Frequency-based impedance adjustment in tuning circuits

Abstract

SOLUTION: A substrate processing system for processing a substrate within a processing chamber includes a matching network, a tuning circuit, and a controller. The matching network receives a first RF signal having a first frequency from a RF generator and impedance matches an input of the matching network to an output of the RF generator. The tuning circuit is distinct from the matching network and includes a circuit component having a first impedance. The tuning circuit receives an output of the matching network and outputs a second RF signal to a first electrode in a substrate support. The controller determines a target impedance for the circuit component, and based on the target impedance, signal the RF generator to adjust the first frequency of the first RF signal received at the matching network to a second frequency to alter the first impedance of the circuit component to match the target impedance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Application No. 62 / 935,976, filed on November 15, 2019. The entire disclosure of the application referenced above is incorporated herein by reference.

[0002] The present disclosure relates to an electrostatic holding device using electrostatic attraction, and more particularly, to a clamping electrode of an electrostatic holding device and a tuning circuit for a radio frequency (RF) electrode.

Background Art

[0003] The background description provided herein is for the purpose of generally presenting the content of the present disclosure. Within the scope described in this background art section, research by the inventors named at the present time, as well as aspects of the description that cannot be separately regarded as prior art at the time of filing, are not recognized as prior art against the present disclosure, whether explicitly or implicitly.

[0004] A substrate processing system can be used to perform etching, deposition, and / or other processing of a substrate such as a semiconductor wafer. Exemplary processes that can be performed on a substrate include, but are not limited to, plasma enhanced chemical vapor deposition (PECVD) processes, physical vapor deposition (PVD) processes, ion implantation processes, and / or other etching, deposition, and cleaning processes. As an example, during an etching process, the substrate can be placed on an electrostatic chuck (ESC) within the substrate processing system, and a thin film on the substrate is etched.

Summary of the Invention

[0005] A substrate processing system for processing a substrate within a processing chamber is provided. The substrate processing system includes a matching network, a first tuning circuit, and a controller. The matching network receives a first radio frequency signal having a first frequency from a radio frequency generator and is configured to impedance match the input of the matching network to the output of the radio frequency generator. The first tuning circuit, which is different from the matching network, includes a first circuit component having a first impedance. The first tuning circuit receives the output of the matching network and is configured to output a second radio frequency signal to a first electrode on a substrate support. The controller determines a target impedance for the first circuit component and, based on the target impedance, sends a signal to the radio frequency generator to adjust the first frequency of the first radio frequency signal received by the matching network to a second frequency and change the first impedance of the first circuit component to match the target impedance.

[0006] In another aspect, the substrate processing system further includes a radio frequency generator configured to generate a first radio frequency signal having a first frequency based on a control signal and having a center frequency. The controller is configured to generate the control signal. The first frequency is within a predetermined range of the center frequency.

[0007] In another aspect, the matching network provides the first radio frequency signal to the first tuning circuit without changing the first frequency of the first radio frequency signal.

[0008] In another aspect, the controller is configured to adjust the first frequency to a second frequency independent of impedance matching the input of the matching network to the output of the radio frequency generator.

[0009] In another aspect, the controller is configured to adjust the first frequency to a second frequency without affecting the impedance matching between the matching network and the radio frequency generator.

[0010] In other features, the matching network is configured to maintain impedance matching between the input of the matching network and the output of the radio frequency generator while the controller adjusts the first frequency to the second frequency.

[0011] In other features, the first tuning circuit includes a first circuit component and a second circuit component. The first circuit component is connected to the first electrode. The second circuit component is connected to the second electrode on the substrate support. The controller is configured to adjust the first frequency to the second frequency to adjust the first impedance of the first circuit component and the second impedance of the second circuit component, and change the power distribution from the first tuning circuit to the first electrode and the second electrode.

[0012] In other features, the frequency of the second radio frequency signal is the same as the frequency of the first radio frequency signal.

[0013] In other features, when the controller adjusts the first impedance to match the target impedance, in addition to adjusting the first frequency to the second frequency, the controller is configured to adjust the capacitance or inductance of the first circuit component.

[0014] In other features, the controller is configured to maintain at least one of the capacitance or inductance of the first circuit component at a fixed value while adjusting the first impedance.

[0015] In other features, the first tuning circuit distributes the total power received from the matching network to the first circuit component and the second circuit component. The controller is configured to adjust the first frequency to the second frequency and adjust the first portion of the total power provided to the first circuit component and the second portion of the total power provided to the second circuit component.

[0016] In other features, the substrate processing system further includes a source terminal and a substrate support including a first electrode and a second electrode. The first electrode and the second electrode receive power from a matching network via the source terminal. The first tuning circuit is a first impedance set connected in series between the first electrode and the matching network, where the first impedance set is the first impedance set that receives a second radio frequency signal from the matching network via the source terminal, or a second impedance set connected between the output of the matching network and a reference terminal, where the second impedance set includes at least one of the second impedance sets that receives a second radio frequency signal from the matching network via the source terminal.

[0017] In other features, the first tuning circuit includes a first impedance set and a second impedance set.

[0018] In other features, the substrate processing system further includes a second tuning circuit, a third tuning circuit, and a third electrode. The first tuning circuit is connected to the first electrode to modify the output of the matching network and generate a second radio frequency signal. The second tuning circuit is connected to the second electrode and is configured to modify the output of the matching network to generate a third radio frequency signal provided to the second electrode. The third tuning circuit is connected to the third electrode and is configured to modify the output of the matching network to generate a fourth radio frequency signal provided to the third electrode.

[0019] In other features, the substrate support is an electrostatic chuck. The first electrode and the second electrode are clamp electrodes configured to receive a clamp voltage to clamp the substrate to the substrate support. The third electrode is a bias electrode configured to receive a bias voltage.

[0020] In other features, the substrate support is an electrostatic chuck. The first electrode is a clamp electrode. The second electrode and the third electrode are bias electrodes.

[0021] In other features, a matching network is not connected between (i) the source terminal and (ii) the first and second electrodes.

[0022] In other features, the first circuit component is connected to the first and second electrodes on the substrate support and affects the power distribution to the first and second electrodes.

[0023] In other features, a method of operating a substrate processing system is provided. The method includes selecting a process, determining a recipe including system operation parameters for the selected process, determining a first target impedance value for the frequency of the radio frequency generator and the impedance of the tuning circuit based on the selected process and system operation parameters, sending a signal to the radio frequency generator to generate a first radio frequency signal, impedance matching the output of the radio frequency generator via a matching network, the matching network being different from the tuning circuit, tuning the signal output of the matching network via the tuning circuit to generate a second radio frequency signal, providing the second radio frequency signal to the first electrode on the substrate support, and adjusting the first frequency of the first radio frequency signal to a second frequency to adjust the impedance of the tuning circuit to match the first target impedance value.

[0024] In other features, the method further includes adjusting the first frequency to the second frequency regardless of impedance matching the input of the matching network to the output of the radio frequency generator.

[0025] In other features, the method further includes adjusting the first frequency to the second frequency without affecting the impedance matching between the matching network and the radio frequency generator.

[0026] In another aspect, the method further includes maintaining impedance matching between the input of the matching network and the output of the radio frequency generator via the matching network while adjusting the first frequency to the second frequency.

[0027] In another aspect, the method further includes collecting sensor output data, determining a second target impedance value based on the sensor output data, and adjusting the impedance of the tuning circuit by adjusting the first frequency to a third frequency to match the second impedance value.

[0028] In another aspect, the method further includes adjusting at least one of the capacitance or inductance of the impedance to match the impedance to a first target impedance value.

[0029] In another aspect, the method further includes adjusting the impedance by adjusting the first frequency to the second frequency without adjusting the capacitance of the impedance to match the impedance to a first impedance value.

[0030] In another aspect, the method further includes adjusting the impedance by adjusting the first frequency to the second frequency without adjusting the inductance of the impedance to match the impedance to a first impedance value.

[0031] In another aspect, the impedance is connected in parallel to a first electrode and a second electrode on a substrate support and affects the power distribution to the first electrode and the second electrode.

[0032] In other features, the method further includes placing a substrate on a substrate support in a processing chamber and performing a processing operation for a selected process, including providing power from a matching network to a first electrode and a second electrode on the substrate support. The tuning circuit is a first impedance set connected in series between the first electrode and the matching network, where the first impedance set is the first impedance set that receives a second radio frequency signal from the matching network, or a second impedance set connected between the output of the matching network and a reference terminal, where the second impedance set includes at least one of the second impedance sets that receive a second radio frequency signal from the matching network.

[0033] In other features, the method further includes, while performing the processing operation, (i) adjusting a first frequency to a second frequency and (ii) adjusting at least one of the capacitance or inductance of the first impedance set or the second impedance set.

[0034] In other features, the method further includes collecting sensor output data while performing the processing operation, determining one or more parameters based on the sensor output data, and adjusting the impedance value of the first impedance set or the second impedance set based on the one or more parameters.

[0035] In other features, the method further includes determining a feature or characteristic of the processing chamber and setting the impedance value of the first impedance set or the second impedance set based on the feature or characteristic.

[0036] In other features, the method further includes determining a feature or characteristic of the substrate support and setting the impedance value of the first impedance set or the second impedance set based on the feature or characteristic.

[0037] In another aspect, the method further includes adjusting at least one impedance of the first impedance set or the second impedance set to follow respective trajectories based on the change in characteristics.

[0038] In another aspect, the method further includes calculating or determining a trajectory based on at least one of a feature; a characteristic; one or more other features of a substrate, a substrate support, or a processing chamber; and one or more other characteristics of a substrate, a substrate support, or a processing chamber.

[0039] In another aspect, the method further includes determining a feature or characteristic of a substrate and setting an impedance value of a tuning circuit based on the feature or characteristic.

[0040] In another aspect, the method further includes supplying a clamp voltage to a first electrode via a matching network to clamp the substrate to a substrate support, supplying a bias voltage to a second electrode, and tuning the clamp voltage and the bias voltage via a tuning circuit or another tuning circuit. The substrate support is an electrostatic chuck.

[0041] In another aspect, a substrate processing system is provided that includes a matching network, a tuning circuit, and a controller. The matching network receives a first radio frequency signal having a first frequency from a radio frequency generator and is configured to impedance match an input of the matching network to an output of the radio frequency generator. The tuning circuit is different from the matching network and is configured to output a second radio frequency signal to a first electrode in a substrate support and output a third radio frequency signal to a second electrode in the substrate support based on an output of the matching network. The controller is configured to send a signal to the radio frequency generator and adjust the power distribution to the first and second electrodes in the substrate support by adjusting the first frequency of the first radio frequency signal received by the matching network to a second frequency.

[0042] In another feature, the matching network provides the first radio frequency signal to the tuning circuit without changing the first frequency of the first radio frequency signal.

[0043] In another feature, the controller is configured to adjust the first frequency to a second frequency regardless of impedance matching the input of the matching network to the output of the radio frequency generator.

[0044] In another feature, the controller is configured to adjust the first frequency to a second frequency without affecting the impedance matching between the matching network and the radio frequency generator.

[0045] In another feature, the matching network is configured to maintain impedance matching between the input of the matching network and the output of the radio frequency generator while the controller adjusts the first frequency to the second frequency.

[0046] In another feature, the tuning circuit includes a first circuit component and a second circuit component. The first circuit component is connected to a first electrode. The second circuit component is connected to a second electrode, and when the first frequency is adjusted to the second frequency, the first impedance of the first circuit component and the second impedance of the second circuit component are changed.

[0047] In another feature, the tuning circuit supplies a total amount of power to the first electrode and the second electrode. When the first frequency is adjusted to the second frequency, the first impedance and the second impedance are adjusted, thereby adjusting a first percentage of the total amount of power supplied to the first electrode and a second percentage of the total amount of power supplied to the second electrode.

[0048] In another feature, the controller is configured to adjust the capacitance or inductance of the first circuit component while adjusting the first frequency to the second frequency.

[0049] In another aspect, the controller is configured to maintain at least one of the capacitance or inductance of the first circuit component at a fixed value while adjusting the first frequency to the second frequency.

[0050] Other fields to which the present disclosure is applicable will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

Brief Description of the Drawings

[0051] The present disclosure will be more fully understood from the detailed description and the accompanying drawings.

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[0065] In these drawings, reference numerals may be reused to refer to similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0066] In a capacitively coupled plasma (CCP) system, an RF voltage signal can be supplied to a showerhead and / or a substrate support (e.g., an electrostatic chuck or pedestal) within a processing chamber to generate and maintain a plasma (e.g., a plasma provided during an etching or deposition process) during substrate processing. By way of example, the substrate support can include a plurality of electrodes for receiving an RF voltage. The electrodes may have different sizes and shapes and may be located at different locations within the substrate support.

[0067] The examples described herein include (i) a frequency controller for setting and adjusting the RF generator frequency, and (ii) a tuning circuit for controlling the RF voltage supplied to the electrodes of the substrate support. The tuning circuit is different from the matching network connected between the RF generator and the tuning circuit. Specifically, the tuning circuit is not included in the matching network and is separated from the matching network. The frequency controller adjusts the RF generator frequency and adjusts the power distribution within and throughout the substrate support. The RF generator frequency is adjusted independent of impedance matching and / or minimization of reflected power. The frequency controller adjusts the frequency to effectively adjust the impedance of the tuning circuit, which affects power distribution and on-wafer processing. The disclosed frequency adjustment can be implemented without directly changing the variable capacitance and inductance of the circuit components included in the tuning circuit, or can be implemented in addition to directly adjusting the capacitance and inductance of the circuit components. In one embodiment, the change in the RF generator frequency is within a predefined frequency range where impedance mismatch does not occur between the RF generator and the matching network. In another embodiment, the change in the RF generator frequency exists over an operating frequency range that may cause one or more impedance mismatches between the RF generator and the matching network. In this latter embodiment, the matching network is configured to actively maintain impedance matching over the operating frequency range of the RF generator.

[0068] Adjusting the RF generator frequency to adjust the impedance of the tuning circuit and change the power distribution in the substrate support is different from adjusting the frequency of the RF generator for the purpose of impedance matching. The RF generator frequency can be adjusted to change the impedance of the matching network and match the impedance of the output of the RF generator. This is done without changing the power distribution in the substrate support and / or wafer uniformity. In contrast, the adjustment of the RF generator frequency for adjusting power distribution and on-wafer processing can be implemented to provide or change wafer uniformity.

[0069] The tuning circuit includes variable and / or fixed impedances that can be tuned for the substrate processing being performed. The RF voltage and corresponding current supplied to the electrodes can be controlled to change the mode of the generated plasma. During processing, the substrate is placed on a substrate support, and one or more layers of the substrate (e.g., film layers) can be, for example, etched or deposited. By adjusting the RF voltages supplied to different electrodes, the parameters of one or more layers can be spatially varied and / or tuned across the wafer according to the location of the electrodes. As an example, the parameters of one or more layers can include uniformity values, stress values, refractive indices, etching rates, deposition rates, thickness values, and / or other intrinsic property values that are measured quantities.

[0070] RF power is disclosed as being provided from one or more RF power sources. In one embodiment, the RF power is provided by supplying RF power from a single RF power source to a common node. The RF power is then supplied from the common node to different electrodes of the substrate support via respective paths. The paths include tuning circuits and / or impedances that change the corresponding RF voltage, current level, phase, and / or frequency components. The impedance can include impedances connected in series or shunt. Other embodiments including multiple power sources, multiple nodes, and various paths are disclosed herein.

[0071] The RF voltage and current levels provided to the electrodes in the substrate support can also be changed by adjusting the size, shape, and pattern of the electrodes. For example, the RF voltage provided to the plasma from annular and / or circular electrodes, the substrate processing performed using annular and / or circular electrodes, and / or the resulting substrate characteristics can be varied and / or tuned by changing the radius of the electrodes.

[0072] A substrate processing system can have a plurality of features, characteristics, and / or parameters that provide degrees of freedom and can be set and / or adjusted to control the manner in which layers of a substrate result during substrate processing. For example, the RF power level, chamber shape, use of a focusing ring, pattern of holes in a showerhead, shape of the showerhead, electrode pattern, gas pressure, gas composition, etc. can be set and / or controlled to provide a configuration and profile of a target layer to the resulting substrate.

[0073] The disclosed examples provide another degree of freedom for tuning the profile of one or more layers of a substrate. The degree of freedom is provided by setting and / or adjusting the impedance of a tuning circuit (e.g., selection, change, and / or control of capacitance, inductance, reactance, resistance, layout, etc.). The profile refers to the above-described parameters of one or more layers.

[0074] The radial profile of a substrate can be changed, for example, by varying a metallic or dielectric annular element near the circumferential edge of the substrate. This can include adjusting parameters such as gas pressure, gas flow rate, gas composition, RF discharge power, frequency of the RF signal provided to the electrode of the substrate support, and / or other parameters. Varying these parameters at specific locations to provide features of the target layer (e.g., thickness or shape of a particular layer at the circumferential edge) can change other parameters and / or affect other features at the same location and / or other locations. Thus, these parameters do not independently adjust specific features. As another example, the circumferential edge of a substrate can be changed by using a focusing ring located outside the circumferential edge of the substrate. However, the use of a focusing ring can affect the gas flow rate at the center of the substrate, which can affect the process and thus the results at the center of the substrate. Other exemplary layer features are the depth or width of a particular trench, distance between trenches, distance between conductive elements, composition of the layer, etc.

[0075] The greater the number of parameters and degrees of freedom in setting and controlling the profiling of one or more layers of a substrate, the higher the likelihood of being able to provide specific features without adversely affecting other features. Also, as the number of parameters and degrees of freedom increases, the number, configuration, and layout (or pattern) of features that can be formed increase. The examples disclosed herein enhance the flexibility of substrate layer design and the selectivity of location-specific design, enabling the substrate processing system to provide a diverse set of features.

[0076] FIG. 1 shows a substrate processing system 100 incorporating an ESC (or substrate support) 101. The ESC refers to a substrate support including a clamp electrode to which a voltage is applied, and generates an attractive force for clamping the substrate to the ESC. The ESC 101 can be configured the same as or similar to any of the ESCs disclosed herein. Although FIG. 1 shows a capacitively coupled plasma (CCP) system, the embodiments disclosed herein are applicable to transformer coupled plasma (TCP) systems, electron cyclotron resonance (ECR) plasma systems, inductively coupled plasma (ICP) systems, and / or other systems, as well as plasma sources including a substrate support. The embodiments are applicable to physical vapor deposition (PVD) processes, plasma enhanced chemical vapor deposition (PECVD) processes, chemically enhanced plasma vapor deposition (CEPVD) processes, ion implantation processes, plasma etching processes, and / or other etching, deposition, and cleaning processes.

[0077] The ESC 101 can include a top plate 102 and a base plate 103. Although the ESC 101 is shown as having two plates, the ESC 101 may include a single plate. The plates 102, 103 can be formed of ceramic and / or other materials. Each of the ESCs in FIGS. 1-5 and 7-11 is shown as having certain features and not having other features, but each of the ESCs may be modified to include any of the features disclosed herein as well as in FIGS. 1-5 and 7-11.

[0078] Although the ESC 101 is shown as being attached to the bottom of the processing chamber and not configured to rotate, the ESC 101 and other ESCs disclosed herein may be configured as a spin chuck that is attached to the bottom or top of the processing chamber and rotated during substrate processing. When attached to the top of the processing chamber, the ESC 101 may have a configuration similar to that disclosed herein, but be inverted upside down and may include peripheral substrate holding, clamping, and / or clasping hardware.

[0079] The substrate processing system 100 includes a processing chamber 104. The ESC 101 is surrounded within the processing chamber 104. The processing chamber 104 also surrounds other components such as the upper electrode 105 and includes RF plasma. During operation, the substrate 107 is placed on the top plate 102 of the ESC 101 and electrostatically clamped.

[0080] As an example only, the upper electrode 105 can include a showerhead 109 for introducing and distributing gas. The showerhead 109 can include a stem portion 111 that includes one end connected to the upper surface of the processing chamber 104. The showerhead 109 is generally cylindrical and extends radially outward from the opposite end of the stem portion 111 at a location spaced from the upper surface of the processing chamber 104. The surface facing the substrate or the showerhead 109 includes holes through which process gas or purge gas flows. Alternatively, the upper electrode 105 may include a conductive plate and the gas may be introduced in another manner. One or both of the plates 102, 103 can function as a lower electrode.

[0081] One or both of plates 102 and 103 may include a temperature control element (TCE). As an example, FIG. 1 shows a top plate 102 that includes a TCE 110 and is used as a heating plate. An intermediate layer 114 is disposed between plates 102 and 103. The intermediate layer 114 can couple the top plate 102 to the base plate 103. As an example, the intermediate layer can be formed of an adhesive material suitable for coupling the top plate 102 to the base plate 103. The base plate 103 may include one or more gas channels 115 and / or one or more coolant channels 116 for flowing backside gas to the back side of the substrate 107 and for flowing coolant through the base plate 103.

[0082] The RF generation system 120 generates an RF voltage and outputs it to the upper electrode 105 and the lower electrode (e.g., one or more of plates 102 and 103). One of the upper electrode 105 and the ESC 101 can be DC grounded, AC grounded, or at a floating potential. As a mere example, the RF generation system 120 may be controlled by a system controller 121 and include one or more RF generators 122 (e.g., capacitively coupled plasma RF power generators, bias power generators, and / or other RF power generators) that generate an RF voltage, and the RF voltage is supplied to the upper electrode 105 and / or the ESC 101 by one or more matching and distribution networks 124. The system controller 121 includes a frequency controller 119 that sets and adjusts the frequency of the RF signals output from the RF generators 123, 125. The frequency can be adjusted to adjust the power distribution within and throughout the ESC 101.

[0083] As an example, a first RF generator 123, a second RF generator 125, a first RF matching network 127, and a second RF matching network 129 are shown. The first RF generator 123 and the first RF matching network 127 can either provide an RF voltage or simply connect the showerhead 109 to a ground reference. The second RF generator 125 and the second RF matching network 129, each or collectively referred to as a power supply, can provide an RF / bias voltage to the ESC 101. In one embodiment, the first RF generator 123 and the first RF matching network 127 provide power to ionize gas and drive the plasma. In another embodiment, the second RF generator 125 and the second RF matching network 129 provide power to ionize gas and drive the plasma. One of the RF generators 123, 125 can be a high-power RF generator that generates power of, for example, 6 to 10 kilowatts (kW) or more.

[0084] The second RF matching network 129 provides impedance matching such that the input of the second impedance matching network 129 matches the output impedance of the second RF generator 125. The second RF matching network 129 can (i) maintain the fixed capacitance and inductance values of the circuit components (e.g., capacitors and inductors) of the second RF matching network 129 that provide impedance matching over the operating frequency range of the RF generator 125, or (ii) adjust the capacitance and / or inductance values of the impedance 128 of the matching network 129 to maintain impedance matching over the operating frequency range of the RF generator 125. This is done to minimize the reflected power returning to the RF generator 125. The second impedance matching network 129 provides impedance matching independent of the frequency of the RF signal output from the second RF generator 125. The second RF matching network 129 includes impedances (e.g., capacitors and inductors) 128 that supply power to RF electrodes such as RF electrodes 131, 133 within plates 102, 103. The RF electrodes can be located on one or both of the plates 102, 103. The RF electrodes can be located, for example, near the upper surface of the ESC 101 when used as clamp electrodes and / or at other locations on the ESC 101 when used for RF biasing purposes. A portion of the electrode may be used as both a clamp electrode and an RF biasing electrode.

[0085] The RF electrode can receive power from other power sources. By way of example, a portion of the RF electrode can receive power from the power supply 135 instead of, or in addition to, receiving power from the second RF matching network 129. In one embodiment, the power supply 135 does not include a matching network and / or the matching network is not disposed between the power supply 135 and the RF electrode. A portion of the RF electrode can receive power from the second RF matching network 129 and / or the power supply 135 and can electrostatically clamp the substrate to the top plate 102. The power supply 135 can be controlled by the system controller 121. The tuning circuit 139 can be connected (i) between the second RF matching network 129 and the corresponding electrodes 131, 133, 137 and (ii) between the power supply 135 and the corresponding electrodes 131, 133, 137. In one embodiment, the tuning circuit 139 is disposed outside the processing chamber 104 downstream and separated from the second RF matching network 129. Examples of the tuning circuit 139 are shown in FIGS. 2-11.

[0086] The gas delivery system 130 includes one or more gas sources 132-1, 132-2, …, and 132-N (collectively gas sources 132), where N is an integer greater than zero. The gas sources 132 supply one or more precursors and their gas mixtures. The gas sources 132 can also supply etching gases, carrier gases, and / or purge gases. Vaporized precursors may also be used. The gas sources 132 are connected to the manifold 140 by valves 134-1, 134-2, …, and 134-N (collectively valves 134), and mass flow controllers 136-1, 136-2, …, and 136-N (collectively mass flow controllers 136). The output of the manifold 140 is supplied to the processing chamber 104. By way of example only, the output of the manifold 140 is supplied to the showerhead 109.

[0087] The substrate processing system 100 further includes a cooling system 141 that includes a temperature controller 142 that can be connected to the TCE 110. In one embodiment, the TCE 110 is not included. Although shown separately from the system controller 121, the temperature controller 142 may be implemented as part of the system controller 121. One or more of the plates 102, 103 may include a plurality of temperature control zones (e.g., four zones each including four temperature sensors).

[0088] The temperature controller 142 controls the operation of the TCE 110, and thus the temperature, and can control the temperatures of the plates 102, 103 and the substrate (e.g., substrate 107). The temperature controller 142 and / or the system controller 121 can control the flow rate of the backside gas (e.g., helium) to the gas channel 115 for cooling the substrate by controlling the flow from one or more of the gas sources 132 to the gas channel 115. The temperature controller 142 also communicates with the coolant assembly 146 and can control the flow of the first coolant (the pressure and flow rate of the cooling fluid) through the channel 116. The first coolant assembly 146 can receive the cooling fluid from a reservoir (not shown). For example, the coolant assembly 146 can include a coolant pump and a reservoir. The temperature controller 142 operates the coolant assembly 146 to flow the coolant through the channel 116 to cool the base plate 103. The temperature controller 142 can control the rate at which the coolant flows and the temperature of the coolant. The temperature controller 142 controls the current supplied to the TCE 110, as well as the pressure and flow rate of the gas and / or coolant supplied to the channels 115, 116, based on parameters detected by the sensors 143, 144 within the processing chamber 104. The sensors 143, 144 can include resistive temperature devices, thermocouples, digital temperature sensors, temperature probes, and / or other suitable temperature sensors. The sensors 143, 144 and / or other sensors included in the substrate processing system 100 can be used to detect parameters such as temperature, gas pressure, voltage, current level, etc. During the etching process, the substrate 107 can be heated to a predetermined temperature (e.g., 120 degrees Celsius (°C)) in the presence of a high-power plasma. The flow of gas and / or coolant through the channels 115, 116 reduces the temperature of the base plate 103, thereby reducing the temperature of the substrate 107 (e.g., cooling from 120 °C to 80 °C).

[0089] The valve 156 and the pump 158 can be used to discharge reactants from the processing chamber 104. The system controller 121 can control the components of the substrate processing system 100, including controlling the supplied RF power level, the pressure and flow rate of the supplied gas, RF matching, etc. The system controller 121 controls the states of the valve 156 and the pump 158. The robot 170 can be used to feed a substrate onto the ESC 101 and remove the substrate from the ESC 101. For example, the robot 170 can transfer the substrate between the ESC 101 and the load lock 172. The robot 170 can be controlled by the system controller 121. The system controller 121 can control the operation of the load lock 172.

[0090] Valves, gas and / or coolant pumps, power supplies, RF generators, etc. may be referred to as actuators. TCEs, gas channels, coolant channels, etc. may be referred to as temperature adjustment elements.

[0091] The system controller 121 can control the impedance state of the tuning circuit 139 directly by adjusting the variable capacitance and / or inductance of the circuit components of the tuning circuit 139, or indirectly via the frequency controller 119. The frequency controller 119 can control and / or instruct the RF generator 125 to output an RF signal having a frequency determined to adjust the impedance of the tuning circuit 139. Alternatively, or in addition to the described frequency adjustment, the system controller 121 can directly adjust the impedance of the tuning circuit 139 by sending a signal to the tuning circuit 139 and adjusting the capacitance and / or inductance values of the capacitors and inductors of the tuning circuit 139. Examples of capacitors and inductors are shown in FIGS. 7-11. The impedance of the tuning circuit 139 can be adjusted based on feedback signals received from one or more of the sensors 143, 144, 145, and / or other sensors within the ESC 101, the processing chamber 104, the second RF matching network 129, and / or the power supplies 125, 135. The sensor 145 can detect the voltage, current level, and power level in the second RF matching network 129. The sensor 144 is shown on the base plate 103, but one or more of the sensors may be located on the top plate 102. The sensor 144 can be located anywhere within the ESC 101. The sensor 143 can be located anywhere within the processing chamber 104.

[0092] The system controller 121 can also control the state of the impedance 128. The state of the impedance 128 can be set such that one or more impedances of one or more outputs of the second RF matching network 129 match the impedance seen at the input of the tuning circuit 139. The impedance seen at the input of the tuning circuit 139 is based on the impedance of the ESC 101 and the tuning circuit 139. When adjusting the impedance of the tuning circuit 139, the system controller 121 can also adjust the impedance of the second RF matching network 129 accordingly.

[0093] In FIGS. 2-11 described below, a specific number of tuning circuits, impedances, clamp electrodes, RF electrodes, and / or other elements are shown, but any number can be included. Also, the tuning circuits, impedances, clamp electrodes, and RF electrodes are shown in a specific arrangement and have a specific size, shape, and pattern, but the described elements may have different arrangements and different sizes, shapes, and patterns.

[0094] FIG. 2 shows a capacitive coupling circuit 200 including a clamp tuning circuit 202, an RF tuning circuit 204, a clamp electrode 206, and an RF electrode 208. The impedance of the elements (e.g., capacitors and / or inductors) of the tuning circuits 202, 204 can be frequency-dependent. A cross-sectional view of the showerhead (or upper electrode) 210 and the ESC 212 is shown. The showerhead 210 can be connected to a reference potential or ground 214. In one embodiment, the showerhead 210 is RF powered by the first RF matching network 127 of FIG. 1. Plasma 216 is provided between the showerhead 210 and the ESC 212. The substrate 218 is disposed on the ESC 212.

[0095] The clamp tuning circuit 202 can be used to control the clamp voltage, current level, phase, power level, and / or frequency provided to the clamp electrode 206. The RF tuning circuit 204 may be used to control the bias voltage, current level, power level, and / or frequency provided to the RF electrode 208. The tuning circuits 202, 204 receive power P inner , P outer from, for example, the second RF matching network 129 (or the first power supply) and / or the power supply 135 (or the second power supply) of FIG. 1 and can be used to adjust the voltage drop across the entire plasma. This may include adjusting the voltage difference between each pair of points on and across the surface of the ESC 101 of FIG. 1. Examples of the tuning circuits 202, 204 are shown in FIG. 6. The tuning circuits 202, 204 may include one or more of the impedances as shown in FIG. 6. The tuning circuits 202, 204 may not include a parallel impedance path or may include a transmission line instead of a series impedance path. Exemplary parallel and series impedance paths are shown in FIG. 6. Examples of the impedances that may be included in the tuning circuits 202, 204 are shown in FIGS. 7-11. The impedances are connected in series or in parallel, are shunt impedances, and / or may include capacitors, inductors, resistors, reactances, transmission lines, short circuits or open circuits, filtering elements (or filters) and / or other impedances. By way of example, the clamp electrode 206 may be circular and the RF electrode 208 may be annular.

[0096] FIG. 3 shows a capacitive coupling circuit 300 including a first clamp tuning circuit 302, a second clamp tuning circuit 303, an external RF tuning circuit 304, a first clamp electrode 306, a second clamp electrode 307, and an RF electrode 308. The impedance of the elements (e.g., capacitors and / or inductors) of the tuning circuits 302, 303, 304 may depend on the frequency. A cross-sectional view of the showerhead (or upper electrode) 310 and the ESC 312 is shown. The showerhead 310 can be connected to a reference potential or ground 314. In one embodiment, the showerhead 310 is RF powered by the first RF matching network 127 of FIG. 1. A plasma 316 is provided between the showerhead 310 and the ESC 312. The substrate 318 is disposed on the ESC 312.

[0097] The clamp tuning circuits 302, 303 can be used to control the clamp voltage, current level, power level, and / or frequency provided to the clamp electrodes 306, 307. The RF tuning circuit 304 may be used to control the bias voltage, current level, power level, and / or frequency provided to the RF electrode 308. The tuning circuits 302, 303, and 304 can receive power P clamp1 , P clamp2 , and P outer from, for example, the second RF matching network 129 (or the first power supply) of FIG. 1, the power supply 135 (or the second power supply) of FIG. 1, and / or one or more other power supplies. The tuning circuits 302, 303, 304 can be used to adjust the voltage drop across the entire plasma. In one embodiment, P clamp1 is P clamp2is equal to. Examples of the tuning circuits 302, 303, 304 are shown in FIG. 6. The tuning circuits 302, 303, 304 may include one or more of the impedances as shown in FIG. 6. The tuning circuits 302, 303, 304 may not include a parallel impedance path, or may include a transmission line instead of a series impedance path. Examples of the impedances that may be included in the tuning circuits 302, 303, 304 are shown in FIGS. 7 to 11. The impedances are connected in series or in parallel, are shunt impedances, and / or may include capacitors, inductors, resistors, reactances, transmission lines, short circuits or open circuits, filtering elements and / or other impedances. By way of example, the clamp electrodes 306, 307 may be circular and the RF electrode 308 may be annular.

[0098] FIG. 4 shows a capacitive coupling circuit 400 including a clamp tuning circuit 402, an internal RF tuning circuit 404, an external RF tuning circuit 405, a clamp electrode 406, an internal bias electrode 408, and an external bias electrode 409. The impedances of the elements (e.g., capacitors and / or inductors) of the tuning circuits 402, 404, 405 may be frequency dependent. A cross-sectional view of the showerhead (or upper electrode) 410 and the ESC 412 is shown. The showerhead 410 can be connected to a reference potential or ground 414. In one embodiment, the showerhead 410 is RF powered by the first RF matching network 127 of FIG. 1. Plasma 416 is provided between the showerhead 410 and the ESC 412. The substrate 418 is disposed on the ESC 412.

[0099] The clamp tuning circuit 402 can be used to control the clamp voltage, current level, phase, power level, and / or frequency provided to the clamp electrode 406. The RF tuning circuits 404, 405 may be used to control the bias voltage, current level, power level, and / or frequency provided to the bias electrodes 408, 409. The tuning circuits 402, 404, 405 can receive power P clamp , P inner , P outer from, for example, the second RF matching network 129 (or the first power supply) of FIG. 1, the power supply 135 (or the second power supply) of FIG. 1, and / or one or more other power supplies. The tuning circuits 402, 404, 405 can be used to adjust the voltage drop across the entire plasma. Examples of the tuning circuits 402, 404, 405 are shown in FIG. 6. The tuning circuits 402, 404, 405 can include one or more of the impedances as shown in FIG. 6. The tuning circuits 402, 404, 405 may not include a parallel impedance path, or may include a transmission line instead of a series impedance path. Examples of the impedances that can be included in the tuning circuits 402, 404, 405 are shown in FIGS. 7-11. The impedances are connected in series or in parallel, are shunt impedances, and / or may include capacitors, inductors, resistors, reactances, transmission lines, short circuits or open circuits, filtering elements and / or other impedances. By way of example, the clamp electrode 406 and the internal bias electrode 408 can be circular, and the external bias electrode 409 can be annular.

[0100] FIG. 5 shows a capacitive coupling circuit 500 including a clamp tuning circuit 502, a first internal RF tuning circuit 504, a second internal tuning circuit 505, an external RF tuning circuit 506, a clamp electrode 507, a first internal bias electrode 508, a second internal bias electrode 509, and an external bias electrode 510. The impedance of the elements (e.g., capacitors and / or inductors) of the tuning circuits 502, 504, 505, 506 may depend on the frequency. A cross-sectional view of a showerhead (or upper electrode) 511 and an ESC 512 is shown. The showerhead 511 can be connected to a reference potential or ground 514. In one embodiment, the showerhead 511 is RF powered by the first RF matching network 127 of FIG. 1. A plasma 516 is provided between the showerhead 511 and the ESC 512. The substrate 518 is disposed on the ESC 512.

[0101] The clamp tuning circuit 502 can be used to control the clamp voltage, current level, power level, and / or frequency provided to the clamp electrode 507. The RF tuning circuits 504, 505, 506 may be used to control the bias voltage, current level, phase, power level, and / or frequency provided to the bias electrodes 508, 509, 510. The tuning circuits 502, 504, 505, 506 are powered by power P from, for example, the second RF matching network 129 (or first power supply) of FIG. 1, the power supply 135 (or second power supply) of FIG. 1, and / or one or more other power supplies clamp , P inner1 , P inner2 , P outercan be received. The tuning circuits 502, 504, 505, 506 can be used to adjust the voltage drop across the entire plasma. Examples of the tuning circuits 502, 504, 505, 506 are shown in FIG. 6. The tuning circuits 502, 504, 505, 506 can include one or more of the impedances as shown in FIG. 6. The tuning circuits 502, 504, 505, 506 may not include a parallel impedance path, or may include a transmission line instead of a series impedance path. Examples of the impedances that can be included in the tuning circuits 502, 504, 505, 506 are shown in FIGS. 7 to 11. The impedance can be connected in series or in parallel, be a shunt reactance, and / or include a capacitor, an inductor, a resistor, a reactance, a transmission line, a short circuit or an open circuit, a filtering element and / or other impedance. By way of example, the clamp electrode 507 and the bias electrodes 508, 509 can be circular, and the external bias electrode 510 can be annular.

[0102] FIG. 6 shows a tuning circuit 600 for an electrode (or load) 602 such as a clamp electrode or a bias electrode. The tuning circuit 600 can replace any one of the tuning circuits 202, 204, 302, 304, 305, 402, 404, 405, 502, 504, 505, and 506 of FIGS. 2-5. Examples of the tuning circuit 600 are shown in FIGS. 9-10. The tuning circuit 600 can receive RF power from an RF power source 604 such as one of the power supplies 129, 135 of FIG. 1. The RF power source 604 can include a matching network and / or an RF generator such as the matching network 129 and the RF generator 125. The tuning circuit 600 can include a series impedance path 605 with a series impedance set 606 and a parallel impedance path 607 with a parallel impedance set 608. The impedance of the impedance sets 606, 608 can be frequency-dependent. The series impedance set 606 includes one or more impedances 609 connected in series between the RF power source 604 and the load 602. The series impedance set 606 and the one or more impedances 609 are connected between the load 602 and the source terminal 610. The source terminal 610 is connected to the RF power source 604. The parallel impedance set 608 is connected between (i) the source terminal 610 connected between the RF power source 604 and the series impedance set 606 and (ii) a reference terminal or ground 612. The parallel impedance set 608 can include one or more impedances 613 connected in parallel between the source terminal 610 and the reference terminal 612.

[0103] One or more of the impedances 609, 613 can be a fixed impedance. Additionally, or alternatively, one or more of the impedances 609, 613 can be a variable impedance, which can be adjusted, for example, by the system controller 121 of FIG. 1 based on the current process recipe, the current operating parameters, parameters measured and / or determined based on the output of one or more sensors (e.g., the sensor 143 of FIG. 1), and / or the characteristics and / or properties of the processing system, the ESC, and the substrate.

[0104] In FIGS. 7-11 below, certain impedances are shown, but other impedances may be included. The impedance may include "stray" inductance from wires and / or other conductive circuit elements.

[0105] FIG. 7 shows that the tuning circuit 700 can be connected to a single RF power source 702. The tuning circuit 700 includes inductors L1-L3 and capacitors C1-C3 connected in series for two clamp electrodes 706, 708 and the bias electrode ring 710. The impedances of inductors L1-L3 and capacitors C1-C3 are frequency-dependent. The RF power source 702 can operate in the same manner as the power sources 129, 135 of FIG. 1 and can be connected to a reference terminal or ground 711. The RF power source 702 may include a matching network and / or an RF generator such as the matching network 129 and the RF generator 125. In one embodiment (referred to as a grounded pedestal configuration), the RF power source 702 is not included and the capacitors C1-C3 are connected to ground 711.

[0106] In FIG. 7, cross-sectional views of the electrodes 706, 708, 710 are shown. The electrodes 706, 708, 710 can be arranged concentrically. L1 and C1 are connected in series between (i) the RF power source 702 and the common terminal 712 and (ii) the first internal clamp electrode 706. L2 and C2 are connected in series between (i) the RF power source 702 and the common (or source) terminal 712 and (ii) the central terminal 714 connected to two points on the bias electrode ring 710. L3 and C3 are connected in series between (i) the RF power source 702 and the common terminal 712 and (ii) the second internal clamp electrode 708.

[0107] The inductors L1-L3 and capacitors C1-C3 may have fixed values or may be variable devices controlled by the system controller 121 of FIG. 1 as described above. Although the inductors L1-L3 and capacitors C1-C3 are shown, other impedances may be incorporated into the tuning circuit 700.

[0108] FIG. 7 provides an example where power is provided to a common node (or terminal) and split to provide power to a plurality of electrodes. The impedance of each path to each electrode can be varied by the impedance (or inductance and capacitance connected in series) in the corresponding path.

[0109] FIG. 8 shows that the tuning circuit 800 can be connected to a single RF power source 802. The tuning circuit 800 includes shunt inductors L1 - L3 and shunt capacitors C1 - C3 for two clamp electrodes 804, 806 and a bias electrode ring 808. The impedance of the shunt inductors L1 - L3 and shunt capacitors C1 - C3 is frequency - dependent. The RF power source 802 can operate similar to the power sources 129, 135 of FIG. 1 and can be connected to a reference terminal or ground 811. The RF power source 802 can include a matching network and / or an RF generator such as the matching network 129 and the RF generator 125. The RF power source 802 is connected to a common (or source) terminal 812 that is connected to the clamp electrodes 804, 806 and a central terminal 814.

[0110] In one embodiment (referred to as a grounded pedestal configuration), the RF power source 802 is not included and the terminal 812 is connected to the ground 811. When the terminal 812 is connected to the ground 811, one or more series - connected impedances can be connected (i) between the node 820 and the ground 811, (ii) between the node 822 and the ground 811, and / or between the node 824 and the ground 811. The one or more series - connected impedances described can be similar to the impedances L1 - L3 and C1 - C3 or can include other impedances. This can occur, for example, when RF power is provided to the corresponding showerhead.

[0111] Cross-sectional views of electrodes 804, 806, and 808 are shown. Electrodes 804, 806, and 808 can be arranged concentrically. L1 and C1 are connected in parallel between node (or first terminal) 820 and ground 811. The first terminal 820 is connected between common terminal 812 and the first clamp electrode 804. L2 and C2 are connected in parallel between node (or second terminal) 822 and ground 811. The second terminal 822 is connected between common terminal 812 and the first clamp electrode 804. L3 and C3 are connected in parallel between node (or third terminal) 824 and ground 811. The third terminal 824 is connected between common terminal 812 and the second clamp electrode 806.

[0112] Inductors L1 - L3 and capacitors C1 - C3 can have arbitrary and / or predefined fixed values or, as described above, can be variable devices controlled by the system controller 121 of FIG. 1. Although inductors L1 - L3 and capacitors C1 - C3 are shown, other impedances may be incorporated into the tuning circuit 800.

[0113] FIG. 8 provides another example where power is provided to a common node and split to provide power to multiple electrodes. The impedance of each path to each electrode can be varied by a shunt impedance (or shunt inductance and capacitance) connected to the corresponding path.

[0114] FIG. 9 shows a tuning circuit 900 connected to dual RF power supplies 902, 904. The tuning circuit 900 includes inductors L1 - L3 and capacitors C1 - C3 connected in series for two clamp electrodes 906, 908 and bias electrode ring 910, and shunt inductors L4 - L6 and capacitors C4 - C6. The impedance of inductors L1 - L6 and capacitors C1 - C6 is frequency - dependent. The RF power supplies 902, 904 can operate in the same manner as the power supplies 129, 135 of FIG. 1 and can be connected to a reference terminal or ground 911. The RF power supplies 902, 904 can include a matching network and / or an RF generator such as the matching network 129 and RF generator 125. The RF power supplies 902, 904 are connected to a common (or source) terminal 912 and can provide power at the same frequency or different frequencies.

[0115] In one embodiment (referred to as a grounded pedestal configuration), the RF power supplies 902, 904 are not included and the terminal 912 is connected to ground 911. When the terminal 912 is connected to ground 911, one or more series - connected impedances can be connected (i) between node 920 and ground 911, (ii) between node 922 and ground 911, and / or between node 924 and ground 911. The one or more series - connected impedances described can be similar to impedances L1 - L3 and C1 - C3 or can include other impedances. This can occur, for example, when RF power is provided to a corresponding shower head.

[0116] Inductor L1 and capacitor C1 are connected in series between the common terminal 912 and the first clamp electrode 906. Inductor L2 and capacitor C2 are connected in series between the center terminal 914 and the common terminal 912. The center terminal is connected to two points on the bias electrode ring 910.

[0117] A cross-sectional view of electrodes 906, 908, and 910 is shown. Electrodes 906, 908, and 910 can be arranged concentrically. L4 and C4 are connected in parallel between node (or first terminal) 920 and ground 911. The first terminal 920 is connected between capacitor C1 and common terminal 912. L5 and C5 are connected in parallel between node (or second terminal) 922 and ground 911. The second terminal 922 is connected between capacitor C2 and common terminal 912. L6 and C6 are connected in parallel between node (or third terminal) 924 and ground 911. The third terminal 924 is connected between capacitor C3 and common terminal 912.

[0118] Inductors L1 - L6 and capacitors C1 - C6 can have arbitrary and / or predefined fixed values, or can be variable devices controlled by the system controller 121 of FIG. 1 as described above. Although inductors L1 - L6 and capacitors C1 - C6 are shown, other impedances may be incorporated into the tuning circuit 900. L4 - L6 and C4 - C6 can be any network, and may not include inductors and / or capacitors.

[0119] FIG. 10 shows that two tuning circuits 1000, 1002 can be connected to respective RF power supplies 1004, 1006. The first tuning circuit 1000 includes inductors L1, L3 and capacitors C1, C3 connected in series for two clamp electrodes 1010, 1012, and shunt inductors L4, L6 and capacitors C4, C6. The impedances of inductors L1 - L6 and capacitors C1 - C6 are frequency - dependent. The second tuning circuit 1002 includes an inductor L2 and a capacitor C2 connected in series for a bias electrode ring 1014, and shunt inductors L5 and capacitors C5. The RF power supplies 1004, 1006 can operate in the same manner as the power supplies 129, 135 of FIG. 1 and can be connected to a reference terminal or ground 1016. The RF power supplies 1004, 1006 can include a matching network and / or an RF generator such as the matching network 129 and the RF generator 125. The RF power supply 1004 is connected to a common (or source) terminal 1018 that is connected to C1, C3, C4, C6, L4, L6. The RF power supply 1006 is connected to a central terminal 1020 via C2 and L2. The RF power supplies 1004, 1006 can provide power at the same frequency or at different frequencies.

[0120] Inductor L1 and capacitor C1 are connected in series between the common terminal 1018 and the first clamp electrode 1010. Inductor L2 and capacitor C2 are connected in series between the central terminal 1020 and the RF power supply 1006. The central terminal 1020 is connected to two points on the bias electrode ring 1014.

[0121] A cross-sectional view of electrodes 1010, 1012, and 1014 is shown. Electrodes 1010, 1012, and 1014 can be arranged concentrically. L4 and C4 are connected in parallel between the first terminal 1030 and ground 1016. The first terminal 1030 is connected between the capacitor C1 and the common terminal 1018. L5 and C5 are connected in parallel between the second terminal 1032 and ground 1016. The second terminal 1032 is connected between the capacitor C2 and the common terminal 1018. L6 and C6 are connected in parallel between the third terminal 1034 and ground 1016. The third terminal 1034 is connected between the capacitor C3 and the common terminal 1018.

[0122] Inductors L1 - L6 and capacitors C1 - C6 can have arbitrary and / or predefined fixed values, or can be variable devices controlled by the system controller 121 of FIG. 1 as described above. Although inductors L1 - L6 and capacitors C1 - C6 are shown, other impedances may be incorporated into the tuning circuit 1000. L4 - L6 and C4 - C6 can be any network, and may not include inductors and / or capacitors.

[0123] In one embodiment, the RF power source 1004 is not included and the terminal 1018 is connected to ground 1016. In another embodiment, the RF power source 1006 is not included and the terminal 1032 is connected to ground 1016. In yet another embodiment, neither RF power source 1004 nor 1006 is included and both terminals 1018 and 1032 are connected to ground 1016. When terminal 1018 and / or terminal 1032 is connected to ground 1016, one or more series-connected impedances can be connected (i) between node 1030 and ground 1016, (ii) between node 1034 and ground 1016, and / or between node 1032 and ground 1016. The one or more series-connected impedances described can be similar to impedances L1 - L3 and C1 - C3, or can include other impedances. This can occur, for example, when RF power is provided to the corresponding showerhead.

[0124] FIG. 11 shows a tuning circuit 1100 including parallel-connected capacitors C1, C2 and inductors L1, L2 for two clamp electrodes 1102, 1104 and a bias electrode ring 1106. The impedances of inductors L1 to L2 and capacitors C1 to C2 are frequency-dependent. Electrodes 1102, 1104, 1106 can be arranged concentrically. Capacitors C1 and C2 are connected in series (i) between clamp electrodes 1102, 1104 and (ii) between power terminals 1110, 1112. Inductors L1, L2 are connected in parallel with capacitors C1, C2 respectively and are connected in series (i) between clamp electrodes 1102, 1104 and (ii) between power terminals 1110, 1112. Center terminals 1114, 1116 are connected between capacitors C1, C2 and between inductors L1, L2 respectively. Center terminals 1114, 1116 are connected to both (i) two points on bias electrode ring 1106 and (ii) a third (or center) power terminal 1118. Power terminals 1110, 1112 are connected to clamp electrodes 1102, 1104 respectively. Power terminals 1110, 1112, 1118 can be connected to respective power supplies such as any of the power supplies disclosed herein. In one embodiment, one or more of power terminals 1110, 1112, 1118 are not connected to an RF power supply and are connected to a reference terminal or ground.

[0125] Inductors L1 to L2 and capacitors C1 to C2 can have arbitrary and / or predetermined fixed values or can be variable devices controlled by the system controller 121 of FIG. 1 as described above. Although inductors L1 to L2 and capacitors C1 to C2 are shown, other impedances may be incorporated into tuning circuit 1100. Inductors L1 to L2 and capacitors C1 to C2 are coupling elements connected between electrodes and provide power to each electrode at multiple frequencies.

[0126] The resonance circuit 1100 can be used in combination with any of the circuits shown in FIGS. 3, 5, and 7-10. For example, the capacitors C1, C2 and the inductors L1, L2 may similarly be connected to the electrodes 306, 307 and the electrode rings 308 in FIG. 3, the electrodes 508, 509 and the electrode ring 510 in FIG. 5, the electrodes 706, 708 and the electrode ring 710 in FIG. 7, the electrodes 804, 806 and the electrode ring 808 in FIG. 8, the electrodes 906, 908 and the electrode ring 910 in FIG. 9, and the electrodes 1010, 1012 and the electrode ring 1014 in FIG. 10.

[0127] In the above examples of FIGS. 2-11, when power is provided at multiple frequencies, the path to a given electrode can include a frequency-dependent filtering element that provides power to that electrode at a specific frequency. The impedance described above may include a frequency-dependent filtering element. Additionally, the power provided to different electrodes can be provided by separate (or different) power sources operating at the same frequency or different frequencies, whereby the power provided by the power source is the same frequency or different frequencies. FIGS. 9-10 show examples that include multiple power sources. Alternatively, one or more of the power sources may be omitted, and the corresponding terminals (e.g., terminals 912, 1018, 1032) may be connected to a reference terminal or ground.

[0128] FIG. 12 shows an exemplary method of operating a substrate processing system that includes setting and adjusting the frequency of an RF generation signal and optionally adjusting the capacitance and inductance values of a tuning circuit for the electrodes of an electrostatic chuck. In one embodiment, the capacitor and inductor of the tuning circuit are maintained at fixed values while one or more frequencies are adjusted to adjust the spatial power distribution across the ESC (e.g., ESC 101 of FIG. 1). The spatial power distribution refers to the power distribution across the ESC. This may include distributions in the lateral, radial, axial, vertical, azimuthal directions, etc. The following operations are mainly described with respect to the embodiments of FIGS. 1-11, but the operations can be readily modified to apply to other embodiments of the present disclosure. The operations may be performed iteratively. The operations may be performed, for example, by system controller 121 and / or frequency controller 119 of FIG. 1.

[0129] The method can start from 1200. At 1202, the process to be implemented is selected. Exemplary processes include a cleaning process, an etching process, a deposition process, an annealing process, etc. At 1204, a recipe including system operation parameters is determined for the selected process being implemented. Exemplary system operation parameters are as follows: gas pressure and flow rate; process chamber temperature, ESC temperature, and substrate temperature; the center frequency of the RF signal output from the RF generator, and the corresponding frequency operation range; the total power supplied to each set of one or more electrodes in each of the plurality of zones of the electrode; RF bias voltage; clamp voltage; electrode voltage, current level, power level, and / or frequency, etc. As an example, the frequency operation range can be ±5% or more of the center frequency. As an example, the RF generator can have a center frequency of 13.56 megahertz (MHz), and during processing, the frequency of the RF signal output from the RF generator can be adjusted between 12.882 and 14.238 MHz. As another example, the RF generator can have a center frequency of 20 MHz, and during processing, the frequency of the RF signal output from the RF generator can be adjusted between 18 and 22 MHz. The frequency adjustment is not performed for the purpose of impedance matching to minimize reflected power, but is performed during processing, for example, after the plasma is struck and the power distribution in the ESC is adjusted.

[0130] At 1206, the characteristics and / or properties of the process chamber, ESC, and substrate are determined. Exemplary characteristics and properties include the shape value of the process chamber, the configuration of the ESC, the heating and cooling characteristics of the ESC (e.g., heating and cooling rates), the size of the ESC, the configuration of the substrate, the materials of the ESC and / or substrate, etc. This can also include: the number of electrodes per zone; the number of zones; as well as the number of clamp electrodes, RF electrodes, and / or combinations of clamp electrodes and RF electrodes. A part of the electrodes in the ESC101 can be used for both the purposes of clamping and RF bias, and thus both the clamp voltage and the RF bias voltage are provided.

[0131] At 1208, system operation parameters can be set by system controller 121 and / or frequency controller 119. This may include controlling the operation of the above-described actuator. At 1210, the impedance value of the tuning circuit is set based on the selected process, recipe, and system operation parameters. The impedance value can also, or alternatively, be set based on the characteristics and / or properties of the processing chamber, ESC, and / or substrate. As an example, a look-up table associating the impedance value with other parameters, characteristics, and / or properties described herein may be stored in the memory of system controller 121 and / or accessed by system controller 121. System controller 121 can also set the impedance 128 of the second RF matching network 129 as described above.

[0132] At 1212, the substrate can be placed on the ESC. This may include providing a clamping voltage for clamping the substrate to the ESC. At 1214, processing operations are performed. Exemplary processing operations include cleaning operations, gas flow, plasma flow and collisions, etching operations, deposition operations, annealing operations, post-annealing operations, purging of the process chamber, etc.

[0133] Operations 1216, 1218, 1220, 1222 can be performed while operation 1212 is being carried out. At 1216, a sensor output signal including sensor output data of the substrate processing system is monitored. This may include receiving signals from sensors 143, 144, 145 of FIG. 1.

[0134] At 1218, the parameter can be determined based on sensor output signals, data, and / or corresponding measurement values from sensors 143, 144, 145 and / or other sensors, such as temperature, gas pressure, the frequency of the RF signal generated by the RF generator, voltage, current level, power level, etc. The frequency can be adjusted while supplying the same amount of total power to the RF and / or clamp electrodes. By way of example, referring to FIG. 7, the RF power supply 702 can provide an RF signal having a specific frequency to the electrodes 706, 708, 710 via L1 - L3 and C1 - C3.

[0135] The power distribution to the electrodes 706, 708, 710 depends on the frequencies and impedance values of L1 - L3 and C1 - C3. The frequency of the RF signal can be adjusted to adjust the power distribution. By adjusting the frequency, the effective impedance of L1 - L3 and C1 - C3 changes. The inductance and capacitance values of L1 - L3 and C1 - C3 can be fixed or adjusted to adjust the power distribution. The amount of power distributed to the electrodes 706, 708, and 710 may be the same or different depending on the frequency of the RF signal and the impedance values of L1 - L3 and C1 - C3. In one embodiment, the total amount of power supplied to the electrodes 706, 708, 710 remains at a fixed level while the frequency of the RF signal supplied to the tuning circuit and / or the impedance, inductance, and / or capacitance changes.

[0136] At 1220, the system controller 121 and / or the frequency controller 119 can determine whether to adjust the frequency of the RF generated signal, the impedance value of the tuning circuit, and / or the capacitance and inductance values of the tuning circuit based on the measured values and / or the determined parameters. In one embodiment, a target impedance value is determined and then the frequency is set based on the target impedance value. The capacitance and inductance values of the capacitor and inductor of the tuning circuit can be adjusted based on the target impedance value and the set frequency. These determinations can be based on the selected process, recipe, system operating parameters, and / or the characteristics and / or properties of the processing chamber, ESC, and / or substrate. The characteristics can be changed dynamically. In one embodiment, the impedance value is adjusted to follow a predefined trajectory based on the change in characteristics. The predefined trajectory can be, for example, a predefined curve stored in memory. A table associating the impedance value with other values and parameters can be stored in memory. If one or more impedance values are changed, operation 1222 is performed; otherwise, operation 1216 can be performed. In one embodiment, the power supplied to one or more electrodes is modulated by changing the value of the corresponding impedance. This can be done to change the stress, thickness, uniformity, refractive index, etching rate, deposition rate, and / or other intrinsic values and / or profile parameters of the substrate.

[0137] At 1222, the system controller 121 adjusts one or more impedance values of the tuning circuit, for example, by changing the inductance, capacitance, impedance, and / or resistance of one or more capacitors and inductors of the tuning circuit. The adjustment (or amount of adjustment) can be based on measured and / or determined parameters, selected processes, recipes, system operating parameters, and / or characteristics and / or properties of the processing chamber, ESC, and / or substrate. The system controller 121 can also adjust the impedance 128 of the second RF matching network 129 as described above. Following operation 1222, operation 1216 can be performed.

[0138] At 1224, the system controller 121 determines whether to modify the current process or perform another process. Operation 1202 can be performed if the current process is modified or another process is performed. If the current process is not modified and no further processes are performed, the method can end at 1226.

[0139] The operations described above are meant to be exemplary examples. The operations may be performed sequentially, synchronously, simultaneously, continuously during overlapping periods, or in a different order depending on the application. Also, depending on the embodiment and / or sequence of events, any of the operations may or may not be performed or skipped.

[0140] FIG. 13 shows an example of an ESC (or substrate support) 1300 that includes an outer ring electrode 1302 and two internal electrodes 1304, 1306. Electrodes 1302, 1304, 1306 are provided as examples of two internal electrodes and an outer ring electrode, as shown in FIGS. 3, 5, and 7-11. The internal electrodes 1304, 1306 are “D”-shaped electrodes and can be disposed radially inward of the outer ring electrode 1302. Gaps 1308 and 1310 exist between the internal electrodes 1304, 1306 and the outer ring electrode 1302. The outer ring electrode 1302 can include an outer ring 1311 and a linear central member 1312 that extends between the internal electrodes 1304, 1306. Gaps 1314 and 1316 can exist between the internal electrodes 1304, 1306 and the central member 1312. The central member 1312 extends through the central region 1320 of the outer ring 1311 between the internal electrodes 1304, 1306 and divides the central region 1320 equally. In one embodiment, power is provided to the outer ring electrode 1302 at the center of the central member 1312. Power can be provided to portions of the internal electrodes 1304, 1306 near the center of the central member 1312.

[0141] The above example provides an RF tuning system for indirectly and directly adjusting the impedance of a tuning circuit and varying the power distribution to electrodes within an ESC. Frequency tuning at an RF generator can be used to rapidly and substantially change the power distribution, which affects the results of the on-wafer process. The RF tuning system can effect power modulation to the electrodes through frequency tuning and / or direct physical adjustment of the impedance of the tuning circuit. The use of frequency tuning in combination with direct adjustment of the impedance can increase the tuning range and / or improve the tuning accuracy. The tuning circuit has an impedance for setting and adjusting the parameters of electrodes within an electrostatic chuck and / or other pedestal (or substrate support). The pedestal may not be an electrostatic chuck. This provides spatial tuning of the power delivered to the plasma within a processing chamber (e.g., a PECVD reactor). The example provides new control parameters for film deposition and uniformity. As an example including an external annular electrode and an internal circular electrode, the relative intensity of the plasma around the outer periphery of the substrate can be varied by modulating the power supplied to the electrodes. This can be achieved by modulating (or adjusting) the corresponding impedance, as described above. Unlike varying gas parameters or overall power, modulating the power supplied to the electrodes does not necessarily change overall parameters that affect the entire substrate, but can vary selected regions of the film on the substrate (e.g., the circumferential edge of the film on the substrate). This is different from conventional techniques that involve the use of metal or dielectric rings that change the outer portion of the plasma and can result in fluctuations in the gas flow, with the overall effect of changing more of the film on the substrate than just the circumferential edge of the film.

[0142] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or its use in any way. The broad teachings of the disclosure can be implemented in a variety of forms. Accordingly, while this disclosure includes specific examples, it will be apparent to those skilled in the art from this disclosure, the drawings, and the following claims that other modifications are possible and that the true scope of the disclosure should not be limited to such examples. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without changing the principles of the disclosure. Further, while each embodiment has been described above as having certain features, any one or more of these features described with respect to any embodiment of the disclosure may be implemented in, and / or combined with, any other embodiment (even if such combinations are not explicitly described). In other words, the described embodiments are not mutually exclusive, and swapping one or more embodiments with each other is within the scope of the disclosure.

[0143] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Also, when a relationship between a first element and a second element is described in the above disclosure, unless explicitly described as "direct," the relationship may be a direct relationship with no other intervening elements between the first element and the second element, but there is also a possibility of an indirect relationship with one or more intervening elements (spatially or functionally) between the first element and the second element. As used herein, the expression "at least one of A, B, and C" should be interpreted in the sense of a logical (A or B or C) using non-exclusive logical OR, and should not be interpreted in the sense of "at least one of A, at least one of B, and at least one of C."

[0144] In some embodiments, the controller is part of a system, and such a system may be part of the examples described above. Such a system can include semiconductor processing equipment that includes one or more processing tools, one or more chambers, one or more processing platforms, and / or certain processing components (such as wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling system operation before, during, and after processing of a semiconductor wafer or substrate. Such electronics may be referred to as a "controller" and may control various components or sub-parts of one or more systems. The controller may be programmed to control any of the processes disclosed herein, depending on the processing requirements and / or the type of system. Such processes include delivery of processing gases, temperature setting (e.g., heating and / or cooling), pressure setting, vacuum setting, power setting, radio frequency (RF) generator setting, RF matching circuit setting, frequency setting, flow rate setting, fluid delivery setting, position and motion setting, loading and unloading of wafers to and from tools, and loading and unloading of wafers to and from other transfer tools and / or load locks connected or interfaced to a particular system.

[0145] In a broad sense, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuits may include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application-specific integrated circuit (ASIC), and / or one or more microprocessors, i.e., a microcontroller that executes program instructions (e.g., software). The program instructions are instructions communicated to the controller in the form of various individual settings (or program files), and may define operation parameters for performing a specific process on, or for, a semiconductor wafer or for a system. The operation parameters may, in some embodiments, be part of a recipe defined by a process engineer to implement one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0146] In some embodiments, the controller may be part of a computer that is integrated or coupled with the system, or otherwise network-connected to the system, or coupled to such a computer, or a combination thereof. For example, the controller may be within the "cloud" or may be all or part of a fab host computer system. This enables remote access to wafer processing. The computer enables remote access to the system, monitors the current progress of the fabrication operation, considers the history of past fabrication operations, considers trends or performance criteria from multiple fabrication operations, changes the parameters of the current process, sets the processing steps following the current process, or starts a new process. In some examples, a remote computer (e.g., a server) can provide a process recipe to the system over a network. Such a network may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, and such parameters and / or settings are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data. Such data specifies parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, for example, by including one or more individual controllers that are network-connected to each other and cooperate towards a common purpose (such as the processes and controls described herein). Examples of distributed controllers for such purposes would include one or more integrated circuits on a chamber that are remotely located (e.g., at the platform level or as part of a remote computer) and communicate with one or more integrated circuits combined to control the process in the chamber.

[0147] Exemplary systems can include, but are not limited to, a plasma etching chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etching chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etching (ALE) chamber or module, an ion implantation chamber or module, a tracking chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacture of semiconductor wafers.

[0148] As described above, depending on one or more process steps performed by a tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, proximate tools, tools located throughout the factory, a main computer, another controller, or a tool used for material transport to load and unload wafer containers to and from tool locations and / or load ports within a semiconductor manufacturing facility.

Claims

1. A substrate processing system, comprising: A matching network configured to receive a first radio frequency signal having a first frequency from a radio frequency generator and impedance-match the input of the matching network to the output of the radio frequency generator; A first tuning circuit different from the matching network and having a first circuit component with a first impedance, the first tuning circuit being configured to receive the output of the matching network and output a second radio frequency signal to a first electrode on a substrate support; A controller configured to determine a target impedance for the first circuit component, and based on the target impedance, send a signal to the radio frequency generator to adjust the first frequency of the first radio frequency signal received by the matching network to a second frequency, and change the first impedance of the first circuit component to match the target impedance; A substrate processing system.

2. The substrate processing system according to claim 1, further comprising: The radio frequency generator having a center frequency and configured to generate the first radio frequency signal having the first frequency based on a control signal; The controller is configured to generate the control signal; The first frequency is within a predetermined range of the center frequency. A substrate processing system.

3. The substrate processing system according to claim 1, wherein: The matching network provides the first radio frequency signal to the first tuning circuit without changing the first frequency of the first radio frequency signal.

4. The substrate processing system according to claim 1, wherein: The controller is configured to adjust the first frequency to the second frequency independently of impedance-matching the input of the matching network to the output of the radio frequency generator.

5. The substrate processing system according to claim 1, wherein: The controller is configured to adjust the first frequency to the second frequency without affecting the impedance-matching between the matching network and the radio frequency generator.

6. The substrate processing system according to claim 1, wherein the matching network is configured to maintain impedance matching between an input of the matching network and an output of the radio frequency generator while the controller adjusts the first frequency to the second frequency.

7. The substrate processing system according to claim 1, wherein the first tuning circuit includes the first circuit component and a second circuit component, the first circuit component is connected to the first electrode, the second circuit component is connected to a second electrode on the substrate support, the controller is configured to adjust the first frequency to the second frequency to adjust the first impedance of the first circuit component and the second impedance of the second circuit component, and change power distribution from the first tuning circuit to the first electrode and the second electrode. Substrate processing system.

8. The substrate processing system according to claim 1, wherein the frequency of the second radio frequency signal is the same as the frequency of the first radio frequency signal.

9. The substrate processing system according to claim 1, wherein when the controller changes the first impedance to match the target impedance, in addition to adjusting the first frequency to the second frequency, the controller is configured to adjust the capacitance or inductance of the first circuit component.

10. The substrate processing system according to claim 1, wherein the controller is configured to maintain at least one of the capacitance or inductance of the first circuit component at a fixed value while adjusting the first impedance.

11. The substrate processing system according to claim 1, wherein the first tuning circuit distributes the total amount of power received from the matching network to the first circuit component and the second circuit component, the controller is configured to adjust the first frequency to the second frequency and adjust a first portion of the total amount of power provided to the first circuit component and a second portion of the total amount of power provided to the second circuit component. Substrate processing system.

12. The substrate processing system according to claim 1, wherein a source terminal, The substrate support including the first electrode and the second electrode, wherein the first electrode and the second electrode receive power from the matching network via the source terminal, and the substrate support further includes the first tuning circuit a first impedance set connected in series between the first electrode and the matching network, the first impedance set being a first impedance set that receives the second radio frequency signal from the matching network via the source terminal, or a second impedance set connected between the output of the matching network and the reference terminal, the second impedance set being a second impedance set that receives the second radio frequency signal from the matching network via the source terminal comprising at least one of a substrate processing system

13. The substrate processing system according to claim 12, further comprising a second tuning circuit, a third tuning circuit, and a third electrode, the first tuning circuit is connected to the first electrode to correct the output of the matching network and generate the second radio frequency signal, the second tuning circuit is connected to the second electrode and is configured to correct the output of the matching network to generate a third radio frequency signal provided to the second electrode, the third tuning circuit is connected to the third electrode and is configured to correct the output of the matching network to generate a fourth radio frequency signal provided to the third electrode, a substrate processing system

14. The substrate processing system according to claim 1, wherein the first circuit component is connected to the first electrode and the second electrode in the substrate support and affects the power distribution to the first electrode and the second electrode, a substrate processing system

15. A substrate processing system, comprising a matching network configured to receive a first radio frequency signal having a first frequency from a radio frequency generator and impedance-match the input of the matching network to the output of the radio frequency generator, and A tuning circuit different from the integration network, the tuning circuit being configured to output a second radio frequency signal to a first electrode on a substrate support and output a third radio frequency signal to a second electrode on the substrate support based on an output of the integration network. A controller configured to send a signal to the radio frequency generator and adjust the power distribution to the first electrode and the second electrode in the substrate support by adjusting the first frequency of the first radio frequency signal received by the integration network to a second frequency. A substrate processing system comprising the above. **Claim 16** The substrate processing system according to claim 15, wherein the integration network provides the first radio frequency signal to the tuning circuit without changing the first frequency of the first radio frequency signal. **Claim 17** The substrate processing system according to claim 15, wherein the controller is configured to adjust the first frequency to the second frequency regardless of impedance matching between the input of the integration network and the output of the radio frequency generator. **Claim 18** The substrate processing system according to claim 15, wherein the controller is configured to adjust the first frequency to the second frequency without affecting the impedance matching between the integration network and the radio frequency generator. **Claim 19** The substrate processing system according to claim 15, wherein the integration network is configured to maintain impedance matching between the input of the integration network and the output of the radio frequency generator while the controller adjusts the first frequency to the second frequency. **Claim 20** The substrate processing system according to claim 15, wherein the tuning circuit includes a first circuit component and a second circuit component, the first circuit component is connected to the first electrode, the second circuit component is connected to the second electrode, and when the first frequency is adjusted to the second frequency, a first impedance of the first circuit component and a second impedance of the second circuit component are changed. A substrate processing system.

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