RF Impedance Matching Network for Substrate Processing Platforms

Abstract

Methods and apparatuses for using a matching network to process a substrate are provided herein. For example, a matching network configured for use with a plasma processing chamber includes a local controller connectable to a system controller of the plasma processing chamber, a first electromotive capacitor connected to the local controller, a second electromotive capacitor connected to the first electromotive capacitor, a first sensor at an input of the matching network and a second sensor at an output of the matching network for acquiring in-line RF voltage, current, phase, harmonic, and impedance data, respectively, and an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting the local controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to substrate processing platforms, and more particularly to RF impedance matching networks for substrate processing platforms. [Background technology]

[0002] Conventional plasma processing chambers (reactors) may include one or more RF impedance matching networks, which may include a local controller, typically developed based on a serial communication protocol, used between the RF source and the plasma processing chamber to optimize power efficiency. Matching network settings and tuning algorithms may be stored in local memory, and at the tuned matching point, maximum power is delivered from the RF source into the plasma load and nearly zero power is reflected back to the RF source. The local controller, developed based on a serial communication protocol such as RS-232 or RS-485, monitors data from one or more match sensors and automatically adjusts one or more motorized variable capacitors using a tuning algorithm. In some instances, such as when multiple RF frequencies are used, the corresponding matching networks are isolated from each other and operate independently of each other. Summary of the Invention

[0003]

[0009] Provided herein are methods and apparatus for using a matching network to process a substrate. In at least some embodiments, a matching network configured for use with a plasma processing chamber includes a local controller connectable to a system controller of the plasma processing chamber, a first electromotive capacitor connected to the local controller, a second electromotive capacitor connected to the first electromotive capacitor, a first sensor at an input of the matching network and a second sensor at an output of the matching network for acquiring in-line RF voltage, current, phase, harmonic, and impedance data, respectively, and an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting the local controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor.

[0004] According to at least some embodiments, a plasma processing system includes an RF generator; a plasma processing chamber including a system controller connected to the RF generator and configured to process a substrate; and a matching network including a local controller connectable to the system controller of the plasma processing chamber; a first electromotive capacitor connected to the local controller; a second electromotive capacitor connected to the first electromotive capacitor; a first sensor at an input of the matching network and a second sensor at an output of the matching network for obtaining in-line RF voltage, current, phase, harmonic, and impedance data, respectively; and an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting the local controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor.

[0005] According to at least some embodiments, a plasma processing system includes: a plasma processing chamber including a first RF generator and a second RF generator; a system controller connected to each of the first RF generator and the second RF generator and configured to process a substrate; first and second matching networks, each including a first electromotive capacitor and a second electromotive capacitor connected to the first electromotive capacitor; a first sensor at an input and a second sensor at an output for acquiring in-line RF voltage, current, phase, harmonic, and impedance data, respectively, wherein the first electromotive capacitor of the first matching network is connected to the first electromotive capacitor of the second matching network; and an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting at least one of a local controller or a system controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor of each of the first matching network and the second matching network.

[0006] Other and further embodiments of the present disclosure are described below.

[0007] Embodiments of the present disclosure, briefly summarized above and discussed in more detail below, can be understood by reference to exemplary embodiments thereof as depicted in the accompanying drawings. The accompanying drawings, however, illustrate only typical embodiments of the present disclosure and are not, therefore, to be considered limiting of scope, since the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagrammatic cross-sectional view of a processing chamber in accordance with at least some embodiments of the present disclosure. [Figure 2] FIG. 1 is a block diagram of a matching network in accordance with at least some embodiments of the present disclosure. [Figure 3] FIG. 1 is a block diagram of a dual frequency matching network in accordance with at least some embodiments of the present disclosure. [Figure 4] FIG. 1 is a block diagram of a dual frequency matching network in accordance with at least some embodiments of the present disclosure. [Figure 5] 1 is a flowchart of a method for processing a substrate in accordance with at least some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] For ease of understanding, the same reference numbers have been used, where possible, to designate identical elements that are common to the figures. The figures may not be drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0010] Embodiments of a substrate processing platform are provided herein. For example, the apparatus described herein uses one or more matching networks that can connect to one or more RF power sources and a plasma processing chamber. One or more components of the matching networks communicate with each other via Ethernet for Control and Automation Technology (EtherCAT). Thus, the matching networks described herein offer advantages in performance, flexibility, and scalability because EtherCAT provides fast tuning speeds, short response times, and coordinated, intelligent real-time control. In addition, the disclosed EtherCAT-based distributed matching networks described herein offer improved tuning reliability, system scalability, and enable advanced tuning algorithms for sophisticated voltage waveform engineering applications.

[0011] 1 is a cross-sectional view of an example plasma processing system including a processing chamber 100 suitable for performing one or more plasma processes according to the present disclosure. Suitable processing chambers that may be adapted for use with the teachings disclosed herein include, for example, one or more etch processing chambers available from Applied Materials, Inc. of Santa Clara, Calif. Other processing chambers may be adapted to benefit from one or more of the methods of the present disclosure.

[0012] The processing chamber 100 includes a chamber body 102 and a chamber lid 104 that enclose an interior volume 106. The chamber body 102 is typically fabricated from aluminum, stainless steel, or other suitable material. The chamber body 102 generally includes a sidewall 108 and a bottom 110. A substrate support pedestal access port (not shown) is typically defined in the sidewall 108 and selectively sealed by a slit valve to facilitate entry and exit of the substrate 103 from the processing chamber 100. An exhaust port 126 is defined in the chamber body 102 and couples the interior volume 106 to a pumping system 128. The pumping system 128 typically includes one or more pumps and a throttle valve that are utilized to evacuate and regulate the pressure of the interior volume 106 of the processing chamber 100. In embodiments, the pump system 128 maintains pressure inside the interior volume 106 at an operating pressure typically between about 1 mTorr and about 500 mTorr, between about 5 mTorr and about 100 mTorr, or between about 5 mTorr and about 50 mTorr, depending on process needs.

[0013] The chamber lid 104 is supported in a sealing manner on a sidewall 108 of the chamber body 102. The chamber lid 104 may be opened to allow access to the interior volume 106 of the processing chamber 100. The chamber lid 104 includes a window 142 that facilitates optical process monitoring. In one embodiment, the window 142 is comprised of quartz or another suitable material that is transparent to signals utilized by an optical monitoring system 140 mounted outside the processing chamber 100.

[0014] The optical monitoring system 140 is positioned to view at least one of the interior volume 106 of the chamber body 102 and / or the substrate 103 positioned on the substrate support pedestal assembly 148 through a window 142. In one embodiment, the optical monitoring system 140 is coupled to the chamber lid 104 to facilitate an integrated deposition process that uses optical metrology to provide process state monitors (such as plasma monitors, temperature monitors, and the like) that provide information that enables process adjustments to compensate for incoming substrate pattern feature mismatches (such as thickness, and the like) when needed.

[0015] In an embodiment, a gas panel 158 is coupled to the processing chamber 100 to provide process and / or cleaning gases to the interior volume 106. In the example depicted in FIG. 1 , inlet ports 132′, 132″ are provided in the chamber lid 104 to allow gases to be delivered from the gas panel 158 to the interior volume 106 of the processing chamber 100. In an embodiment, the gas panel 158 is adapted to provide an inert gas, such as oxygen and argon, or an oxygen and helium process gas or gas mixture through the inlet ports 132′, 132″ and into the interior volume 106 of the processing chamber 100. In one embodiment, the process gas provided from the gas panel 158 includes at least a process gas including an oxidizer, such as oxygen gas. In embodiments, the process gas including an oxidizer may further include an inert gas, such as argon or helium. In some embodiments, the process gas includes a reducing agent, such as hydrogen, and may be mixed with an inert gas, such as argon, or other gases, such as nitrogen or helium. In some embodiments, chlorine gas may be provided alone or in combination with at least one inert gas, such as nitrogen, helium, or argon. Non-limiting examples of oxygen-containing gases include one or more of O, CO, N, O, N0, O, O, H, O, and the like. Non-limiting examples of nitrogen-containing gases include N, NH, and the like. Non-limiting examples of chlorine-containing gases include HCl, Cl, CCl, and the like. In an embodiment, a showerhead assembly 130 is coupled to the interior surface 114 of the chamber lid 104. The showerhead assembly 130 includes a plurality of apertures that allow gases to flow through the showerhead assembly 130 from inlet ports 132′, 132″ into the interior volume 106 of the processing chamber 100 in a predetermined distribution across the surface of the substrate 103 being processed in the processing chamber 100.

[0016] In some embodiments, the processing chamber 100 may utilize capacitively coupled RF energy for plasma processing, or in some embodiments, the processing chamber 100 may use inductively coupled RF energy for plasma processing. In some embodiments, a remote plasma source 177 may optionally be coupled to the gas panel 158 to facilitate separating the gas mixture from the remote plasma before entering the interior volume 106 for processing. In some embodiments, RF source power 143 is coupled to the showerhead assembly 130 through a matching network 141. The RF source power 143 may typically produce up to about 5000 W, e.g., between about 200 W and about 5000 W, or between 1000 W and 3000 W, or about 1500 W, and optionally at a tunable frequency in the range of about 50 kHz to about 200 MHz.

[0017] The showerhead assembly 130 additionally includes a region that is transparent to optical metrology signals. The optically transparent region or passage 138 is adapted to allow the optical monitoring system 140 to capture the interior volume 106 and / or the substrate 103 positioned on the substrate support pedestal assembly 148. The passage 138 may be a material, aperture, or multiple apertures formed or disposed within the showerhead assembly 130 that is substantially transparent to the wavelengths of energy generated by and reflected back to the optical monitoring system 140. In one embodiment, the passage 138 includes a window 142 to prevent gas leakage through the passage 138. The window 142 may be a sapphire plate, a quartz plate, or other suitable material. Alternatively, the window 142 may be disposed within the chamber lid 104.

[0018] In one embodiment, the showerhead assembly 130 is configured with multiple zones that allow separate control of gas flow into the interior volume 106 of the processing chamber 100. In the example illustrated in FIG. 1 , the showerhead assembly 130 as an inner zone 134 and an outer zone 136 that are separately coupled to a gas panel 158 through inlet ports 132′, 132″.

[0019] In some embodiments, a substrate support pedestal assembly 148 is disposed within the interior volume 106 of the processing chamber 100 below a gas distribution assembly, such as the showerhead assembly 130. The substrate support pedestal assembly 148 grips the substrate 103 during processing. The substrate support pedestal assembly 148 typically includes a plurality of lift pins (not shown) disposed therethrough that are configured to lift the substrate 103 from the substrate support pedestal assembly 148 and facilitate exchange of the substrate 103 by a robot (not shown) in a conventional manner. An inner liner 118 may closely surround the periphery of the substrate support pedestal assembly 148.

[0020] In one embodiment, the substrate support pedestal assembly 148 includes a mounting plate 162, a base 164, and an electrostatic chuck 166. The mounting plate 162 is coupled to the bottom 110 of the chamber body 102 and includes passages for routing utilities such as fluids, power lines, and sensor leads, among others, to the base 164 and the electrostatic chuck 166. The electrostatic chuck 166 includes an electrode 180 (e.g., a clamping electrode) for holding the substrate 103 below the showerhead assembly 130. The electrostatic chuck 166 is powered by a chuck power supply 182 to generate an electrostatic force that grips the substrate 103 against the chuck surface, as is conventionally known. Alternatively, the substrate 103 may be held against the substrate support pedestal assembly 148 by a clamp, vacuum, or gravity.

[0021] The base 164 or electrostatic chuck 166 may include a heater 176, at least one optional embedded insulator 174, and a plurality of conduits 168, 170 to control the lateral temperature profile of the substrate support pedestal assembly 148. The conduits 168, 170 are fluidly coupled to a fluid source 172 that circulates a temperature-regulating fluid through the conduits 168, 170. The heater 176 is regulated by a power supply 178. The conduits 168, 170 and heater 176 are utilized to control the temperature of the base 164, heating and / or cooling the electrostatic chuck 166, and ultimately the temperature profile of the substrate 103 disposed on the electrostatic chuck 166. The temperatures of the electrostatic chuck 166 and base 164 may be monitored using a plurality of temperature sensors 190, 192. The electrostatic chuck 166 may further include a plurality of gas passages (not shown), such as grooves, formed in the substrate support pedestal support surface of the electrostatic chuck 166 and fluidly coupled to a source of heat transfer (or backside) gas, such as helium (He). In operation, the backside gas is provided at a controlled pressure into the gas passages to enhance heat transfer between the electrostatic chuck 166 and the substrate 103. In embodiments, the temperature of the substrate may be maintained at 20° C. to 450° C., such as 100° C. to 300° C., or 150° C. to 250° C.

[0022] In one embodiment, the substrate support pedestal assembly 148 includes an electrode 180 configured as a cathode and coupled to multiple RF bias power supplies 184, 186. The RF bias power supplies 184, 186 are coupled between the electrode 180 disposed within the substrate support pedestal assembly 148 and another electrode, such as the showerhead assembly 130 or the chamber lid 104 of the chamber body 102. The RF bias power excites and sustains a plasma discharge formed from gases disposed within the processing region of the chamber body 102.

[0023] 1 , in some embodiments, the dual RF bias power supplies 184, 186 are coupled to the electrode 180 disposed within the substrate support pedestal assembly 148 through one or more matching networks 188 (one matching network is shown in FIG. 1 ). The matching network 188 is connected to the RF bias power supplies 184, 186 through a 50 Ω transmission line. The RF bias power supplies 184 and 186 may provide power at frequencies between 100 kHz and 200 MHz. In at least some embodiments, transistor-transistor logic (TTL) signals may be provided to the input and output sensors of the matching network 188 directly from the RF bias power supplies 184 and 186 for fast response and short tune times. Signals generated by RF bias power supply 184 and RF bias power supply 186 are delivered by a single feed through a matching network 188 to substrate support pedestal assembly 148 to ionize a gas mixture provided in a plasma processing chamber, such as process chamber 100, thereby providing the ion energy necessary to perform etching, deposition, or other plasma-enhanced processes. RF bias power supply 184 and RF bias power supply 186 are typically capable of producing RF signals having a frequency of about 100 kHz to about 200 MHz (e.g., about 13.56 MHz + / - 5%) and a power of between about 0 watts and about 6000 watts (e.g., about 50 W for low-power operation to about 6000 W for high-power operation), 1 watt (W) to about 100 W, or about 1 W to about 30 W. Bias power 189 may be coupled to electrode 180 to control the characteristics of the plasma.

[0024] During operation, a substrate 103 is disposed on a substrate support pedestal assembly 148 in a plasma processing chamber, such as process chamber 100. Process gases and / or gas mixtures are introduced into the chamber body 102 from a gas panel 158 through a showerhead assembly 130. A vacuum pumping system, such as pumping system 128, maintains pressure inside the chamber body 102 while removing deposition by-products.

[0025] A controller 150 (e.g., a system controller) is coupled to the processing chamber 100 to control its operation. The controller 150 includes a central processing unit 152, a memory 154, and support circuits 156 that are utilized to control process sequences and regulate gas flows from a gas panel 158. The central processing unit 152 may be any type of general-purpose computer processor that may be used in industrial environments. Software routines may be stored in the memory 154, such as random access memory, read-only memory, a floppy or hard disk drive, or other form of digital storage. The support circuits 156 are conventionally coupled to the central processing unit 152 and may include cache, clock circuits, input / output systems, power supplies, and the like. Bidirectional communication between the controller 150 and various components of the processing chamber 100 is handled through numerous signal cables.

[0026] In at least some embodiments, controller 150 communicates via EtherCAT with RF bias power supply 184 and RF bias power supply 186 (and / or bias power 189), the matching network controller, and all components in the matching network, thus providing advanced multi-frequency superimposed plasma etching capabilities, as will be described in more detail below.

[0027] 2 is a block diagram of a matching network 188 configured for use with the processing chamber 100 in accordance with at least some embodiments of the present disclosure. In at least some embodiments, the matching network 188 can be an L-type or a Pi-type matching network.

[0028] Matching network 188 includes a local controller, one or more sensors, and one or more electromotive capacitors, all of which are connected via EtherCAT (illustrated by dashed line 201). EtherCAT is a real-time industrial Ethernet protocol that provides high speed and accurate synchronization during plasma processing due to its short cycle time and low jitter. One or more other interfaces may be used to connect the components of matching network 188 to each other and / or to an RF generator and plasma processing chamber to matching network 188. For example, transmission line 203 (illustrated by a solid line) may be used to connect an RF generator to matching network 188 and the matching network 188 to a plasma processing chamber, for example, to supply RF power to the plasma processing chamber.

[0029] In at least some embodiments, the local controller 200 functions as a local EtherCAT master, and all matching network components, e.g., sensors, electromotive capacitors, are EtherCAT slave devices controlled by the local controller 200. For example, commands sent by the local controller 200 (e.g., an EtherCAT master controller) are passed to all EtherCAT slave devices. A first electromotive capacitor 202 (vacuum capacitor) with an EtherCAT interface may be connected to the local controller 200 and a second electromotive capacitor 204 (vacuum capacitor) with an EtherCAT interface. The first electromotive capacitor 202 may be connected to the second electromotive capacitor 204 in a series or parallel configuration. For example, in the illustrated embodiment, the first electromotive capacitor 202 is connected in parallel with the second electromotive capacitor 204. The first electromotive capacitor 202 and the second electromotive capacitor 204 are electromotive variable capacitors configured to be adjusted during operation. For example, the local controller may be configured to adjust the first electromotive capacitor 202 and the second electromotive capacitor 204 to minimize reflected power during plasma processing.

[0030] The local controller 200 may be connected (directly or indirectly) to a first sensor 206 disposed at the input of the matching network 188 and a second sensor 208 disposed at the output of the matching network 188 for obtaining in-line RF voltage, current, phase, harmonic, and impedance data, respectively. In at least some embodiments, the first sensor 206 and the second sensor 208 may be multi-frequency voltage / current probes. The measured data may be used for automatic impedance tuning, load impedance monitoring, etc.

[0031] In at least some embodiments, interlock circuitry 207 may be connected to and configured with local controller 200 to prevent RF generator failure. For example, interlock circuitry 207 may include fault protection circuitry configured to shut down RF power output from the RF generator when the reflected RF power exceeds a predetermined percentage (e.g., >20%) of the forward power, which is the RF power delivered by the RF generator through matching network 188 to a load, e.g., a plasma in a processing chamber.

[0032] As noted above, the EtherCAT communication interface connects the local controller 200 to the first electromotive capacitor 202, the second electromotive capacitor 204, the first sensor 206, and the second sensor 208. The EtherCAT communication interface directly connects an RF generator (e.g., RF bias power supplies 184, 186 (and / or bias power 189)) to each of the first sensor 206 and the second sensor 208, e.g., for transmitting a TTL signal 205 from the RF generator to each of the first sensor 206 and the second sensor 208 for fast response and short tune time.

[0033] In at least some embodiments, when connected to the RF generator and to the plasma processing chamber, the local controller 200 is configured as an EtherCAT master device that controls and monitors local EtherCAT slave devices, such as sensors and stepper motors. The local controller 200 may also be integrated with an EtherCAT slave controller, such that the local controller 200 acts as an EtherCAT slave device and the controller 150 operates as the EtherCAT master device. That is, the local controller 200 is configured to perform master-to-slave transitions with respect to the controller 150. The tool controller may be implemented on an industrial computer and embedded with the required drivers. In such embodiments, the local controller 200 may receive feedback requests from the controller 150 during plasma processing and provide feedback in response to those feedback requests. For example, the local controller 200 may receive inline RF voltage, current, phase, harmonics, and impedance data acquired via the first sensor 206 and the second sensor 208. The sensor data and variable capacitor position are transmitted to the controller 150 and combined with other system processed data, such as forward and reflected power data from the RF bias power supply 184 and the RF bias power supply 186, which can create coordinated intelligent real-time control during operation.

[0034] Matching network 188 may include at least one of a first network port 210 (e.g., a dual RJ45-type port) configured to connect to controller 150 and a second serial port configured to connect to an external computing device (e.g., a laptop or other suitable computing device) for manual control of matching network 188. For example, in at least some embodiments, controller 150 may connect to first network port 210 of matching network 188 for plasma process control. Local controller 200 may receive in-line RF voltage, current, phase, harmonics, and impedance data obtained via first sensor 206 and second sensor 208. Sensor data and variable capacitor position are transmitted to controller 150 and combined with other system processing data, such as forward and reflected power data from RF bias power supply 184 and RF bias power supply 186, which may create coordinated, intelligent, real-time control during operation. In at least some embodiments, matching network 188 may also include a second serial port 212 configured to connect to a computing device 214 for algorithm uploading and for manual control of the matching network, for example, by using external software and an application programming interface (API). In at least some embodiments, the external software and API may be uploaded, stored in memory 154, accessed by controller 150, and / or in a memory (not shown) of local controller 200. In at least some embodiments, sensor data obtained from first sensor 206 and second sensor 208 may be accessed from computing device 214. Additionally, when connected to second serial port 212, computing device 214 may be configured to control first electromotive capacitor 202 and second electromotive capacitor 204.The provision of the first network port 210 and the second serial port 212 provides the matching network 188 with greater flexibility than prior matching networks. For example, advanced process-related control algorithms can be deployed in real time, and the matching network 188 can operate fully autonomously, in coordination with the controller 150, and / or manually controlled via the computing device 214. If required during processing, the EtherCAT-based distributed RF impedance matching network described herein allows a user using the computing device 214 to have full control over the matching network 188 and the components associated with the matching network 188.

[0035] 3 is a block diagram of a dual frequency matching network 300 according to at least some embodiments of the present disclosure. For example, a dual frequency matching network 300 with an external local controller is illustrated. The dual frequency matching network 300 in FIG. 3 is substantially similar to the matching network 188 in FIG. 2. Therefore, only features unique to the dual frequency matching network 300 in FIG. 3 will be described herein.

[0036] For example, dual-frequency matching network 300 may include two independent matching networks, e.g., matching network 188a and matching network 188b, controlled by external common controller 302. Unlike local controller 200, external common controller 302 in FIG. 3 is located outside of matching network 188a and matching network 188b. External common controller 302 may communicate with controller 150 using either TCP / IP or EtherCAT protocols and ports. External common controller 302 may further be accessed by a computing device (e.g., a laptop) via, for example, one or more of the serial ports described above.

[0037] 3, RF bias power supply 184 and RF bias power supply 186 are connected to matching networks 188a and 188b and are synchronized and controlled by controller 150. In addition, first electromotive capacitors 202 of matching networks 188a and 188b are connected to each other via EtherCAT. Furthermore, interlock circuitry 207 of matching networks 188a and 188b is directly connected to first sensor 206 and the corresponding vacuum variable capacitor stepper motor in the same loop. When a system fault or unexpected condition is detected or predicted from a user-defined model, a safety interlock can be triggered on a sub-millisecond timescale to protect the system.

[0038] 3, the external common controller 302 can provide fast tuning speeds and short response times. Additionally, the controller 150 can enable coordinated intelligent real-time control, improve tuning reliability, and provide system scalability. An additional control port (not shown, e.g., a serial port configured to connect to a computing device) gives the RF matching network improved flexibility for deployment of advanced, process-related tuning algorithms. User-defined tuning algorithms with different control parameters can be loaded for different process conditions.

[0039] Figure 4 is a block diagram of a dual frequency matching network 400 in accordance with at least some embodiments of the present disclosure. The dual frequency matching network 400 in Figure 4 is substantially similar to the dual frequency matching network 300 in Figure 3. Therefore, only the features that are unique to the dual frequency matching network 400 in Figure 4 will be described herein.

[0040] In the embodiment of FIG. 4 , the local controller 200 and the external common controller 302 are not used, and the controller 150 can communicate with both the RF bias power supply 184 and the RF bias power supply 186, as well as all components within the matching networks 188a and 188b. Therefore, advanced multi-frequency superposition plasma etching can be achieved. In addition, a dual even harmonic generator with precise phase locking can be used to manipulate the voltage waveform. For example, the RF bias power supply 184 can have a frequency of approximately 13.56 MHz, while the RF bias power supply 186 can have a frequency of approximately 27.12 MHz. Alternatively, with odd harmonic dual frequencies, the RF bias power supply 184 can have a fundamental frequency of 13.56 MHz, while the RF bias power supply 186 can have an odd frequency of 40.68 MHz. Thus, full-range control of plasma characteristics can be achieved by varying the phase and amplitude of multiple frequencies.

[0041] In standard control mode, motorized vacuum capacitors may be tuned based on sensor readings within the same matchbox enclosure (e.g., matching network enclosure). Alternatively, or in addition, the EtherCAT-based distributed RF impedance matching network described herein enables advanced component regrouping capabilities, where components physically separated within different matchbox enclosures may be virtually regrouped for various process requirements. For example, as shown in FIG. 4, first motorized capacitor 202 and second motorized capacitor 204 are within a first matchbox enclosure (e.g., matching network 188a), while first motorized capacitor 202 and second motorized capacitor 204 are within a second matchbox enclosure (e.g., matching network 188b). The EtherCAT-based distributed RF impedance matching network may regroup the first and second motorized capacitors 202, 204 in the first matchbox enclosure together with the second motorized capacitor 204 in the second matchbox enclosure as a new virtual match that may be tuned based on readings of one or more of the sensors in the first matchbox enclosure (or the second matchbox enclosure). For example, in at least one embodiment, the EtherCAT-based distributed RF impedance matching network may regroup the first and second motorized capacitors 202, 204 in the first matchbox enclosure together with the second motorized capacitor 204 in the second matchbox enclosure as a new virtual match that may be tuned based on readings of the first sensor 206. In at least some embodiments, other regrouping scenarios may also be used (e.g., a first electrically powered capacitor 202 and a second electrically powered capacitor 204 in a second matchbox enclosure together with a first electrically powered capacitor 202 in a first matchbox enclosure).

[0042] Thus, at 502, the method 500 may include processing a substrate in a processing chamber. Then, at 504, the method 500 may include acquiring at least one of in-line RF voltage, current, phase, harmonics, and impedance data from a sensor in a matching network (matchbox enclosure) over an EtherCAT communication interface. Then, at 506, the method 500 may include transmitting at least one of the in-line RF voltage, current, phase, harmonics, and impedance data over the EtherCAT communication interface to at least one of a local controller of the matching network or a system controller of the processing chamber, where at least one of the local controller or the system controller is controllable by a local user and / or a remote user. Next, at 508, the method 500 may include adjusting at least one of the first and second electromotive capacitors disposed in the matching network and, when needed, regrouping the first and second electromotive capacitors in the matching network with another electromotive capacitor disposed in a different matching network (matchbox enclosure) connected to at least one of the local controller or the system controller.

[0043] The matching network described herein can provide full-range control of plasma characteristics (e.g., etch characteristics) by varying the phase and amplitude of the multiple frequencies used by RF bias power supply 184 and RF bias power supply 186; for example, the matching network can seamlessly tune two harmonically related generators. For example, all sensor readings obtained from first sensor 206 and second sensor 208 can be sent over EtherCAT to controller 150 via local controller 200 for advanced correlation tuning, allowing sheath voltage to be customized on sub-millisecond timescales. When more harmonically related generators are used, for example, for complex voltage waveforms, the EtherCAT-based distributed matching network 188 can tune all frequencies simply based on voltage and current sensor readings from first sensor 206 and second sensor 208 at the fundamental frequency.

[0044] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. 1. A matching network configured for use with a plasma processing chamber, comprising: a local controller connectable to a system controller of the plasma processing chamber; a first electromotive capacitor connected to the local controller; a second electromotive capacitor connected to the first electromotive capacitor; a first sensor at the input of the matching network and a second sensor at the output of the matching network for obtaining in-line RF voltage, current, phase, harmonic, and impedance data, respectively; an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting the local controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor; A matching network, including:

2. 10. The matching network of claim 1, further comprising interlock circuitry coupled to the local controller and configured to shut down RF power output from the RF generator when reflected RF power exceeds a predetermined percentage of forward power.

3. 2. The matching network of claim 1, wherein the first electromotive capacitor is connected in parallel with the second electromotive capacitor.

4. The matching network of claim 1 , wherein the matching network is one of an L-type or a π-type.

5. 10. The matching network of claim 1, further comprising at least one of a first serial port configured to connect to the system controller and a second serial port configured to connect to an external computing device for manual control of the matching network.

6. 2. The matching network of claim 1, wherein the EtherCAT communication interface directly connects an RF generator to each of the first sensor and the second sensor for transmitting TTL signals from the RF generator to each of the first sensor and the second sensor.

7. the local controller is an EtherCAT master device, and the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor are EtherCAT slave devices; 7. The matching network of claim 1, wherein when connected, the local controller is configured to perform a master-to-slave conversion such that the system controller is the EtherCAT master device and the local controller is an EtherCAT slave device.

8. an RF generator; a plasma processing chamber including a system controller connected to the RF generator and configured to process a substrate; A matching network, a local controller connectable to the system controller of the plasma processing chamber; a first electromotive capacitor connected to the local controller; a second electromotive capacitor connected to the first electromotive capacitor; a first sensor at the input of the matching network and a second sensor at the output of the matching network for obtaining in-line RF voltage, current, phase, harmonic, and impedance data, respectively; an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting the local controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor; a matching network, including 1. A plasma processing system comprising:

9. 10. The plasma processing system of claim 8, wherein the matching network further comprises interlock circuitry coupled to the local controller and configured to shut down RF power output from the RF generator when reflected RF power exceeds a predetermined percentage of forward power.

10. 9. The plasma processing system of claim 8, wherein the first electromotive capacitor is connected in parallel with the second electromotive capacitor.

11. 9. The plasma processing system of claim 8, wherein the matching network is one of an L-type or a π-type.

12. 10. The plasma processing system of claim 8, further comprising at least one of a first network port configured to connect to the system controller and a second serial port configured to connect to an external computing device for manual control of the matching network.

13. 10. The plasma processing system of claim 8, wherein the EtherCAT communication interface directly connects the RF generator to each of the first sensor and the second sensor for transmitting TTL signals from the RF generator to each of the first sensor and the second sensor.

14. the local controller is an EtherCAT master device, and the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor are EtherCAT slave devices; 14. The plasma processing system of claim 8, wherein when connected, the local controller is configured to perform a master-to-slave conversion such that the system controller is the EtherCAT master device and the local controller is an EtherCAT slave device.

15. a first RF generator and a second RF generator; a plasma processing chamber including a system controller connected to each of the first RF generator and the second RF generator and configured to process a substrate; a first matching network and a second matching network, each comprising: a first electromotive capacitor; a second electromotive capacitor connected to the first electromotive capacitor; a first sensor at an input and a second sensor at an output for acquiring in-line RF voltage, current, phase, harmonic, and impedance data, respectively, wherein the first electromotive capacitor of the first matching network is connected to the first electromotive capacitor of the second matching network; an Ethernet for Control Automation Technology (EtherCAT) communication interface connecting at least one of a local controller or the system controller to the first electromotive capacitor, the second electromotive capacitor, the first sensor, and the second sensor of each of the first matching network and the second matching network; a first matching network and a second matching network, 1. A plasma processing system comprising:

16. 16. The plasma processing system of claim 15, wherein each of the first matching network and the second matching network further comprises interlock circuitry connected to at least one of the local controller or the system controller, the interlock circuitry configured to shut down RF power output from an RF generator when reflected RF power exceeds a predetermined percentage of forward power.

17. 16. The plasma processing system of claim 15, wherein the first electromotive capacitor is connected in parallel with the second electromotive capacitor.

18. 16. The plasma processing system of claim 15, wherein the first matching network and the second matching network are one of an L-type or a π-type.

19. 16. The plasma processing system of claim 15, wherein each of the first matching network and the second matching network further comprises at least one of a first network port configured to connect to the system controller and a second serial port configured to connect to an external computing device for manual control of the first matching network and the second matching network.

20. 20. The plasma processing system of claim 15, wherein the EtherCAT communication interface directly connects the first and second RF generators to each of the first and second sensors for transmitting TTL signals from the first and second RF generators to each of the first and second sensors.

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