Capacitive sensing data integration for plasma chamber condition monitoring

Abstract

Capacitance sensors and integration of capacitance sensing data for plasma chamber condition monitoring are described. In an example, a plasma chamber monitoring system includes a plurality of capacitance sensors, a capacitance digitizer, and an application processing server coupled to the capacitance digitizer, the application processing server including system software. The capacitance digitizer includes an isolation interface coupled to the plurality of capacitance sensors, a power supply coupled to the isolation interface, a field programmable gate array firmware coupled to the isolation interface, and an application specific integrated circuit coupled to the field programmable gate array firmware.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Application No. 16 / 812,081, filed March 6, 2020, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0003] Embodiments of the present disclosure relate to the field of plasma chamber condition monitoring, and in particular to integration of capacitive sensing data for plasma chamber condition monitoring.

[0004] Description of Related Art

[0005] Fabrication of microelectronic devices, display devices, microelectromechanical systems (MEMS), and the like, requires the use of one or more processing chambers. For example, processing chambers, such as, but not limited to, plasma etch chambers, plasma enhanced chemical vapor deposition chambers, physical vapor deposition chambers, plasma treatment chambers, or ion implantation chambers, can be used to fabricate various devices. As the dimensions in the devices continue to shrink to smaller critical dimensions, the need for uniform processing conditions (e.g., uniformity across a single substrate, uniformity between different batches of substrates, and uniformity between chambers in a facility) becomes increasingly important in high volume manufacturing (HVM) environments.

[0006] There are many different origins of non-uniformity in processing. One such origin is the conditions of the chamber itself. That is, as a substrate is processed in a chamber, the chamber environment can change. For example, in an etch process, etch byproducts can deposit on the interior surfaces of the chamber due to re-deposition processing. The build-up of re-deposition layers on the interior surfaces of the chamber can change the plasma chemistry in subsequent iterations of the processing recipe and cause process drift.

[0007] To combat process drift, processing chambers can be cleaned periodically. In-situ chamber cleaning (ICC) can be implemented to reset the chamber conditions. Currently, ICC is primarily recipe based. That is, a set recipe is executed in order to clean the processing chamber. Some ICC can use optical emission spectroscopy (OES) systems for end point determination of the processing recipe. However, there is no way to directly measure the conditions of the interior surfaces of the processing chamber (e.g., thickness of re-deposition layers, thickness of aging layers, etc.).

[0008] The processing chamber can also be opened to manually clean portions of the processing chamber or to replace worn consumables within the processing chamber. However, opening the processing chamber results in significant downtime because the processing chamber needs to be pumped back down to the desired vacuum pressure, aged, and the chamber needs to be re-qualified before production substrates can be processed. The opening of the processing chamber can occur at predetermined intervals (e.g., after a certain number of substrates are processed), or after a deviation is detected. Relying on predetermined intervals can result in opening the chamber too frequently. Thus, reducing throughput. In the case of deviation detection, the chamber conditions are corrected after damage has already been done to production substrates. Thus, reducing throughput. SUMMARY

[0009] Embodiments of the present disclosure include integration of capacitive sensing data for plasma chamber condition monitoring.

[0010] In an embodiment, a plasma chamber monitoring system includes a plurality of capacitive sensors, a capacitive digitizer, and an application processing server coupled to the capacitive digitizer, the application processing server including system software. The capacitive digitizer includes an isolation interface coupled to the plurality of capacitive sensors, a power supply coupled to the isolation interface, a field programmable gate array firmware coupled to the isolation interface, and an application specific integrated circuit coupled to the field programmable gate array firmware.

[0011] In another embodiment, an internal connection for a plasma chamber monitoring system includes a first connector to couple to a capacitive digitizer of a capacitive sensor module, a second connector to couple to an electronic device and an external power supply, and a shielded cable coupled to and between the first connector and the second connector. The shielded cable includes a shielded metal to physically connect the internal connection to a frame of a plasma chamber, a power supply line housed within the shielded metal, a ground line housed within the shielded metal, and one or more communication lines housed within the shielded metal.

[0012] In another embodiment, a method for collecting data for plasma chamber condition monitoring includes streaming data from a capacitance sensor module to a data server. The data includes capacitance data and temperature data. The method further includes collecting the data on an application processing server. The method further includes correlating the data to one or more process recipe operations. The method further includes synchronizing the capacitance sensor module to the one or more process recipe operations. BRIEF DESCRIPTION OF DRAWINGS

[0013] FIG. 1 is a schematic diagram illustrating a conventional plasma chamber monitoring system.

[0014] Figure 2A FIG. 2 is a schematic diagram illustrating a plasma chamber monitoring system according to an embodiment of the present disclosure.

[0015] Figure 2B FIG. 3 is a schematic diagram illustrating a plasma chamber monitoring system according to another embodiment of the present disclosure.

[0016] Figure 3 FIG. 4 illustrates internal connections for a plasma chamber monitoring system according to an embodiment of the present disclosure.

[0017] Figure 4 FIG. 5 is a schematic diagram illustrating plasma chamber monitoring hardware according to another embodiment of the present disclosure.

[0018] Figure 5A FIG. 6 is a plot of capacitance and temperature data including signal data and noise according to an embodiment of the present disclosure.

[0019] Figure 5B FIG. 7 is a plot of capacitance and temperature data according to an embodiment of the present disclosure. Figure 5A FIG. 8 is a plot of capacitance and temperature data after a filtering operation according to an embodiment of the present disclosure.

[0020] Figure 5C FIG. 9 is a plot of capacitance and temperature data after data processing and fitting according to an embodiment of the present disclosure. Figure 5B FIG. 10 is a plot of capacitance and temperature data according to an embodiment of the present disclosure.

[0021] Figure 6 FIG. 11 is a plot of capacitance parameter definition according to an embodiment of the present disclosure.

[0022] Figure 7A FIG. 12 is a plot of high order regression fitting such as quadratic and exponential fitting according to an embodiment of the present disclosure.

[0023] Figure 7B FIG. 13 is a plot of exemplary data from temperature parameter extraction / regression modeling according to an embodiment of the present disclosure.

[0024] Figure 8A cross-sectional view of a plasma processing chamber including one or more capacitive sensors is illustrated according to an embodiment of the present disclosure.

[0025] Figure 9 This is a schematic diagram illustrating a cross-sectional view of a capacitive sensor according to an embodiment of the present disclosure.

[0026] Figure 10 The illustration shows a schematic diagram of a sensor system including a sensor module with a capacitive sensor, according to an embodiment of the present disclosure.

[0027] Figure 11 According to embodiments of the present disclosure, schematic diagrams of an integrated processing device including capacitive sensor modules at various locations are provided.

[0028] Figure 12A This is a schematic diagram illustrating a cross-sectional view of a plasma processing apparatus including one or more sensor modules, according to an embodiment of the present disclosure.

[0029] Figure 12B It is based on the embodiments of this disclosure. Figure 12A A schematic diagram depicting the layout of the access pipes within the spokes of the main chamber component of a plasma processing device.

[0030] Figure 13 This is a cross-sectional view of a processing device that may include one or more capacitive sensor modules according to embodiments of the present disclosure.

[0031] Figure 14 A block diagram of an exemplary computer system for processing tools is illustrated according to embodiments of the present disclosure. Detailed Implementation

[0032] A capacitive sensor and capacitive sensing data integration for monitoring plasma chamber conditions are described. In the following description, numerous specific details, such as chamber configuration and capacitive sensor architecture, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that embodiments of this disclosure can be implemented without these specific details. In other instances, well-known aspects (e.g., detailed chamber descriptions) have not been described in detail to avoid unnecessarily obscuring embodiments of this disclosure. Furthermore, it should be understood that the various embodiments illustrated in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0033] One or more embodiments are capacitive sensors and systems for monitoring conditions in a processing chamber. Embodiments may be applied to or may include data integration and processing algorithms, strategy sensors located in the processing chamber, sensor structures and materials, electronics, data processing algorithms, and system integration of one or more sensors with processing tools.

[0034] According to embodiments of the present disclosure, sensors are used for monitoring chamber walls in one or more of at least four locations: chamber walls, chamber lid, in a floor under vacuum (SVF) port, and / or at an edge ring. The sensor module / housing structures and assemblies described herein can be compatible with process temperatures up to, for example, 400°C. Particular embodiments can include a capacitive wall sensor, an on-chip thermal sensor, and / or a sensor on a substrate such as a ceramic substrate.

[0035] To provide context, the sensors and sensor locations disclosed herein enable measurement of capacitance changes (and optionally, temperature) to be directly correlated to conditions such as wall deposition or cleaning in each operation of a process recipe for ICC optimization or chamber seasoning, and to minimize preventive maintenance (PM) frequency (e.g., more than 2x reduction) compared to other chamber wall monitoring methods (e.g., optical, piezoelectric, RF impedance, etc.). Embodiments can also enable prediction of process stability or drift to significantly improve productivity and yield.

[0036] Some embodiments involve a combination of two sensing technology implementations: a capacitive sensor and a thermal sensor, for example, for chamber wall condition monitoring with high sensitivity and real-time measurement. Embodiments involving sensors on a substrate can be implemented to not only provide the benefits of sensor module miniaturization and signal integrity, but also robust device performance and reliability. Data synchronization schemes and process algorithms can enable direct feedback to process control.

[0037] In some embodiments, the in-chamber sensors described herein can be used to measure byproduct accumulation, optimize ICC routines, identify excursions, and / or provide faster PM recovery. Some embodiments enable temperature measurement in locations where current technology methods cannot perform temperature measurement. Implementation of the embodiments described herein can enable chamber matching, optimization of seasoning procedures, identification of excursions, prediction of particle generation, prediction of process performance (e.g., etch rate and etch non-uniformity, etc.), PM prediction, ring erosion prediction for ring position compensation, process excursion prediction, measurement of wall absorption and desorption, semiconductor foundry excursion detection, and / or chamber baseline monitoring for mixed lots.

[0038] Embodiments described herein can relate to data synchronization for sensor data. In one embodiment, the data synchronization methods described herein can be implemented to associate sensor data (e.g., wall sensor data) with process information having a predefined integration time, such as a process recipe operation. In particular such embodiments, the predefined integration time is on the order of, for example, 20 ms, 50 ms, 100 ms, etc. In one embodiment, the data synchronization methods described herein can be implemented to associate sensor data, such as wall sensor data, with other in-situ sensor data (e.g., optical emission spectroscopy (OES) data, pressure data, gas flow data, temperature data, radio frequency (RF) data, etc.). In one embodiment, the data synchronization methods described herein can be implemented to enable automated extraction of data from wall (or other location) sensors for process characterization and process development. In one embodiment, the data synchronization methods described herein can be implemented to enable the use of wall sensors to establish new metrology techniques for process control and monitoring.

[0039] For comparison purposes, FIG. 1 is a schematic diagram illustrating a conventional plasma chamber monitoring system 100. Referring to FIG. 1, the system 100 includes a capacitance sensor module 102 having a capacitance sensor 104 coupled to a dedicated electronics device 106 by an internal connection 108. The dedicated electronics device 106 includes a memory card 110, such as an SD card. Sensor data is delivered to an offline personal computer 112 by a manual process 114. A user interface 116 is coupled to the offline personal computer 112 by a path 118.

[0040] Referring again to FIG. 1, each controller assembly of the conventional plasma chamber monitoring system 100 supports only one capacitance sensor. Data is captured and stored locally on a removable media. There is no connection to a process control server. Likewise, data is manually moved to a process control server for offline analysis.

[0041] In contrast to FIG. 1, Figure 2A is a schematic diagram illustrating a plasma chamber monitoring system 200 in accordance with embodiments of the present disclosure. Referring to Figure 2A , the system 200 couples a plurality of capacitance sensors (e.g., exemplary four sensors shown as 204A, 204B, 204C, and 204D) to a dedicated electronics device 206 by corresponding internal connections 208A, 208B, 208C, or 208D. The dedicated electronics device 206 is coupled to a server 210 by an internal connection 212, such as an etherCAT line.

[0042] Referring again to Figure 2AIn embodiments, each controller assembly of the plasma chamber monitoring system 200 supports multiple capacitive sensors. Data is captured and transmitted in real-time, for example, over etherCAT to a processing server. The system 200 enables capacitive sensor data to be synchronized with process recipe information and / or other system sensors. In one embodiment, data is streamed from the sensors to a data server. In one embodiment, there is an interface (e.g., etherCAT) to external electronic device controllers and corresponding data processing units. In one embodiment, sensor data is correlated to process information. In one embodiment, the system 200 can enable or perform operations such as data extraction, data processing, and / or data analysis.

[0043] The system 200 can also perform and control sensor state. In embodiments, the data server is able to condition and prime sensors to initialize sensors, reset sensors, and / or actively compensate for sensor drift. In embodiments, the data server is able to perform data processing such as data denoising and regression, parameter extraction, and data modeling. The data server can also implement algorithms for machine learning using sensors to predict and monitor process and chamber performance.

[0044] Figure 2B FIG. 2 is a schematic diagram illustrating a plasma chamber monitoring system 200 according to another embodiment of the present disclosure.

[0045] Referring to Figure 2B The plasma chamber monitoring system 250 includes multiple capacitive sensors (four sensors are illustrated as 254A, 254B, 254C, and 254D in the illustrated example; however, any suitable number of sensors can be used) with capacitive digital converters (CDCs). The output of the CDCs is a stream of digital data in any format, for example, I2C, SPI, or UART. The plasma chamber monitoring system 250 can also include an application processing server 276 coupled to the capacitive digital converter outputs via an electronic device plug-in module (EPM) 260. The application processing server 276 includes system software. The EPM 260 includes an isolation interface 262 coupled to the multiple outputs of the CDCs of the capacitive sensors 254A, 254B, 254C, and 254D, a power supply 265 coupled 266 to the isolation interface 262, a field programmable gate array (FPGA) firmware 268 coupled 270 to the isolation interface 262, and an application specific integrated circuit (ASIC) 272 coupled 274 to the field programmable gate array firmware 268.

[0046] In one embodiment, the application specific integrated circuit 272 of the EPM 260 is an etherCAT application specific integrated circuit. In one such embodiment, the etherCAT application specific integrated circuit provides both seamless integration of system software and control of multiple capacitive sensors 254A, 254B, 254C, and 254D. In another such embodiment, the etherCAT application specific integrated circuit initializes and calibrates individual capacitive sensors of the multiple capacitive sensors 254A, 254B, 254C, and 254D. In one embodiment, the application specific integrated circuit 272 of the EPM 260 is coupled to the application processing server 276 by an etherCAT connection coupling 278.

[0047] In one embodiment, the application processing server 276 synchronizes capacitive sensor data from the multiple capacitive sensors 254A, 254B, 254C, and 254D with a process recipe. In one embodiment, the field programmable gate array firmware 268 of the EPM 260 provides deterministic timing and simultaneous communication with multiple capacitive sensors of the multiple capacitive sensors 254A, 254B, 254C, and 254D.

[0048] In one embodiment, individual capacitive sensors of the multiple capacitive sensors 254A, 254B, 254C, and 254D are coupled in parallel to the isolation interface 262 of the EPM 260, as depicted. In one embodiment, individual capacitive sensors of the multiple capacitive sensors 254A, 254B, 254C, and 254D are each coupled to the isolation interface 262 of the EPM 260 by internal connections including internal integrated circuit bus (I2C, SPI, UART, etc.) and power lines.

[0049] Referring again to the drawings generally Figure 2B In embodiments, the application processing server of the plasma chamber monitoring system 250 synchronizes capacitive sensor data with a process recipe and other system sensors to improve results on the wafer. In embodiments, the etherCAT device definition is tailored to ensure seamless system software integration and control of multiple capacitive sensors simultaneously. In embodiments, custom firmware on the ECAT ASIC initializes and calibrates the capacitive sensors to deliver fast integration time, high precision, and repeatable measurements. In embodiments, the custom firmware is able to monitor sensor drift (capacitance drift, temperature drift) as feedback and compensate for sensor offset using predetermined algorithms to re-set the sensor. In embodiments, the custom FPGA firmware enables deterministic timing and simultaneous communication with multiple capacitive sensors. In embodiments, the power distribution and isolation design ensures high signal-to-noise ratio (SNR) of the capacitive sensor analog measurements and robustness of data communication.

[0050] In another aspect, a connector for interfacing with a sensor module is described. The connector can route power from an EPM to a sensor. The connector can provide a shared ground between the sensor and the EPM. The connector can provide a data stream from the sensor to the EPM. The connector can synchronize sensor data timing. The connector can be used to provide a hardware radio frequency (RF) ground plane.

[0051] As an example connector, Figure 3 An embodiment according to the present disclosure illustrates an internal connection 300 for a plasma chamber monitoring system.

[0052] Referring to Figure 3 The internal connection 300 includes a first connector 306 for coupling to a capacitance-to-digital converter of a capacitance sensor module 302, a second connector 308 for coupling to an EPM 310 and an external power source 312, such as a 5V DC power source, and a shielded cable 304 coupled to and between the first connector 306 and the second connector 308. The shielded cable 304 includes a shield metal 328, for example, for physically connecting the internal connection 300 at a location 330 to a frame of a plasma chamber. The shielded cable 304 includes a power supply line (line from 326A to 326B) housed within the shield metal 328, a ground line (line from 324A to 324B) housed within the shield metal 328, and one or more communication lines 322 (shown as two) housed within the shield metal 328.

[0053] In one embodiment, the power supply line (line from 326A to 326B) housed within the shield metal 328 is a 3 to 4 volt power supply line. In one embodiment, each of the one or more communication lines 322 housed within the shield metal 328 is or includes a data bus (I2C, SPI, or UART). In one embodiment, the ground line (line from 324A to 324B) housed within the shield metal 328 provides a shared ground for the capacitance sensor module 302 and the electronics 310. In one embodiment, the one or more communication lines 322 housed within the shield metal 328 synchronize sensor data timing.

[0054] In another aspect, a hardware implementation is described. As an example implementation, Figure 4 is a schematic diagram of a plasma chamber monitoring hardware 400 according to another embodiment of the present disclosure.

[0055] Referring to Figure 4The plasma chamber monitoring hardware 400 includes a sensor ASIC 402 (such as a wall sensor ASIC), an application printed circuit board (PCB) 404, and an etherCAT master 406 including a device 407. The sensor ASIC 402 is coupled 410 / 412 to one (or more) connectors 408 on the PCB 404. The one (or more) connectors 408 are coupled 416 / 418 to a power supply 414 on the PCB 404. The power supply 414 is coupled to a power source 420 (e.g., 24V source), which is coupled to ground 422. The PCB 404 includes an insulating barrier 424. The power supply 414 is coupled 428 to an insulator 426 of the insulating barrier 424. The insulator 426 is coupled 432 to one or more application integrated circuits 430 on the insulating barrier 424. A second PCB 434 is included in the insulating barrier 424 of the application PCB 404. The second PCB 434 includes an etherCAT ASIC 436, an FPGA 438, and an insulator 440. The one or more application integrated circuits 430 of the insulating barrier 424 are coupled 437 to the insulator 440 of the second PCB 434. The etherCAT ASIC 436 is coupled 442 to the insulator 440 of the second PCB 434 and is coupled 444 to the FPGA 438. The FPGA 438 is also coupled 446 to the insulator 440 of the second PCB 434. A power supply 448 is coupled to the insulator 440 of the second PCB 434. The second PCB 434 also includes an etherCAT connector 452 coupled 454 to the etherCAT ASIC 436. The etherCAT connector 452 of the second PCB is coupled to the etherCAT master 406 and can also be coupled 460 to an additional etherCAT connector 458 on the application PCB 404. The additional etherCAT connector 458, if included, can be coupled 462 to the etherCAT master 406, as depicted.

[0056] Referring again to the drawings generally Figure 4 In embodiments, the etherCAT plug-in module includes an interface to sensors with connectors having I2C or serial peripheral interface (SPI). In embodiments, the hardware provides power to one or more sensors. In embodiments, an FPGA and ASIC are included for data streaming and data extraction control. In embodiments, the hardware includes firmware implementation for sensor operation configuration and channel allocation. In embodiments, the hardware includes an etherCAT (ECAT) processing unit. In embodiments, the hardware includes a connector to an ECAT master. In embodiments, the hardware provides a connector scheme for minimizing RF noise.

[0057] In system or hardware implemented embodiments described herein, the base configuration can include one or more of the following: (1) channel configuration and reconfiguration, including multi-channel capability, (2) each sensor can be operated individually or all sensors can be bound together, which can depend on or be controlled by software commands, and / or (3) input / output channel reconfiguration, including temperature channel control (e.g., for an external thermal sensor), clock (CLK) control (e.g., dual conversion time), and / or capacitor conversion time control.

[0058] In software implemented embodiments described herein, the requirements can include one or more of the following: (1) data streaming from the sensor to a data server, sensor data collection on the server, correlation with process sequences, and synchronization of the sensor with the manufacturing process, (2) data processing and parameter extraction, which can include data filtering (e.g., sensor data filtering and de-noising), sensor data regression modeling, sensor parameter extraction, and process report generation, (3) sensor operation control, with (a) start-up mode, which can re-set the power cycle of the plug-in sensor, provide sensor initialization, read data and verify sensor status, and / or output capacitance (pF) and temperature (degrees) values, (b) production mode, which can synchronize with the process recipe, flow capacitance, and temperature data before the start of the process recipe (e.g., to provide data buffer time), provide time-stamping in line with the process recipe time, and / or enable data collection during tool idle; (c) engineering mode, which can manually determine data flow and data logging; (d) perform calibration and / or offset correction; (e) compensate for parasitic capacitance (e.g., by system offset calibration and / or gain factor calibration), (f) effect drift compensation (zeroing), and / or (g) perform data collection by data streaming and storage.

[0059] According to one or more embodiments described herein, the sensor produces two types of traces: capacitance and temperature. In one embodiment, for engineering use cases, raw data for both capacitance and temperature are saved as-is in the server. During processing, data collection is synchronized with the process sequence. Data collection can be performed during idle state. Data flow during idle state can be used as a baseline for the capacitance sensor for calibration, compensation, and re-setting. In addition, data flow during idle state is also used to monitor chamber baseline conditions and detect deviations in the chamber. The data is further processed and reported. In one embodiment, for production use cases, the temperature trace is saved. The temperature trace is also processed and the capacitance trace is processed.

[0060] According to one or more embodiments described herein, data processing, such as filtering and de-noising, involves (1) moving average (N~2) calculation, which can be based on the following equation: and / or (2) parameter extraction, can include regression modeling, data extraction and filtering (from sensor module), data report generation (capacitance vs. time / process operation), and / or use of temperature data (vs. time / process operation).

[0061] According to one or more embodiments described herein, data processing flow (which can include use of data processing algorithms) can involve (1) data (capacitance and temperature) flow and state (such as plasma off, plasma on, and idle state) collection; (2) data filtering by recipe (e.g., plasma off) and / or by denoising process (e.g., moving average); (3) data fitting, which can involve use of regression model, model fitting, parameter extraction, and / or data output algorithm, and / or (4) process feedback for process control.

[0062] In another aspect, an exemplary implementation of data integration for capacitance sensor data (in some embodiments, temperature data can also be included) is described based on an exemplary data set.

[0063] Figure 5A is a plot 500 of capacitance and temperature data including signal data for temperature 502 and capacitance 504 according to embodiments of the present disclosure. The capacitance and temperature data of plot 500 can be raw capacitance and temperature data provided to a server.

[0064] Figure 5B is a plot 520 of capacitance and temperature data of plot 500 after filtering operation according to embodiments of the present disclosure. The capacitance and temperature data of plot 520 includes temperature data 502 and denoised capacitance data 522. The resulting filtered traces can be based on RF power setpoint.

[0065] Figure 5C is a plot 540 of capacitance and temperature data of plot 520 after data processing and fitting according to embodiments of the present disclosure. In one embodiment, the individual capacitance and temperature traces can be fitted using a model that can be applied previously. Data can be output by associating the parameters extracted from the traces with recipe operations, recording the fitted parameters with associated process recipe operations, and / or by generating a data plot (e.g., extracted parameters vs. process time or operation). Process feedback control can be implemented by monitoring the above parameters for outlier detection, drift, etch rate (ER) / process control (PC) / other sensor data, etc. Data can be used to provide a visual indicator for wall cleaning / contamination status of a plasma processing chamber.

[0066] Figure 6 is a plot 600 of capacitance parameter definition according to embodiments of the present disclosure. Referring to Figure 6In embodiments, the capacitance data is when the plasma is off, e.g., data 606 is in the range from plasma off event 602 to plasma on event 604. A trace (such as 606) is extracted between plasma events, as defined by the recipe setpoint. Trace data processing and parameters are extracted. The extracted parameters can be associated with previous steps / recipes / operations. In one embodiment, the trace length = tw-to, where xs < trace length < ys. If the trace length is less than xs, it is ignored. If the trace length is greater than ys, it can be truncated to include only the first ys.

[0067] In embodiments, the capacitance parameter extraction / regression model can include first order parameters: capacitance baseline: Cbase; capacitance change: ACi = C inf -Cbase; capacitance drift during plasma off: ACoff= C o -C inf ; average capacitance during plasma off (e.g., used to determine deposition / cleaning amount): C ave = mean[C o : C w ]- Cbase, where AC, C ave .

[0068] Figure 7A is a plot 700 of high order regression fits (such as quadratic fit 702 and exponential fit 704) according to embodiments of the present disclosure. The regression processing can involve (1) extracting the fit parameters by regression processing, (2) deriving Co, t, and Cinf from the fit parameters, and (3) recording Co, t, Cinf, and R2.

[0069] Figure 7B is a plot 750 of exemplary data from a temperature parameter extraction / regression model according to embodiments of the present disclosure. The temperature parameter extraction / regression processing can involve (1) extracting the temperature trace corresponding to the same times as the capacitance trace defined above: trace length (756, excluding portions 758 and 760) = tw; if trace length < zs, it is ignored, but if trace length is greater than zs, it is truncated to include only the first zs, (2) fitting using a linear model: temperature = M* time + T o , and (3) recording M, To (752), and Tw (754).

[0070] Figure 8 is a cross-sectional view of a plasma processing chamber including one or more capacitance sensors according to embodiments of the present disclosure.

[0071] Referring to Figure 8The plasma processing chamber 800 includes a chamber wall 802 that surrounds a processing region 811. A wafer or substrate 812 can be processed in the processing region 811. A chamber lid 804 is above the chamber wall 802, the chamber lid 804 is above the processing region 811. A chamber floor 806 is below the chamber wall 802, the chamber floor 806 is below the processing region 811. A support pedestal 808 is in the processing region 811 (and more specifically, can include a support surface 810 in the processing region 811). The support pedestal 808 is below the chamber lid 804 and above the chamber floor 806, and is surrounded by the chamber wall 804.

[0072] Referring again to Figure 8 In an embodiment, the chamber wall 804 has an opening through the chamber wall 804. A capacitance sensor module 816 is in the opening of the chamber wall 804. In another embodiment, the chamber lid 804 includes a capacitance sensor module 814. In another embodiment, the chamber floor 806 includes an exhaust port. A capacitance sensor module 820 is within or adjacent to the exhaust port. In another embodiment, the support pedestal includes a ring structure (e.g., at location 818) that surrounds a substrate support region. The ring structure includes an opening through the ring structure. A capacitance sensor module is in the opening of the ring structure. In an embodiment, the plasma processing chamber 800 includes one or more of the following: the capacitance sensor module 816 in the opening of the chamber wall 804, the capacitance sensor module 814 in the chamber lid 804, the capacitance sensor module within or adjacent to the exhaust port 820 of the chamber floor 806, and / or the capacitance sensor module in the opening of the ring structure, e.g., at location 818.

[0073] Figure 9 is a schematic diagram illustrating a cross-sectional view of a capacitance sensor according to embodiments of the present disclosure.

[0074] Referring again to Figure 9The capacitive sensor module 900 includes a drive electrode 904 and a sense electrode 902. A measured capacitance 908 of the material 906 between the drive electrode 904 and the sense electrode 902 can vary with changes or variations in the composition, thickness, etc. of the material 906. In one embodiment, the material 906 represents material for deposition on a wafer or substrate in a processing chamber. While the intent is to remove / exclude such excess material 906 that is not deposited on the wafer or substrate, some of the material 906 can accumulate in the processing chamber, and eventually on the capacitive sensor module 900 in the processing chamber. In another embodiment, the material 906 represents etch byproducts formed when a wafer or substrate is etched in a processing chamber. While the intent is to remove / exclude such etch byproducts 906, some of the etch byproducts 906 can accumulate in the processing chamber, and eventually on the capacitive sensor module 900 in the processing chamber.

[0075] The sensor system can include a sensor module, interface electronics, a controller, and integration with a chamber data server for process control and data / process synchronization. As an example, Figure 10 is a schematic diagram illustrating a sensor system including a sensor module with a capacitive sensor, in accordance with embodiments of the present disclosure.

[0076] Referring to Figure 10 , the sensor system includes a sensor module 1002 coupled to a controller 1004, which in turn is coupled to a user interface 1006. The sensor module 1002 includes a capacitive sensor (shown schematically as 1010, or structurally as 1020). The capacitive sensor 1010 is coupled to a capacitive digital converter (CDC) interface circuit 1012. Communication within the module 1002 can be along path 1014A from the capacitive sensor 1010 to the CDC interface circuit 1012, and / or can be along path 1014B from the CDC interface circuit 1012 to the capacitive sensor 1010. Communication outside the module 1002 can be along paths 1016A and 1016B between the CDC interface circuit 1012 and the controller 1004. The controller 1004 can be coupled to the CDC interface circuit 1012 by Vdd 1018.

[0077] Referring again to Figure 10 , a cross-sectional view of a sensor 1020 is shown, in accordance with embodiments. In embodiments, the sensor 1020 includes a substrate 1022, with an electrode 1024 disposed on the substrate 1022. In embodiments, the electrode 1024 is or includes a conductive material that is compatible with microelectronic processing operations. For example, materials for the electrode 1024 can include, but are not limited to, aluminum, molybdenum, tungsten, titanium, nickel, chromium, and alloys thereof.

[0078] In embodiments, the electrode 1024 is electrically coupled to a pad 1030 on the backside of the substrate 1022 through a conductive path 1028 that passes through the substrate 1022. For example, the conductive path 1028 can include one or more vias, traces, etc. In embodiments, the conductive path 1028 embedded in the substrate 1022 includes a conductive material such as, but not limited to, tungsten, molybdenum, titanium, tantalum, alloys thereof, etc. In embodiments, the pad 1030 includes a material such as, but not limited to, titanium, nickel, palladium, copper, etc. In some embodiments, the pad 1030 is a multi-layer stack to improve integration with the CDC. For example, the pad 1030 can include a stack such as titanium / nickel / palladium, titanium / copper / palladium, or other material stack commonly used for internal connection pads.

[0079] In embodiments, the electrode 1024 and the top surface of the substrate 1022 are covered by a layer 1026 (e.g., a barrier layer). In embodiments, the cover layer 1026 is a material that is resistant to attack or erosion by plasma chemistry and limits diffusion. In the particular case of an etch chamber, a common etchant used is fluorine. As such, the layer 1026 used in such conditions should be resistant to fluorine etchant. In particular embodiments for a plasma chamber used for etching, the layer 1022 can include one or more of: metal oxides, metal fluorides, and metal oxyfluorides. The layer 1022 can include a material such as, but not limited to, aluminum oxide, magnesium oxide, yttrium oxyfluoride, yttrium zirconium oxyfluoride, yttrium aluminum oxide, or hafnium oxide.

[0080] In embodiments, the substrate 1022 includes a suitable substrate material that is resistant to processing conditions (e.g., etch conditions) within a processing chamber. The substrate 1022 can be a ceramic material, glass, or other insulating material. In some embodiments, the substrate 1022 is a flexible substrate such as a polymeric material. For example, the substrate 1022 can include a material such as, but not limited to, silicon, silicon oxide, aluminum oxide, aluminum nitride, plastic, or other insulating material. To allow for manufacturing of large volumes of sensors, the substrate 1022 can be a material that is compatible with high volume manufacturing (HVM) processing. That is, the substrate 1022 can be a material that is available in panel form, wafer form, etc.

[0081] According to embodiments of the present disclosure, both a capacitive sensor and a thermal sensor are integrated (embedded) into one sensor module. In one such embodiment, the wall sensor module includes a capacitive sensor, a CDC, and a thermal sensor and a housing unit that assembles the capacitive sensor, the CDC, and the thermal sensor together.

[0082] Referring again to Figure 10In embodiments, a thermal sensor is disposed on the substrate 1022. For example, the thermal sensor can be formed over a backside surface of the substrate 1022 (i.e., on a surface opposite the electrodes 1024). The thermal sensor can include any suitable sensing technology. For example, the thermal sensor can include a plurality of traces to form a resistance temperature detector (RTD). However, it should be understood that other thermal sensors can be used, such as but not limited to a thermocouple (TC) sensor, or a thermistor (TR) sensor, or an optical thermal sensor. In one embodiment, the thermal sensor is directly integrated on the substrate 1022. However, it should be understood that in some embodiments, a discrete component including the thermal sensor can be mounted to the substrate 1022. In other embodiments, the thermal sensor can be integrated into a CDC attached to the sensor 1020.

[0083] According to one or more embodiments of the present disclosure, a method of integrating data for plasma chamber condition monitoring includes streaming data from a capacitance sensor module to a data server. The data includes capacitance data and temperature data. The method further includes collecting the data on an application processing server. The method further includes correlating the data to one or more processing recipe operations. The method further includes synchronizing the capacitance sensor module with the one or more processing recipe operations.

[0084] In embodiments, the method of integrating data for plasma chamber condition monitoring further includes, after collecting the data on the application processing server and before correlating the data to the one or more processing recipe operations, performing data processing and parameter extraction. In one such embodiment, performing data processing includes filtering the data and de-noising the data. In a particular such embodiment, filtering the data and de-noising the data includes using a moving average method. In another such embodiment, performing data processing and parameter extraction includes regression modeling the data.

[0085] In embodiments, the method of integrating data for plasma chamber condition monitoring further includes monitoring one or more parameters of the one or more processing recipe operations using the capacitance sensor module. In one such embodiment, the method further includes determining a clean / contamination state of the plasma chamber based on the monitoring of the one or more parameters of the one or more processing recipe operations using the capacitance sensor module.

[0086] Wall / Cap sensor solution

[0087] The following are exemplary parameters and corresponding (a) importance, (b) solutions, and (c) benefits / uses.

[0088] Temperature of wall and cap: (a) first wafer effects (critical dimension (CD) and etch rate (ER)), particles, coefficient of thermal expansion (CTE); (b) thermometer on back of sensor; (c) accurate measurement of in-situ temperature. ICCs can be triggered to bring walls / caps to target temperature.

[0089] Chamber conditions : (a) first wafer effects, long term ER / CD drift, preventative maintenance (PM) recovery, stepwise stability of process; (b) direct detection of deposition and removal, outgassing monitoring; (c) monitor chamber conditions after each wafer / ICC and each step, process stability, reduced PM, faster time to identify and resolve drift issues.

[0090] Deviation detection (e.g., backflow) : (a) unknown yield detractors, process excursion; (b) continuously measure, detect shifts in chamber conditions; (c) detect adsorption and desorption of residual species.

[0091] Mixed runs (more / less byproducts) : (a) impact chamber conditions; (b) direct detection of deposition and removal of the deposition; (c) monitor chamber wall conditions for optimal recipe or lot order to minimize process cross-talk.

[0092] ICC optimization : (a) process chamber (PC) / ER / CD stability; (b) direct detection of deposition and removal of the deposition; (c) detect inefficient ICCs and develop optimal ICC recipe on the fly, monitor liner / chamber wall conditions for surface protection of chamber walls / liners for etch (e.g., BCl3 / Cl2-based etch) processes.

[0093] Capacitance sensor solution

[0094] The following are exemplary parameters and corresponding (a) importance, (b) solution, and (c) benefit / use.

[0095] Deposition on single ring : (a) particles; (b) install cap sensors into single ring; (c) develop more efficient ICCs without coupons, end point cleaning on a regular basis.

[0096] Single ring corrosion monitor : (a) ring corrosion; (c) determine when to replace ring, assist in automatic setting of ring height.

[0097] RF on by product monitor : (a) additional method of capturing end point detection (EPD), particles; (b) install cap sensors in lower chamber near SFV; (c) detect when etch punches through one film to the next, determine byproducts in lower chamber.

[0098] Wear rate of parts (break time) : (a) Rapidly determine the impact of process changes on MTBC; (b) Develop sensors for fabricated chamber materials installed on parts in specific locations; (c) Rapidly determine the impact of process changes on parts to calculate MTBC.

[0099] Residual chemical reaction sensor (on wafer) : (a) Queue time; (b) Establish sensors into test wafers to measure chemical reactions after processing; (c) Understand queue time and process optimization to reduce / eliminate residual chemical reactions.

[0100] PVD / CVD / ALD chamber wall : (a) Chamber wall cleaning and aging; (b) Install sensors in specific locations to monitor wall conditions; (c) In-situ monitoring of chamber walls.

[0101] Case study

[0102] The following are exemplary problems and corresponding (a) impacts, and (b) mitigation or elimination of impact wall / cap sensor detection solutions.

[0103] CD impact due to cap / wall temperature after some idle time (due to failure or other delay) : (a) 1 to 3 wafers are scrapped; (b) Sensor automatically detects temperature out of specification and invokes a temperature up procedure.

[0104] Unoptimized ramp up procedure : (a) Loss of production time; (b) Endpoint detection (EPD) temperature up / aging procedure.

[0105] Backflow event (e.g., back-up pump failure) : (a) Wafer scrap due to chamber condition shift; (b) Automatic detection of changes in wall / cap conditions.

[0106] Semiconductor foundry deviation (e.g., power glitch) : (a) Wafer scrap, requalification, need for PM; (b) Determine which chamber is problematic without running etch rate (ER) monitors.

[0107] Recipe that exceeds cap thermal budget : (a) Cap breakage, wafer scrap, need for PM; (b) Faulty chamber if cap temperature is out of specification.

[0108] Unoptimized ICC, monitor wafer run impacts chamber conditions : (a) Shorter MTBC, extended aging, ICC, yield loss; (b) Detect and monitor wall / cap conditions.

[0109] Plasma stability : (a) Yield loss; (b) Detect changes in capacitance at high speed (e.g., 50 hz).

[0110] Transition from application A to application B(a) over / under conditioning (e.g., lost production time / first wafer effect); (b) determining when the chamber is ready for production.

[0111] In embodiments, a capacitive sensor assembly (or sensor assembly) includes a sensor module and a sensor housing assembly. The sensor module can include a capacitor (e.g., a first electrode and a second electrode) disposed above a substrate. The sensor module can also include a capacitive to digital converter (CDC) for converting a capacitance output from the capacitor into a digital signal for subsequent processing. To integrate the sensor module with a processing tool, a sensor housing assembly can be used to house the sensor module. The sensor housing assembly can include features that secure the sensor module within a processing chamber while allowing the capacitor of the sensor module to be exposed to the processing environment. The sensor housing assembly can also include components for interfacing with a port through a chamber wall or chamber lid of a processing tool so as to allow real-time capture of data.

[0112] In particular embodiments, the sensor housing assembly includes a hollow shaft and a cap. The sensor module can be secured against an end of the shaft by the cap. A bore through the cap exposes the capacitor of the sensor module. The hollow shaft allows internal connections (e.g., wires, pins, etc.) from the sensor module to be protected from the processing environment and fed to a vacuum electrical feedthrough to exit the chamber without breaking the chamber vacuum.

[0113] Different locations of the sensor module can be implemented by modifications to the individual components of the sensor housing assembly and / or by modifications to how the components interface with the chamber itself. For example, in the example of a chamber wall sensor, the shaft can extend through a port in the chamber wall and the vacuum electrical feedthrough can be external to the chamber. In the example of a lid sensor, the shaft can extend from the lid into the chamber and the vacuum electrical feedthrough can be embedded in the lid. In the example of a processing ring sensor, the shaft can extend upward from a bottom chamber surface and intersect a plasma screen adjacent to the processing ring. In such embodiments, the vacuum electrical feedthrough can be positioned within a port through the bottom chamber surface. In the example of an exhaust region sensor, the shaft can be inserted through a port through the chamber wall and the vacuum electrical feedthrough can be external to the chamber wall. In some embodiments, an adapter can be fitted around portions of the sensor housing assembly to provide a hermetic seal along ports of any size.

[0114] In some embodiments, portions of the sensor assembly may be considered consumable parts. For example, the sensor module may be replaced after a certain period of time or after significant sensor drift is detected. The sensor housing assembly is easily removable to allow for simple replacement. In a particular embodiment, the shaft may have a threaded end to screw into the main housing attached to the vacuum feedthrough. Thus, the shaft and other components attached to it (e.g., caps and sensor modules) can be removed and replaced by screwing a new shaft into the main housing. In other embodiments, the entire sensor assembly may be considered a consumable part and may be replaced after a certain period of time or after significant sensor drift is detected.

[0115] Providing a capacitive sensor module (such as those described herein) within the processing apparatus allows for monitoring of chamber conditions during the execution of various processing recipes, during substrate transitions, during cleaning operations (e.g., ICC operations), during chamber validation, or at any other desired time. Furthermore, the architecture of the sensor modules disclosed herein allows for integration in many different locations. This flexibility allows for the simultaneous monitoring of many different components of the processing apparatus, providing enhanced capabilities to determine the cause of chamber drift. For example, Figure 11 A schematic diagram is provided illustrating an integrated processing device 1100 comprising a capacitive sensor module 1111 located at various positions.

[0116] like Figure 11 As shown, the processing apparatus 1100 may include a chamber 1142. A cathode liner 1145 may surround a lower electrode 1161. A substrate 1105 may be attached to the lower electrode 1161. A processing ring 1197 may surround the substrate 1105, and a plasma screen 1195 may surround the processing ring 1197. In an embodiment, a cover assembly 1110 may seal the chamber 1142. The chamber 1142 may include a processing region 1102 and an exhaust region 1104. The exhaust region 1104 may be accessible to an exhaust port 1196.

[0117] In some embodiments, a sidewall sensor module 1111A can be positioned along a sidewall of the chamber 1142. In some embodiments, the sidewall sensor module 1111A is through a wall of the chamber 1142 and exposed to the processing region 1102. In some embodiments, a lid sensor module 1111B is integrated with the lid assembly 1110 and faces the processing region 1102. In some embodiments, a process ring sensor module 1111C is positioned adjacent to the process ring 1197. For example, the process ring sensor module 1111C can be integrated with the plasma screen 1195 that surrounds the process ring 1197. In yet another embodiment, an exhaust region sensor module 1111D can be located in the exhaust region 1104. For example, the exhaust region sensor module 1111D can be through a bottom surface of the chamber 1142. As shown, each sensor module 1111 includes electrical leads 1199 that exit the chamber 1142. Thus, real-time monitoring can be implemented using the sensor modules 1111.

[0118] In embodiments, the sidewall sensor module 1111A is in a position 1120A along a side of the chamber 1142. In one embodiment, the sidewall sensor module 1111A is in a position 1122A laterally adjacent to the substrate 1105 support region of the lower electrode 1161. In one embodiment, the sidewall sensor module 1111A is in a position 1124A vertically between the substrate 1105 support region of the lower electrode 1161 and the lid assembly 1110. In one embodiment, the sidewall sensor module 1111A is in a position 1126A vertically between the substrate 1105 support region of the lower electrode 1161 and the floor of the processing apparatus 1100.

[0119] In embodiments, the lid sensor module 1111B is in a position 1120B along the lid assembly 1110. In one embodiment, the lid sensor module 1111B is in a position 1122B coaxial with the substrate 1105 support region of the lower electrode 1161. In one embodiment, the lid sensor module 1111B is in a position 1124B vertically above the substrate 1105 support region of the lower electrode 1161. In one embodiment, the lid sensor module 1111B is in a position 1126B vertically above an area outside of the substrate 1105 support region of the lower electrode 1161.

[0120] In embodiments, the process ring sensor module 1111C is in an inner periphery of the plasma screen 1195. In another embodiment, the process ring sensor module 1111C is in an outer periphery of the plasma screen 1195.

[0121] In embodiments, the exhaust region sensor module 1111D is in a position 1120D along a bottom surface of the chamber 1142. In one embodiment, the exhaust region sensor module 1111D is in a position 1122D vertically below a region outside of the substrate support region of the lower electrode 1161. In one embodiment, the exhaust region sensor module 1111D is in a position 1124D vertically below the substrate support region of the lower electrode 1161.

[0122] In embodiments, one or more of the capacitive sensor modules 1111 further include a thermal sensor. In one such embodiment, a capacitive sensor module includes a capacitive sensor proximate to a substrate processing region and includes a thermal sensor distal from the substrate processing region. In another such embodiment, a capacitive sensor module includes a capacitive sensor proximate to a substrate support region and includes a thermal sensor distal from the substrate support region.

[0123] Figure 12A A schematic cross-sectional view of a plasma processing apparatus 1200 including one or more sensor modules, such as those described herein, is illustrated in accordance with embodiments. The plasma processing apparatus 1200 can be a plasma etch chamber, a plasma enhanced chemical vapor deposition chamber, a physical vapor deposition chamber, a plasma processing chamber, an ion implantation chamber, or other suitable vacuum processing chamber. As shown in Figure 12A As shown in FIG. 12, the plasma processing apparatus 1200 generally includes a chamber lid assembly 1210 collectively enclosing a processing region 1202 and an exhaust region 1204, a chamber body assembly 1240, and an exhaust assembly 1290. In practice, process gas is directed into the processing region 1202 and ignited into a plasma using RF power. A substrate 1205 is positioned on a substrate support assembly 1260 and exposed to the plasma generated in the processing region 1202 to perform a plasma process, such as etching, chemical vapor deposition, physical vapor deposition, implantation, plasma anneal, plasma treatment, abatement, or other plasma process on the substrate 1205. A vacuum is maintained in the processing region 1202 by the exhaust assembly 1290, which removes spent process gas and byproducts from the plasma process via the exhaust region 1204.

[0124] The lid assembly 1210 generally includes an upper electrode 1212 (or anode) isolated from and supported by the chamber body assembly 1240, and a chamber lid 1214 that encloses the upper electrode 1212. The upper electrode 1212 is coupled to the RF power source 1203 via a conductive gas inlet pipe 1226. The conductive gas inlet pipe 1226 is coaxial with the central axis of the chamber body assembly 1240, such that both RF power and process gas are provided symmetrically. The upper electrode 1212 includes a showerhead plate 1216 attached to a heat transfer plate 1218. The showerhead plate 1216, heat transfer plate 1218, and gas inlet pipe 1226 are all made of an RF conductive material, such as aluminum or stainless steel.

[0125] The showerhead plate 1216 has a central manifold 1220 and one or more outer manifolds 1222 for distributing process gas into the processing region 102. The one or more outer manifolds 1222 surround the central manifold 1220. The central manifold 1220 receives process gas from the gas source 1206 via the gas inlet pipe 1226, and the outer manifolds 1222 receive process gas from the gas source 1206 via gas inlets 1227, which can be the same or a different mixture than the gas received in the central manifold 1220. The dual manifold configuration of the showerhead plate 1216 allows for improved control of gas delivery into the processing region 1202. The multi-manifold showerhead plate 116 can enhance center-to-edge control of processing results relative to a conventional single manifold version.

[0126] Heat transfer fluid is delivered to the heat transfer plate 1218 from a fluid source 1209 through a fluid inlet pipe 1230. The fluid is circulated through one or more fluid channels 1219 provided in the heat transfer plate 1218, and returned to the fluid source 1209 through a fluid outlet pipe 1231. Suitable heat transfer fluids include water, water-based ethylene glycol mixtures, perfluoropolyether (e.g., Fluorinert® fluids), oil-based heat transfer fluids, or similar fluids. The fluid is circulated through one or more fluid channels 1219 provided in the heat transfer plate 1218, and returned to the fluid source 1209 through a fluid outlet pipe 1231. Suitable heat transfer fluids include water, water-based ethylene glycol mixtures, perfluoropolyether (e.g., Fluorinert® fluids), oil-based heat transfer fluids, or similar fluids.

[0127] The chamber body assembly 1240 includes a chamber body 1242 made of a process- environment-resistant, electrically-conductive material (e.g., aluminum or stainless steel). A substrate support assembly 1260 is centrally disposed within the chamber body 1242 and is positioned to support a substrate 1205 in a processing region 1202 symmetrically about a central axis (CA). The substrate support assembly 1260 can also support a process ring 1297 that surrounds the substrate 1205. The chamber body 1242 includes ledges that support an outer flange of an upper liner assembly 1244. The upper liner assembly 1244 can be composed of an electrically-conductive, process-compatible material such as aluminum, stainless steel, and / or yttria (e.g., yttria-coated aluminum). In effect, the upper liner assembly 1244 shields an upper portion of the chamber body 1242 from plasma in the processing region 1202 and can be removed to allow for periodic cleaning and maintenance. An inner flange of the upper liner assembly 1244 supports an upper electrode 1212. An insulator 1213 is located between the upper liner assembly 1244 and the upper electrode 1212 to provide electrical isolation between the chamber body assembly 1240 and the upper electrode 1212.

[0128] The upper liner assembly 1244 includes an outer wall 1247, a bottom wall 1248, and an inner wall 1249 attached to the inner and outer flanges. The outer wall 1247 and the inner wall 1249 are substantially vertical, cylindrical walls. The outer wall 1247 is positioned to shield the chamber body 1242 from plasma in the processing region 1202, and the inner wall 1249 is positioned to at least partially shield sides of the substrate support assembly 1260 from plasma in the processing region 1202. The bottom wall 1248 joins the inner wall 1249 and the outer wall 1247 except in certain areas that form exhaust passages 1289.

[0129] Access to the processing region 1202 is through a slit valve tunnel 1241 disposed in the chamber body 1242, which allows the substrate 1205 to be passed into and out of the substrate support assembly 1260. The upper liner assembly 1244 has a slot 1250 disposed therethrough to match the slit valve tunnel 1241 to allow the substrate 1205 to pass therethrough. A door assembly (not shown) closes the slit valve tunnel 1241 and the slot 1250 during operation of the plasma processing apparatus.

[0130] The substrate support assembly 1260 generally includes a lower electrode 1261 (or cathode) and a hollow pedestal 1262 through the center of which a central axis (CA) passes and is supported by a central support member 1257 disposed in the center region 1256 and supported by the chamber body 1242. The central axis (CA) also passes through the center of the central support member 1257. The lower electrode 1261 is coupled to the RF power source 1203 through a matching network (not shown) and a cable (not shown) that is routed through the hollow pedestal 1262. When RF power is supplied to the upper electrode 1212 and the lower electrode 1261, an electric field formed therebetween ignites a process gas present in the processing region 1202 into a plasma.

[0131] The central support member 1257 is sealed to the chamber body 1242 (such as by fasteners and O-rings (not shown)) and the lower electrode 1261 is sealed to the central support member 1257 (such as by bellows 1258). Thus, the center region 1256 is sealed from the processing region 1202 and the center region 1256 can be maintained at atmospheric pressure while the processing region 1202 is maintained at vacuum conditions.

[0132] An actuation assembly 1263 is positioned within the center region 1256 and attached to the chamber body 1242 and / or the central support member 1257. The actuation assembly 1263 provides vertical movement of the lower electrode 161 relative to the chamber body 142, the central support member 1257, and the upper electrode 1212. Such vertical movement of the lower electrode 1261 within the processing region 1202 provides a variable gap between the lower electrode 1261 and the upper electrode 1212 allowing increased control over the electric field formed therebetween, in turn, providing better control over the density in the plasma formed in the processing region 1202. Additionally, since the substrate 1205 is supported by the lower electrode 1261, the gap between the substrate 1205 and the showerhead plate 1216 can also be varied, resulting in better control over the distribution of process gas across the substrate 1205.

[0133] In one embodiment, the lower electrode 1261 is an electrostatic chuck and thus includes one or more electrodes (not shown) disposed therein. A voltage source (not shown) biases the one or more electrodes relative to the substrate 1205 to create an attractive force to maintain the substrate 1205 in place during processing. A cable coupling the one or more electrodes to the voltage source is routed through the hollow pedestal 1262 and exits the chamber body 1242 via one of a plurality of access tubes 1280.

[0134] Figure 12Bis a schematic depiction of the layout of access tubes 1280 within spokes 1291 of chamber body assembly 1240. As shown, spokes 1291 and access tubes 1280 are arranged symmetrically in a spoke pattern about the central axis (CA) of processing apparatus 1200. In the illustrated embodiment, three identical access tubes 1280 are disposed through chamber body 1242 into central region 1256 to facilitate the supply of a plurality of tubes and cables from outside chamber body 1242 to lower electrode 1261. Each of spokes 1291 is adjacent to exhaust passages 1289, which fluidly couple the processing region 1202 above central region 1256 with the exhaust region 1204 below central region 1256. The symmetric arrangement of access tubes 1280 further provides electrical and thermal symmetry in chamber body 1242, particularly in processing region 1202, to allow for more uniform plasma formation in processing region 1202 and improved control of plasma density on the surface of substrate 1205 during processing.

[0135] Similarly, exhaust passages 1289 are positioned symmetrically about the central axis (CA) in upper liner assembly 1244. Exhaust passages 1289 allow gas to exhaust from processing region 1202 through exhaust region 1204 and out of chamber body 1242 through exhaust ports 1296. Exhaust ports 1296 are centered about the central axis (CA) of chamber body assembly 1240, such that gas is uniformly drawn through exhaust passages 1289.

[0136] Referring again to Figure 12A An electrically conductive mesh liner 1295 is positioned on upper liner assembly 1244. Mesh liner 1295 can be composed of an electrically conductive, process compatible material, such as aluminum, stainless steel, and / or yttria (e.g., yttria-coated aluminum). Mesh liner 1295 can have a plurality of apertures (not shown) formed therethrough. The apertures can be positioned symmetrically about the central axis of mesh liner 1295 to allow exhaust gas to be uniformly drawn therefrom, thereby facilitating uniform plasma formation in processing region 1202 and allowing for better control of plasma density and gas flow in processing region 1202. In one embodiment, the central axis of mesh liner 1295 is aligned with the central axis (CA) of chamber body assembly 1240.

[0137] Mesh liner 1295 can be electrically coupled to upper liner assembly 1244. When an RF plasma is present in processing region 1202, RF current seeking a return path to ground can travel along the surface of mesh liner 1295 to the outer wall 1247 of upper liner assembly 1244. Thus, the annular symmetric configuration of mesh liner 1295 provides a symmetric RF return to ground and bypasses any geometric asymmetry of upper liner assembly 1244.

[0138] In an embodiment, one or more sensor modules can be located at various locations throughout the processing apparatus 1200. For example, a sensor module (or a portion of a sensor module) can be located in one or more locations, such as but not limited to along a sidewall of the chamber 1242, in the exhaust region 1204, adjacent to the processing ring 1297 (e.g., integrated into the mesh liner 1295), or integrated with the lid assembly 1210. Thereby, detection of various chamber conditions in multiple locations can be determined by the processing apparatus 1200. The chamber conditions supplied by the one or more sensor modules can be used to modify one or more parameters, e.g., processing recipe parameters, cleaning processes for the processing apparatus 1200, component replacement determinations, etc.

[0139] In an embodiment, the processing apparatus 1200 includes a chamber wall capacitive sensor module, e.g., at location 1299A. In an embodiment, the processing apparatus 1200 includes a chamber lid capacitive sensor module, e.g., at location 1299B. In an embodiment, the processing apparatus 1200 includes a chamber floor or exhaust port capacitive sensor module within or adjacent to an exhaust port, e.g., at location 1299D. In an embodiment, the processing apparatus 1200 includes a ring structure capacitive sensor module, e.g., at location 1299C.

[0140] In an embodiment, the processing apparatus 1200 includes two or more different capacitive sensors selected from the group consisting of: a chamber wall capacitive sensor module, a chamber lid capacitive sensor module, a chamber floor or exhaust port capacitive sensor module, a ring structure capacitive sensor module. In an embodiment, the processing apparatus 1200 includes two or more identical capacitive sensors selected from the group consisting of: a chamber wall capacitive sensor module, a chamber lid capacitive sensor module, a chamber floor or exhaust port capacitive sensor module, a ring structure capacitive sensor module.

[0141] In an embodiment, one or more of the chamber wall capacitive sensor module, the chamber lid capacitive sensor module, the chamber floor or exhaust port capacitive sensor module, and / or the ring structure capacitive sensor module further includes a thermal sensor. In one embodiment, such a chamber wall capacitive sensor module, chamber lid capacitive sensor module, or chamber floor or exhaust port capacitive sensor module includes a capacitive sensor proximate to the processing region 1202, and includes a thermal sensor distal from the processing region 1202. In one embodiment, a ring structure capacitive sensor module includes a capacitive sensor proximate to a substrate 1205 support region, and includes a thermal sensor distal from the substrate 1205 support region.

[0142] Although Figure 12A and 12BThe processing equipment 1200 in FIG. 1 provides a particular example that can benefit from tools including, for example, the sensor modules disclosed herein, it should be understood that embodiments are not limited to Figure 12A and Figure 12B particular configurations. That is, many different plasma chamber configurations, such as but not limited to plasma chamber configurations used in the microelectronics manufacturing industry, can also benefit from integration of sensor modules, such as disclosed herein.

[0143] For example, Figure 13 is a cross-sectional view of a processing equipment 1300 that can include one or more capacitive sensor modules, such as those described above, in accordance with embodiments of the present disclosure. The plasma processing equipment 100 can be a plasma etch chamber, a plasma enhanced chemical vapor deposition chamber, a physical vapor deposition chamber, a plasma processing chamber, an ion implantation chamber, or other suitable vacuum processing chamber.

[0144] The processing equipment 1300 includes a chamber 1342 that is grounded. In some cases, the chamber 1342 can also include a liner (not shown) to protect the interior surfaces of the chamber 1342. The chamber 1342 can include a processing region 1302 and an exhaust region 1304. A lid assembly 1310 can be used to seal the chamber 1342. Process gas is supplied from one or more gas sources 1306 through mass flow controllers 1349 to the lid assembly 1310 and into the chamber 1305. An exhaust port 1396 proximate the exhaust region 1304 can maintain a desired pressure within the chamber 1342 and remove byproducts from processing in the chamber 1342.

[0145] The lid assembly 1310 generally includes an upper electrode comprising a showerhead plate 1316 and a heat transfer plate 1318. The lid assembly 1310 is isolated from the chamber 1342 by an insulating layer 1313. The upper electrode is coupled to a source RF generator 1303 through a match (not shown). The source RF generator 1303 can have a frequency of, for example, between 100 and 180 MHz, for example, in a frequency band of 162 MHz in particular embodiments. Gases from the gas sources 1306 enter a manifold 1320 within the showerhead plate 1316 and exit through openings in the showerhead plate 1316 into the processing region 1302 of the chamber 1342. In embodiments, the heat transfer plate 1318 includes channels 1319 through which a heat transfer fluid flows. The showerhead plate 1316 and the heat transfer plate 1318 are made of an RF-conductive material, such as, for example, aluminum or stainless steel. In certain embodiments, gas nozzles or other suitable gas distribution assemblies are provided for distributing process gases into the chamber 1342 in place of (or in addition to) the showerhead plate 1316.

[0146] The processing region 1302 can include a lower electrode 1361 on which a substrate 1305 is secured. Portions of a processing ring 1397 that surround the substrate 1305 can also be supported by the lower electrode 1361. The substrate 1305 can be inserted into (or extracted from) the chamber 1342 through a slit valve tunnel 1341 that passes through the chamber 1342. A door for the slit valve tunnel 1341 is omitted for simplicity. The lower electrode 1361 can be an electrostatic chuck. The lower electrode 1361 can be supported by a support member 1357. In embodiments, the lower electrode 1361 can include multiple heating zones, each of which can be independently controlled to a temperature set point. For example, the lower electrode 1361 can include a first heating zone proximate a center of the substrate 1305 and a second heating zone proximate a periphery of the substrate 1305. A bias power RF generator 1325 is coupled to the lower electrode 1361 through a match 1327. If desired, the bias power RF generator 1325 provides bias power to energize a plasma. The bias power RF generator 1325 can have a low frequency, for example, between about 2 MHz and 60 MHz, and in particular embodiments, in the 13.56 MHz frequency band.

[0147] In embodiments, one or more sensor modules can be located at various locations throughout the processing apparatus 1300. For example, a sensor module (or a portion of a sensor module) can be located in one or more locations, such as but not limited to at a location 1399A along a sidewall of the chamber 1342, at a location 1399D proximate or in the exhaust region 1304, at a location 1399C proximate or within the processing ring 1397, and / or integrated with the lid assembly 1310, for example, at a location 1399B. As such, detection of various chamber conditions in multiple locations can be determined by the processing apparatus 1300. The chamber conditions supplied by the one or more sensor modules can be used to modify one or more parameters, for example, processing recipe parameters, cleaning processes for the processing apparatus 1300, component replacement determinations, etc.

[0148] Referring now to Figure 14 a block diagram of an exemplary computer system 1460 of a processing tool is illustrated, in accordance with embodiments. In embodiments, the computer system 1460 is coupled to a processing tool and controls processing in the processing tool. The computer system 1460 can be communicatively coupled to one or more sensor modules, such as those disclosed herein. The computer system 1460 can utilize output from the one or more sensor modules in order to modify one or more parameters, for example, processing recipe parameters, cleaning processes for the processing tool, component replacement determinations, etc.

[0149] The computer system 1460 can be connected (e.g., networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. The computer system 1460 can operate in the capacity of a server 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 computer system 1460 can be a personal computer (PC), a tablet computer, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a 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 illustrated for the computer system 1460, 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 discussed herein.

[0150] The computer system 1460 can include a computer program product, or software 1422, having a non-transitory machine-readable medium (or more than one medium) storing instructions executable by the computer system 1460 (or other electronic device) to perform a process according to an embodiment. The machine-readable medium (or media) includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, the machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory ("ROM"), random access memory ("RAM"), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0151] In an embodiment, the computer system 1460 includes a system processor 1402, a main memory 1404 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 1406 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory 1418 (e.g., a data storage device), which communicate with each other via a bus 1430.

[0152] The system processor 1402 represents one or more general-purpose processing devices such as a microsystem processor, central processing unit, or the like. More particularly, the system processor can be a complex instruction set computing (CISC) microsystem processor, reduced instruction set computing (RISC) microsystem processor, very long instruction word (VLIW) microsystem processor, system processor implementing other instruction sets, or system processors implementing a combination of instruction sets. The system processor 1402 can 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 system processor (DSP), network system processor, or the like. The system processor 1402 is configured to execute the processing logic 1426 for performing the operations described herein.

[0153] The computer system 1460 can further include a system network interface device 1408 to communicate with other devices or machines on a network. The computer system 1460 can also include a visual display unit 1410 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 1412 (e.g., a keyboard), a cursor control device 1414 (e.g., a mouse), and a signal generation device 1416 (e.g., a speaker).

[0154] The secondary memory 1418 can include machine-accessible storage media 1431 (or more specifically, computer-readable storage media) on which are stored one or more sets of instructions (e.g., software 1422) embodying any one or more of the methodologies or functions described herein. The software 1422 can also reside, completely or at least partially, within the main memory 1404 and / or system processor 1402 during execution thereof by the computer system 1460, the main memory 1404 and the system processor 1402 also constituting machine-readable storage media. The software 1422 can further be transmitted or received over a network 1461 via the system network interface device 1408. In embodiments, the network interface device 1408 can operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling.

[0155] While the machine-accessible storage media 1431 is shown in an example embodiment to be a single medium, the term "machine-readable storage medium" should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store the one or more sets of instructions. The term "machine-readable storage medium" shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies

[0156] Accordingly, embodiments of the present disclosure include a capacitive sensor and a capacitive sensing location for plasma chamber condition monitoring.

[0157] The above description of the illustrated embodiments of the present disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. While specific implementations of, and examples for, the present disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present disclosure, as those skilled in the relevant art will recognize.

[0158] These modifications can be made to the disclosure in light of the above detailed description. The terms used in the following claims should not be construed to limit the present disclosure to the specific implementations disclosed in the specification and claims. Rather, the scope of the present disclosure is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.

[0159] Example Embodiment 1 : A plasma chamber monitoring system comprising: a plurality of capacitive sensors, a capacitive digital converter, and an application processing server coupled to the capacitive digital converter, the application processing server comprising system software. The capacitive digital converter comprising: an insulation interface coupled to the plurality of capacitive sensors; a power supply coupled to the insulation interface; a field programmable gate array firmware coupled to the insulation interface; and an application specific integrated circuit coupled to the field programmable gate array firmware.

[0160] Example Embodiment 2: The plasma chamber monitoring system of example embodiment 1, wherein the application specific integrated circuit of the capacitive digital converter is an etherCAT application specific integrated circuit.

[0161] Example Embodiment 3: The plasma chamber monitoring system of example embodiment 2, wherein the etherCAT application specific integrated circuit provides both seamless integration of the system software and control of a plurality of capacitive sensors of the plurality of capacitive sensors.

[0162] Example Embodiment 4: The plasma chamber monitoring system of example embodiment 2 or 3, wherein the etherCAT application specific integrated circuit initializes and calibrates each capacitive sensor of the plurality of capacitive sensors.

[0163] Example Embodiment 5: The plasma chamber monitoring system of example embodiment 1, 2, 3, or 4, wherein the application processing server synchronizes capacitive sensor data from the plurality of capacitive sensors with a process recipe.

[0164] Example Embodiment 6: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, or 5, wherein the field programmable gate array firmware of the capacitance-to-digital converter provides deterministic timing and simultaneous communication with multiple ones of the plurality of capacitive sensors.

[0165] Example Embodiment 7: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, 5, or 6, wherein each of the plurality of capacitive sensors is coupled in parallel to the insulated interface of the capacitance-to-digital converter.

[0166] Example Embodiment 8: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, 5, 6, or 7, wherein each of the plurality of capacitive sensors is coupled to the insulated interface of the capacitance-to-digital converter by an internal connection, the internal connection comprising an internal integrated circuit bus and a power line.

[0167] Example Embodiment 9: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, 5, 6, 7, or 8, wherein one or more of the plurality of sensors is located at a chamber wall of the plasma chamber.

[0168] Example Embodiment 10: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein one or more of the plurality of sensors is located at a chamber lid of the plasma chamber.

[0169] Example Embodiment 11: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein one or more of the plurality of sensors is located at an exhaust region of the plasma chamber.

[0170] Example Embodiment 12: The plasma chamber monitoring system of example embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein one or more of the plurality of sensors is located at a process ring within the plasma chamber.

[0171] Example Embodiment 13: An internal connection for a plasma chamber monitoring system, the internal connection comprising: a first connector to couple to a capacitance-to-digital converter of a capacitance sensor module; a second connector to couple to an electronic device and an external power source; a shielded cable coupled to and between the first connector and the second connector. The shielded cable comprises: a shielded metal for physically connecting the internal connection to a frame of a plasma chamber; a power supply line housed within the shielded metal; a ground line housed within the shielded metal; and one or more communication lines housed within the shielded metal.

[0172] Example Embodiment 14: The internal connection of Example Embodiment 13, wherein the power supply line housed within the shielded metal is a 3 to 4 volt power supply line.

[0173] Example Embodiment 15: The internal connection of Example Embodiment 13 or 14, wherein each of the one or more communication lines housed within the shielded metal is or comprises an Inter-Integrated Circuit bus.

[0174] Example Embodiment 16: The internal connection of Example Embodiment 13, 14, or 15, wherein the ground line housed within the shielded metal provides a shared ground for the capacitance sensor module and the electronic device.

[0175] Example Embodiment 17: The internal connection of Example Embodiment 13, 14, 15, or 16, wherein the one or more communication lines housed within the shielded metal synchronize sensor data timing.

[0176] Example Embodiment 18: The internal connection of Example Embodiment 13, 14, 15, 16, or 17, wherein a sensor of the capacitance sensor module is located at a chamber wall of a plasma chamber.

[0177] Example Embodiment 19: The internal connection of Example Embodiment 13, 14, 15, 16, 17, or 18, wherein a sensor of the capacitance sensor module is located at a chamber lid of a plasma chamber.

[0178] Example Embodiment 20: The internal connection of Example Embodiment 13, 14, 15, 16, 17, 18, or 19, wherein a sensor of the capacitance sensor module is located at an exhaust region of a plasma chamber.

[0179] Example Embodiment 21 : The internal connection of example embodiment 13, 14, 15, 16, 17, 18, 19, or 20, wherein the sensor of the capacitance sensor module is located at a process ring within the plasma chamber.

[0180] Example Embodiment 22: A method of integrating data for plasma chamber condition monitoring, the method comprising: streaming data from a capacitance sensor module to a data server. The data comprises capacitance data and temperature data. The method further comprises: collecting the data on an application processing server. The method further comprises: correlating the data to one or more process recipe operations. The method further comprises: synchronizing the capacitance sensor module with the one or more process recipe operations.

[0181] Example Embodiment 23: The method of example embodiment 22, further comprising the step of: performing data processing and parameter extraction on the application processing server after collecting the data and before correlating the data to one or more process recipe operations.

[0182] Example Embodiment 24: The method of example embodiment 23, wherein performing the data processing comprises: filtering the data and de-noising the data.

[0183] Example Embodiment 25: The method of example embodiment 24, wherein filtering the data and de-noising the data comprises: using a moving average method.

[0184] Example Embodiment 26: The method of example embodiment 23, 24, or 25, wherein performing the data processing and the parameter extraction comprises: regression modeling the data.

[0185] Example Embodiment 27: The method of example embodiment 22, 23, 24, 25, or 26, further comprising: monitoring one or more parameters of the one or more process recipe operations using the capacitance sensor module.

[0186] Example Embodiment 28: The method of example embodiment 27, further comprising: determining a clean / contamination state for a plasma chamber based on the monitoring of the one or more parameters of the one or more process recipe operations using the capacitance sensor module.

[0187] Example Embodiment 29: The method of example embodiment 22, 23, 24, 25, 26, 27, or 28, wherein plasma chamber condition monitoring is performed at a chamber wall of a plasma chamber.

[0188] Example Embodiment 30: The method of example embodiment 22, 23, 24, 25, 26, 27, 28, or 29, wherein plasma chamber condition monitoring is performed at a chamber lid of a plasma chamber.

[0189] Example 31. The method of example 22, 23, 24, 25, 26, 27, 28, 29, or 30, wherein the plasma chamber condition monitoring is performed at an exhaust region of the plasma chamber. Example 32. The method of example 22, 23, 24, 25, 26, 27, 28, 29, 30, or 31, wherein the plasma chamber condition monitoring is performed at a process ring within the plasma chamber.

Claims

1. A plasma chamber monitoring system, comprising: a plurality of capacitive sensors; a capacitive digital converter, comprising: an insulated interface coupled to the plurality of capacitive sensors; a power supply coupled to the insulated interface; a field programmable gate array firmware coupled to the insulated interface; and an application specific integrated circuit coupled to the field programmable gate array firmware; and an application processing server coupled to the capacitive digital converter, the application processing server comprising system software.

2. The plasma chamber monitoring system of claim 1, wherein the application specific integrated circuit of the capacitive digital converter is an etherCAT application specific integrated circuit.

3. The plasma chamber monitoring system of claim 2, wherein the etherCAT application specific integrated circuit provides seamless integration of the system software and control of a plurality of capacitive sensors of the plurality of capacitive sensors simultaneously.

4. The plasma chamber monitoring system of claim 2, wherein the etherCAT application specific integrated circuit initializes and calibrates each capacitive sensor of the plurality of capacitive sensors.

5. The plasma chamber monitoring system of claim 1, wherein the application processing server synchronizes capacitive sensor data from the plurality of capacitive sensors with a process recipe.

6. The plasma chamber monitoring system of claim 1, wherein the field programmable gate array firmware of the capacitive digital converter provides deterministic timing and simultaneous communication with a plurality of capacitive sensors of the plurality of capacitive sensors.

7. The plasma chamber monitoring system of claim 1, wherein each capacitive sensor of the plurality of capacitive sensors is coupled in parallel to the insulated interface of the capacitive digital converter.

8. The plasma chamber monitoring system of claim 7, wherein each capacitive sensor of the plurality of capacitive sensors is coupled to the insulated interface of the capacitive digital converter by an internal connection, the internal connection comprising an internal integrated circuit bus and a power supply line.

Images