of a sensor device 200 (e.g., a sensor wafer) including an integrated SAW sensor assembly 210 according to an aspect of the present disclosure. The sensor device 200 includes a base substrate 202 and one or more SAW sensor assemblies 210A-D incorporated on the surface of the base substrate 202. The SAW sensor assemblies 210A-D can each include RF antennas 208A-D, matching circuits 206A-D, and / or SAW sensors 204A-D, which are parts of the integrated device. Alternatively, one or more SAW sensor assemblies 210A-D may include integrated components of SAW sensors 204A-D connected to separate RF antennas and separate discrete matching circuits, may include integrated SAW sensors 204A-D and matching circuits 206A-D connected to separate discrete antennas, and / or may include integrated SAW sensors 204A-D and antennas 208A-D connected to separate discrete matching circuits. In some embodiments, the sensor wafer has at least one layer of a piezoelectric material, and a plurality of integrated SAW sensors 204A-D are formed in the at least one layer, and optionally, one or more integrated antennas 208A-D and / or integrated matching circuits 206A-D are disposed on the at least one layer. These components will be described in more detail below with reference to FIGS. 3A-B.

[0036] As shown in FIG. 2, the base substrate 202 can be a disk-shaped structure including a flat surface (e.g., a wafer). In other embodiments, the base substrate 202 can be formed in other flat shapes that can be used for transfer, deposition, and processing by a processing system (e.g., the processing system 100 of FIG. 1). The base substrate 202 can be fabricated from a conventional wafer-based substrate such as silicon, and can be LiNbO3, LiTaO3, or La3Ga5SiO 14It can include piezoelectric materials such as, or can be partially or completely coated by such piezoelectric materials. In some embodiments, the base substrate can be entirely made of a piezoelectric material without using a conventional wafer-based substrate (e.g., silicon). In some embodiments, the base substrate can include a piezoelectric substrate that includes or is composed of a piezoelectric material.

[0037] As shown in FIG. 2, the sensor device 200 includes a plurality of SAW sensor assemblies 210A - D incorporated in and / or deposited on the surface of a base substrate 202. The sensor device 200 can include one or more SAW sensor assemblies 210A - D. Although four sensor assemblies 210A - D are shown as an example, more or fewer sensor assemblies can be included in the sensor device 200. The SAW sensor assemblies 210 can be arranged in a sensor array, where each integrated SAW sensor assembly 210 measures the environmental conditions at various positions on the base substrate 202. In some embodiments, each SAW sensor assembly is formed on a common piezoelectric substrate or on another substrate on which a piezoelectric layer is formed (e.g., on the same wafer). Alternatively, one or more SAW sensor assemblies can be formed on a separate piezoelectric substrate or a substrate including a piezoelectric layer, forming separate sensor assemblies (e.g., formed on a separate piezoelectric substrate together with other SAW sensor assemblies and then diced and packaged to form separate SAW sensor assemblies). Subsequently, the separate sensor assemblies can be attached to the base substrate 202. In such embodiments, the base substrate 202 can be a piezoelectric material or not. Each SAW sensor assembly 210A - D can be attached or disposed at different positions on the base substrate 202.

[0038] As shown in FIG. 2, the SAW sensor assemblies 210A - D each include RF antennas 208A - D, matching circuits 206A - D, and SAW sensors 204A - D. The RF antennas 208A - D, matching circuits 206A - D, and SAW sensors 204A - D can each include planar conductors. For example, the RF antennas 208A - D, matching circuits 206A - D, and SAW sensors 204A - D can each be formed by depositing a single conductive layer (e.g., one layer for the IDT and / or reflector, one layer for the antenna, and one layer for the matching network) for each conductive element. In some embodiments, the RF antennas 208A - D, matching circuits 206A - D, and SAW sensors 204A (including, for example, one or more IDTs and / or one or more reflectors) can form a single conductive layer, where depositing each element can be performed together in one lithography step. The RF antennas 208A - D, matching circuits 206A - D, and / or SAW sensors 204A of a single SAW sensor assembly 120A - D can be integrated with each other on the base substrate 202 (or on another piezoelectric substrate or material). Further, in some embodiments, some or all of the SAW sensor assemblies 120A - D (including these SAW sensors, matching networks, and antennas) are integrally combined together on the base substrate 202. The RF antennas 208A - D, matching circuits 206A - D, and SAW sensors 204A can include various materials and configurations as described in other embodiments of this specification.

[0039] In some embodiments, the sensor device 200 can include a protective coating or layer disposed on one or more SAW sensor assemblies 210. The protective coating can include a dielectric material having resistance to high temperatures (e.g., 300 - 1000 °C). Examples of dielectric coatings that can be used include Al2O 3、 AlN, Y2O3, Y3Al5O 12 , yttrium-based oxides, fluorides, and / or oxyfluorides, etc. are included.

[0040] In some embodiments, the sensor device 200 includes a layer on the back surface of the base substrate 202 opposite the SAW sensor assembly 210. The layer on the back surface may include or be a metal layer. The metal layer can be used to minimize interference from other signals (e.g., the RF antenna 129 of FIG. 1 in another chamber) and, optionally, can provide improved support for holding the sensor device 200 by a chuck (e.g., an electrostatic chuck).

[0041] In some embodiments, the sensor device 200 may include a shielding structure disposed across a region of the base substrate over the SAW sensor 204 or a portion thereof. The shielding structure can include a recess above the region of the base substrate 202 and allow for the propagation of SAWs across the surface of the base substrate 202. The shielding structure can include a material having resistance to high temperatures and / or pressure resistance. In some embodiments, the material is a metal such as stainless steel, aluminum, or an aluminum alloy. In some embodiments, the material is a ceramic, which can be a dielectric material. In some embodiments, the shielding structure is disposed across a larger portion of the base substrate 202. For example, the shielding structure can include a cover that completely encloses the sensor device 200.

[0042] In some embodiments, as shown in FIG. 2, the SAW sensor assemblies 210A - D can be disposed on the same side (e.g., the front side) of the substrate. However, in other embodiments, the SAW sensor assemblies 210A - D can be disposed on both the front and back sides of the substrate. For example, a first set of SAW sensor assemblies (which can operate at a first resonance frequency) can be disposed on a first side of the base substrate 202, and a second set of SAW sensors (which can operate at a second resonance frequency) can be disposed on a second side of the base substrate 202.

[0043] In some embodiments, SAW sensor assemblies 210A - D can be arranged in proximity to each other. In some embodiments, SAW sensor assemblies can be co - located or can share components (e.g., the RF antenna 208A, matching circuit 206A, and / or SAW sensor of a first SAW sensor assembly can be part of another SAW sensor assembly). In one embodiment, a first IDT can be adjacent to a second IDT. The first IDT can generate a SAW that is reflected by a reflector and returned to the second IDT. In one embodiment, the SAW reflector of a SAW sensor (e.g., 204A) can be used to reflect a SAW from a second SAW sensor assembly. In other examples, two SAW sensor assemblies can include SAW sensors that generate SAWs and propagate them across the same region of the substrate 202. In other examples, a SAW sensor assembly can be formed such that the IDTs of SAW sensors 204 are arranged adjacent to each other and propagate SAWs in two different directions.

[0044] Figures 3A - B illustrate various embodiments of SAW sensor assemblies 300A - B according to aspects of the present disclosure. The SAW sensor assembly 300 can include RF antennas 306A - B, matching circuits 304A - B, and SAW sensors 302A - B. The SAW sensor assembly can be used, for example, on the sensor device 200 of FIG. 2.

[0045] The RF antennas 306A - B can include planar conductors or multiple conductive layers coupled together to receive and / or transmit RF signals. As used herein, components that are coupled together may be directly coupled or indirectly coupled. For example, an IDT coupled to an antenna may be directly coupled to the antenna or indirectly coupled to the antenna via a matching network between the IDT and the antenna. The RF antennas 306A - B can operate as a filter associated with a specific RF range. The RF antennas 306A - B can include resonator antennas (e.g., dielectric resonator antennas, etc.), fractal antennas, or some other type of antenna. The RF antennas 306A - B may have a flat structure or may be formed to be generally flat or coplanar with the surface of the substrate (e.g., can be a planar conductor). The matching circuits 304A - B are coupled to the RF antennas 306A - B and the SAW sensors 302A - B. The matching circuits 304A - B can include a combination of circuit components such as resistors, capacitors, and / or inductors to match the impedance and / or load of the RF antennas 306A - B. The matching circuits 304A - B can be designed in an embodiment to minimize signal reflection between the RF antennas 306A - B and the SAW sensors 302A - B. Each SAW sensor 302A - B is coupled to its respective RF antenna 306A - B via its respective matching circuit 304A - B. As shown in FIGS. 3A - B, the SAW sensors 302A - B can include interdigital transducers (IDTs) 310A - B. The IDTs 310A - B include two comb - shaped electrodes that mesh with each other. The IDTs 310A - B can be disposed on a piezoelectric material (e.g., the base substrate 202 of FIG. 2). The IDT receives an input signal (e.g., an alternating current (AC) signal) from the matching circuit 304 and, based on that signal, generates an electric field in the gap between the conductive fingers of the electrodes. This electric field causes a SAW to be generated on the surface of the piezoelectric material.

[0046] As shown in FIG. 3A, the SAW sensor 302A may include SAW reflectors 312A - B. The SAW generated by the IDT 310 propagates along the surface of the piezoelectric material to the SAW reflectors 312A - B. The SAW reflectors 312A - B may include strips of conductive material (e.g., planar conductors) designed to reflect a portion of the incident SAW generated by the IDT 310A. The reflected portion of the SAW may be reflected back to the IDT 310A. The IDT 310A can combine the SAWs reflected by the plurality of reflectors 312A - B to generate a vibration potential. The vibration potential can be sent to the RF antenna 306. The RF antenna 306 outputs a transmitted RF signal associated with the vibration potential, and this transmitted RF signal can be received by an RF signal receiving device (e.g., the RF antenna 129 in FIG. 1). The vibration potential generated by the IDT 310A contains information indicating the state of the environment disposed between the IDT 310 and the SAW reflector 312. The environmental state can be indicated by the change in frequency between the RF signal transmitted to the SAW sensor assembly 300 and the RF signal returned and received. The returned and received signal may contain information indicating the environmental state. For example, for a given temperature or pressure, the length of the piezoelectric material may increase or contract, changing the pitch, phase, and overall delay of the signal, which can be calibrated to a specific temperature or pressure. In some embodiments, the reflectors can be spatially arranged and calibrated such that the change in frequency between the RF signals is associated with a change in the environmental state (e.g., a change in temperature or pressure).

[0047] In some embodiments, the SAW reflectors 312A - B can be arranged on one or more sides of the IDT 310A as shown in FIG. 3A. The SAW reflectors can, in some embodiments, vary in distance from each other and thickness. Alternatively, the SAW reflectors can have a uniform thickness and / or spacing.

[0048] As shown in FIG. 3B, the SAW sensor 302B includes a series of delay lines 314A - C. The SAW generated by the IDT 310 propagates along the surface of the piezoelectric material to the delay lines 314A - C. The delay lines 314A - C may include strips of conductive material (e.g., planar conductors) designed to reflect and / or delay the SAW generated by the IDT 310. The delayed and reflected SAWs return to the IDT 310 and are combined together. The relative delays of the reflected SAWs interfere with each other constructively and destructively, resulting in an oscillating potential that indicates the measured environmental condition. The oscillating potential is sent to the RF antenna 306 and can further be sent to other devices (e.g., the RF antenna 129 of FIG. 1). The oscillating potential contains information indicating the state of the environment between the IDT 310 and the delay lines 314. The environmental condition can be indicated by a change in the frequency of the return RF signal transmitted by the RF antenna 306 or by the relative delay of the reflected SAWs. In some embodiments, the reflectors 314A - C can be spatially arranged and calibrated such that the relative delay between a first set of delay lines (e.g., 314A) and a second set of delay lines (e.g., 314B) is associated with the measured environmental condition such as temperature or pressure.

[0049] In some embodiments, SAW sensors 302A - B include a second IDT (not shown). The first IDTs 310A - B can capture an incoming electrical signal and generate a SAW associated with the incoming signal. The SAW can travel across the piezoelectric material and can be received by the second IDT. In some embodiments, the SAW can pass through conductive elements (e.g., delay lines 314) on the surface of the piezoelectric material before reaching the second IDT. The second IDT can generate a vibration potential associated with the received SAW. The vibration potential can be transmitted to an RF antenna attached to the matching circuit via the matching circuit connected to the second IDT. A change between a first vibration potential based on the received RF signal and a second vibration potential generated by the IDT based on the received SAW can indicate the measured environmental condition. In some embodiments, multiple IDTs can share a common RF antenna and / or matching network.

[0050] In some embodiments, all of the RF antennas 306A - B, the matching circuits 304A - B, and the SAW sensors 302A - B including the IDTs 310A - B are integrated together on a common piezoelectric material. As further described in other embodiments, the SAW sensor assemblies 300A - B can be fully integrated into the piezoelectric material. This allows the entire SAW sensor assembly 300A - B to be fabricated together on a substrate (e.g., a wafer) as a single integrated device, rather than fabricating each component separately in multiple assembly steps and separate component fabrication steps. Fabricating a sensor device with all of the above components as a single integrated device enables the use of a more compact sensor device, reduces manufacturing costs, shortens the time, and reduces the number of required manufacturing steps. Also, fabricating a single device can make the fabricated components compatible with each other. Additionally, the inefficiency of matching the component specifications can be eliminated.

[0051] FIG. 4 is a flowchart of a method 400 for fabricating a SAW sensor assembly according to an aspect of the present disclosure. Method 400 may be executed, in an embodiment, to manufacture a sensor device (e.g., sensor assembly 110 of FIG. 1).

[0052] Referring to FIG. 4, at block 410, a conductive structure is formed on a substrate on which at least one layer of piezoelectric material is disposed, and an RF antenna is formed on the piezoelectric material. The RF antenna may correspond to any of the RF antennas described above. The piezoelectric material may be any of the piezoelectric materials described above. Forming the first conductive structure may include performing a photoresist deposition process for depositing a photoresist on the piezoelectric material, performing a patterning process (e.g., using a lithography apparatus) for curing a selective portion of the photoresist, and performing an etching process (e.g., in an etching chamber) for etching away either the cured or uncured portion of the photoresist. Next, a deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may be performed (e.g., in a deposition chamber) to deposit a conductive layer (e.g., a metal layer) on the piezoelectric material and the photoresist formed thereon. Thereafter, a selective etching process (e.g., in an etching chamber) may be performed to remove the photoresist and the conductive material formed thereon, leaving the first conductive structure.

[0053] In block 420, a second conductive structure is formed on the piezoelectric structure to form a matching circuit, which may have an electrical connection to the first conductive structure that constitutes the RF antenna (e.g., may be connected to the RF antenna). The matching circuit may correspond to the matching circuit described above. Forming the second conductive structure may include performing a photoresist deposition process for depositing a photoresist on the piezoelectric material, performing a patterning process (e.g., using a lithography apparatus) for curing a selective portion of the photoresist, and performing an etching process (e.g., in an etching chamber) for etching away either the cured or uncured portion of the photoresist. Then, a deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may be performed (e.g., in a deposition chamber) to deposit a conductive layer (e.g., a metal layer) on the piezoelectric material and the photoresist formed thereon. Thereafter, a selective etching process (e.g., in an etching chamber) may be performed to remove the photoresist and the conductive material formed thereon, leaving the second conductive structure. The second conductive structure may be formed simultaneously with the first conductive structure. Thus, a series of processes (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) may be executed to form both the first conductive structure and the second conductive structure simultaneously or in parallel.

[0054] In block 430, a third conductive structure is formed on the piezoelectric structure to form an interdigital transducer (IDT) on the piezoelectric material. The IDT can be connected to the RF antenna via a matching circuit. The IDT can include the features and configurations of the IDT (e.g., IDT 310 in FIG. 3) disclosed in other embodiments of the present disclosure. Forming the third conductive structure can include performing a photoresist deposition process for depositing a photoresist on the piezoelectric material, performing a patterning process (e.g., using a lithography apparatus) for curing a selective portion of the photoresist, and performing an etching process (e.g., in an etching chamber) for etching away either the cured or uncured portion of the photoresist. Then, a deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) can be performed (e.g., in a deposition chamber) to deposit a conductive layer (e.g., a metal layer) on the piezoelectric material and the photoresist formed thereon. Thereafter, a selective etching process (e.g., in an etching chamber) can be performed to remove the photoresist and the conductive material formed thereon, leaving the third conductive structure. The third conductive structure can be formed simultaneously with the first conductive structure and / or the second conductive structure. Thus, a series of processes (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) can be executed to form the first conductive structure, the second conductive structure, and the third conductive structure simultaneously or in parallel.

[0055] In block 440, a fourth conductive structure is formed on the piezoelectric material to form at least one of a) one or more SAW reflectors, or b) a second IDT electrode. The SAW reflector and the second IDT can be separated from the IDT by a span of the piezoelectric material through which the SAW can propagate. Thereby, the second IDT and / or the reflector can be communicatively connected to the first IDT via the SAW. The SAW reflector can include the features and configurations of the SAW reflectors disclosed elsewhere in this disclosure (e.g., the SAW reflector 312 in FIG. 3). The second IDT can include the features and configurations of the IDTs disclosed in other embodiments of this disclosure (e.g., the IDT 310 in FIG. 3). Forming the fourth conductive structure can include performing a photoresist deposition process for depositing a photoresist on the piezoelectric material, performing a patterning process (e.g., using a lithography apparatus) for curing a selective portion of the photoresist, and performing an etching process (e.g., in an etching chamber) for etching away either the cured or uncured portion of the photoresist. Next, a deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) can be performed (e.g., in a deposition chamber) to deposit a conductive layer (e.g., a metal layer) on the piezoelectric material and the photoresist formed thereon. Thereafter, a selective etching process (e.g., in an etching chamber) can be performed to remove the photoresist and the conductive material formed thereon, leaving the fourth conductive structure. The fourth conductive structure can be formed simultaneously with the first conductive structure, the second conductive structure, and / or the third conductive structure. Thus, a series of processes (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) can be executed to form the first conductive structure, the second conductive structure, the third conductive structure, and the fourth conductive structure simultaneously or in parallel.

[0056] In block 450, optionally, a fifth conductive structure is formed on the piezoelectric material to form one or more waveguides between the IDTs. Forming the fifth conductive structure can include performing a photoresist deposition process for depositing a photoresist on the piezoelectric material, performing a patterning process (e.g., using a lithography apparatus) for selectively curing portions of the photoresist, and performing an etching process (e.g., in an etching chamber) for etching away either the cured or uncured portions of the photoresist. Next, a deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) can be performed (e.g., in a deposition chamber) to deposit a conductive layer (e.g., a metal layer) on the piezoelectric material and the photoresist formed thereon. Thereafter, a selective etching process (e.g., in an etching chamber) can be performed to remove the photoresist and the conductive material formed thereon, leaving the fifth conductive structure. The fifth conductive structure can be formed simultaneously with the first, second, third, and / or fourth conductive structures. Thus, a series of processes (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) can be executed to form the first, second, third, fourth, and fifth conductive structures simultaneously or in parallel.

[0057] In some embodiments, the conductive structures forming the RF antenna, matching circuit, IDT, SAW reflector, and / or waveguide form a single conductive layer. The processes of blocks 410, 420, 430, 440, and / or 450 can be performed together such that each conductive structure is deposited together. Alternatively, one or more layers can be formed separately.

[0058] In some embodiments, method 400 may further include depositing a protective coating over the RF antenna and / or matching circuitry. The protective coating may include a dielectric material that has resistance to plasma, has resistance to high temperatures, and / or has resistance to high pressures. Examples of dielectric coatings that may be used include Al2O3, AlN, Y2O3, Y3Al5O 12 , yttrium-based oxides, fluorides, and / or oxyfluorides, and the like.

[0059] In some embodiments, depositing the protective layer or coating may be performed using atomic layer deposition, chemical vapor deposition, physical vapor deposition, or plasma-enhanced versions thereof.

[0060] Figures 5A - B are perspective views from above of various embodiments of a SAW sensor 500 with dielectric coatings 530, 540 according to aspects of the present disclosure. SAW sensors 500A - B include an IDT 520 having two comb-shaped meshed electrodes, the two electrodes being disposed on a base substrate 510 having at least one layer of piezoelectric material. The SAW sensor further includes a dielectric coating 530 disposed over the IDT 520 and the base substrate 510. SAW sensors 500A - B can additionally include one or more additional IDTs and / or reflectors spaced apart from the IDT 520 on the base substrate 510. The dielectric coating 530 can additionally coat the additional IDT(s) and / or reflector, and / or the region of the base substrate 510 between the IDT and the additional IDT and / or reflector. In embodiments where the integrated SAW sensor assembly also includes an RF antenna and matching network, the RF antenna and matching network can also be coated by the dielectric coating 530.

[0061] In some embodiments, the IDT 520 receives an electrical signal (e.g., an alternating current signal) and generates a SAW across the surface of a piezoelectric material. The generated SAW includes a propagation speed and a resonance frequency. By laying down the dielectric coating 530, it is possible to adjust the resonance frequency of the SAW sensor. The dielectric coating 530 can adjust the propagation speed of the SAW, and as a result, the resonance frequency is lowered. The dielectric coating 530 may include a thin and uniform dielectric layer. Examples of dielectric coatings that can be used include Al2O3, AlN, Y2O3, Y3Al5O 12 , yttrium-based oxides, fluorides, and / or oxyfluorides, etc. are included.

[0062] In some embodiments, the target resonance frequency is determined by determining the base resonance frequency of the SAW sensor such that the base frequency to which a first frequency shift is applied results in the target resonance frequency, and determining the thickness and / or material for coating the surface of the SAW sensor associated with the first frequency shift. In some embodiments, for example, as shown in FIG. 5A, a single dielectric layer (or a dielectric layer of a first material and / or thickness) can be laid on the SAW sensor. However, in other embodiments, for example, as shown in FIG. 5B, a plurality of dielectric layers of the same or different materials and / or thicknesses can be laid to adjust the resonance frequency of the IDT 520. For example, as shown in the figure, the dielectric coating 530 is the first layer and the dielectric coating 540 is the second layer. Alternatively, a single dielectric coating (including one layer) may be used, and this single dielectric coating may have a different thickness and / or material from the dielectric coating 530 used in FIG. 5A.

[0063] In some embodiments, the SAW sensors 500A - B can be fabricated according to the method 400 of FIG. 4 and / or the method 800 of FIG. 8.

[0064] In some embodiments, the resonance frequency shift of a SAW sensor can be determined as a result of laying down any number of dielectric coatings of various materials and thicknesses on the IDT of the SAW sensor, using sensor data processing and analysis, image processing algorithms, machine learning (ML) algorithms for generating one or more trained machine learning models, deep ML algorithms, and / or other signal processing algorithms for analyzing SAW sensor data. Using these models, analyses, and / or algorithms, for a given SAW sensor, combinations of dielectric materials and thicknesses and the resulting resonance frequency shifts can be calculated, predicted, and evaluated. Additionally or alternatively, such techniques can be used with SAW sensor data to design multiple SAW sensors that can operate together in proximity without their signals being confused. In some embodiments, training data for training an ML model is obtained by imaging using a scanning device or other types of sensors or cameras, and the resonance frequency shift of a SAW sensor previously coated with a dielectric material of a specified material and thickness can be measured.

[0065] One type of machine learning model that can be used is an artificial neural network, such as a deep neural network. An artificial neural network generally includes a feature representation element that includes a classifier or regression layer that maps features to a desired output space. For example, a Convolutional Neural Network (CNN) functions as a host for multiple layers of convolutional filters. At lower layers, pooling is performed, which can handle non-linearity, and on top of that, a multi-layer perceptron is generally added, and the upper-level features extracted by the convolutional layer are mapped to a decision (e.g., classification output). Deep learning is a class of machine learning algorithms that uses a cascade of multiple layers of non-linear processing units for feature extraction and transformation. Each successive layer uses the output from the previous layer as input. A deep neural network can learn in a supervised (e.g., classification) and / or unsupervised (e.g., pattern analysis) form. A deep neural network has a hierarchy of layers, where different layers learn different levels of representation corresponding to different levels of abstraction. In deep learning, each level learns to transform its input data into a slightly more abstract and complex representation. For example, in an image recognition application, the raw input can be a matrix of pixels, i.e., the first representation layer can abstract the pixels and encode the edges, the second layer can configure and encode the arrangement of the edges, the third layer can encode higher-level shapes (e.g., teeth, lips, gums, etc.), the fourth layer can recognize that the image contains a face, or can define a bounding box around the teeth in the image. In particular, the deep learning process can learn for itself which features to place at which level is optimal. The "deep" in "deep learning" refers to the number of layers that transform the data. More precisely, a deep learning system has a substantial depth of the CAP (credit assignment path). The CAP is the chain of transformations from input to output.The CAP describes the potential causal relationship between the input and the output. In the case of a feedforward neural network, the depth of the CAP is the depth of the network, which can be the number of hidden layers + 1. In the case of a recurrent neural network, since the signal may propagate through one layer multiple times, the depth of the CAP can be unlimited.

[0066] In one embodiment, a neural network is trained using a training data set that includes a plurality of data points, where each data point includes a SAW sensor configuration (e.g., including an IDT with a specific finger configuration and / or a specific configuration of a reflector), and may include a specific piezoelectric material and / or a dielectric coating having a known material and / or thickness. Each training data point can additionally include or be associated with attributes of the SAW, such as SAW frequency, phase, time delay, etc. The neural network can be trained using the training data set to receive an input of the SAW sensor configuration and a target SAW attribute and output a proposal for a dielectric coating having a specific material and / or thickness that, when deposited on the SAW sensor, causes the SAW sensor to generate a SAW having the target SAW attribute.

[0067] FIG. 6 is a graph 600 showing a frequency shift 610 at the base resonance frequency of a SAW sensor according to an aspect of the present disclosure. The first peak 606 shows an IDT without a dielectric coating having a first resonance frequency. The second peak 608 shows an IDT having a dielectric coating having a second resonance frequency. The distance between the peaks represents the frequency shift 610 which is the result of laying the dielectric coating. It is possible to adjust the resonance frequency using the dielectric coating. As the thickness of the dielectric coating increases, the magnitude of the frequency shift 610 increases. In some embodiments, the dielectric coating can also protect the SAW sensor from extreme environmental conditions (e.g., from a plasma environment, from a corrosive chemical environment, etc.). As shown in FIG. 6, there is a signal intensity decrease 612 resulting from the dielectric coating. The dielectric coating can also, in embodiments, protect the SAW sensor from excessive exposure and prevent signal saturation from the environment.

[0068] FIG. 7 is a top perspective view of a sensor device 700 according to an aspect of the present disclosure. The sensor device 700 has a base substrate 702 and includes SAW sensor assemblies 704A - B disposed on the base substrate 702. The SAW sensor assemblies 704A - B include RF antennas 710, matching circuits 708, and SAW sensors 706A - B. The SAW sensor assemblies 704A - B including the RF antennas 710, the matching circuits 708, and the SAW sensors 706A - B can include the features and configurations of the SAW sensors disclosed elsewhere in this specification (e.g., the base substrate 202 and the SAW sensor assembly 210 of FIG. 2, the SAW sensor assembly 300 of FIG. 3).

[0069] As shown in FIG. 7, SAW sensors 706A-706B can be disposed on the piezoelectric material of the base substrate 702, and the piezoelectric material can be attached or deposited on the base substrate 702. For example, the piezoelectric substrates of SAW sensors 706A-B can be attached to a silicon wafer. In other embodiments, the SAW sensor assembly can be fully integrated into the base substrate 702. For example, the base substrate 702 includes a common piezoelectric material, and the RF antennas 710, matching circuits 708, and SAW sensors 706A-B of one or more SAW sensor assemblies 704A-B can be integrated with each other on the common piezoelectric material. Alternatively, one or more of the RF antenna 710 or the matching circuit 708 can be separate devices not integrated into the base substrate 702.

[0070] As shown in FIG. 7, each of the SAW sensors 706A-B can include an IDT disposed on a piezoelectric material and a dielectric coating covering the IDT. In some embodiments, the dielectric coatings of each SAW sensor assembly 706A-B can include the same thickness and material. In other embodiments, the thickness and / or material of the dielectric coating can be unique for each SAW sensor assembly 704. The unique resonance frequencies of the various SAW sensor assemblies can be used to measure the environmental conditions and map the measured values for a particular SAW sensor and thus for the position on the base substrate 702.

[0071] In some embodiments, the dielectric coating can cover a portion of the SAW sensor assembly 704 having the SAW sensors 706A-B. However, in other embodiments, the dielectric coating can cover the entire SAW sensor assembly 704 including the RF antenna 710 and the matching circuit 708.

[0072] In some embodiments, each sensor assembly may include a SAW sensor assembly 704 comprising SAW sensors 706A - B having the same base resonance frequency. The SAW sensors 706A - B can be adjusted to generate SAWs with various acoustic frequencies by generating different resonance frequency shifts by laying dielectric coatings of different thicknesses and / or materials on each of the SAW sensors 7086A - B. For example, the first SAW sensor 706A can have a first dielectric coating having a first thickness, and the second SAW sensor 706B can have a second dielectric coating having a second thickness.

[0073] In some embodiments, a combination of a SAW sensor assembly including a dielectric coating and / or a SAW sensor assembly without a dielectric coating (not shown) can be combined on the same base substrate 702 as the SAW sensor assembly 704 including the dielectric coating.

[0074] FIG. 8 is a flowchart of a method 800 for fabricating a SAW sensor assembly according to aspects of the present disclosure.

[0075] Referring to FIG. 8, at block 810, the processing system can determine the current RF resonance frequency range of the SAW sensor. The SAW sensor can include the features and configurations of the SAW sensors disclosed elsewhere in this specification (e.g., the SAW sensor 500 of FIG. 5).

[0076] At block 820, the processing system can determine the target RF resonance frequency range of the SAW sensor.

[0077] In block 830, the processing system can determine at least one of a dielectric coating material or a dielectric coating thickness that adjusts the signal propagation speed and adjusts the current RF resonance frequency range relative to the target RF resonance frequency range. In one embodiment, the design of the SAW sensor (and optionally, the target SAW attributes) is input into a trained machine learning model, which outputs a proposal for the material of the dielectric coating and / or the thickness of the dielectric coating. In some embodiments, the processing system determines a combination of dielectric materials and layers to deposit on the SAW sensor. In some embodiments, the determined materials and thicknesses depend on the specifications of the SAW sensor (e.g., surface area, maximum thickness, etc.).

[0078] In block 840, the processing system can deposit a dielectric coating on the SAW sensor. The dielectric coating can have at least one of the dielectric coating material or the dielectric coating thickness determined in block 830.

[0079] In block 850, the processing system can determine whether the resonance frequency is within a threshold difference range of the target RF resonance frequency. The processing system can measure the current resonance frequency and compare the result with the target resonance frequency determined in block 820. If the resonance frequency is within the threshold difference range, method 800 may be completed. However, if the resonance frequency is not within the threshold difference range of the target frequency, the method returns to block 810 and repeats the steps of the method to determine and deposit another dielectric coating.

[0080] Figures 9A - C show various embodiments of the electrode configurations of IDTs 900A - B of a SAW sensor according to aspects of the present disclosure. IDTs 900A - C each include two comb electrodes having interdigitated fingers 910A - C arranged in one configuration on a substrate having at least one layer of piezoelectric material.

[0081] In some embodiments, IDT900A - C receive an electrical signal (e.g., an RF signal) and generate a SAW associated with the received electrical signal. In other embodiments, IDT900A - C receive a SAW and generate an electrical signal (e.g., an RF signal) associated with the received SAW. In either case, the configuration of the meshing fingers 910A - C of the electrodes can cause signal modulation within any signal passing through IDT900A - C.

[0082] Embodiments of the present disclosure include various configurations of the meshing fingers 910A - C. As shown in FIG. 9A, for example, IDT900A can include a first arrangement of alternating meshing fingers 910A. This first arrangement can obtain an unmodulated signal 920A having a specific resonance frequency and / or phase. As shown in FIG. 9B, for example, IDT900B can include a second arrangement of meshing fingers 910B that includes at least two fingers from the same electrode arranged adjacent to each other. With this configuration, a modulated signal 920B can be obtained. In some embodiments, the modulated signal 920B can include the same resonance frequency as 920A, but a phase shift has occurred or the signal has been otherwise altered. As described in FIG. 9C, it is also possible to adjust the pitch or spacing between the meshing fingers to generate a modulated signal having an adjusted or modulated frequency.

[0083] In some embodiments, the configuration of the meshing fingers (e.g., 910B) can obtain signal modulation that identifies the IDT (e.g., 910B). For example, a modulated signal (e.g., 920B) includes a unique signal modulation (e.g., phase shift 930) that functions as an identifier for a further signal processing device (e.g., RF antenna 129 of FIG. 1). In a further example, a signal generated by a SAW sensor can include information identifying a measurable environmental condition and signal modulation identifying the SAW sensor that transmitted the information - containing signal.

[0084] In some embodiments, signal modulation including a phase shift of the original signal can be obtained by signal modulation generated by the configuration of the meshing fingers. For example, as shown in FIG. 9B, due to the configuration of the meshing finger 910B, a signal having the same frequency as the unmodulated signal and with phase shifts 930 performed at various positions throughout the signal is obtained. In some embodiments, the modulated signal includes the same frequency as the unmodulated signal.

[0085] The IDTs 900A - C shown in FIGS. 9A - C can be subsets or subsections of IDTs used in various embodiments of the present disclosure. For example, the configuration shown by IDT900A can be repeated for a longer IDT. In other examples, the IDT900B shown in FIG. 9B can include more meshing fingers than shown, and these fingers can include various arrangements that result in various phase and / or frequency modulations. For example, IDT900B can be associated with a phase shift of the signal pulse, but when combined with other subsections (not shown), it can generate signal modulation of a signal composed of multiple modulated pulses, resulting in a modulated signal. In some embodiments, the configurations shown by IDT900A and IDT900B can be combined such that they have both a phase shift region and a region where no modulation occurs. For example, the IDT can include alternating subsections including IDT900A and IDT900B, resulting in signal modulation. Additionally, the IDT can include alternating subsections including IDT900A, IDT900B, and / or IDT900C, resulting in signal modulation.

[0086] In some embodiments, IDT900A - C can be part of a SAW sensor (e.g., SAW sensor 204 in FIG. 2) of a sensor assembly (e.g., SAW sensor assembly 210 in FIG. 2) of a sensor device (e.g., sensor device 200 in FIG. 2). Various SAW sensor assemblies can be arranged across a base substrate (e.g., a wafer). Each SAW sensor assembly can include a SAW sensor with an IDT having a unique configuration of digital meshing fingers. Each SAW sensor can return information with a signal having signal modulation that measures an environmental condition and identifies the SAW sensor assembly that sent the information. By having unique signal modulation, it can be seen that each sensor can operate within a range of overlapping or equivalent resonance frequencies and can further be distinguished from other sensors. For example, since the measured environmental condition also includes signal modulation that identifies a sensor located within a first region of the base substrate where the signal sending the information associated with the environmental condition is located, it can be mapped to the first region of the base substrate.

[0087] In some embodiments, the configuration of the meshing fingers can be combined with other embodiments of the present disclosure to identify a sensor. For example, the configuration of meshing fingers 910 can be combined with the spatial arrangement of SAW reflector 1004 as described in connection with FIG. 10. Thereby, a further modulated signal can be obtained, which is the signal that uniquely identifies the SAW sensor. In another example, the configuration of meshing fingers 910 can be combined with the laying of dielectric coding 530 described in connection with FIG. 5. Thereby, a signal modulation combined with an adjusted frequency can be obtained, which is the signal modulation that uniquely identifies the SAW sensor. By the combination of the above - mentioned techniques, the density of SAW sensors that can be arranged together and uniquely identified on a sensor wafer can be increased.

[0088] Figures 10A - B show various spatial arrangements of the SAW reflectors of SAW sensors 1000A - B according to aspects of the present disclosure. SAW sensors 1000A - B include IDTs 1002A - B and a set 1004A - D of one or more SAW reflectors arranged in a certain spatial arrangement on a piezoelectric substrate or on a substrate (e.g., a semiconductor substrate) on which a piezoelectric layer is placed. IDTs 1002A - B are designed to receive an electrical signal and generate a SAW that propagates across the surface of the piezoelectric material of the piezoelectric substrate or piezoelectric layer. The generated SAW is reflected by SAW reflectors 1004A - D and returned to IDTs 1002A - B. IDTs 1002A - B newly generate a potential associated with the reflected SAW. The SAW reflectors can be spatially arranged to apply signal modulation to the reflected SAW wave returning to IDTs 1002A - B.

[0089] As shown, a single IDT 1002A - B performs both generating a SAW based on the received RF signal and receiving the reflection of the SAW and then generating a new RF signal therefrom. In such an embodiment, the generation of the SAW and the reception of the reflected SAW are temporally offset such that an RF signal is received at time 1 and a new RF signal is generated at time 2. In some embodiments (not shown), two IDTs are juxtaposed or arranged adjacent to each other. A first IDT can receive an RF signal and generate a SAW, and a second IDT can receive the reflected SAW and generate a new RF signal. In such a configuration, the first IDT and the second IDT can operate in parallel. Thus, the second IDT can output a new RF signal while the first IDT is receiving an incoming RF signal.

[0090] Embodiments of the present disclosure include various spatial arrangements of SAW reflectors 1004A - D. For example, as shown in SAW reflectors 1004A - B, a SAW sensor can include a set of uniformly distributed SAW reflectors. In other examples, a SAW sensor can include a set of SAW reflectors that are not uniformly distributed and can be placed at specific intervals. In other examples, as shown in SAW reflectors 1004C - D, a SAW sensor can include a set of one or more grouped SAW reflectors. In other examples, as shown by SAW reflector 1004D, a SAW sensor can include a set of one or more grouped SAW reflectors with various intervals.

[0091] In some embodiments, the spatial arrangement of SAW reflectors 1004A - D results in signal modulation that identifies the SAW sensor. For example, each of the previously described examples shown in FIGS. 10A - B can result in signal modulation specific to each SAW sensor. For example, signal modulation can result in a change in phase, a change in frequency, and / or a signal delay as a result of constructive and destructive interference of the reflected SAWs when they return to IDTs 1002A - B.

[0092] For example, the spacing 1010A - D between groups of SAW reflectors can result in unique signal modulation. For example, in FIG. 10B, SAW reflector 1004C is divided into a first group of reflectors 1009A group and a second group of reflectors 1009B, and SAW reflector 1004D is divided into a first group of reflectors 1009C and a second group of reflectors 1009D. All reflectors within the first group 1009A, 1009C have a first pitch or spacing, and all reflectors within the second group 1009B, 1009D also have the first pitch or spacing. The first pitch or spacing can be, for example, on the order of approximately the spacing of one wavelength of the SAW. The first group 1009A can be separated from the second group 1009B by a gap or space 1010D that is not necessarily the full wavelength of the SAW. Similarly, the first group 1009C can be separated from the second group 1009D by the gap or space 1010D. In an embodiment, the gap or space 1010D can have lengths such as 1 / 4 wavelength, 1 / 2 wavelength, 1 and 1 / 4 wavelength, 1 and 1 / 2 wavelength, 1 and 3 / 4 wavelength, 2 and 1 / 4 wavelength, 2 and 1 / 2 wavelength, 2 and 3 / 4 wavelength... In a further example, the spatial dispersion of SAW reflectors 1004A - D can include 1 / 2 wavelength and / or 1 / 4 wavelength spacing between the SAW reflectors. In some embodiments, the SAW reflectors are arranged in groups, where the first group of SAW reflectors can be offset from the second group of SAW reflectors by, for example, a half wavelength or 1 / 4 wavelength. In one embodiment, each SAW reflector of the first group of SAW reflectors is spaced from one or more of the nearest SAW reflectors in that group by a spacing corresponding to the wavelength of the SAW. Additionally, each SAW reflector of the second group of SAW reflectors can be spaced from one or more of the nearest SAW reflectors in that group by a spacing corresponding to the wavelength of the SAW. In some embodiments, combinations of 1 / 2 wavelength, 1 / 4 wavelength, and / or full wavelength spacings can be used to generate unique signal modulation to identify SAW sensors 1000A - B.In some embodiments, SAW sensors 1000A - B can be part of a sensor assembly (e.g., SAW sensor assembly 210 in FIG. 2) of a sensor device (e.g., sensor device 200 in FIG. 2). Various SAW sensor assemblies comprising a SAW sensor including an IDT and a set of SAW reflectors arranged in a unique spatial arrangement can be arranged across a base substrate (e.g., a wafer). Each SAW sensor can return information with a signal having a signal modulation that measures an environmental condition and identifies the SAW sensor assembly that transmitted the information. By having a unique signal modulation, it can be seen that each sensor can operate within a range of overlapping or equivalent resonance frequencies and can further be distinguished from other sensors. For example, since the measured environmental condition also includes a signal modulation that identifies a sensor located within a first region of the base substrate where the signal sending information associated with the environmental condition is located, it can be mapped to the first region of the base substrate.

[0093] In some embodiments, the spatial arrangement of the SAW reflectors can be combined with other embodiments of the present disclosure to identify SAW sensors. For example, the unique spatial arrangement of SAW reflectors 1004A - D of a SAW sensor can be combined with the unique arrangement of the meshing fingers 910 of the IDT described in connection with FIG. 9. Thereby, a further modulated signal that uniquely identifies the SAW sensor can be obtained. In another example, the unique spatial arrangement of SAW reflector 1004 can be combined with the deposited dielectric coating 530 described in connection with FIG. 5. Thereby, a signal modulation combined with an adjusted frequency can be obtained, which is a signal modulation that uniquely identifies the SAW sensor.

[0094] Figures 11 to 14 are top perspective views of various embodiments of sensor devices 1100 to 1400 according to aspects of the present disclosure. The sensor devices include substrates 1102 to 1402 having at least one layer of piezoelectric material (e.g., a piezoelectric substrate or a semiconductor substrate on which a piezoelectric layer is disposed), and SAW sensor assemblies 1104 to 1404 and 1108 to 1208 designed to receive and / or transmit RF signals associated with measuring environmental conditions of the environment using SAWs 1106 to 1406. The sensor assembly may include an RF antenna, a matching circuit, and a SAW sensor having an IDT. The sensor assembly may include features and configurations of the SAW sensor assembly (e.g., sensor device 200) disclosed elsewhere in this specification. In the following exemplary embodiments, various configurations for measuring environmental conditions within a region on the surface of the piezoelectric material between multiple sensor assemblies by sending SAWs between the multiple sensor assemblies are disclosed.

[0095] In some embodiments, for example, as shown in FIG. 11, the sensor device 1100 may include a first SAW sensor assembly 1104A that is designed to receive an incoming RF signal and generate a SAW 1106A that propagates across the surface of a substrate 1102, which may be a substrate on which a piezoelectric substrate or piezoelectric layer is placed. The SAW 1106 is received by a second SAW sensor assembly 1108A that is designed to generate a potential associated with the received SAW 1106A and output a transmitted RF signal associated with the potential, where the output of the transmitted RF signal includes information indicating the state of the environment between the first SAW sensor assembly 1104A and the second SAW sensor assembly 1108A. In some embodiments, a waveguide is disposed between the first SAW sensor assembly 1104A and the second SAW sensor assembly 1108A. The waveguide can maintain the SAW propagating between the first SAW sensor assembly 1104A and the second SAW sensor assembly 1108A. In some embodiments, the first SAW sensor assembly 1104A and the second SAW sensor assembly 1108A are part of a single integrated device. In some embodiments, the alignment network and / or antenna of the SAW sensor assemblies 1104A, 1108A are not part of the integrated device but rather separate components. In some embodiments, the waveguide disposed between the first SAW sensor assembly 1104A and the second SAW sensor assembly 1108A is part of the integrated device together with the first SAW sensor assembly 1104A and / or the second SAW sensor assembly 1108A. In further embodiments, the sensor device may include a first set of SAW sensor assemblies 1104, each of which generates a SAW 1106 that is received by a second set of SAW sensor assemblies 1108. In an embodiment, each of the SAW sensor assemblies may be part of a single integrated device. In some embodiments, a waveguide is disposed between one or more respective pairs of the first SAW sensor assemblies 1104A - D and the second SAW sensor assemblies 1108A - D.

[0096] In some embodiments, as shown, for example, in FIG. 12, the sensor device 1200 may include a set of SAW generation sensor assemblies 1204 designed to receive an incoming RF signal and generate a SAW 1206 that propagates across the surface of a substrate 1202, which may be a piezoelectric substrate or a substrate including a piezoelectric layer. The sensor device 1200 may also include a SAW reception sensor assembly 1208 designed to receive the SAW 1206 generated by the set of SAW generation sensor assemblies 1204. The SAW reception sensor assembly 1208 may be designed to generate a vibration potential associated with each of the SAWs 1206 generated by the SAW generation sensor assemblies 1204. The SAW reception sensor assembly 1208 outputs a transmitted RF signal according to each vibration potential, where each RF signal includes information indicating the environmental state of the environment disposed between the SAW reception sensor assembly 1208 and the associated SAW generation sensor assembly (e.g., 1204A). In some embodiments, a first waveguide may be disposed between the SAW reception sensor assembly 1208 and the first SAW sensor assembly 1204A, and a second waveguide may be disposed between the SAW generation assembly 1208 and the second SAW sensor assembly 1204B. In some embodiments, the first SAW sensor assembly 1204A, the second SAW sensor assembly 1204B, and the SAW reception sensor assembly 1208 are part of a single integrated device. In some embodiments, the alignment network and / or antenna of the SAW sensor assemblies 1204A, 1204B, 1208 are not part of the integrated device, but rather are separate components. In some embodiments, the first waveguide disposed between the first SAW sensor assembly 1204A and the SAW reception sensor assembly 1208 and the second waveguide disposed between the second SAW sensor assembly 1204B and the SAW reception sensor assembly 1208 are part of the integrated device together with the first SAW sensor assembly 1204A, the second SAW sensor assembly 1204B, and / or the SAW reception sensor assembly 1208.In a further embodiment, the sensor device 1200 may include a plurality of sets of SAW generating sensor assemblies (e.g., 1204) and a plurality of SAW receiving sensor assemblies (e.g., 1208) for receiving SAWs (e.g., 1206) generated by each set of SAW generating sensor assemblies.

[0097] In some embodiments, as shown, for example, in FIG. 13, the sensor device 1300 may include two sensor assemblies 1304A and 1304B each disposed on a piezoelectric substrate 1302 (or on a substrate on which a piezoelectric layer is disposed). Each sensor assembly 1304A and 1304B can receive an incoming RF signal and generate a SAW 1306 associated with the received incoming RF signal. The SAW 1306 generated by each signal is received by the other sensor assembly. For example, the SAW 1306 generated by the first sensor assembly 1304A is received by the second sensor assembly 1304B, and the SAW 1306 generated by the second sensor assembly 1304B is received by the first sensor assembly 1304A. Each sensor assembly 1304 can generate a vibration potential associated with the corresponding SAW 1306 received by each sensor assembly 1304. Each sensor assembly 1304 can output a transmitted RF signal according to each vibration potential, where each transmitted RF signal includes information indicating the environmental state of the environment disposed between the two sensor assemblies 1304A and 1304B. In a further embodiment, the processing system (e.g., the processing system 100 of FIG. 1) can adjust the transmission of the incoming RF signal such that the sensor assemblies alternately perform the roles of SAW generation and vibration potential generation. In other embodiments, the processing system can adjust the transmission of the incoming RF signal such that each sensor assembly 1304 generates a SAW in synchronization with the other sensor assembly 1304. In a further embodiment, the sensor device 1300 may include a plurality of pairs of sensors operating according to the exemplary embodiments described above with reference to the sensor assemblies 1304A and 1304B.

[0098] In some embodiments, a waveguide is disposed between a first SAW sensor assembly 1304A and a second SAW sensor assembly 1304B. In some embodiments, the first SAW sensor assembly 1304A and the second SAW sensor assembly 1304B are part of a single integrated device. In some embodiments, the matching network and / or antenna of the SAW sensor assemblies 1304A - B are not part of the integrated device, but rather are separate components. In some embodiments, the waveguide disposed between the first SAW sensor assembly 1304A and the second SAW sensor assembly 1304B is part of the integrated device together with the first SAW sensor assembly 1304A and / or the second SAW sensor assembly 1304B.

[0099] In some embodiments, as shown in FIG. 14, the sensor device 1400 may include a plurality of sensor assemblies 1404 disposed on the surface of a substrate 1402 having at least one layer of piezoelectric material. The sensor device 1400 may include a SAW sensor assembly 1404A designed to receive an incoming RF signal and generate a SAW 1406 received by a plurality of SAW sensor assemblies 1404B, 1404C, and 1404D. The sensor device 1400 may further include a SAW sensor assembly 1404B configured to receive a SAW 1406A from another SAW sensor assembly 1404A, generate a vibration potential associated with the SAW, and output a transmitted RF signal associated with the generated vibration potential. The SAW sensor assembly 1404B may also be designed to generate a SAW 1408 in response to receiving an incoming RF signal. The sensor device may further include a SAW sensor assembly 1404C designed to receive SAWs 1408 and 1406B from a plurality of SAW sensor assemblies 1404A and 1404B. The SAW sensor assembly 1404C can generate a vibration potential for each received SAW and output a transmitted RF signal associated with each of the generated vibration potentials. The SAW sensor assembly 1404C may also be designed to generate a SAW 1410 in response to receiving an incoming RF signal. The sensor device may further include a SAW sensor assembly 1404D designed to receive SAWs 1410 and 1406C from a plurality of SAW sensor assemblies 1404C and 1404A. The SAW sensor assembly 1404D can generate a potential for each received SAW and output a transmitted RF signal associated with each of the generated vibration potentials.

[0100] In some embodiments, one or more SAW sensor assemblies 1404A - D are part of the same integrated device. In some embodiments, a waveguide is disposed between one or more SAW sensor assemblies 1404A - D, for example, between SAW sensor assembly 1404A and SAW sensor assembly 1404D, and / or between SAW sensor assembly 1404A and SAW sensor assembly 1404C. In an embodiment, the waveguide can be part of an integrated device that includes one or more SAW sensor assemblies. For example, the waveguide can be a planar conductor formed on a piezoelectric material, on which the SAW sensor assembly is formed.

[0101] In some embodiments, a combination of the embodiments shown in FIGS. 11 - 14 is used. For example, sensor assemblies 1104, 1108, 1204, 1208, 1304, and 1404 can be used on the surface of a piezoelectric substrate, in any combination with each other, to measure environmental conditions in various regions across the surface of the piezoelectric substrate in response to receiving an incoming RF signal.

[0102] In the foregoing description, numerous specific details, such as examples of particular systems, components, methods, etc., have been set forth in order to provide a good understanding of some embodiments of the present disclosure. It will be apparent to those skilled in the art that at least some embodiments of the present disclosure can be practiced without these specific details. In other instances, well - known components or methods are not described in detail or are presented in a simplified block diagram so as not to unnecessarily obscure the present disclosure. Accordingly, the specific details described are merely illustrative. Specific embodiments may vary from these illustrative details and still be considered within the scope of the present disclosure.

[0103] Throughout this specification, references to "one embodiment" or "an embodiment" mean that the particular features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment. Thus, appearances of the phrases "in an embodiment" or "in one embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. In addition, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". As used herein, the term "about" or "approximately" when used means that the stated nominal value is correct within a range of ±10%.

[0104] The steps of the methods herein are presented and described in a particular order, but the order of each method step can be changed, whereby a particular step can be performed in a reverse order, or a particular operation can be performed at least partially concurrently with other steps. In other embodiments, the instructions for separate steps or secondary steps may be in an intermittent and / or alternating form. In one embodiment, a plurality of metal bonding steps are performed as one step.

[0105] It should be understood that the foregoing description is illustrative and not restrictive. Many other embodiments will be apparent to those of ordinary skill in the art upon reading and understanding the foregoing specification. Accordingly, the scope of the present disclosure is defined by reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A sensor device, a first integrated sensor assembly, disposed on a substrate including at least one layer of piezoelectric material, and adapted to measure an environmental condition of an environment in response to receiving a first incoming RF signal, a first surface acoustic wave (SAW) sensor, a first interdigital transducer (IDT) formed on a first region of the piezoelectric material, the first IDT generating a first SAW based on the environmental condition in response to receiving the first incoming RF signal, and at least one of a) one or more SAW reflectors communicatively connected to the first IDT and formed on a second region of the piezoelectric material, or b) a second IDT formed on a third region of the piezoelectric material comprising a first surface acoustic wave (SAW) sensor, a first RF antenna formed on a fourth region of the piezoelectric material, and comprising, a sensor device, wherein the first SAW sensor and the RF antenna are integrated with each other on the piezoelectric material.

2. The sensor device according to claim 1, wherein the first integrated sensor assembly further comprises a matching circuit connected to the RF antenna and the first IDT and formed on a fifth region of the piezoelectric material.

3. The sensor device according to claim 2, wherein the RF antenna, the matching circuit, the first IDT, and at least one of a) the one or more SAW reflectors or b) the second IDT each comprise one or more planar conductors disposed on the piezoelectric material.

4. The sensor device according to claim 2, further comprising a protective coating or cover disposed on the RF antenna and the matching circuit.

5. a second integrated sensor assembly, disposed on the piezoelectric material and adapted to measure the environmental condition of the environment in response to receiving the first incoming RF signal or a second incoming RF signal, a second SAW sensor, a third IDT formed on a fifth region of the piezoelectric material, and at least one of a) one or more additional SAW reflectors communicatively connected to the third IDT and formed on a sixth region of the piezoelectric material, or b) a fourth IDT formed on a seventh region of the piezoelectric material comprising a second SAW sensor, A second RF antenna connected to the third IDT and formed on an eighth region of the piezoelectric material, comprising The second SAW sensor and the second RF antenna are integrated with each other on the piezoelectric material, the first SAW sensor is adapted to operate within a first frequency range, and the second SAW sensor is adapted to operate within a second frequency range different from the first frequency range. The sensor device according to claim 1. **Claim 6** The sensor device according to claim 1, wherein the substrate includes a piezoelectric substrate including the piezoelectric material. **Claim 7** The sensor device according to claim 1, wherein the substrate includes a substrate made of a first material and a piezoelectric layer on the substrate, and the piezoelectric layer includes the piezoelectric material. **Claim 8** The first SAW sensor is The second IDT formed on the third region of the piezoelectric material, Receiving the first SAW from the first IDT, and Generating a first vibration potential associated with the first acoustic frequency of the received first SAW The second IDT for performing the above, A second RF antenna connected to the second IDT, the second RF antenna for outputting a first transmission RF signal according to the first vibration potential, The sensor device according to claim 1, further comprising. **Claim 9** The second RF antenna further receives the first incoming RF signal or the second incoming RF signal, The second IDT further generates a second SAW based on the environmental state in response to receiving the first incoming RF signal or the second incoming RF signal, The first IDT is Receiving the second SAW from the second IDT, and Further generating a second vibration potential associated with the second acoustic frequency of the received second SAW, The first RF antenna further outputs a second transmission RF signal according to the second vibration potential. The sensor device according to claim 8. **Claim 10** The first integrated sensor assembly is A third IDT formed on a fifth region of the piezoelectric material, Receiving the first SAW from the first IDT, and A third IDT for generating a second vibration potential associated with the first acoustic frequency of the received first SAW, A third RF antenna connected to the third IDT, the third RF antenna for further outputting a second transmitted RF signal according to the second oscillating potential; The sensor device according to claim 8, further comprising.

11. The second RF antenna further receives the first received RF signal or the second received RF signal, The second IDT further generates a second SAW based on the environmental state in response to receiving the first received RF signal or the second received RF signal, The third IDT, Receiving the second SAW from the second IDT; Further generating a third oscillating potential associated with a combination of the first acoustic frequency of the received first SAW and the second acoustic frequency of the received second SAW; The sensor device according to claim 10, wherein the third RF antenna further outputs a third transmitted RF signal according to the second oscillating potential.

12. The first integrated sensor assembly, A third IDT formed on a fifth region of the piezoelectric material; A third RF antenna connected to the third IDT; Further comprising, The second RF antenna further receives the first received RF signal or the second received RF signal, The second IDT further generates a second SAW based on the environmental state in response to receiving the first received RF signal or the second received RF signal, The third IDT, Receiving the second SAW from the second IDT; Further generating a second oscillating potential associated with the acoustic frequency of the received second SAW; The sensor device according to claim 8, wherein the third RF antenna further outputs a second transmitted RF signal according to the second oscillating potential.

13. The first integrated sensor assembly, A third IDT formed on a fifth region of the piezoelectric material; A third RF antenna connected to the third IDT; Further comprising, The third RF antenna further receives the first received RF signal or the second received RF signal, The third IDT further generates a second SAW based on the environmental state in response to receiving the first received RF signal or the second received RF signal, The second IDT, Receiving the second SAW from the third IDT; generating a second vibration potential associated with a combination of the first acoustic frequency of the received first SAW and the second acoustic frequency of the received second SAW; The sensor device according to claim 8, wherein the second RF antenna further outputs a second transmitted RF signal according to the second vibration potential.

14. The sensor device according to claim 8, wherein the first SAW sensor further includes a waveguide formed on the piezoelectric material between the first IDT and the second IDT.

15. A method of manufacturing a sensor device, comprising: depositing a first conductive structure on a piezoelectric substrate, the first conductive structure forming a radio frequency (RF) antenna; depositing a second conductive structure on the piezoelectric substrate, the second conductive structure forming a matching circuit connected to the RF antenna; depositing a third conductive structure on the piezoelectric substrate, the third conductive structure forming a first interdigital transducer (IDT) connected to the RF antenna, the IDT being a component of a surface acoustic wave (SAW) sensor; depositing a fourth conductive structure on the piezoelectric substrate, the fourth conductive structure forming at least one of a) one or more SAW reflectors, or b) a second IDT; By doing so, an integrated sensor assembly is fabricated A method including.

16. The method according to claim 15, wherein the first conductive structure, the second conductive structure, the third conductive structure, and the fourth conductive structure form a single conductive layer, and depositing the first conductive structure, the second conductive structure, the third conductive structure, and the fourth conductive structure is performed together.

17. The method according to claim 15, wherein the RF antenna, the matching circuit, the first IDT, and at least one of the one or more SAW reflectors or the second IDT each include one or more planar conductors.

18. Depositing a protective coating on at least one of the first conductive structure or the second conductive structure The method according to claim 15, further comprising.

19. An integrated sensor device, comprising: A first surface acoustic wave (SAW) sensor disposed on a substrate including at least one layer of piezoelectric material and adapted to measure an environmental condition in response to receiving a first incoming RF signal, a first interdigital transducer (IDT) formed on a first region of the piezoelectric material for generating a first SAW based on the environmental condition in response to receiving the first incoming RF signal comprising a first surface acoustic wave (SAW) sensor; a second SAW sensor disposed on the piezoelectric material and adapted to measure the environmental condition in response to receiving the first incoming RF signal or a second incoming RF signal, a second IDT formed on a second region of the piezoelectric material for generating a second SAW based on the environmental condition in response to receiving the first incoming RF signal or the second incoming RF signal comprising a second SAW sensor; comprising; wherein the first SAW sensor is adapted to operate within a first frequency range, the second SAW sensor is adapted to operate within a second frequency range different from the first frequency range, the integrated first SAW sensor is disposed on a first surface of the substrate, and the integrated second SAW sensor is disposed on a second surface of the substrate, an integrated sensor device. **Claim 20** A system comprising: a processing chamber; one or more RF antennas for transmitting a first RF signal within the processing chamber and receiving a second RF signal propagated from within the processing chamber; a sensor wafer disposed within the processing chamber; comprising; wherein the sensor wafer includes at least one layer of piezoelectric material; a first integrated sensor assembly, wherein the first integrated sensor assembly is a first surface acoustic wave (SAW) sensor disposed on the at least one layer of the piezoelectric material and adapted to measure an environmental condition within the processing chamber in response to receiving the first RF signal and output a second RF signal having data associated with the measured environmental condition, comprising a first SAW sensor; wherein the first SAW sensor A first interdigital transducer (IDT) formed on a first region of the piezoelectric material, the first IDT generating a first SAW based on the environmental state in response to receiving the first RF signal; a) one or more SAW reflectors communicatively connected to the first IDT and formed on a second region of the piezoelectric material, or b) a second IDT formed on a third region of the piezoelectric material, at least one of; an RF antenna formed on a fourth region of the piezoelectric material; comprising; A system in which the first SAW sensor and the RF antenna are integrated with each other on the piezoelectric material.

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