Surface Acoustic Wave Sensor Assembly

Abstract

A sensor device is provided that includes an integrated sensor assembly having a surface acoustic wave (SAW) sensor disposed 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) disposed 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.

Description

[Technical field]

[0001] Some embodiments of the present disclosure generally relate to a sensor device having a surface acoustic wave (SAW) sensor assembly for measuring an environmental condition of an environment. [Background technology]

[0002] A surface acoustic wave (SAW) is a sound wave that travels parallel to the surface of an elastic material. A general mathematical discussion of SAW was first reported by Lord Rayleigh in 1855, but applications in electronics were not exploited until 1965 when White and Voltmer et al. utilized interdigital transducers on piezoelectric materials. SAWs are used in electronics, especially RF / IF filters. The conversion of electrical energy to mechanical energy (in the form of SAWs) is achieved through the use of piezoelectric materials. Piezoelectric materials are materials that have the ability to generate an internal charge from mechanical stress and to generate internal mechanical strain in response to the application of an electric field. SAW transducers are often used on the surface of piezoelectric materials to convert electrical energy to mechanical energy (e.g., SAWs) as well as SAWs to electrical energy. SAW devices use SAWs in electronic components to provide several different functions including delay lines, filters, resonators, correlators, converters, sensors, etc. SAW devices can be arranged on a wafer to perform their respective functions. Summary of the Invention

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

[0004] In a further embodiment, the sensor assembly may include a second IDT for receiving the SAW from the first IDT and generating an oscillating potential associated with an acoustic frequency of the received SAW. The oscillating potential may include information associated with a measured environmental condition over an area of ​​a surface of the piezoelectric substrate or layer. The sensor assembly may include a second RF antenna and a second matching circuit for outputting an outgoing RF signal associated with the oscillating potential.

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

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

[0007] In an exemplary embodiment, a method for fabricating a sensor assembly is disclosed. The method begins with 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 resonant frequency, for example based on the pitch between fingers in the IDT. The method continues by tuning the resonant frequency of the IDT by depositing a dielectric coating on the conductive layer, the dielectric coating having a thickness of material, where at least the thickness or material is associated with a shift in the base resonant frequency, and the IDT including the dielectric coating has a tuned resonant frequency.

[0008] In another embodiment, the sensor assembly may include one or more SAW sensors adapted to measure an environmental condition in response to receiving an incoming RF signal. The first SAW sensor may 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 interdigitated electrodes including interdigitated conductive fingers in a first arrangement. The interdigitated 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 another embodiment, the sensor assembly may include a SAW sensor disposed on a substrate having at least one layer of piezoelectric material. The SAW may be adapted to measure an environmental condition of an environment in response to receiving an incoming RF signal. The SAW sensor may 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 may further include a collection 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 specific to the SAW sensor.

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

[0011] [Figure 1] FIG. 1 illustrates a simplified top view of an exemplary processing system according to an aspect of the present disclosure. [Diagram 2] FIG. 2 is a top perspective view of a sensor device including an integrated SAW sensor assembly according to an embodiment of the present disclosure. [Figure 3A-B] 1 illustrates various embodiments of a SAW sensor assembly according to aspects of the present disclosure. [Figure 4] 1 is a flowchart of a method for making a SAW sensor assembly according to an embodiment of the present disclosure. [Figure 5A-B] 1A-1D are top perspective views of various embodiments of a SAW sensor including a dielectric coating in accordance with aspects of the present disclosure. [Figure 6] 1 is a graph illustrating a frequency shift in the base resonant frequency of a SAW sensor, according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a top perspective view of a sensor device according to an aspect of the present disclosure. [Figure 8] 1 is a flowchart of a method for making a SAW sensor assembly according to an embodiment of the present disclosure. [Figure 9A] 1 illustrates one embodiment of an electrode configuration for an IDT of a SAW sensor, according to aspects of the present disclosure. [Figure 9B] 1 illustrates one embodiment of an electrode configuration for an IDT of a SAW sensor, according to aspects of the present disclosure. [Figure 9C] 1 illustrates one embodiment of an electrode configuration for an IDT of a SAW sensor, according to aspects of the present disclosure. [Figure 10A-B] 1 illustrates various spatial arrangements of a SAW reflector of a SAW sensor according to an embodiment of the present disclosure. [Figure 11] FIG. 2 illustrates a top perspective view of one embodiment of a sensor device in accordance with aspects of the present disclosure. [Figure 12] FIG. 2 illustrates a top perspective view of one embodiment of a sensor device in accordance with aspects of the present disclosure. [Figure 13] FIG. 2 illustrates a top perspective view of one embodiment of a sensor device in accordance with aspects of the present disclosure. [Figure 14] FIG. 2 illustrates a top perspective view of one embodiment of a sensor device in accordance with aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The disclosed embodiments provide a sensor device including a SAW sensor assembly and associated methods for fabricating the SAW sensor assembly. The SAW sensor assembly may 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 may be formed on a piezoelectric substrate or other type of substrate, such as a semiconductor substrate with a piezoelectric layer. The SAW sensor receives an incoming RF signal and generates a SAW to measure environmental conditions, such as pressure and temperature, of an environment (e.g., a surface of the piezoelectric substrate or layer). Various disclosed embodiments provide ways to passively measure environmental conditions (e.g., without active devices such as a power source), make measurements over a surface area of ​​the piezoelectric substrate or layer, fine-tune the SAW sensor, and / or distinguish between various SAW sensors of the sensor assembly.

[0013] Various embodiments may be or utilize a device having a sensor assembly including a SAW sensor disposed on a substrate (e.g., a piezoelectric substrate or a piezoelectric layer disposed on a substrate) having at least one layer of piezoelectric material and adapted to measure an environmental condition of an environment in response to receiving an incoming RF signal. The SAW sensor may include an antenna, a matching circuit, and an interdigital transducer (IDT) disposed on a surface of the piezoelectric material. The SAW sensor may generate a SAW to measure an environmental condition without the use of active circuitry (e.g., a battery-powered CMOS device). The antenna, matching circuit, and interdigital transducer may 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 may be adapted to measure an environmental condition of an environment in response to receiving an incoming radio frequency (RF) signal. The SAW sensor may include an IDT formed on the piezoelectric substrate. In response to receiving the incoming RF signal, the IDT may generate a SAW based on the environmental condition (e.g., having at least one of an amplitude, a frequency, a time delay, a phase, or a wavelength that depends on the environmental condition). The SAW sensor may include one or more SAW reflectors that reflect the SAW back to the IDT. The IDT may then generate a new outgoing RF signal based on the received reflected SAW. For example, the IDT may generate an oscillatory potential associated with an acoustic frequency of the reflected SAW. The oscillatory potential may include information associated with the measured environmental condition over an area of ​​a surface of the piezoelectric material. The SAW sensor assembly may further include a matching circuit attached to the RF antenna and the first IDT. The matching circuit may be connected to the RF antenna and the first IDT. The SAW sensor, the RF antenna, and the matching circuit may be integrated with each other on the piezoelectric material.

[0015] In some embodiments, a sensor assembly may include a SAW sensor having two IDTs separated by a surface of a piezoelectric substrate or a piezoelectric layer on a substrate. A first IDT may be used to receive an incoming RF signal and generate a SAW, which is passed along the surface of the piezoelectric substrate or layer to the other IDT. The other IDT may receive the SAW and generate an oscillatory potential associated with the acoustic frequency of the SAW. This oscillatory potential may contain information associated with a measured environmental condition (e.g., temperature, pressure, etc.), where the environment includes the area between the IDTs. Each IDT may 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, a SAW sensor can include two IDTs (one generating the SAW and the other receiving the SAW and generating a new outgoing RF signal therefrom). The additional IDT can generate an oscillatory potential associated with the acoustic frequency of the received SAW. This oscillatory potential can include information associated with the measured environmental condition across an area of ​​the surface of the piezoelectric material (e.g., the piezoelectric substrate or layer). In an embodiment including a second IDT, the SAW sensor assembly can further include a second RF antenna that outputs the 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 the SAW sensor, the RF antenna, and the matching circuit on the piezoelectric material.

[0017] In an exemplary embodiment, a method for fabricating a sensor device is disclosed. The method may include fabricating an integrated sensor assembly by depositing a first conductive structure on a substrate having at least one layer of piezoelectric material, the first conductive structure forming a radio frequency (RF) antenna. The method may further include depositing a second conductive structure on the piezoelectric material, the second conductive structure forming a matching circuit connected to the RF antenna. The method may further include depositing a third conductive structure on the piezoelectric material, the third conductive structure forming an interdigital transducer (IDT) connected to the RF antenna, where the IDT is a component of a surface acoustic wave (SAW) sensor. The method may further include depositing a fourth conductive structure on the piezoelectric material, the fourth conductive structure forming 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 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, which in embodiments may each be a planar conductor. Fabricating a sensor device having all of the above elements in one integrated device allows for the use of smaller sensor devices, which can reduce manufacturing costs and time and reduce 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 resonant frequency. The first IDT may include a dielectric coating having a thickness and / or material associated with a shift in the base resonant frequency, the first IDT including the dielectric coating having a tuned resonant frequency. In a further embodiment, the sensor assembly may include various SAW sensors, each having an IDT including a dielectric coating of a different thickness and / or material, such that each respective IDT has a different tuned resonant frequency. The unique frequencies may allow a reader to receive and distinguish between outgoing RF signals generated by different SAW sensors. This allows for the manufacture of sensor wafers in which multiple (e.g., 5-20 or more) SAW sensors are disposed on the same sensor wafer. The signals generated by each SAW sensor on the sensor wafer may be received by a reader. The reader (or a controller connected thereto) may then determine which SAW sensor generated each particular outgoing RF signal based on the frequency of the outgoing RF signal. This allows the detector and / or controller to determine different environmental conditions at different locations on the sensor wafer.

[0019] In an exemplary embodiment, a method for fabricating a sensor assembly is disclosed. The method can begin with 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 resonant frequency, for example based on the pitch between fingers in the IDT. The method continues by tuning the resonant frequency of the IDT by depositing a dielectric coating on the conductive layer, the dielectric coating having a thickness of material, where at least the thickness or material is associated with a shift in the base resonant frequency, and the IDT including the dielectric coating has a tuned resonant frequency.

[0020] In some embodiments, the sensor assembly includes a SAW sensor including an IDT having two interdigitated electrodes including a configuration of interdigitated conductive fingers. The configuration of the interdigitated conductive fingers can generate a signal modulation of a signal passed through the IDT. The signal modulation can identify the SAW sensor. Additionally or alternatively, the sensor assembly can include a SAW sensor including an IDT and a collection of SAW reflectors having a spatial arrangement that causes a reflected SAW to have a signal modulation that is specific to the SAW sensor.

[0021] In one example, a sensor assembly may include a plurality of SAW sensors adapted to measure an environmental condition in response to receiving an incoming RF signal. A first SAW sensor may include a piezoelectric substrate and a first IDT formed on the piezoelectric substrate. The first IDT may include two interdigitated electrodes including interdigitated conductive fingers in a first arrangement. The interdigitated 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. A second SAW sensor may include a second IDT formed on the piezoelectric substrate (or a different piezoelectric substrate). The second IDT may include two interdigitated electrodes including interdigitated conductive fingers in a second arrangement. The interdigitated conductive fingers in the second arrangement generate a 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 may be identified based on their associated signal modulations. This allows for the fabrication of sensor wafers in which multiple (e.g., 5-20 or more) SAW sensors are located on the same sensor wafer. The signals generated by each SAW sensor on the sensor wafer can be received by a reader. The reader (or a controller connected to it) can then determine which SAW sensor generated each particular RF signal based on the frequency of that RF signal. This allows the detector and / or controller to determine different environmental conditions at different locations on the sensor wafer.

[0022] Any of the previously disclosed embodiments may be combined. For example, a sensor wafer may include a first SAW sensor having a first dielectric coating, a first arrangement of IDT fingers, and / or a first arrangement of reflectors, and a second SAW sensor having a second dielectric coating, a second arrangement of IDT fingers, and / or a second arrangement of reflectors. Each of the first and second SAW sensors may be part of a respective integrated sensor assembly, optionally including a respective antenna and matching network. In some embodiments, an integrated sensor assembly of multiple SAW sensors is included on a shared piezoelectric substrate or on another substrate on which the piezoelectric layer is placed.

[0023] The above and similar embodiments provide several advantages and improvements in the field of manufacturing and signal processing of sensor assemblies, such as SAW sensors, sensor wafers including one or more SAW sensors disposed on the sensor wafer, etc. Such advantages include improvements in SAW sensor assemblies, such as improved performance of SAW sensors, wider application of SAW sensors, improved signal differentiation between SAW sensors, and reduced manufacturing costs and complexity of SAW sensors.

[0024] Sensor performance can be improved by, for example, a sensor assembly (e.g., a SAW sensor) that uses passive circuitry. Passive circuitry allows for measuring environments at more extreme levels (e.g., high temperature and pressure) without being constrained by the specification limitations of active devices. For example, the use of an IDT connected to a unique antenna allows for a wider range of applications for the SAW sensor. An IDT connected to a unique antenna can be used to measure environmental conditions over a wider range of environments by sending a SAW between IDTs arranged over a wider area of ​​the piezoelectric substrate. Improved signal differentiation between SAW sensors can be achieved by creating a sensor assembly that includes SAW sensors tuned to operate at different frequencies, for example, by laying down 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 using the arrangement of interlocking conductive fingers of the IDT electrodes and / or the spatial arrangement of the SAW reflector.

[0025] FIG. 1 illustrates a simplified top view of an exemplary processing system 100 according to aspects of the disclosure. The processing system 100 includes a factory interface 91 to which multiple substrate cassettes 102 (e.g., front opening unified pods (FOUPs) and side storage pods (SSPs)) can be coupled for transporting substrates (e.g., wafers such as silicon wafers) into the processing system 100. FOUPs, SSPs, and other substrate cassettes may be collectively referred to herein as storage locations. In some embodiments, one or more of the substrate cassettes 102 includes one or more sensor wafers 110 having a SAW sensor assembly disposed or incorporated therein in addition to or in place of the wafers being processed. The SAW sensor assemblies of the sensor wafers 110 may be used to measure environmental conditions of an environment (e.g., temperature, pressure, etc.). For example, the sensor wafers 110 may be used to measure environmental conditions within one or more processing chambers 107, as well as other compartments and chambers as will be described. The factory interface 91 can also transfer the sensor wafer 110 into and out of the processing system 100 using the same functions for transferring wafers to be processed and / or processed wafers, as described below.

[0026] The processing system 100 may also include first vacuum ports 103a, 103b that may couple the factory interface 91 to respective stations 104a, 104b, which may be, for example, degassing chambers and / or load locks. Second vacuum ports 105a, 105b may be coupled to respective stations 104a, 104b and disposed between the stations 104a, 104b and a transfer chamber 106 to facilitate transfer of substrates into the transfer chamber 106. The transfer chamber 106 includes a number 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 may include one or more of an etch chamber, a deposition chamber (including an atomic layer deposition chamber, a chemical vapor deposition chamber, a physical vapor deposition chamber, or plasma enhanced versions thereof), and / or an annealing chamber, etc. The processing chamber 107 may 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 robot arm that can be or include a selective compliance assembly robot arm (SCARA) robot, such as a two-link SCARA robot, a three-link SCARA robot, a four-link SCARA robot, etc. The factory interface robot 111 can include an end effector at the end of the robot arm. The end effector can be configured to grasp and handle a particular object, such as a wafer. The factory interface robot 111 can be configured to transfer objects between substrate cassettes 102 (e.g., FOUPs and / or SSPs) and stations 104a, 104b (which can be, for example, load locks).

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

[0030] The processing system may include one or more RF antennas 129 in the processing chamber 107. The RF antenna 129 may be mounted on or disposed within a wall of the processing chamber 107, in embodiments. The RF antenna may be disposed within a component of the chamber, in some embodiments. For example, the RF antenna 129 may be disposed within a chuck (e.g., an electrostatic chuck) or within a showerhead of the processing chamber. Additionally or alternatively, the one or more RF antennas 129 may 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 may be communicatively connected to the SAW sensor assembly on the sensor wafer 110. For example, an RF signal may be transmitted from the RF antenna 129 to the SAW sensor assembly on the sensor wafer 110, and a return signal may be generated by the SAW sensor assembly and received by the same RF antenna or another RF antenna 129. The return signal may include information indicative of a measurement of an environmental condition of an environment (e.g., on the surface of the SAW sensor assembly) inside a process chamber, load lock, transfer chamber, etc. The RF antenna may be connected to a transceiver that generates an RF signal and / or receives an RF signal. In some embodiments, one or more RF antennas associated with a process chamber are connected to an RF transmitter, and one or more RF antennas associated with a process chamber are connected to an RF receiver. The sensor wafer may not include any power components (e.g., any batteries), and may instead be powered by the received RF signal generated by the RF antenna 129. Thus, the sensor wafer may be a passive device.

[0032] A controller 109 may control various aspects of the processing system 100 and may be communicatively coupled to the RF antenna 129. The controller 109 may be and / or include a computing device such as a personal computer, a server computer, a programmable logic controller (PLC), a microcontroller, or the like. The controller 109 may include one or more processing devices such as a microprocessor, a central processing unit, or the like. More specifically, the processing devices may be complex instruction set computing (CISC) microprocessors, reduced instruction set computing (RISC) microprocessors, very long instruction word (VLIW) microprocessors, processors implementing other instruction sets, or processors implementing combinations of instruction sets. The processing devices 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), a network processor, or the like.

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

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

[0035] 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 embodiment of the disclosure. The sensor device 200 includes a base substrate 202 and one or more SAW sensor assemblies 210A-D integrated on a surface of the base substrate 202. Each of the SAW sensor assemblies 210A-D may include an RF antenna 208A-D, a matching circuit 206A-D, and / or a SAW sensor 204A-D, which are part of an integrated device. Alternatively, one or more of the SAW sensor assemblies 210A-D may include integrated components of a SAW sensor 204A-D connected to a separate RF antenna and a separate and separate matching circuit, may include integrated SAW sensors 204A-D and matching circuits 206A-D connected to a separate and separate antenna, and / or may include integrated SAW sensors 204A-D and antennas 208A-D connected to separate and separate matching circuits. In some embodiments, the sensor wafer comprises at least one layer of piezoelectric material having a plurality of integrated SAW sensors 204A-D formed thereon, and optionally one or more integrated antennas 208A-D and / or integrated matching circuits 206A-D disposed thereon, which are described in more detail below with reference to Figures 3A-B.

[0036] 2, the base substrate 202 can be a disk-like structure including a flat surface (e.g., a wafer). In other embodiments, the base substrate 202 can be formed into 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 made of a conventional wafer-based substrate such as silicon, LiNbO3, LiTaO3, or La3Ga5SiO 14The piezoelectric material may include, or may be partially or completely covered by, a piezoelectric material such as. In some embodiments, the base substrate may be made entirely of piezoelectric material, rather than using a traditional wafer-based substrate (e.g., silicon). In some embodiments, the base substrate may 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 number of SAW sensor assemblies 210A-D integrated and / or deposited on a surface of a base substrate 202. The sensor device 200 may 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 may be included in the sensor device 200. The SAW sensor assemblies 210 may be arranged in a sensor array, where each integrated SAW sensor assembly 210 measures environmental conditions at various locations on the base substrate 202. In some embodiments, each SAW sensor assembly is formed on a common piezoelectric substrate or other substrate on which a piezoelectric layer is formed (e.g., on the same wafer). Alternatively, one or more SAW sensor assemblies may be formed on a separate piezoelectric substrate or substrate including a piezoelectric layer to form separate sensor assemblies (e.g., formed on a separate piezoelectric substrate with other SAW sensor assemblies and then diced and packaged to form separate SAW sensor assemblies). The separate sensor assemblies may then be mounted on the base substrate 202. In such an embodiment, the base substrate 202 may or may not be a piezoelectric material. Each SAW sensor assembly 210A-D may be mounted or positioned at a different location on the base substrate 202.

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

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

[0040] In some embodiments, the sensor device 200 includes a layer on the back side of the base substrate 202 opposite the SAW sensor assembly 210. The layer on the back side may include or be a metal layer. The metal layer may be used to minimize interference from other signals (e.g., RF antenna 129 of FIG. 1 in another chamber) and may optionally 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 over an area of ​​the base substrate over the SAW sensor 204 or a portion thereof. The shielding structure may include a recess above the area of ​​the base substrate 202 to allow propagation of the SAW across the surface of the base substrate 202. The shielding structure may include a material that is resistant to high temperatures and / or pressure. 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 may be a dielectric material. In some embodiments, the shielding structure is disposed over a larger portion of the base substrate 202. For example, the shielding structure may include a cover that completely encapsulates the sensor device 200.

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

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

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

[0045] The RF antennas 306A-B may include planar conductors or multiple conductive layers coupled together to receive and / or transmit RF signals. Herein, components 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 may act as filters associated with a particular RF range. The RF antennas 306A-B may include a resonator antenna (e.g., a dielectric resonator antenna), a fractal antenna, or some other type of antenna. The RF antennas 306A-B may have a planar structure or may be formed to be generally flat or flush with the surface of the substrate (e.g., may be planar conductors). The matching circuits 304A-B are coupled to the RF antennas 306A-B and the SAW sensors 302A-B. The matching circuits 304A-B may 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. In an embodiment, the matching circuits 304A-B may be designed to minimize signal reflection between the RF antennas 306A-B and the SAW sensors 302A-B. Each SAW sensor 302A-B is coupled to a respective RF antenna 306A-B via a respective matching circuit 304A-B. As shown in FIGS. 3A-B, the SAW sensors 302A-B may include interdigital transducers (IDTs) 310A-B. The IDTs 310A-B include two interdigitated comb-shaped electrodes. The IDTs 310A-B may be disposed on a piezoelectric material (e.g., the base substrate 202 in FIG. 2). The IDTs receive an input signal (e.g., an alternating current (AC) signal) from the matching circuit 304 and generate an electric field in the gap between the conductive fingers of the electrodes based on the signal. This electric field generates a SAW 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 may combine the SAWs reflected by the multiple reflectors 312A-B together to generate an oscillating potential. The oscillating potential may be sent to the RF antenna 306. The RF antenna 306 outputs an outgoing RF signal associated with the oscillating potential, which may be received by an RF signal receiving device (e.g., RF antenna 129 of FIG. 1). The oscillating potential generated by the IDT 310A includes information indicative of a condition of an environment disposed between the IDT 310 and the SAW reflector 312. The environmental condition may be indicated by a change in frequency of the RF signal transmitted to the SAW sensor assembly 300 and the RF signal received back. The signal received back may contain information indicative of the environmental condition. For example, for a given temperature or pressure, the piezoelectric material may strengthen or contract in length, changing the pitch, phase, and overall delay of the signal, which may be calibrated to a particular temperature or pressure. In some embodiments, the reflector may be spatially positioned and calibrated such that a change in frequency between the RF signals is associated with a change in the environmental condition (e.g., a change in temperature or pressure).

[0047] In some embodiments, SAW reflectors 312A-B may be disposed on one or more sides of IDT 310A, as shown in Figure 3A. The SAW reflectors may vary in distance between each other and in thickness in some embodiments. Alternatively, the SAW reflectors may be uniform in 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 reflected SAWs combine together back at the IDT 310. The relative delays of the reflected SAWs interfere with each other constructively and destructively, resulting in an oscillating potential indicative of the measured environmental condition. The oscillating potential is sent to the RF antenna 306 and may be further sent to other devices (e.g., RF antenna 129 of FIG. 1). The oscillating potential contains information indicative of the condition of the environment between the IDT 310 and the delay lines 314. The environmental condition may be indicated by a change in 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 related to a measured environmental condition, such as temperature or pressure.

[0049] In some embodiments, the SAW sensor 302A-B includes a second IDT (not shown). The first IDT 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 a conductive element (e.g., delay line 314) on the surface of the piezoelectric material before reaching the second IDT. The second IDT can generate an oscillating potential associated with the received SAW. The oscillating potential can be transmitted through a matching circuit connected to the second IDT to an RF antenna attached to the matching circuit. A change between the first oscillating potential based on the received RF signal and the second oscillating potential generated by the IDT based on the received SAW can indicate a measured environmental condition. In some embodiments, multiple IDTs can share a common RF antenna and / or matching network.

[0050] In some embodiments, the RF antennas 306A-B, matching circuits 304A-B, and SAW sensors 302A-B including IDTs 310A-B are all integrated together on a common piezoelectric material. As further described in other embodiments, the SAW sensor assemblies 300A-B may 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) instead of fabricating the components together in multiple assembly steps and separate component fabrication steps. Fabricating a sensor device having all of the above components in a single integrated device allows for the use of smaller sensor devices, reducing manufacturing costs, time, and the number of manufacturing steps required. Fabricating a single device also allows for interchangeability between the components being fabricated. Inefficiencies in matching component specifications may also be eliminated.

[0051] 4 is a flow chart of a method 400 for fabricating a SAW sensor assembly according to an aspect of the present disclosure. The method 400 may be performed in embodiments to manufacture a sensor device (e.g., the sensor assembly 110 of FIG. 1).

[0052] Referring to FIG. 4, in block 410, a conductive structure is formed on a substrate having at least one layer of piezoelectric material thereon to form an RF antenna 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 step to deposit a photoresist on the piezoelectric material, performing a patterning step (e.g., using a lithography device) to harden selective portions of the photoresist, and performing an etching step (e.g., in an etching chamber) to etch away either the hardened or unhardened portions of the photoresist. A deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may then 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. A selective etching process may then be performed (e.g., in an etching chamber) to remove the photoresist and the conductive material formed thereon to leave 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 constituting 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 step to deposit a photoresist on the piezoelectric material, performing a patterning step (e.g., using a lithography device) to harden selective portions of the photoresist, and performing an etching step (e.g., in an etching chamber) to etch away either the hardened or unhardened portions of the photoresist. A deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may then 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. A selective etching process may then be performed (e.g., in an etching chamber) 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, and thus a sequence of steps (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) may be performed to form both the first and second conductive structures simultaneously or in parallel.

[0054] At block 430, a third conductive structure is formed on the piezoelectric structure to form an interdigital transducer (IDT) on the piezoelectric material. The IDT may be connected to an RF antenna via a matching network. The IDT may include features and configurations of the IDTs disclosed in other embodiments of the present disclosure (e.g., IDT 310 of FIG. 3). Forming the third conductive structure may include performing a photoresist deposition step to deposit a photoresist on the piezoelectric material, performing a patterning step (e.g., using a lithography device) to harden selective portions of the photoresist, and performing an etching step (e.g., in an etching chamber) to etch away either the hardened or unhardened portions of the photoresist. A deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may then 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. A selective etching process can then be performed (e.g., in an etching chamber) to remove the photoresist and the conductive material formed thereon, leaving behind 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 steps (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) can be performed to form the first conductive structure, the second conductive structure, and the third conductive structure simultaneously or in parallel.

[0055] At 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 second IDT may be separated from the IDT by a span of the piezoelectric material through which the SAW may propagate. This allows the second IDT and / or reflector to be communicatively connected to the first IDT via the SAW. The SAW reflector may include features and configurations of a SAW reflector disclosed elsewhere in this disclosure (e.g., SAW reflector 312 of FIG. 3). The second IDT may include features and configurations of an IDT disclosed in other embodiments of this disclosure (e.g., IDT 310 of FIG. 3). Forming the fourth conductive structure may include performing a photoresist deposition step to deposit a photoresist on the piezoelectric material, performing a patterning step (e.g., using a lithography device) to harden selective portions of the photoresist, and performing an etching step (e.g., in an etching chamber) to etch away either the hardened or unhardened portions of the photoresist. A deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may then 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. A selective etching process may then be performed (e.g., in an etching chamber) to remove the photoresist and the conductive material formed thereon to leave the fourth conductive structure. The fourth conductive structure may be formed simultaneously with the first conductive structure, the second conductive structure, and / or the third conductive structure. Thus, a series of steps (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) can be performed to simultaneously or in parallel form the first conductive structure, the second conductive structure, the third conductive structure, and the fourth conductive structure.

[0056] At 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 may include performing a photoresist deposition step to deposit a photoresist on the piezoelectric material, performing a patterning step (e.g., using a lithography device) to harden selective portions of the photoresist, and performing an etching step (e.g., in an etching chamber) to etch away either the hardened or unhardened portions of the photoresist. A deposition process (e.g., atomic layer deposition, physical vapor deposition, chemical vapor deposition, etc.) may then 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. A selective etching process may then be performed (e.g., in an etching chamber) to remove the photoresist and the conductive material formed thereon to leave the fifth conductive structure. The fifth conductive structure may be formed simultaneously with the first conductive structure, the second conductive structure, the third conductive structure, and / or the fourth conductive structure. Thus, a series of steps (e.g., processes such as photoresist deposition, lithography, etching, metal deposition, etching, etc.) can be performed to simultaneously or in parallel form a first conductive structure, a second conductive structure, a third conductive structure, a fourth conductive structure, and a fifth conductive structure.

[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 steps of blocks 410, 420, 430, 440, and / or 450 can be performed together such that the conductive structures are deposited together. Alternatively, one or more layers can be formed separately.

[0058] In some embodiments, the method 400 may further include depositing a protective coating over the RF antenna and / or the matching circuit. The protective coating may include a dielectric material that may be plasma resistant, high temperature resistant, and / or high pressure resistant. 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] 5A-B are top perspective views of various embodiments of SAW sensors 500 having dielectric coatings 530, 540 thereon, according to aspects of the disclosure. The SAW sensors 500A-B include an IDT 520 having two interdigitated electrodes disposed on a base substrate 510 having at least one layer of piezoelectric material. The SAW sensors further include a dielectric coating 530 disposed on the IDT 520 and the base substrate 510. The SAW sensors 500A-B may 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 may additionally coat the additional IDT(s) and / or reflector and / or an area 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 may also be coated with the dielectric coating 530 .

[0061] In some embodiments, the IDT 520 receives an electrical signal (e.g., an AC signal) and generates a SAW across the surface of the piezoelectric material. The generated SAW has a propagation velocity and a resonant frequency. By applying a dielectric coating 530, it is possible to adjust the resonant frequency of the SAW sensor. The dielectric coating 530 can adjust the propagation velocity of the SAW, thereby lowering the resonant frequency. The dielectric coating 530 can include a thin uniform dielectric layer. Examples of dielectric coatings that can be used include Al2O3, AlN, Y2O3, Y3Al5O 12 , yttrium-based oxides, fluorides and / or oxyfluorides, and the like.

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

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

[0064] In some embodiments, processing and analysis of sensor data, image processing algorithms, machine learning (ML) algorithms that generate one or more trained machine learning models, deep ML algorithms, and / or other signal processing algorithms for analyzing SAW sensor data can be used to determine the resonant frequency shift of a SAW sensor as a result of laying down any number of dielectric coatings of various materials and thicknesses over the IDT of the SAW sensor. These models, analyses, and / or algorithms can be used to calculate, predict, and evaluate combinations of dielectric materials and thicknesses and the resulting resonant frequency shift for a given SAW sensor. Additionally or alternatively, such techniques can be used with SAW sensor data to design multiple SAW sensors that can operate together in close proximity without their signals being confused. In some embodiments, training data for training the ML model can be obtained by imaging using a scanning device or other type of sensor or camera to measure the resonant frequency shift of a SAW sensor that has previously been coated with a dielectric material of a specified material and thickness.

[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 typically includes a feature representation component that includes a classifier or regression layer that maps features to a desired output space. For example, a Convolutional Neural Network (CNN) hosts multiple layers of convolution filters. Lower layers include pooling to address nonlinearities, and multi-layer perceptrons are typically added on top to map the features from the upper layers extracted by the convolutional layers to a decision (e.g., classification output). Deep learning is a class of machine learning algorithms that uses a cascade of multiple layers of nonlinear processing units for feature extraction and transformation. Each successive layer uses the output from the previous layer as input. Deep neural networks can be trained in supervised (e.g., classification) and / or unsupervised (e.g., pattern analysis) forms. Deep neural networks have a hierarchy of layers, where different layers learn different levels of representations that correspond 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 may be a matrix of pixels; a first representation layer may abstract the pixels and encode edges, a second layer may construct and encode the arrangement of edges, a third layer may encode higher level shapes (e.g. teeth, lips, gums, etc.), and a fourth layer may recognize that an image contains a face or define a bounding box around teeth in the image. In particular, the deep learning process is able to teach itself which features are best placed at which level. The "deep" in "deep learning" refers to the number of layers that transform the data. More precisely, deep learning systems have a substantial CAP (credit assignment path) depth. A CAP is a chain of transformations from input to output.CAP describes the potential causal relationships between inputs and outputs. For feedforward neural networks, the depth of the CAP is the depth of the network, which can be the number of hidden layers + 1. For recurrent neural networks, the depth of the CAP can be unlimited, since a signal may propagate through a layer multiple times.

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

[0067] FIG. 6 is a graph 600 illustrating a frequency shift 610 in the base resonant frequency of a SAW sensor according to an embodiment of the disclosure. A first peak 606 represents an IDT without a dielectric coating with a first resonant frequency. A second peak 608 represents an IDT with a dielectric coating with a second resonant frequency. The distance between the peaks represents the frequency shift 610 resulting from laying down a dielectric coating. A dielectric coating can be used to tune the resonant frequency. 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 reduction 612 in signal strength resulting from the dielectric coating. The dielectric coating can also, in embodiments, protect the SAW sensor from overexposure and prevent signal saturation from the environment.

[0068] 7 is a top perspective view of a sensor device 700 according to an embodiment 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 an RF antenna 710, a matching circuit 708, and SAW sensors 706A-B. The SAW sensor assemblies 704A-B including the RF antenna 710, the matching circuit 708, and the SAW sensors 706A-B may include features and configurations of SAW sensors disclosed elsewhere herein (e.g., the base substrate 202 and SAW sensor assembly 210 of FIG. 2, the SAW sensor assembly 300 of FIG. 3).

[0069] As shown in FIG. 7, the SAW sensors 706A-706B can be disposed on a piezoelectric material of a base substrate 702, which can be affixed or deposited on the base substrate 702. For example, the piezoelectric substrate of the SAW sensors 706A-B can be affixed to a silicon wafer. In other embodiments, the SAW sensor assemblies can be fully integrated into the base substrate 702. For example, the base substrate 702 can include a common piezoelectric material, and the RF antenna 710, matching circuit 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 matching circuit 708 can be separate devices that are not integrated into the base substrate 702.

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

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

[0072] In some embodiments, a SAW sensor assembly 704 may include SAW sensors 706A-B, each sensor assembly having the same base resonant frequency. The SAW sensors 706A-B may be tuned to generate different SAW acoustic frequencies by providing a dielectric coating of different thicknesses and / or materials to each SAW sensor 7086A-B to produce different resonant frequency shifts. For example, a first SAW sensor 706A may have a first dielectric coating having a first thickness and a second SAW sensor 706B may have a second dielectric coating having a second thickness.

[0073] In some embodiments, a combination of SAW sensor assemblies including a dielectric coating and / or a SAW sensor assembly not including a dielectric coating (not shown) may be combined on the same base substrate 702 as a SAW sensor assembly 704 including a dielectric coating.

[0074] FIG. 8 is a flow chart of a method 800 for fabricating a SAW sensor assembly according to an embodiment of the present disclosure.

[0075] 8, in block 810, the processing system may determine a current RF resonant frequency range of the SAW sensor. The SAW sensor may include features and configurations of SAW sensors disclosed elsewhere herein (e.g., SAW sensor 500 of FIG. 5).

[0076] In block 820, the processing system may determine a target RF resonant frequency range for 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 resonant frequency range to the target RF resonant frequency range. In one embodiment, the SAW sensor design (and, optionally, the target SAW attributes) is input to a trained machine learning model, which outputs a recommendation for the dielectric coating material and / or the dielectric coating thickness. In some embodiments, the processing system determines the combination of dielectric materials and layers to deposit on the SAW sensor. In some embodiments, the determined materials and thicknesses depend on the SAW sensor specifications (e.g., surface area, maximum thickness, etc.).

[0078] In block 840, the processing system may deposit a dielectric coating over the SAW sensor. The dielectric coating may 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 may determine whether the resonant frequency is within a threshold difference of the target RF resonant frequency. The processing system may measure the current resonant frequency and compare the result to the target resonant frequency determined in block 820. If the resonant frequency is within the threshold difference, the method 800 may be complete. However, if the resonant frequency is not within the threshold difference 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] 9A-C show various embodiments of electrode configurations for IDTs 900A-B of a SAW sensor according to aspects of the disclosure. The IDTs 900A-C each include two interdigitated electrodes with interdigitated fingers 910A-C arranged in a configuration on a substrate having at least one layer of piezoelectric material.

[0081] In some embodiments, the IDTs 900A-C receive an electrical signal (e.g., an RF signal) and generate a SAW associated with the received electrical signal. In other embodiments, the IDTs 900A-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 electrode interdigital fingers 910A-C can produce signal modulation in any signal passing through the IDTs 900A-C.

[0082] Embodiments of the present disclosure include various configurations of interlocking fingers 910A-C. For example, an IDT 900A may include a first arrangement of interlocking interlocking fingers 910A, as shown in FIG. 9A. This first arrangement may result in an unmodulated signal 920A having a particular resonant frequency and / or phase. For example, an IDT 900B may include a second arrangement of interlocking fingers 910B, as shown in FIG. 9B, including at least two fingers from the same electrode positioned adjacent to each other. This arrangement may result in a modulated signal 920B. In some embodiments, the modulated signal 920B may include the same resonant frequency as 920A, but with a phase shift or otherwise altered signal. The pitch or spacing between the interlocking fingers may also be adjusted to produce a modulated signal having an adjusted or modulated frequency, as described in FIG. 9C.

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

[0084] In some embodiments, the signal modulation produced by the interlocking finger configuration can result in a signal modulation that includes a phase shift of the original signal. For example, as shown in FIG. 9B, the interlocking finger 910B configuration results in a signal that is at the same frequency as the unmodulated signal, but with a phase shift 930 at various positions across the signal. In some embodiments, the modulated signal includes the same frequency as the unmodulated signal.

[0085] The IDTs 900A-C shown in FIGS. 9A-C may be subsets or subsections of an IDT used in various embodiments of the present disclosure. For example, the configuration shown by IDT 900A may be repeated for a longer IDT. In other examples, the IDT 900B shown in FIG. 9B may include more interlocking fingers than shown, which may include various arrangements that result in various phase and / or frequency modulation. For example, the IDT 900B may be associated with a phase shift of the pulses of a signal, but when combined with other subsections (not shown), may result in signal modulation of the signal comprised of multiple modulated pulses, resulting in a modulated signal. In some embodiments, the configurations shown by IDT 900A and IDT 900B may be combined to have both phase shifted regions and regions where no modulation occurs. For example, an IDT may include alternating subsections including IDT 900A and IDT 900B, resulting in signal modulation. Additionally, the IDT may include alternating subsections including IDT 900A, IDT 900B and / or IDT 900C, resulting in signal modulation.

[0086] In some embodiments, the IDTs 900A-C may be part of a SAW sensor (e.g., SAW sensor 204 of FIG. 2) of a sensor assembly (e.g., SAW sensor assembly 210 of FIG. 2) of a sensor device (e.g., sensor device 200 of FIG. 2). Various SAW sensor assemblies may be disposed across a base substrate (e.g., a wafer). Each SAW sensor assembly may include a SAW sensor with an IDT having a unique configuration of digital interlocking fingers. Each SAW sensor may measure an environmental condition and return information in a signal having a signal modulation that identifies the SAW sensor assembly that transmitted the information. It is appreciated that by having a unique signal modulation, each sensor may operate within a range of overlapping or comparable resonant frequencies and yet be distinguished from other sensors. For example, a measured environmental condition may be mapped to a first region of a base substrate because a signal carrying information associated with the environmental condition also includes a signal modulation that identifies a sensor located within the first region of the base substrate.

[0087] In some embodiments, the interlocking finger configuration can be combined with other embodiments of the present disclosure to identify the sensor. For example, the interlocking finger 910 configuration can be combined with the spatial arrangement of the SAW reflector 1004 as described in connection with FIG. 10 to obtain a further modulated signal that uniquely identifies the SAW sensor. In another example, the interlocking finger 910 configuration can be combined with the laying down of the dielectric coating 530 as described in connection with FIG. 5 to obtain a signal modulation combined with a tuned frequency that uniquely identifies the SAW sensor. The combination of the above techniques can increase the density of SAW sensors that can be placed together on a sensor wafer and are uniquely identifiable.

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

[0089] As shown, a single IDT 1002A-B both generates a SAW based on a received RF signal and receives a reflection of the SAW and generates a new RF signal therefrom. In such an embodiment, the generation of the SAW and the reception of the reflected SAW are offset in time 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 positioned adjacent to each other. A first IDT can receive an RF signal and generate a SAW, and a second IDT can receive a reflected SAW and generate a new RF signal. In such a configuration, the first and second IDTs 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, a SAW sensor may include a collection of uniformly distributed SAW reflectors, as shown by SAW reflectors 1004A-B. In other examples, a SAW sensor may include a collection of SAW reflectors that may not be uniformly distributed and may be uniquely spaced. In other examples, a SAW sensor may include a collection of one or more SAW reflectors that are grouped together, as shown by SAW reflectors 1004C-D. In other examples, a SAW sensor may include a collection of one or more SAW reflectors that are variously spaced apart, as shown by SAW reflector 1004D.

[0091] In some embodiments, the spatial arrangement of the SAW reflectors 1004A-D results in signal modulation specific to the SAW sensor. For example, each of the previously described embodiments shown in Figures 10A-B can result in signal modulation that is unique to each SAW sensor. For example, the signal modulation can result in phase changes, frequency changes, and / or signal delays as a result of constructive and destructive interference of the reflected SAWs upon returning to the 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 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 in the first group 1009A, 1009C have a first pitch or spacing, and all reflectors in the second group 1009B, 1009D also have a first pitch or spacing. The first pitch or spacing can be, for example, approximately the spacing of one wavelength of the SAW. The first group 1009A may be separated from the second group 1009B by a gap or space 1010D, which may not be a full wavelength of the SAW. Similarly, the first group 1009C may be separated from the second group 1009D by a gap or space 1010D. In an embodiment, the gap or space 1010D may have a length of ¼ wavelength, ½ wavelength, ¼ wavelength, ½ wavelength, ¾ wavelength, 1 and ¼ wavelength, 1 and ½ wavelength, 1 and ¾ wavelength, 2 and ¼ wavelength, 2 and ½ wavelength, 2 and ¾ wavelength.... In a further example, the spatial distribution of the SAW reflectors 1004A-D may include ½ wavelength and / or ¼ wavelength spacing between the SAW reflectors. In some embodiments, the SAW reflectors are arranged in groups, where a first group of SAW reflectors may be offset from a second group of SAW reflectors, for example, by a half wavelength or a quarter wavelength. In one embodiment, each SAW reflector of the first group of SAW reflectors is spaced from one or more immediately adjacent SAW reflectors of the group by a distance that may correspond to the wavelength of the SAW. Additionally, each SAW reflector of the second group of SAW reflectors may be spaced from one or more immediately adjacent SAW reflectors from the group by a distance that may correspond to the wavelength of the SAW. In some embodiments, a combination of half wavelength, quarter wavelength and / or full wavelength spacing may be used to generate a unique signal modulation that may identify the SAW sensors 1000A-B.In some embodiments, the SAW sensors 1000A-B may be part of a sensor assembly (e.g., SAW sensor assembly 210 of FIG. 2) of a sensor device (e.g., sensor device 200 of FIG. 2). Various SAW sensor assemblies, each comprising a SAW sensor including an IDT and a collection of SAW reflectors arranged in a unique spatial arrangement, may be arranged across a base substrate (e.g., a wafer). Each SAW sensor may measure an environmental condition and return information in a signal having a signal modulation that identifies the SAW sensor assembly that transmitted the information. It is appreciated that by having a unique signal modulation, each sensor may operate within a range of overlapping or comparable resonant frequencies and may still be distinguished from other sensors. For example, a measured environmental condition may be mapped to a first region of a base substrate because a signal carrying information associated with the environmental condition also includes a signal modulation that identifies a sensor located within the first region of the base substrate.

[0093] In some embodiments, the spatial arrangement of the SAW reflector can be combined with other embodiments of the present disclosure to identify the SAW sensor. For example, the unique spatial arrangement of the SAW reflectors 1004A-D of the SAW sensor can be combined with the unique arrangement of the interlocking fingers 910 of the IDT, as described in conjunction with FIG. 9. This can result in a further modulated signal that uniquely identifies the SAW sensor. In another example, the unique spatial arrangement of the SAW reflector 1004 can be combined with the laid down dielectric coating 530, as described in conjunction with FIG. 5. This can result in a signal modulation combined with a tuned frequency that uniquely identifies the SAW sensor.

[0094] 11-14 are top perspective views of various embodiments of sensor devices 1100-1400 according to aspects of the disclosure. The sensor devices include a substrate 1102-1402 (e.g., a piezoelectric substrate or a semiconductor substrate with a piezoelectric layer thereon) having at least one layer of piezoelectric material, and a SAW sensor assembly 1104-1404 and 1108-1208 designed to receive and / or transmit RF signals associated with measuring environmental conditions of an environment using SAWs 1106-1406. 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 SAW sensor assemblies (e.g., sensor device 200) disclosed elsewhere herein. The following exemplary embodiments disclose various configurations for sending SAWs between multiple sensor assemblies to measure environmental conditions within an area on a surface of a piezoelectric material between the multiple sensor assemblies.

[0095] In some embodiments, for example as shown in Fig. 11, the sensor device 1100 may include a first SAW sensor assembly 1104A designed to receive an incoming RF signal and generate a SAW 1106A that propagates across a surface of a substrate 1102, which may be a piezoelectric substrate or a substrate on which a piezoelectric layer is placed. The SAW 1106 is received by a second SAW sensor assembly 1108A designed to generate an electrical potential associated with the received SAW 1106A and output an outgoing RF signal associated with the electrical potential, where the output of the outgoing RF signal includes information indicative of a 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 support 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 matching network and / or antenna of the SAW sensor assemblies 1104A, 1108A are not part of the integrated device, but rather are 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 with the first SAW sensor assembly 1104A and / or the second SAW sensor assembly 1108A. In further embodiments, the sensor device can include a first set of SAW sensor assemblies 1104, each generating a SAW 1106 that is received by a second set of SAW sensor assemblies 1108. In embodiments, each of the SAW sensor assemblies can 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, for example as shown in FIG. 12, a sensor device 1200 may include a set of SAW generating sensor assemblies 1204 designed to receive an incoming RF signal and generate a SAW 1206 that propagates across a 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 receiving sensor assembly 1208 designed to receive the SAW 1206 generated by the set of SAW generating sensor assemblies 1204. The SAW receiving sensor assembly 1208 may be designed to generate an oscillating potential associated with each of the SAWs 1206 generated by the SAW generating sensor assemblies 1204. The SAW receiving sensor assembly 1208 outputs an outgoing RF signal in accordance with each oscillating potential, where each RF signal includes information indicative of an environmental condition of an environment located between the SAW receiving sensor assembly 1208 and an associated SAW generating sensor assembly (e.g., 1204A). In some embodiments, a first waveguide may be disposed between the SAW generating sensor assembly 1208 and the first SAW sensor assembly 1204A, and a second waveguide may be disposed between the SAW generating 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 receiving sensor assembly 1208 are part of a single integrated device. In some embodiments, the matching networks and / or antennas of the SAW sensor assemblies 1204A, 1204B, 1208 are not part of an integrated device, but rather are separate components. In some embodiments, a first waveguide disposed between the first SAW sensor assembly 1204A and the SAW receiving sensor assembly 1208 and a second waveguide disposed between the second SAW sensor assembly 1204B and the SAW receiving sensor assembly 1208 are part of an integrated device together with the first SAW sensor assembly 1204A, the second SAW sensor assembly 1204B, and / or the SAW receiving sensor assembly 1208.In a further embodiment, the sensor device 1200 may include multiple sets of SAW generating sensor assemblies (e.g., 1204) and multiple 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 in FIG. 13, for example, a 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 may 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 may generate an oscillating potential associated with the corresponding SAW 1306 received by each sensor assembly 1304. Each sensor assembly 1304 can output an outgoing RF signal according to the respective oscillating potential, where each outgoing RF signal includes information indicative of an environmental condition of the environment located 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 coordinate the transmission of the incoming RF signal such that the sensor assemblies alternate between the role of SAW generation and oscillating potential generation. In another embodiment, the processing system can coordinate 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 can include multiple pairs of sensors operating according to the exemplary embodiment described above detailing the sensor assemblies 1304A and 1304B.

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

[0099] In some embodiments, as shown in FIG. 14, a sensor device 1400 may include a plurality of sensor assemblies 1404 disposed on a 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 that is received by a plurality of SAW sensor assemblies 1404B, 1404C, and 1404D. The sensor device 1400 may include a SAW sensor assembly 1404B configured to receive a SAW 1406A from another SAW sensor assembly 1404A, generate an oscillating potential associated with the SAW, and output an outgoing RF signal associated with the generated oscillating potential. The SAW sensor assembly 1404B may also be designed to generate a SAW 1408 in response to receiving the incoming RF signal. The sensor device may further include a SAW sensor assembly 1404C designed to receive the SAWs 1408 and 1406B from the plurality of SAW sensor assemblies 1404A and 1404B. The SAW sensor assembly 1404C can generate an oscillating potential for each received SAW and output an outgoing RF signal associated with each generated oscillating potential. The SAW sensor assembly 1404C can also be designed to generate a SAW 1410 in response to receiving the incoming RF signal. The sensor device can further include a SAW sensor assembly 1404D designed to receive the SAWs 1410 and 1406C from the multiple SAW sensor assemblies 1404C and 1404A. The SAW sensor assembly 1404D can generate an oscillating potential for each received SAW and output an outgoing RF signal associated with each generated oscillating potential.

[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 embodiments, a waveguide may be part of an integrated device that includes one or more SAW sensor assemblies. For example, the waveguide may be a planar conductor formed on a piezoelectric material on which the SAW sensor assemblies are formed.

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

[0102] In the foregoing specification, numerous specific details are described, such as examples of specific systems, components, methods, etc., to provide a thorough understanding of some embodiments of the present disclosure. It will be apparent to one of ordinary skill in the art that at least some embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known components or methods have not been described in detail or have been presented in simplified block diagram form in order not to unnecessarily obscure the present disclosure. Thus, the specific details described are merely illustrative. Particular embodiments may vary from these example details and still be considered to be within the scope of the present disclosure.

[0103] Throughout this specification, reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in an embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. In addition, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". When the term "about" or "approximately" is used herein, this is intended to mean that the stated nominal value is correct within ±10%.

[0104] Although the method steps herein are shown and described in a particular order, the order of each method step may be changed, such that certain steps may be performed in reverse order, or certain operations may be performed at least partially simultaneously with other steps. In other embodiments, the ordering of separate steps or sub-steps may be intermittent and / or alternating. In one embodiment, multiple metallurgical bonding steps are performed as a single step.

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

Claims

1. A sensor device, comprising: a first integrated sensor assembly, the 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 of an environment in response to receiving a first incoming RF signal; a first interdigital transducer (IDT) formed on a first region of the piezoelectric material, the first IDT generating a first SAW in response to receiving the first incoming RF signal based on the environmental condition; and a second IDT formed on a second region of the piezoelectric material, the second IDT receiving the first SAW from the first IDT and generating a first vibration potential associated with a first acoustic frequency of the received first SAW; a first surface acoustic wave (SAW) sensor including: a first RF antenna formed on a third region of the piezoelectric material; and a second RF antenna coupled to the second IDT, the second RF antenna being formed in a fourth region of the piezoelectric material; Equipped with the first SAW sensor, the first RF antenna, and the second RF antenna are integrated with one another on the piezoelectric material; the second RF antenna receives the first incoming RF signal; the second IDT further generates a second SAW in response to receiving the first incoming RF signal based on the environmental condition; the first IDT further receives the second SAW from the second IDT; the first IDT further generates a second oscillatory potential associated with a second acoustic frequency of the received second SAW; the first RF antenna further outputs an outgoing RF signal according to the second oscillating potential. Sensor device.

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

3. The sensor device of claim 2 , wherein the RF antenna, the matching circuit, the first IDT, and the second IDT each include one or more planar conductors disposed on the piezoelectric material.

4. The sensor device of claim 2 , further comprising a protective coating or cover disposed over the first RF antenna and the matching circuit.

5. A second integrated sensor assembly, a second SAW sensor 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 the second incoming RF signal; a third IDT formed on a fifth region of the piezoelectric material; and At least one of: a) one or more SAW reflectors communicatively coupled 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. a second SAW sensor including: a third RF antenna coupled to the third IDT and formed on an eighth region of the piezoelectric material; Equipped with 2. The sensor device of claim 1, wherein a third SAW sensor and the second RF antenna are integrated together on the piezoelectric material, the first SAW sensor adapted to operate within a first frequency range, and the second SAW sensor adapted to operate within a second frequency range different from the first frequency range.

6. The sensor device of claim 1 , wherein the substrate comprises a piezoelectric substrate comprising the piezoelectric material.

7. The sensor device of claim 1 , wherein the substrate comprises a substrate constructed from a first material and a piezoelectric layer on the substrate, the piezoelectric layer comprising the piezoelectric material.

8. the second RF antenna further receives a second incoming RF signal; the second IDT further generates a third SAW in response to receiving the second incoming RF signal based on the environmental condition; The first IDT is receiving the third SAW from the second IDT; generating a third oscillatory potential associated with a third acoustic frequency of the received third SAW; The sensor device of claim 1 , wherein the first RF antenna further outputs a second outgoing RF signal according to the third oscillating potential.

9. the first integrated sensor assembly comprising: a third IDT formed on a fifth region of the piezoelectric material, receiving the first SAW from the first IDT; a third IDT for generating a third oscillating potential associated with the first acoustic frequency of the received first SAW; a third RF antenna connected to the third IDT for further outputting a second outgoing RF signal according to the third oscillating potential; The sensor device of claim 1 further comprising:

10. the second RF antenna further receives the first incoming RF signal or a second incoming RF signal; the second IDT further generates a third SAW in response to receiving the first incoming RF signal or the second incoming RF signal based on the environmental condition; The third IDT is receiving the third SAW from the second IDT; generating a fourth oscillatory potential associated with a combination of the first acoustic frequency of the received first SAW and the second acoustic frequency of the received third SAW; The sensor device of claim 9 , wherein the third RF antenna further outputs a third outgoing RF signal according to the fourth oscillating potential.

11. the first integrated sensor assembly comprising: a third IDT formed on a fifth region of the piezoelectric material; and a third RF antenna connected to the third IDT; Further comprising: the second RF antenna further receives the first incoming RF signal or a second incoming RF signal; the second IDT further generates a third SAW in response to receiving the first incoming RF signal or the second incoming RF signal based on the environmental condition; The third IDT is receiving the third SAW from the second IDT; generating a third oscillatory potential associated with an acoustic frequency of the received third SAW; The sensor device of claim 1 , wherein the third RF antenna further outputs a second outgoing RF signal according to the third oscillating potential.

12. the first integrated sensor assembly comprising: a third IDT formed on a fifth region of the piezoelectric material; and a third RF antenna connected to the third IDT; Further comprising: the third RF antenna further receives the first incoming RF signal or the second incoming RF signal; the third IDT further generates a third SAW in response to receiving the first incoming RF signal or the second incoming RF signal based on the environmental condition; The second IDT is receiving the third SAW from the third IDT; generating a third oscillatory potential associated with a combination of the first acoustic frequency of the received first SAW and a third acoustic frequency of the received third SAW; The sensor device of claim 1 , wherein the second RF antenna further outputs a second outgoing RF signal according to the third oscillating potential.

13. The sensor device of claim 1 , wherein the first SAW sensor further comprises a waveguide formed on the piezoelectric material between the first IDT and the second IDT.

14. 1. 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 of an environment in response to receiving a first incoming RF signal; a first interdigital transducer (IDT) formed on the 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; a first surface acoustic wave (SAW) sensor including: a second SAW sensor 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 the 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. a second SAW sensor including: Equipped with the second IDT further receives the first SAW from the first IDT and generates a first oscillating potential associated with a first acoustic frequency of the received first SAW, the second IDT being connected to an RF antenna for outputting a first outgoing RF signal according to the first oscillating potential; an integrated sensor device, wherein 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 integrated first SAW sensor being disposed on a first surface of the substrate and the integrated second SAW sensor being disposed on a second surface of the substrate.

15. A sensor device, comprising: a first integrated sensor assembly, the 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 of an environment in response to receiving a first incoming RF signal; a first interdigital transducer (IDT) formed on a first region of the piezoelectric material, the first IDT generating a first SAW in response to receiving the first incoming RF signal and based on the environmental condition; a second IDT formed on a second region of the piezoelectric material, receiving the first SAW from the first IDT; generating a first oscillatory potential associated with a first acoustic frequency of the received first SAW; a second IDT for performing a third IDT formed on a third region of the piezoelectric material, receiving the first SAW from the first IDT; a third IDT for generating a second oscillatory potential associated with the first acoustic frequency of the received first SAW; a first surface acoustic wave (SAW) sensor including: a first RF antenna formed on a fourth region of the piezoelectric material; a second RF antenna connected to the second IDT for outputting a first outgoing RF signal according to the first oscillating potential; a third RF antenna connected to the third IDT for further outputting a second outgoing RF signal according to the second oscillating potential; Equipped with A sensor device, wherein the first SAW sensor and the RF antenna are integrated with each other on the piezoelectric material.

16. A sensor device, comprising: a first integrated sensor assembly, the 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 of an environment in response to receiving a first incoming RF signal; a first interdigital transducer (IDT) formed on a first region of the piezoelectric material, the first IDT generating a first SAW in response to receiving the first incoming RF signal and based on the environmental condition; a second IDT formed on a second region of the piezoelectric material, receiving the first SAW from the first IDT; generating a first vibration potential associated with a first acoustic frequency of the received first SAW; generating a second SAW based on the environmental conditions in response to receiving the first incoming RF signal or the second incoming RF signal; a second IDT for performing a third IDT formed on a third region of the piezoelectric material, receiving the second SAW from the second IDT; generating a second oscillating potential associated with an acoustic frequency of the received second SAW; a first surface acoustic wave (SAW) sensor including: a first RF antenna formed on a fourth region of the piezoelectric material; a second RF antenna connected to the second IDT, the second RF antenna outputting a first outgoing RF signal according to the first oscillating potential and receiving the first incoming RF signal or the second incoming RF signal; a third RF antenna connected to the third IDT, the third RF antenna outputting a second transmitted RF signal according to the second oscillating potential; Equipped with A sensor device, wherein the first SAW sensor and the RF antenna are integrated with each other on the piezoelectric material.

17. A sensor device, comprising: a first integrated sensor assembly, the 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 of an environment in response to receiving a first incoming RF signal; a first interdigital transducer (IDT) formed on a first region of the piezoelectric material, the first IDT generating a first SAW in response to receiving the first incoming RF signal and based on the environmental condition; a second IDT formed on a second region of the piezoelectric material, receiving the first SAW from the first IDT; generating a first vibration potential associated with a first acoustic frequency of the received first SAW; and the second IDT further comprises: receiving a second SAW from a third IDT; generating a second oscillating potential associated with a combination of the first acoustic frequency of the received first SAW and a second acoustic frequency of the received second SAW; and a third IDT formed on a third region of the piezoelectric material, the third IDT generating the second SAW based on the environmental condition in response to receiving the first incoming RF signal or a second incoming RF signal; a first surface acoustic wave (SAW) sensor including: a first RF antenna formed on a fourth region of the piezoelectric material; a second RF antenna connected to the second IDT, the second RF antenna outputting a first transmission RF signal in accordance with the first oscillating potential and outputting a second transmission RF signal in accordance with the second oscillating potential; a third RF antenna coupled to the third IDT, the third RF antenna receiving the first incoming RF signal or the second incoming RF signal; Equipped with A sensor device, wherein the first SAW sensor and the RF antenna are integrated with each other on the piezoelectric material.

18. The sensor device of claim 1, wherein the environment includes a substrate processing chamber.

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