MEMS resonator sensor substrate for sensing plasma, temperature, stress, or deposition

Abstract

Embodiments disclosed herein include a diagnostic substrate and a method of using the diagnostic substrate to extract plasma parameters. In one embodiment, the diagnostic substrate comprises a substrate and an array of resonators across the substrate. In one embodiment, the array of resonators comprises at least a first resonator having a first structure and a second resonator having a second structure. In one embodiment, the first structure is different from the second structure.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority of U.S. Patent Application No. 17 / 367,250, filed Jul. 2, 2021, the entire content of which is incorporated herein by reference.

[0002] Embodiments of the present disclosure relate to the field of semiconductor processing, and more particularly, to micro - electro - mechanical systems (MEMS) sensors for detecting various processing parameters in a processing chamber.

Background Art

[0003] Semiconductor manufacturing processes are often implemented in a plasma environment. For example, a plasma processing chamber is used to deposit materials on a substrate (e.g., plasma - enhanced chemical vapor deposition (PE - CVD), plasma - enhanced atomic layer deposition (PE - ALD), physical vapor deposition (PVD), etc.). Further, a plasma processing chamber can be used to remove materials from a substrate in an etching process. Generally, the metrology used to quantify a given process is limited to the final result of the process. That is, after a substrate has been processed (e.g., using an etching process or a deposition process), metrology is used to determine how much material has been added (e.g., in a deposition process) or removed (e.g., in an etching process).

[0004] Currently, the plasma itself can be monitored by systems such as optical emission spectroscopy (OES). OES can be used, for example, to determine some aspects of the plasma, such as the plasma composition. However, OES is limited in that it cannot take into account plasma properties such as electron density, plasma (electron) temperature, or spatial differences in such properties. A Langmuir probe can also be used to measure plasma properties. The Langmuir probe measures an IV curve and uses the IV curve to determine the properties of the plasma. However, the Langmuir probe is limited in that it is generally macroscale and a large number of Langmuir probes cannot be easily integrated across the surface of the substrate.

Summary of the Invention

[0005] Embodiments disclosed herein include a diagnostic substrate and a method of using the diagnostic substrate to extract plasma parameters. In one embodiment, the diagnostic substrate comprises a substrate and an array of resonators across the substrate. In one embodiment, the array of resonators comprises at least a first resonator having a first structure and a second resonator having a second structure. In one embodiment, the first structure is different from the second structure.

[0006] In an additional embodiment, the diagnostic substrate comprises a substrate and a first resonator attached to the substrate, the first resonator being electrically floating. In one embodiment, the diagnostic substrate further comprises a first guard ring around the first resonator, the first guard ring having a first height. In one embodiment, the diagnostic substrate comprises a second resonator attached to the substrate, the second resonator being electrically floating, and a second guard ring around the second resonator, the second guard ring having a second height, the second height being greater than the first height.

[0007] The embodiments disclosed herein include a method for measuring plasma parameters in a plasma chamber. In one embodiment, the method includes providing a diagnostic substrate in the plasma chamber, the diagnostic substrate comprising a first resonator having a first shape dimension and a second resonator having a second shape dimension. The method may further include measuring baseline responses from the first resonator and the second resonator in a vacuum without plasma. In one embodiment, the method includes striking a plasma in the plasma chamber, with the first resonator and the second resonator being within the plasma, and measuring a first resonance frequency of the first resonator and a second resonance frequency of the second resonator. In one embodiment, the method further includes extracting plasma parameters from the first resonance frequency and the second resonance frequency.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0009] A microelectromechanical systems (MEMS) sensor for detecting various process parameters in a processing chamber is described herein. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to one of ordinary skill in the art that the embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known aspects, such as integrated circuit manufacturing, are not described in detail so as not to unnecessarily obscure embodiments of the present disclosure. Further, it should be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

[0010] As described above, it is currently difficult to measure plasma parameters in a plasma chamber. Currently, plasma can be investigated using an OES tool, but the OES tool cannot provide plasma density and electron temperature. Further, the OES tool cannot provide for substrate measurements such as material deposition, material etching, etc. Further, the measurements cannot be made in real time.

[0011] Accordingly, embodiments disclosed herein include a diagnostic substrate that enables the ability to measure plasma parameters in real time during a plasma process. For example, plasma parameters can include, but are not limited to, electron density, electron temperature, electron energy distribution function (EEDF), ion density, and ion energy distribution function (IEDF). The embodiments disclosed herein can also be used to measure surface parameters such as temperature, deposition or etching rate, surface stress, surface charge, and other parameters related to the diagnostic substrate.

[0012] In one embodiment, the diagnostic substrate may include a plurality of sensors. The sensors described herein may generally be referred to as resonator sensors. For example, the sensors may include MEMS sensors or RF resonators. Resonators that are capacitively and piezoelectrically driven may also be used. The sensors may include, but are not limited to, surface acoustic wave (SAW) sensors, bulk acoustic wave (BAW) sensors, film bulk acoustic resonator (FBAR) sensors, laterally excited bulk acoustic resonator (XBAR), membrane resonators, disk resonators, beam resonators, coil resonators, and the like. That is, while some specific examples of resonator sensors are described in more detail herein, the embodiments should not be construed as being limited by the specific examples described herein.

[0013] It should be understood that the embodiments disclosed herein also enable real-time characterization of various plasma and / or surface properties being investigated. In particular, the embodiments disclosed herein include resonators coupled (either directly or indirectly) to an antenna. An interrogator external to the diagnostic substrate (and external to the processing tool) may receive signals from the antenna.

[0014] In certain embodiments, an array of sensors includes sensors having different shape dimensions. In one example, an array of sensors may include sensors having upper surfaces with different heights from the underlying substrate. In such embodiments, spatial information regarding the plasma may be provided since the individual sensors will be exposed to different portions of the plasma and / or sheath. In another embodiment, the guard rings around the individual sensors may have different shape dimensions. The different shape dimensions of the guard rings may control the apertures around the resonators and enable different interactions with the plasma. In yet another embodiment, the guard rings may have uniform shape dimensions, but different biases may be applied to control the apertures. Further, multiple different biases may be supplied such that a single guard ring has sensors with different apertures.

[0015] Next, referring to FIG. 1, a plan view of a diagnostic substrate 100 according to one embodiment is shown. In the illustrated embodiment, the substrate 101 of the diagnostic substrate 100 is shown as being substantially circular, like a wafer. However, it should be understood that the diagnostic substrate 100 is not limited to wafer-like dimensions. For example, in some embodiments, a rectangular substrate 101 may also be used. In one embodiment, the substrate 101 may be a silicon substrate. However, it should be understood that other materials may also function as the substrate. For example, the substrate 101 may include a silicon-on-insulator (SOI) substrate 101, a III-V semiconductor substrate 101, a glass substrate 101, an organic substrate 101, or any combination thereof.

[0016] As shown, an array of sensors 120 is dispersed across the surface of the substrate 101. In the illustrated embodiment, the array of sensors 120 is arranged in a grid pattern. In other embodiments, a radial pattern may also be used. Additional embodiments may include any suitable pattern. Although fewer than 100 sensors 120 are shown, it should be understood that embodiments may include thousands or tens of thousands of sensors 120. The larger sensor outlines are for illustrative purposes, and embodiments are not limited to macro-sized devices.

[0017] In one embodiment, the sensor 120 may be any type of MEMS or RF resonator. The sensor 120 may include, but is not limited to, surface acoustic wave (SAW) sensors, bulk acoustic wave (BAW) sensors, film bulk acoustic resonators (FBAR) sensors, membrane resonators, disk resonators, beam resonators, coil resonators, and the like. Some examples of specific resonator sensors are shown in more detail below, but it should be understood that many different types of resonators may be used according to the embodiments disclosed herein.

[0018] In one embodiment, each of the sensors 120 can be driven up to its resonance frequency by a circuit (not shown in FIG. 1). In one embodiment, the driving force can be a capacitive force, a piezoelectric force, or the like. The resonance frequency can be transmitted from the diagnostic substrate 100 to an external interrogator (not shown) by an antenna (not shown) on the substrate 101. The sensors 120 can be directly or indirectly coupled to different antennas. The resonance frequency of the sensors 120 can vary depending on various conditions such as changes in plasma parameters, material deposition, material removal, surface temperature, surface charge, stress, etc. The change in the resonance frequency can be used to quantify the various conditions being measured by the sensors 120.

[0019] Next, referring to FIG. 2, a plan view of a diagnostic substrate 200 according to one embodiment is shown. In FIG. 2, for simplicity, the sensors 220 A , 220 B , and 220 C of a representative set are shown. It should be understood that thousands or tens of thousands of sensors 220 can be provided on the substrate 201. In one embodiment, each of the sensors 220 can include a guard ring 222 and a resonator 221. As shown, the sensors 220 A , 220 B , and 220 C have different diameters D. Including sensors 220 with resonators 221 of different diameters enables the ability to provide more accurate values by solving a system of equations with more known variables. Although the variation in the shape dimensions of the sensors 220 is shown as being different diameters D of the resonators 221, it should be understood that other shape changes can also be used to improve the sensitivity of the diagnostic substrate 200. For example, the resonator 221 can have different heights, and the guard ring 222 can have different separations from the resonator 221, or many other different variations.

[0020] Next, referring to FIG. 3A, a cross-sectional view of a diagnostic substrate 300 according to one embodiment is shown. In one embodiment, the diagnostic substrate 300 includes a substrate 301, a first sensor 320 A , and a second sensor 320 Bcomprising. Two sensors 320 A and 320 B Although two sensors 320 are shown in FIG. 3A, it should be understood that hundreds, thousands, or tens of thousands of sensors 320 may be provided on the substrate 301. In one embodiment, the substrate 301 may be a semiconductor substrate, such as a silicon wafer. However, as described above with respect to FIG. 1, it should be understood that the substrate 301 may comprise other materials or form factors.

[0021] In one embodiment, an insulating layer 302 is provided on the substrate 301. In some embodiments, the sensors 320 and the necessary circuitry are provided on the insulating layer 302. In other embodiments, some (or all) of the circuitry for the sensors 320 may be provided within or under the insulating layer 302. In one embodiment, the insulating layer is an oxide (e.g., silicon oxide) or a nitride (e.g., silicon nitride). In one embodiment, an electrode 391 may be provided under the resonator 321. In the illustrated embodiment, the electrode 391 is provided under the insulating layer 302. However, it should be understood that the electrode 391 may also be provided on the insulating layer 302 in some embodiments.

[0022] In one embodiment, each of the sensors 320 may include a resonator 321 and a guard ring 322. The resonator 321 may be a resonant disk in some embodiments. Although the disk resonator 321 is shown in FIG. 3A, it should be understood that the resonator 321 may be any one or more resonant structures. For example, the resonator 321 may include a capacitively driven resonator, a piezoelectrically driven resonator, an electromagnetic resonator, or an acoustic resonator. In certain embodiments, the resonator 321 may alternatively be a SAW, BAW, FBAR, XBAR film, disk, beam, coil, or the like. In one embodiment, the disk resonator 321 is raised above the surface of the insulating layer 302 by pads 324 and posts 323. In one embodiment, the resonator 321 may be a metal material such as copper, tungsten, nickel, or the like. In other embodiments, the resonator 321 may be polysilicon. In one embodiment, the resonator 321 may be electrically floating. That is, the resonator 321 may not be connected to a specific voltage or bias.

[0023] In one embodiment, the guard ring 322 may surround the outer periphery of the disk resonator 321. The guard ring 322 may be connected to a circuit configured to hold the guard ring 322 at a bias potential. As will be described in more detail below, the bias potential can control the apertures on the resonator 321 to limit or increase the interaction with the plasma. In one embodiment, the inner surface of the guard ring 322 is spaced apart from the edge of the resonator 321. That is, the resonator 321 cannot contact the guard ring 322 while resonating. In one embodiment, the electrode 391 drives the resonance of the resonator 321. In other embodiments, the electrode 391 may be omitted. In such embodiments, the resonator 321 may be driven by the guard ring 322. For example, a bias may be applied to the guard ring 322 using a DC signal, and an AC signal may be stacked on the DC signal to drive the resonance in the resonator 321.

[0024] In one embodiment, the upper surface of the guard ring 322 is the sensor 320A may be substantially coplanar with the upper surface of the resonator 321 in. In contrast, the upper surface of the guard ring 322 may be substantially above the upper surface of the resonator 321 in the sensor 320 B . That is, the sensor 320 A may have a different shape dimension or structure from the sensor 320 B . The difference in shape dimensions allows the apertures above the resonator to be different when the same bias is applied to both the guard rings 322.

[0025] In one embodiment, the sensors 320 A and 320 B are configured to measure one or more of plasma characteristics (e.g., plasma density, electron temperature, etc.), substrate temperature, mass change (e.g., by deposition or etching), stress change, or surface potential change. In the case of plasma characteristics, electrons and / or ions from the plasma are attracted to the surface of the resonator 321. The increased charge on the resonator causes a change in the resonant frequency. By determining how many electrons and / or ions are attracted to the surface of the resonator 321, the plasma density or electron temperature can be determined. Similarly, the change in the resonant frequency can also be the result of changes in the mass, stress, temperature, etc. of the resonator 321. To isolate the effect of changing a single variable, multiple different resonators with different shape dimensions, different biases, or other deformation modes can be used. Having multiple different shape dimensions allows the use of a system of simultaneous equations to isolate a given variable that is desired to be measured.

[0026] In one embodiment, the sensors 320 A and 320 B can each be coupled to an antenna 325. In one embodiment, the antenna 325 can be as simple as a conductive trace. In other embodiments, more complex antenna architectures such as patch antennas or dual patch antennas can be provided. For simplicity, a portion of the antenna 325 is shown in FIG. 3A. Generally, the size of the antenna 325 is such that the sensor 320 Aand 320 B is significantly larger than the size of. Antenna 325 is the sensor 320 A and 320 B enables the resonance frequencies of and 320 to be wirelessly transmitted to an interrogator external to the diagnostic substrate 300. In one embodiment, the sensor 320 A and 320 B can be directly coupled to the antenna 325, as shown in FIG. 3A. In other embodiments, the sensor 320 A and 320 B can be indirectly coupled to the antenna 325 (e.g., by capacitive coupling, etc.). In one embodiment, an RF circuit can be fabricated on the substrate between the antenna 325 and the sensor 320 A and 320 B For example, the RF circuit can include a shielded transmission line, a coupler, and / or a filter.

[0027] Referring now to FIG. 3B, a cross-sectional view of the diagnostic substrate 300 according to an additional embodiment is shown. In one embodiment, the diagnostic substrate 300 includes a substrate 301 and has an insulating layer 302 on the substrate 301. The substrate 301 and the insulating layer 302 can be substantially similar to the substrate 301 and the insulating layer 302 described above with respect to FIG. 3A.

[0028] In one embodiment, the diagnostic substrate 300 can include a first sensor 320 A and a second sensor 320 B In one embodiment, the first sensor 320 A and the second sensor 320 B can each have a resonator 321 supported on a post 323 and a pad 324 on the insulating layer 302. The first sensor 320 A and the second sensor 320 B can each also have a guard ring 322 surrounding the outer periphery of the resonator 321. In one embodiment, the first sensor 320 A and the second sensor 320 B can be communicatively coupled to the antenna 325.

[0029] The first sensor 320A may have a different shape dimension or structure from that of the second sensor 320 B In the illustrated embodiment, the first sensor 320 A has a resonator 321 with a first diameter D A and the second sensor 320 B has a resonator 321 with a second diameter D B The second diameter D B may be larger than the first diameter D A Thus, the sensor 320 A and the sensor 320 B can be used together to provide enhanced sensitivity for measuring plasma characteristics.

[0030] Next, referring to FIG. 3C, a cross-sectional view of the diagnostic substrate 300 according to an additional embodiment is shown. The diagnostic substrate 300 in FIG. 3C may be substantially the same as the diagnostic substrate 300 in FIG. 3A, except for the discharge layer 303 under the resonator 321. The discharge layer 303 may be a high-resistance material layer. For example, the discharge layer 303 may comprise lightly doped silicon. The high resistance allows charge to be slowly discharged. This enables the sensor 320 to be reset without the need for a discharge switch.

[0031] Next, referring to FIG. 4, a cross-sectional view of a diagnostic substrate 400 according to an embodiment is shown. In one embodiment, the diagnostic substrate 400 comprises a substrate 401 and an insulating layer 402 on the substrate 401. The substrate 401 and the insulating layer 402 may be substantially the same as the substrate 301 and the insulating layer 302 described in more detail above and will not be repeated here.

[0032] In one embodiment, a pair of sensors 420 A and 420 B is shown in FIG. 4. Although two sensors 420 A and 420 B are shown, it should be understood that hundreds, thousands, or tens of thousands of sensors 420 may be provided across the substrate 401. In one embodiment, the shape dimension of the first sensor 420 A is different from that of the second sensor 420B may be substantially the same as the shape and dimensions thereof. That is, the first sensor 420 A and the second sensor 420 B may each include a resonator 421 supported by posts 423 and pads 424 and surrounded by a guard ring 422. Although shown as a disk resonator 421, it should be understood that the resonator 421 may include any suitable resonator, such as those described in more detail above.

[0033] The first sensor 420 A and the second sensor 420 B The difference between is the bias applied to the guard ring 422. For example, a first bias 431 is applied to the guard ring 422 around the first sensor 420 A and a second bias 432 is applied to the guard ring 422 around the second sensor 420 B The second bias 432 may be greater than the first bias 431. The greater bias 432 reduces the aperture on the resonator 421 compared to the aperture on the resonator 421 provided by the bias 431. That is, the distance between the electromagnetic field lines in the first sensor 420 A is greater than the distance between the electromagnetic field lines in the second sensor 420 B Thus, different amounts of electrons can be collected by the different sensors 420 A and 420 B This difference allows a system of equations to be set up to separate variables of interest, such as plasma density or electron temperature. In one embodiment, the sensors 420 A and 420 B may be coupled to an external interrogator (not shown) by antennas 425.

[0034] In one embodiment, the first bias 431 and the second bias 432 can be DC biases. In other embodiments, the biases 431 and 432 can be AC biases. Embodiments can also include DC biases with an AC bias added on top of the DC bias. In one embodiment, the first bias 431 and the second bias 432 can be dynamic biases. For example, in some embodiments, a bias sweep over a plurality of different voltages can be used.

[0035] Next, referring to FIGS. 5A and 5B, a pair of cross-sectional views of a diagnostic substrate 500 with a first sensor 520 according to one embodiment A is shown. The diagnostic substrate 500 can include a substrate 501 and an insulating layer 502 similar to the substrate 301 and the insulating layer 302 described in more detail above. The first sensor 520 A includes a resonator 521 supported by a post 523 and a pad 524. A guard ring 522 can surround the outer periphery of the resonator 521. Although shown as a disk resonator 521, it should be understood that the resonator 521 can be any suitable resonator, such as those described in more detail above. The first sensor 520 A can be coupled to an antenna 525 for wireless communication with an external interrogator (not shown).

[0036] As shown in FIG. 5A, the guard ring 522 is supplied with a first bias 531. The first bias 531 creates a first aperture on the resonator 521. In FIG. 5B, the guard ring 522 is supplied with a second bias 532. The second bias 532 creates a second aperture on the resonator 521 that is smaller than the first aperture. That is, a single sensor 520 can be supplied with different biases. In some embodiments, the bias can be a bias sweep that includes a plurality of different biases. In one embodiment, the bias can include a DC bias, an AC bias, or both an AC bias and a DC bias.

[0037] Next, referring to FIG. 6A, a cross-sectional view of a diagnostic substrate 600 according to an additional embodiment is shown. In one embodiment, the diagnostic substrate 600 includes a substrate 601 and an insulating layer 602 on the substrate 601. The substrate 601 and the insulating layer 602 can be substantially similar to the insulating layer 302 and the substrate 301 described in more detail above.

[0038] In one embodiment, the diagnostic substrate 600 can include a frame 650 supported by pillars 651. The drive and sense circuitry for the first sensor 620 A and the second sensor 620 B can be under the frame 650. Thus, the drive and sense circuitry is protected from the processing environment. The drive and sense circuitry can include one or more coils 642 and a core 643 disposed under the resonator 641. The core 643 can be a magnetic material that improves the magnetic flux of the coil 642. For example, the core 643 can comprise a ferrite material. The first sensor 620 A and the second sensor 620 B can be directly or indirectly coupled to an antenna 625 to enable wireless communication with an interrogator (not shown) external to the diagnostic substrate 600.

[0039] The resonator 641 can be a membrane that extends across an opening in the frame 650. As shown in FIG. 6A, the resonator 641 in the first sensor 620 A and the second sensor 620 B is provided at the same height relative to the substrate 601. In other embodiments, as shown in FIG. 6B, the resonator 641 of the first sensor 620 A can be at a different height relative to the substrate 601 than the resonator 641 of the second sensor 620 B . In one embodiment, the resonator 641 of the second sensor 620 B can be provided on the bottom surface of the frame 650. Although shown as covering substantially all of the substrate 601 in FIGS. 6A and 6B, it should be understood that the frame 650 can be located over the sensor area and the remainder of the substrate 601 may or may not be covered by the frame 650.

[0040] In the embodiments described above, the disk resonator and the film resonator have been described in detail. However, it should be understood that any resonator architecture may be used in the embodiments disclosed herein. For example, in FIG. 7A, a perspective view of a cantilever beam resonator 720 according to an embodiment is shown. The beam resonator 720 may include an anchor 761 and a beam 762 extending from the anchor 761. The anchor 761 may be coupled (directly or indirectly) to the substrate 701. In FIG. 7B, a plan view of a resonator 720 that operates similarly to a tuning fork is shown according to an embodiment. In FIG. 7B, the resonator 720 includes an anchor 761 and a resonant fork 763 attached to the anchor 761. The anchor 761 may be coupled (directly or indirectly) to the substrate 701. In addition to acoustic resonators, such as those shown in FIGS. 7A and 7B, piezoelectric resonators may also be used. An example of a piezoelectric resonator is shown in FIG. 7C. As shown, a piezoelectric layer 765 may extend across a cavity in the insulating layer 702. A first electrode 767 is under the piezoelectric layer 765, and a second electrode 766 is over the piezoelectric layer 765. Although three additional examples of resonators are shown, it should be understood that the embodiments are not limited to a particular configuration.

[0041] Next, referring to FIG. 8, a flowchart of a process 880 for determining plasma characteristics in a plasma chamber according to one embodiment is shown. In one embodiment, process 880 may begin with operation 881, which includes providing a diagnostic substrate in the plasma chamber. In one embodiment, the diagnostic substrate includes a first resonator having a first shape dimension and a second resonator having a second shape dimension. In one embodiment, the different resonators can be any resonators, such as those described in more detail above. For example, the difference in shape dimensions can be a difference in the height of the resonator relative to the underlying substrate. In other embodiments, the difference in shape dimensions can be a difference in the height of the guard ring around the resonator. In one embodiment, the bias applied to the guard ring can be different for different resonators. In other embodiments, the bias can be modulated for each of the resonators. For example, a bias sweep can be used for each of the resonators. The bias applied to the resonator can include an AC component and a DC component in some embodiments.

[0042] In one embodiment, process 880 can continue with operation 882, which includes generating a plasma in the plasma chamber. In one embodiment, the plasma can be used for any type of plasma process. For example, the plasma can be for a PE-CVD process, a PE-ALD process, a PVD process, an etching process, or any other semiconductor manufacturing process. However, in some embodiments, the baseline response of the resonator can be determined before generating the plasma. For example, process 880 can also include measuring the baseline response from the first and second resonators in a vacuum without plasma.

[0043] In one embodiment, process 880 may continue with operation 883, which includes measuring a first resonance frequency of a first resonator and a second resonance frequency of a second resonator. In one embodiment, the resonance frequencies may differ due to variations in the shape dimensions and / or variations in the bias applied to the guard ring around the resonator. In one embodiment, the first resonance frequency and the second resonance frequency may be different from the frequency of the plasma. In certain embodiments, the first resonance frequency and the second resonance frequency may be about 100 MHz or greater.

[0044] In one embodiment, process 880 may continue with operation 884, which includes extracting plasma parameters from the first resonance frequency and the second resonance frequency. In one embodiment, the resonance frequencies may be wirelessly transmitted by an antenna on the diagnostic substrate to an interrogator external to the plasma chamber. The plasma parameters may include electron density, electron temperature, EEDF, ion density, and IEDF, or any other detectable plasma parameter. In some embodiments, the plasma parameters may be spatial plasma parameters. That is, a single plasma parameter (e.g., plasma density) may be measured at different Z-heights with respect to the diagnostic substrate.

[0045] It should be understood that process 880 can be used to provide different control or chamber health monitoring. For example, process 880 can be used to provide process baselining, fingerprinting (authentication), variation monitoring, chamber matching, or other chamber control. Further, it should be understood that process 880 can be used with a machine learning module and / or an artificial intelligence module. In such embodiments, process 880 can be used to generate data (e.g., plasma parameters) that can be provided as an input to the machine learning module and / or the artificial intelligence module. The machine learning module and / or the artificial intelligence module can use the generated data from process 880 to provide process control functions to one or more processing tools, such as, but not limited to, process baselining, fingerprinting, variation monitoring, chamber matching, or other chamber control.

[0046] FIG. 9 shows a diagrammatic representation of a machine in an exemplary form of a computer system 900 within which a set of instructions for causing the machine to execute any one or more of the methodologies described herein may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), intranet, extranet, or the Internet. The machine may operate as a server machine or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), cellular telephone, web appliance, server, network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is shown, the term "machine" shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein.

[0047] The exemplary computer system 900 includes a processor 902, a main memory 904 (e.g., dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), Rambus DRAM (RDRAM), etc., or read only memory (ROM), flash memory), a static memory 906 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and a secondary memory 918 (e.g., a data storage device), which communicate with each other via a bus 930.

[0048] Processor 902 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, etc. More specifically, processor 902 can be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processor 902 can also be one or more dedicated processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, etc. Processor 902 is configured to execute processing logic 926 for performing the operations described herein.

[0049] Computer system 900 may further include a network interface device 908. Computer system 900 may also include a video display unit 910 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 912 (e.g., a keyboard), a cursor control device 914 (e.g., a mouse), and a signal generation device 916 (e.g., a speaker).

[0050] Secondary memory 918 may include a machine-accessible storage medium (or more specifically, a computer-readable storage medium) 931 storing one or more sets of instructions (e.g., software 922) embodying any one or more of the methodologies or functions described herein. Software 922 may also exist, in whole or at least in part, within main memory 904 and / or within processor 902 during execution of software 922 by computer system 900, and main memory 904 and processor 902 also constitute a machine-readable storage medium. Software 922 may further be transmitted or received over network 961 via network interface device 908.

[0051] The machine-accessible storage medium 931 is shown as a single medium in the exemplary embodiment, but the term "machine-readable storage medium" shall be construed to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated cache and server) that store one or more sets of instructions. The term "machine-readable storage medium" shall also be construed to include any medium that is capable of storing or encoding a set of instructions for machine execution and that causes a machine to perform any one or more of the methodologies of the present disclosure. The term "machine-readable storage medium" shall thus be construed to include, without limitation, solid-state memory and optical and magnetic media.

[0052] According to one embodiment of the present disclosure, a machine-accessible storage medium stores instructions that cause a data processing system to perform a method of measuring plasma parameters in a plasma chamber using a diagnostic substrate having resonators with a plurality of different geometries.

[0053] Accordingly, a method for measuring plasma parameters has been disclosed.

Claims

1. A diagnostic substrate, comprising: a substrate; and an array of resonators extending across the substrate, the array of resonators comprising at least a first resonator having a first structure and a second resonator having a second structure, the first structure being different from the second structure; the first structure comprising a first guard ring around the first resonator, and the second structure comprising a second guard ring around the second resonator; the first guard ring being configured to apply a first bias, and the second guard ring being configured to apply a second bias different from the first bias.

2. The diagnostic substrate according to claim 1, wherein the array of resonators is an electromagnetic resonator or an acoustic resonator.

3. The diagnostic substrate according to claim 1, wherein the array of resonators is configured to detect plasma properties, substrate temperature, mass change, stress change, or surface potential change.

4. The diagnostic substrate according to claim 1, wherein the first structure and the second structure are capacitive resonators or inductive resonators comprising a film, a disk, a beam, or a coil.

5. The diagnostic substrate according to claim 1, wherein the first structure and the second structure are piezoelectric resonators including surface acoustic wave (SAW) resonators, bulk acoustic wave (BAW) resonators, film bulk acoustic resonators (FBAR), or lateral excitation bulk acoustic resonators (XBAR).

6. The diagnostic substrate according to claim 1, wherein the first structure comprises a first resonant member at a first distance in the height direction from the substrate, and the second structure comprises a second resonant member at a second distance in the height direction from the substrate, the first distance being different from the second distance.

7. The diagnostic substrate according to claim 1, wherein the first bias and / or the second bias can comprise a DC component and an AC component.

8. The diagnostic substrate according to claim 1, wherein the first guard ring and the second guard ring have different shape dimensions, and the second guard ring has a different height from the first guard ring.

9. The diagnostic substrate according to claim 1, wherein the first resonator and the second resonator are communicatively coupled to an antenna configured to provide wireless communication of the measured frequency to an external device.

10. Further comprising an RF circuit manufactured on the substrate, the RF circuit comprising one or more of a shielded transmission line, a coupler, and a filter The diagnostic substrate according to claim 1

11. A diagnostic substrate, comprising a substrate; a first resonator attached to the substrate and electrically floating; a first guard ring around the first resonator and having a first height; a second resonator attached to the substrate and electrically floating; a second guard ring around the second resonator and having a second height greater than the first height and comprising The diagnostic substrate, wherein the first guard ring is configured to apply a first bias and the second guard ring is configured to apply a second bias different from the first bias

12. The diagnostic substrate according to claim 11, wherein an upper surface of the first resonator is at a first distance in a height direction from the substrate, an upper surface of the second resonator is at a second distance in the height direction from the substrate, and the second distance is different from the first distance

13. An antenna communicably coupled to the first resonator and the second resonator The diagnostic substrate according to claim 11, further comprising

14. The diagnostic substrate according to claim 1 or 11, wherein the first resonator and the second resonator each comprise a discharge layer including a high-resistance material layer thereunder

15. The diagnostic substrate according to claim 14, wherein the discharge layer comprises low-doped silicon

16. A method of measuring plasma parameters in a plasma chamber, comprising providing a diagnostic substrate in the plasma chamber, the diagnostic substrate comprising a first resonator having a first shape dimension and a second resonator having a second shape dimension; measuring baseline responses from the first resonator and the second resonator in a vacuum without plasma; generating a plasma in the plasma chamber with the first resonator and the second resonator within the plasma; measuring a first resonance frequency of the first resonator and a second resonance frequency of the second resonator extracting the plasma parameter or the wafer parameter from the first resonance frequency and the second resonance frequency; applying a first bias around the first resonator by a first guard ring; applying a second bias around the second resonator by a second guard ring; measuring a resonator response of the first resonator with respect to the first bias and a resonator response of the second resonator with respect to the second bias; including; a method, wherein the first bias is different from the second bias.

17. The method according to claim 16, wherein the plasma parameter is an electron density, an electron temperature, an electron energy distribution function (EEDF), an ion density, or an ion energy distribution function (IEDF), and the wafer parameter is a substrate temperature, a mass change, a stress change, or a surface potential change.

18. The method according to claim 16, wherein the first resonance frequency and the second resonance frequency are different from the plasma frequency.

19. The method according to claim 16, wherein the first bias and the second bias are modulated biases.

20. using the plasma parameter as an input for an artificial intelligence module and / or a machine learning module to perform baselineization of the plasma chamber, fingerprinting of the plasma chamber, monitoring of fluctuations in the plasma chamber, chamber matching, or control of the plasma chamber; The method according to claim 16, further including.

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