Extreme value search control device and method with online parameter adjustment

Abstract

The power supply system includes an RF power source configured to generate an output signal at an output frequency, a signal source configured to generate a perturbation signal, an extremum-seeking frequency controller configured to generate a frequency control signal based on the perturbation signal, and a frequency selector configured to select a perturbation frequency of the perturbation signal that is separated from at least one frequency tone associated with the power supply system. The frequency control signal varies the output frequency of the RF power source. Other exemplary power supply systems, methods for controlling an RF generator, and control systems for controlling an RF generator are also disclosed.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit of U.S. Provisional Application No. 17 / 940,047, filed on 8 September 2022. The disclosures of the above application are incorporated herein by reference in their entirety.

[0002] This disclosure relates to an RF generator system and control of an RF generator. [Background technology]

[0003] Plasma processing is frequently used in semiconductor manufacturing. In plasma processing, ions are accelerated by an electric field to etch material from the substrate surface or deposit material onto the substrate surface. In one basic implementation, the electric field is generated based on an RF or DC power signal produced by the respective radio frequency (RF) or direct current (DC) generators of the power supply system. The power signal generated by the generator must be precisely controlled to effectively perform plasma etching.

[0004] The background art provided herein is for general purposes only to present the context of this disclosure. The work of the inventors designated herein, as well as any aspects of the description that may not be considered prior art at the time of filing, as described in this background art section, are not expressly or implicitly recognized as prior art to this disclosure. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent No. 7,602,127 [Patent Document 2] U.S. Patent No. 8,110,991 [Patent Document 3] U.S. No. 8,395,322 [Patent Document 4] U.S. Patent No. 10,821,542 [Patent Document 5] U.S. Patent No. 10,546,724 [Patent Document 6] U.S. Patent No. 10,049,857 [Patent Document 7] U.S. Patent No. 10,741,363 [Overview of the project] [Means for solving the problem]

[0006] One or more computer systems may be configured to perform a specific operation or action by having software, firmware, hardware, or a combination thereof installed on the system that causes the system to perform an action while in operation. One or more computer programs may be configured to perform a specific operation or action by including instructions that cause the device to perform an action when executed by a data processing device. According to one aspect of this disclosure, a power supply system for supplying power to a load is disclosed. The power supply system includes an RF power source configured to generate an output signal at an output frequency; a signal source configured to generate a perturbation signal; an extremum-finding frequency controller configured to generate a frequency control signal based on the perturbation signal; and a frequency selector configured to select a perturbation frequency of the perturbation signal that is isolated from at least one frequency tone associated with the power supply system. The frequency control signal causes the output frequency of the RF power source to vary. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0007] The implementation may include one or more of the following features: The power supply system may include a power controller coupled to an RF power source, the power controller configured to generate pulses to modulate the output signal of the RF power source, the pulses comprising a first state and a second state. A frequency selector may be configured to select a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state, the first and second perturbation frequencies being different. A frequency selector may be configured to select perturbation frequencies for the first and second states of the pulse. The power supply system may include a power controller coupled to an RF power source, the power controller configured to generate at least two pulses to modulate the output signal of the RF power source, each pulse comprising a first state and a second state, and a frequency selector configured to select a first perturbation frequency for the first state of each of the at least two pulses and a second perturbation frequency for the second state of each of the at least two pulses, the first and second perturbation frequencies being different. The power supply system may include a power controller coupled to an RF power source, the power controller configured to generate pulses to modulate the output signal of the RF power source, and a frequency selector configured to select a perturbation frequency based on the bandwidth of the power controller. The frequency selector may be configured to determine a first delta between the minimum value of the bandwidth and at least one frequency tone, and a second delta between at least one frequency tone and the maximum value of the bandwidth, and to select a perturbation frequency equal to the frequency value of the larger of the first and second deltas. The frequency value may be the midpoint of the larger of the first and second deltas. The frequency selector may be configured to analyze data indicating the operating parameters of the power supply system at the selected perturbation frequency, and to adjust the perturbation frequency of the larger of the first and second deltas if the operating parameters fall below a defined threshold.A frequency selector may be configured to analyze data indicating the operating parameters of a power supply system with an adjusted perturbation frequency, and, if the operating parameters fall below a defined threshold, to readjust the perturbation frequency to the larger of a first delta and a second delta. A frequency selector may be configured to determine at least one frequency tone, which may include an apparent frequency associated with a pulse state. The apparent frequency may be determined based on the duty cycle of the state, the repetition rate of the pulse, and the hold-off time associated with the state. At least one frequency tone may include a first apparent frequency associated with a first state of the pulse and a second apparent frequency associated with a second state of the pulse, and the frequency selector may be configured to select perturbation frequencies for the first and second states, separated from the first and second apparent frequencies. A frequency selector may be configured to perform a transformation to analyze data from one or more feedback signals, and, based on the analyzed data, determine at least one frequency tone. A frequency selector may be configured to select a perturbation frequency based on the analyzed data. A frequency selector may be configured to perform a transformation based on the output response of a perturbed frequency and analyze data from one or more feedback signals. The frequency selector may be configured to adjust the perturbed frequency based on the analyzed data. The data may indicate operating parameters of a power supply system, and the frequency selector may be configured to adjust the perturbed frequency if the operating parameters fall below a defined threshold. The frequency selector may be configured to analyze data indicating the operating parameters of the power supply system at the adjusted perturbed frequency, and to adjust the perturbed frequency again if the operating parameters fall below a defined threshold. Implementations of the described techniques may include hardware, methods or processes, or computer software on a computer-accessible medium.

[0008] According to another aspect of the present disclosure, a method for controlling an RF generator of a power supply system includes the steps of: selecting a perturbation frequency of a perturbation signal, which is isolated from at least one frequency tone associated with the power supply system; generating a perturbation signal having the selected perturbation frequency; and generating a frequency control signal based on the perturbation signal, wherein the frequency control signal causes the output frequency of an RF power source to vary. Other embodiments of this aspect include corresponding computer systems, apparatuses, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0009] The implementation may include one or more of the following features: The method may include a step of generating pulses to modulate the output signal of an RF power source, wherein each pulse includes a first state and a second state, and the step of selecting perturbation frequencies includes a step of selecting perturbation frequencies for the first and second states of the pulse, or a step of selecting a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state that is different from the first perturbation frequency. The method may include a step of generating at least two pulses to modulate the output signal of an RF power source, wherein each pulse includes a first state and a second state, and the step of selecting perturbation frequencies includes a step of selecting a first perturbation frequency for the first state of each of the at least two pulses and a second perturbation frequency for each of the at least two pulses that is different from the first perturbation frequency. The method may include a step of generating pulses to modulate the output signal of an RF power source using a power controller, and the step of selecting perturbation frequencies includes a step of selecting perturbation frequencies based on the bandwidth of the power controller. The method may include the steps of determining a first delta between the minimum value of the bandwidth and at least one frequency tone, and a second delta between at least one frequency tone and the maximum value of the bandwidth, and selecting a perturbation frequency equal to a frequency value of the larger of the first and second deltas. The frequency value may be the midpoint of the larger of the first and second deltas. The method may include the steps of analyzing data indicating the operating parameters of a power supply system with the selected perturbation frequency, and adjusting the perturbation frequency within the larger of the first and second deltas if the operating parameters fall below a defined threshold. The method may include the steps of analyzing data indicating the operating parameters of a power supply system with the adjusted perturbation frequency, and readjusting the perturbation frequency within the larger of the first and second deltas if the operating parameters fall below a defined threshold.The method may include a step of determining at least one frequency tone, the at least one frequency tone may include an apparent frequency associated with a pulse state, and the step of determining at least one frequency tone may include a step of determining an apparent frequency associated with a pulse state based on the duty cycle of the state, the repetition rate of the pulse, and the hold-off time associated with the state. The method may include a step of selecting perturbation frequencies for a first state and a second state of a pulse, separated from a first apparent frequency associated with a first state of the pulse and a second apparent frequency associated with a second state of the pulse. The method may include a step of performing a transformation to analyze data from one or more feedback signals, and a step of determining at least one frequency tone based on the analyzed data. The method may include a step of selecting a perturbation frequency based on the analyzed data. The method may include a step of performing a transformation to analyze data from one or more feedback signals based on the output response with respect to the perturbation frequency. The method may include a step of adjusting the perturbation frequency based on the analyzed data. The data may represent operating parameters of a power supply system, and the method may further include a step of adjusting the perturbation frequency if the operating parameters fall below a defined threshold. The method may include the steps of analyzing data indicating the operating parameters of a power supply system with an adjusted perturbation frequency, and readjusting the perturbation frequency if the operating parameters fall below a defined threshold. Implementations of the described technique may include hardware, methods or processes, or computer software on a computer-accessible medium.

[0010] Another aspect of this disclosure discloses a non-temporary computer-readable medium for storing processor-executable instructions for controlling an RF generator of a power supply system. The RF generator includes an RF power source. The instructions include selecting a perturbation frequency for a perturbation signal, which is isolated from at least one frequency tone associated with the power supply system; generating a perturbation signal having the selected perturbation frequency; and generating a frequency control signal based on the perturbation signal, wherein the frequency control signal causes the output frequency of the RF power source to vary. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0011] The implementation may include one or more of the following features: The instruction may include generating pulses to modulate the output signal of an RF power source using a power controller, and selecting the perturbation frequency of the perturbed signal may include selecting the perturbation frequency based on the bandwidth of the power controller. The instruction may include determining a first delta between the minimum value of the bandwidth and at least one frequency tone, and a second delta between at least one frequency tone and the maximum value of the bandwidth, and selecting the perturbation frequency of the perturbed signal may include selecting the perturbation frequency such that it is equal to the frequency value of the larger of the first and second deltas. The frequency value may be the midpoint of the larger of the first and second deltas. The instruction may include analyzing data indicating the operating parameters of the power system with the selected perturbation frequency, and adjusting the perturbation frequency within the larger of the first and second deltas if the operating parameters fall below a defined threshold. The instruction may include analyzing data indicating the operating parameters of a power supply system with an adjusted perturbation frequency, and if the operating parameters fall below a defined threshold, readjusting the perturbation frequency within the larger of a first delta and a second delta. The instruction may include determining at least one frequency tone, the at least one frequency tone including an apparent frequency associated with a pulse state, and determining at least one frequency tone including determining an apparent frequency associated with a pulse state based on the duty cycle of the state, the repetition rate of the pulse, and the hold-off time associated with the state. The instruction may include determining at least one frequency tone, the at least one frequency tone including a first apparent frequency associated with a first state of the pulse and a second apparent frequency associated with a second state of the pulse, and selecting a perturbation frequency for a perturbation signal including selecting perturbation frequencies for the first and second states that are separated from the first and second apparent frequencies.The command is to perform a conversion based on the output response at the perturbation frequency and analyze the data of one or more feedback signals, where the data may indicate the operating parameters of the power system. The command may include adjusting the perturbation frequency when the operating parameter falls below a defined threshold value. The command may include analyzing the data indicating the operating parameters of the power system at the adjusted perturbation frequency and, when the operating parameter falls below the defined threshold value, readjusting the perturbation frequency. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0012] [[ID=*]]According to another aspect of the present disclosure, a control system for controlling an RF generator of a power system includes a signal source configured to generate a perturbation signal, an extremum search frequency controller configured to generate a frequency control signal based on the perturbation signal, and a frequency selector configured to select a perturbation frequency of the perturbation signal that is separated from at least one frequency tone associated with the power system. The frequency control signal varies the output frequency of the RF power source. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0013] The implementation may include one or more of the following features: The control system may include a power controller configured to generate pulses to modulate the output signal of an RF power source, wherein the pulses include a first state and a second state, the perturbation frequency is the first perturbation frequency, and the frequency selector may be configured to select a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state, wherein the first and second perturbation frequencies are different. The control system may include a power controller configured to generate pulses to modulate the output signal of an RF power source, wherein the pulses include a first state and a second state, and the frequency selector may be configured to select perturbation frequencies for the first and second states of the pulse. The control system may include a power controller configured to generate at least two pulses to modulate the output signal of an RF power source, each of the at least two pulses comprising a first state and a second state, with a perturbation frequency being the first perturbation frequency, and a frequency selector may be configured to select a first perturbation frequency for the first state of each of the at least two pulses and a second perturbation frequency for the second state of each of the at least two pulses, wherein the first and second perturbation frequencies are different. The control system may include a power controller configured to generate pulses to modulate the output signal of an RF power source, and a frequency selector may be configured to select a perturbation frequency based on the bandwidth of the power controller. The frequency selector may be configured to determine a first delta between the minimum value of the bandwidth and at least one frequency tone, and a second delta between at least one frequency tone and the maximum value of the bandwidth, and to select a perturbation frequency equal to the frequency value of the larger of the first and second deltas. The frequency selector may be configured to determine at least one frequency tone.A frequency selector may be configured to perform a conversion to analyze data of one or more feedback signals, determine at least one frequency tone based on the analyzed data, and select a perturbation frequency based on the at least one frequency tone. The frequency selector may be configured to perform a conversion to analyze data of one or more feedback signals and adjust the perturbation frequency based on the analyzed data based on an output response by the perturbation frequency. The data may indicate an operating parameter of a power system, and the frequency selector may be configured to adjust the perturbation frequency when the operating parameter falls below a defined threshold. Implementations of the techniques described may include hardware, a method or process, or computer software on a computer-accessible medium.

[0014] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings herein. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0015] The present disclosure will be more fully understood from the detailed description and the accompanying drawings.

Brief Description of the Drawings

[0016] [Figure 1] FIG. 1 is a schematic block diagram of a power supply system having a plurality of power supplies arranged according to various configurations of the present disclosure. [Figure 2] FIG. 2 is a diagram showing a waveform of an RF signal and a pulse for modulating the RF signal to explain a pulse operation mode. [Figure 3A] FIG. 3 is a diagram showing a plot of a cost function as a function of cost and actuator frequency. [[ID=2^3]] [Figure 3B] FIG. 4 is a diagram showing a plot of a cost function as a function of cost and actuator frequency. [Figure 4]This is a block diagram of an RF power supply system that implements an extreme value search control (ESC)-based method. [Figure 5A] This figure plots the apparent pulse frequency as a function of pulse repetition rate and duty cycle. [Figure 5B] This figure plots the apparent pulse frequency as a function of pulse repetition rate and duty cycle. [Figure 6] This figure shows plots of various waveforms associated with the implemented sinusoidal frequency modulation signal. [Figure 7] This is a block diagram of an RF power supply system arranged in accordance with the principles of this disclosure. [Figure 8A] This figure shows an exemplary method for selecting a perturbation frequency based on the bandwidth of a power control loop arranged in accordance with the principles of this disclosure. [Figure 8B] This figure shows an exemplary method for selecting a perturbation frequency based on the bandwidth of a power control loop arranged in accordance with the principles of this disclosure. [Figure 9] This figure shows an exemplary method for selecting a perturbation frequency, arranged in accordance with the principles of this disclosure. [Figure 10A] This figure shows an exemplary method for selecting a perturbation frequency, arranged in accordance with the principles of this disclosure. [Figure 10B] This figure shows an exemplary method for selecting a perturbation frequency, arranged in accordance with the principles of this disclosure. [Figure 10C] This figure shows an exemplary method for selecting a perturbation frequency, arranged in accordance with the principles of this disclosure. [Figure 10D] This figure shows an exemplary method for selecting a perturbation frequency, arranged in accordance with the principles of this disclosure. [Figure 11A] This figure illustrates an exemplary method for selecting a perturbation frequency based on analyzed feedback data arranged in accordance with the principles of this disclosure. [Figure 11B] This figure illustrates an exemplary method for selecting a perturbation frequency based on analyzed feedback data arranged in accordance with the principles of this disclosure. [Figure 12] This is a functional block diagram of exemplary control modules arranged according to various configurations. [Figure 13] This is a flowchart of the operation of a control system for perturbation frequency selection, arranged in accordance with the principles of this disclosure. [Figure 14] This is a flowchart of the operation of a control system for perturbation frequency selection, arranged in accordance with the principles of this disclosure. [Figure 15] This is a flowchart of the operation of a control system for perturbation frequency selection, arranged in accordance with the principles of this disclosure. [Figure 16] This is a flowchart of the operation of a control system for perturbation frequency selection, arranged in accordance with the principles of this disclosure. [Modes for carrying out the invention]

[0017] In drawings, reference numbers may be reused to identify similar and / or identical elements.

[0018] A power system may include a DC or RF power generator, a matched network, and a load (such as a process chamber, plasma chamber, or reactor with fixed or variable impedance). The power generator produces a DC or RF power signal, which is received by the matched network or an impedance-optimizing controller or circuit. The matched network or impedance-optimizing controller or circuit matches the input impedance of the matched network to the characteristic impedance of the transmission line between the power generator and the matched network. Impedance matching helps to maximize the amount of power transferred to the matched network ("forward power") and minimize the amount of power reflected back from the matched network to the power generator ("reverse power" or "reflected power"). Power supplied to the load can be maximized by minimizing reflected power when the input impedance of the matched network matches the characteristic impedance of the transmission line and the generator.

[0019] In the field of power sources or power supplies, there are typically two methods for applying a power signal to a load. The first, more traditional method is to apply a continuous power signal to the load. In continuous mode or continuous wave mode, the continuous power signal is typically a constant DC or sinusoidal RF power signal that is continuously output to the load by the power source. In the continuous mode method, the power signal is assumed to be a constant DC or sinusoidal output, and the amplitude and / or frequency (of the RF power signal) of the power signal may be varied to vary the output power applied to the load.

[0020] A second technique for applying a power signal to a load involves pulsing the RF signal rather than applying a continuous RF signal to the load. In pulsed or pulsed operating modes, the RF signal is modulated by a modulation signal to define an envelope for the modulated power signal. The RF signal can be, for example, a sinusoidal RF signal or another time-varying signal. The power supplied to the load is typically varied by varying the modulation signal.

[0021] In a typical power supply configuration, the output power applied to the load is determined using sensors that measure the forward and reflected power, or voltage and current, of the RF signal applied to the load. One of these sets of signals is analyzed in a control loop. The analysis typically determines power values ​​used to adjust the power supply output to vary the power applied to the load. In power supply systems where the load is a process chamber or other nonlinear or time-varying load, the applied power is partly a function of the load's impedance, so the varying impedance of the load causes a corresponding variation in the power applied to the load.

[0022] In systems where the fabrication of various devices relies on the introduction of power to a load to control the fabrication process, the power is typically supplied in one of two configurations. In the first configuration, the power is capacitively coupled to the load. Such systems are called capacitively coupled plasma (CCP) systems. In the second configuration, the power is inductively coupled to the load. Such systems are typically called inductively coupled plasma (ICP) systems. Power coupling to the plasma can also be achieved via wave coupling at microwave frequencies. Such techniques typically use electron cyclotron resonance (ECR) or microwave sources. Helicon sources are another form of wave-coupled sources and typically operate at RF frequencies similar to those of conventional ICP and CCP systems. The power supply system may include at least one bias power and / or source power applied to one or more electrodes of the load. The source power typically generates the plasma and controls the plasma density, while the bias power modulates ions in the construction of the sheath. The bias and source may share the same electrode or use separate electrodes, depending on various design considerations.

[0023] When a power supply system drives a time-varying or nonlinear load, such as a process chamber or plasma chamber, the power absorbed by the bulk plasma and plasma sheath results in ion densities with varying ion energies. One characteristic measure of ion energy is the ion energy distribution function (IEDF). The IEDF can be controlled using bias power. One way to control the IEDF for a system in which multiple RF power signals are applied to a load is by varying the multiple RF signals, which are related by amplitude, frequency, and phase. The relative amplitude, frequency, and phase of the multiple RF power signals can also be related by a Fourier series and associated coefficients. The frequencies between the multiple RF power signals can be locked, and the relative phases between the multiple RF signals can also be locked. Examples of such systems can be found by referring to U.S. Patents 7,602,127, 8,110,991, and 8,395,322, all of which are assigned to the assignees of this application and incorporated herein by reference.

[0024] Time-varying or nonlinear loads can be present in various applications. In one application, a plasma processing system may also include components for plasma generation and control. One such component is a nonlinear load implemented as a process chamber, such as a plasma chamber or reactor. As an example, a typical plasma chamber or reactor used in plasma processing systems for thin-film manufacturing, for example, can utilize a dual power system. One power generator (source) controls the plasma generation, and a power generator (bias) controls the ion energy. Examples of dual power systems include those described in U.S. Patents 7,602,127, 8,110,991, and 8,395,322, referenced above. The dual power systems described in the patents referenced above employ a closed-loop control system to adapt the power supply operation for the purpose of controlling the ion density and its corresponding ion energy distribution function (IEDF).

[0025] Several techniques exist for controlling a process chamber, including those that can be used to generate plasma. For example, in an RF power supply system, the phase and frequency of multiple drive RF signals operating at the same or nearly the same frequency can be used to control plasma generation. In the case of RF-driven plasma sources, a periodic waveform that affects the plasma sheath dynamics and corresponding ion energy is commonly known and controlled by the frequency of the periodic waveform and the associated phase-phase interaction. Another technique in RF power supply systems involves dual-frequency control, where two RF frequency sources operating at different frequencies are used to power a plasma chamber to provide substantially independent control of ion and electron density.

[0026] Another approach utilizes a broadband RF power source to drive the plasma chamber. The broadband approach presents several challenges. One challenge is coupling power to the electrodes. A second challenge is that the transfer function of the generated waveform to the actual sheath voltage for the desired IEDF must be formulated for a wide process space to support material surface interactions. One approach, highly sensitive in inductively coupled plasma systems, provides etching rate control by controlling the plasma density by controlling the power applied to the source electrode and by modulating ions by controlling the power applied to the bias electrode, thereby controlling the IEDF. By using source and bias electrode control, the etching rate is controlled via ion density and energy.

[0027] As integrated circuit and device fabrication continues to evolve, so do the power requirements for controlling the fabrication process. For example, in the fabrication of memory devices, the requirements for bias power continue to increase. Increased power generates higher-energy ions for faster surface interactions, thereby increasing etching rate and ion directivity. In RF systems, increased bias power may be accompanied by lower bias frequency requirements, along with an increase in the number of bias power sources coupled to the plasma sheath created in the plasma chamber. Increased power at lower bias frequencies, and an increase in the number of bias power sources, result in intermodulation distortion (IMD) radiation from sheath modulation. IMD radiation can significantly reduce the power supplied by the source from which plasma generation occurs. U.S. Patent No. 10,821,542, “Pulse Synchronization by Monitoring Power in Another Frequency Band,” issued 3 November 2020, assigned to the assignee of this application and incorporated herein by reference, describes a method of pulse synchronization by monitoring power in another frequency band. In the referenced U.S. patent, the pulsation of a second RF generator is controlled by detecting the pulsation of the first RF generator in the second RF generator, thereby synchronizing the pulsation between the two RF generators.

[0028] Figure 1 shows an RF generator or power supply system 10. The power supply system 10 includes a pair of radio frequency (RF) generators or power supplies 12a and 12b, matching networks 18a and 18b, and a load 32, such as a nonlinear load, which may be a plasma chamber, plasma reactor, process chamber, etc. In various configurations, the RF generator 12a is referred to as the source RF generator or power supply, and the matching network 18a is referred to as the source matching network. Also in various configurations, the RF generator 12b is referred to as the bias RF generator or power supply, and the matching network 18b is referred to as the bias matching network. It will be understood that the components may be referred to individually or collectively using reference numbers with and without letters, subscripts, or prime symbols.

[0029] In various configurations, the source RF generator 12a receives a control signal 30 from the matching network 18b and / or a control signal 30' from the bias RF generator 12b. The control signals 30 or 30' represent input signals to the source RF generator 12a that indicate one or more operating characteristics or parameters of the bias RF generator 12b. In various configurations, the synchronous bias detector 34 detects the RF signal output from the matching network 18b to the load 32 and outputs a synchronous or trigger signal 30 to the source RF generator 12a. In various configurations, the synchronous or trigger signal 30', rather than the trigger signal 30, may be output from the bias RF generator 12b to the source RF generator 12a. One difference between the trigger or synchronous signals 30, 30' may arise from the influence of the matching network 18b, which can cause a phase variation between the input signal to the matching network and the output signal from the matching network. Signals 30 and 30' contain information about the operation of the bias RF generator 12b, enabling predictive responsiveness to address periodic fluctuations in the impedance of the load 32 caused by the bias RF generator 12b in various configurations. When there is no control signal 30 or 30', the RF generators 12a and 12b operate autonomously.

[0030] The RF generators 12a, 12b each include an RF power source or amplifier 14a, 14b, sensors 16a, 16b, and processors, controllers, or control modules 20a, 20b. The RF power sources 14a, 14b generate their respective RF power signals 22a, 22b, which are output to their respective sensors 16a, 16b. The RF power signals 22a, 22b pass through the sensors 16a, 16b and are provided to the matching network 18a, 18b as their respective RF power signals f1 and f2. Although the sensors 16a, 16b are shown within their respective RF generators 12a, 12b, they can be located outside the RF power generators 12a, 12b. Such external sensing can occur at the output of the RF generator, at the input of an impedance matching device located between the RF generator and the load, or between the output of an impedance matching device (including within the impedance matching device) and the load.

[0031] Sensors 16a and 16b detect various operating parameters and output signals X and Y. Sensors 16a and 16b may include voltage, current, and / or directional coupler sensors. Sensors 16a and 16b receive (i) voltage V and current I, and / or (ii) forward power P output from their respective power amplifiers 14a, 14b and / or RF generators 12a, 12b. FWD And the reverse or reflected power P received from the respective matched networks 18a, 18b or load 32 connected to the respective sensors 16a, 16b, REV It can detect voltage V, current I, and forward power P. FWD , and reverse power P REVThis could be a scaled version, a filtered version, or a scaled and filtered version of the actual voltage, current, forward power, and reverse power associated with each power source 14a, 14b. Sensors 16a, 16b could be analog or digital sensors, or a combination thereof. In a digital implementation, sensors 16a, 16b may include an analog-to-digital (A / D) converter and a signal sampling component with a corresponding sampling rate. Signals X and Y are voltage V and current I, or forward (or source) power P. FWD , reverse (or reflected) power P REV It can represent any of the following.

[0032] Sensors 16a and 16b generate sensor signals X and Y, which are received by their respective power controllers or control modules 20a and 20b. Control modules 20a and 20b process their respective X and Y signals 24a, 26a, and 24b, and generate one or more feedforward or feedback control signals 28a and 28b to their respective power sources 14a and 14b. Power sources 14a and 14b adjust their RF power signals 22a and 22b based on the received feedback or feedforward control signals. In various configurations, control modules 20a and 20b may control their respective matched networks 18a and 18b via their respective control signals 29a and 29b, for example, based on their X and Y signals 24a, 26a, and 24b, and 26b. In some configurations, the control signals 29a and 29b may be the same as, similar to, or different from, the control signals 28a and 28b. The control modules 20a and 20b may include at least a proportional-integral (PI), proportional-integral-derivative (PID) controller, a linear-second-order regulator (LQR), or a subset thereof, and / or a direct digital synthesis (DDS) component, and / or any of the various components described below with respect to the module.

[0033] In various configurations, control modules 20a, 20b may include functions, processes, processors, or submodules. Control signals 28a, 28b may be control signals or drive signals and may communicate DC offset or rail voltage, voltage or current magnitude, frequency, and phase components, etc. In various configurations, feedback control signals 28a, 28b may be used as inputs to one or more control loops. In various configurations, multiple control loops may include control loops for RF drive and rail voltage. In various configurations, control signals 28a, 28b may be used in single-input single-output (SISO) or multiple-input multiple-output (MIMO) control schemes. An example of a MIMO control scheme can be found by referring to U.S. Patent No. 10,546,724, “Pulsed Bidirectional Radio Frequency Source / Load,” issued on 28 January 2020, which has been assigned to the assignee of this application and is incorporated herein by reference. In other configurations, signals 28a and 28b can provide feedforward control as described in U.S. Patent No. 10,049,857, which is assigned to the assignee of this application and incorporated herein by reference.

[0034] In various configurations, the power supply system 10 may include a controller 20'. The controller 20' may be located outside of either or both of the RF generators 12a, 12b, and may be referred to as the external or common controller 20'. In various configurations, the controller 20' may implement one or more functions, processes, or algorithms described herein with respect to one or both of the controllers 20a, 20b. Thus, the controller 20' communicates with each of the RF generators 12a, 12b via their respective pairs of links 36, 38, which allow for the exchange of data and control signals between the controller 20' and the RF generators 12a, 12b as appropriate. In various configurations, the controllers 20a, 20b, and 20' can provide distributive and collaborative analysis and control of the RF generators 12a, 12b. In various other configurations, the controller 20' can provide control of the RF generators 12a, 12b, eliminating the need for their respective local controllers 20a, 20b.

[0035] In various configurations, the RF power source 14a, sensor 16a, controller 20a, and matching network 18a may be referred to as the source RF power source 14a, source sensor 16a, source controller 20a, and source matching network 18a. Similarly, in various configurations, the RF power source 14b, sensor 16b, controller 20b, and matching network 18b may be referred to as the bias RF power source 14b, bias sensor 16b, bias controller 20b, and bias matching network 18b. In various configurations, as described above, the term source refers to the RF generator that generates the plasma, and the term bias refers to the RF generator that modulates the plasma's ion potential or IEDF. In various configurations, the source and bias RF power supplies operate at different frequencies. In various configurations, the source RF power supply operates at a higher frequency than the bias RF power supply. In various other configurations, the source and bias RF power supplies operate at the same frequency, or substantially the same frequency.

[0036] Depending on the configuration, the source RF generator 12a and the bias RF generator 12b include multiple ports for external communication. The source RF generator 12a includes a pulse-synchronized output port 40, a digital communication port 42, an RF output port 44, and a control signal port 60. The bias RF generator 12b includes an RF input port 48, a digital communication port 50, and a pulse-synchronized input port 52. The pulse-synchronized output port 40 outputs a pulse-synchronized signal 56 to the pulse-synchronized input port 52 of the bias RF generator 12b. The digital communication port 42 of the source RF generator 12a and the digital communication port 50 of the bias RF generator 12b communicate via a digital communication link 57. The control signal port 60 of the source RF generator 12a receives control signals 30 and / or 30'. The RF output port 44 generates an RF control signal 58 which is input to the RF input port 48. In various configurations, the RF control signal 58 is substantially the same as the RF control signal that controls the source RF generator 12a. In various other configurations, the RF control signal 58 is the same as the RF control signal that controls the source RF generator 12a, but is phase-shifted within the source RF generator 12a according to the requested phase shift generated by the bias RF generator 12b. Thus, in various configurations, the source RF generator 12a and the bias RF generator 12b are driven by substantially equal RF control signals, or by substantially equal RF control signals that are phase-shifted by a predetermined amount.

[0037] Figure 2 shows a voltage-to-time plot illustrating a pulsed or pulsed operating mode for supplying power to a load such as the load 32 in Figure 1. More specifically, Figure 2 shows two multi-state pulses P1 and P2 of a pulsed signal 70, each having multiple states S1-S4 and S1-S3, respectively. In Figure 2, the RF signal 80 is modulated by pulses P1 and P2. When the pulse is ON, as shown in state S1 of P1 and state S1 of P2, the RF generator 12 outputs an RF signal 80 with an amplitude defined by the magnitude of the pulse in each state. Conversely, between state S4 of P1 and state S3 of P2, the pulse is OFF, and the RF generator 12 does not output an RF signal 80. Pulses P1 and P2 can repeat in a constant or variable duty cycle, and each pulse P1 and P2 in states S1-S4 and S1-S3 may have the same or varying amplitude and width. Furthermore, the pulsed signal 70 does not necessarily have to be a square wave, as shown in Figure 2. As a non-limiting example, the pulse signal 70 may be trapezoidal, triangular, Gaussian, or other shapes. Furthermore, pulses P1, P2 may have multiple states S1, ..., Sn of varying amplitude, duration, and shape. States S1, ..., Sn may repeat within a fixed or variable period. Also, as shown in Figure 2, the RF signal 80 operates at a frequency that varies between or within states.

[0038] In a typical RF power supply system, a matching network (e.g., matching network 18a in Figure 1) is tuned to achieve maximum power delivery to the load via tunable mechanical components. Maximum power delivery corresponds to minimum reflected power. Because the response time of the electromechanical tuning elements in the matching network is relatively slow, tuning the matching network may require a relatively extended period to complete power tuning. To improve impedance matching, the RF frequency output by a power amplifier (e.g., power amplifier 14a in Figure 1) may also be tuned. Frequency-based tuning improves performance and provides significantly faster response than tuning the electromechanical components of the matching network.

[0039] When employing frequency-based impedance matching, it is desirable to find the optimal frequency that provides minimum reflected power. Minimum reflected power can be expressed through the minimum absolute value |Γ| of the measured complex reflection coefficient gamma. Several existing methods exist for tuning the RF frequency.

[0040] For example, automated frequency tuning is a standard technique for high-speed impedance matching. By tuning the RF carrier frequency, the RF generator steers toward lower reflected power, compensating for transients in the load, even at pulse state change boundaries. Examples of automated frequency tuning methods include extreme value search control (ESC) techniques and closed-form model-based (e.g., transfer function) techniques. An example of an ECS-based technique for performing automatic or automated frequency tuning can be found by referring to U.S. Patent No. 10,741,363, which is assigned to the assignee of this application and incorporated herein by reference.

[0041] The ESC method minimizes reflected power without requiring extensive knowledge of the process. The ESC method implements a dynamic tuning mechanism for automatically tuning the frequency along the direction of the gradient of the cost function without requiring an explicit model of the system or process. The cost function is sometimes called a functional equation that maps a set of points to a single scalar value. The scalar value resulting from the evaluation of the cost function is sometimes called the cost. In frequency tuning applications, this cost is sometimes called the magnitude of gamma squared or gamma mag squared (|Γ|). 2 ), or it may be associated with output response values ​​such as supplied power. Generally, it is desirable to minimize or maximize costs.

[0042] For example, Figure 3A shows the cost function J (or gamma absolute value squared (|Γ|)). 2)) and a plot 300A of the quadratic cost function 302 as the actuator frequency U. As shown, plot 300A includes a maximum 304 and positions 306, 308 along the cost function 302, with each position 306, 308 on a different side of the maximum 304. Thus, all points to the left of the maximum 304 have a positive slope (or gradient), and all points to the right of the maximum 304 have a negative slope. It is desirable to maximize the cost J. When the actuator frequency is at position 306, the actuator frequency can be increased, thereby causing an increase in the cost J (or output response value). In other embodiments, it is desirable to maximize the cost J. When the actuator frequency is at position 308, the actuator frequency can be decreased, thereby causing an increase in the cost J.

[0043] A similar relationship exists for a quadratic cost function having a minimum. For example, FIG. 3B shows a plot 300B of the cost function J (or gamma absolute value squared (|Γ| 2 )) and the actuator frequency U of the quadratic cost function 310. As shown, plot 300B includes a minimum 312 and positions 314, 316 along the cost function 310, with each position 314, 316 on a different side of the minimum 312. Thus, in this example, all points to the left of the minimum 312 have a negative slope, and all points to the right of the minimum 312 have a positive slope. It is desirable to minimize the cost J. When the actuator frequency is at position 314, the actuator frequency can be increased, thereby causing a decrease in the cost J (or output response value). In other embodiments, it is desirable to minimize the cost J. When the actuator frequency is at position 316, the actuator frequency can be decreased, thereby causing a decrease in the cost J.

[0044] <了 In Figures 3A and 3B, it is desirable to understand the directivity of the actuator frequency U required to move the cost function toward the minimum or maximum value in order to maximize or minimize cost J. In some ESC methods, this can be achieved by injecting a sinusoidal perturbation signal over multiple cycles on the actuator to probe the system's response to a changing actuator frequency (e.g., a change in the cost function). For example, based on the sinusoidal perturbation signal, the output response value changes in magnitude and direction depending on where its current position is relative to the minimum or maximum point (e.g., max 304, min 312) (e.g., positions 306, 308, 314, 316 in Figures 3A and 3B). The output response value may be processed to estimate the local slope (or gradient) of the cost function (e.g., cost functions 302, 310), which indicates the direction of actuator frequency adjustment required to move toward the minimum or maximum point. Examples of ESC methods employing sinusoidal perturbation signals can be found in U.S. Patent No. 10,741,363.

[0045] Figure 4 shows an example of a power supply system 400 including an RF generator 410 that implements an ESC-based approach. As shown, the power supply system 400 provides an output to a match network 412, which in turn provides an output to a load 414, such as a nonlinear load or plasma chamber. The RF generator 410 includes a power controller 416, a power amplifier 418, and a sensor 420. The sensor 420 can be implemented as one of the following: a voltage / current sensor (VI sensor) or a directional coupler, as described above. The power controller 416 receives the operating signal input to the power amplifier 418.

[0046]

number

[0047] Outputs.

[0048]

number

[0049] The signal represents a power control signal in response to the feedback signal. Power amplifier 418 is,

[0050]

number

[0051] An output RF signal is generated to the sensor 420 as commanded. The sensor 420 outputs an RF signal to the match network 412 for application to the load 414. The sensor 420 outputs feedback signals X and Y to block 422. In various embodiments, block 422 may be a scaling or calibration module that scales X and Y to output predetermined electrical parameters. Block 422 outputs forward power values

[0052]

number

[0053] The output is sent to adder 424. Adder 424 also receives the power setpoint input and the forward power value.

[0054]

number

[0055] The difference between (error e) fb Determine the error e. fb However, this is input to the power controller 416. Error signal e input to power controller 416 fb This is performed by the power controller 416 on the power amplifier 418.

[0056]

number

[0057] Determine the desired adjustments to the following.

[0058] Block 422 also outputs the absolute value of the reflection coefficient |Γ|. The absolute value of the reflection coefficient |Γ| is input to block 426, and block 426 outputs the transfer function D to remove any DC bias. filt A high-pass filter is implemented with (z). The filtered absolute value of |Γ| is input to mixer 423. Mixer 423 also receives the perturbation signal generated by signal source 429.

[0059]

number

[0060] It also receives. As shown in the diagram, perturbation signal

[0061]

number

[0062] This is a sine wave signal sin(ω pert Represented as t), it is a sine wave or perturbation frequency ω pert Mixer 423 has a perturbation signal.

[0063]

number

[0064] The measured absolute value |Γ| of the complex coefficient is mixed with the perturbation signal. The output of mixer 423 is the perturbation signal.

[0065]

number

[0066] This represents the scaled positive or negative square of [the value]. The output from mixer 423 is used by integrator D esc (z)425 is input, and integrator D esc (z)425 is a frequency control or frequency feedback signal input to the signal combiner or adder 427.

[0067]

number

[0068] This generates a feedback signal.

[0069]

number

[0070] However, perturbation signal

[0071]

number

[0072] Combined with this, the feedback component or frequency control signal

[0073]

number

[0074] This occurs. Feedback component or frequency control signal

[0075]

number

[0076] This can be described in equation (1) below.

[0077]

number

[0078] however,

[0079]

number

[0080] This is a frequency tuning signal component used to adjust the frequency in order to achieve automatic frequency tuning of the power supply system.

[0081]

number

[0082] This is a perturbed signal, or a perturbed signal component.

[0083] u t esc The signal may be a complete frequency control signal (center frequency and AFT offset) or only an automatic frequency tuning (AFT) offset from the center frequency. In various non-limiting embodiments, if the center frequency of the system is 13.56 MHz, u t esc The signal may represent an offset from 13.56 MHz to enable automatic frequency tuning, or it may be the desired output frequency, for example, 13.58 MHz.

[0084] In various other embodiments, the adder 427 controls the operation of the match network 412 by generating a match control signal u similar to that of equation (1) above. t' esc It may output a signal u t' esc This allows for the control of one of the impedance-tuned actuators, such as a reactive component embodied as a capacitor or inductor, in order to vary the reactance of the match network 412.

[0085] In various embodiments, signals generated in system 400 may be impaired by various signal or noise sources having the same or similar frequencies. For example, frequency control or frequency feedback signals.

[0086]

number

[0087] The perturbation signal used to generate it may have a frequency similar to (and possibly identical to) various other signal or noise sources in the system. This, in turn, can impair the system's ability to measure or potentially use the output response (or output gamma squared absolute value) and / or other related signals. Therefore, it is desirable to select a frequency for the perturbation signal that is within a frequency spectrum free of other strong signal components (e.g., other frequency tones). This allows for the isolation of the resulting related signals so that the local gradient of the cost function can be measured reliably and accurately.

[0088] One source of interference can arise from the pulse train itself. For example, frequency tuners are typically layered in that each tuner is receiving data relating to one state of a pulse (or more pulses). This can result in "apparent" pulse frequencies that fluctuate based on the pulsing setup. For example, the apparent pulse frequency associated with each state can be calculated based on the state's duty cycle, the pulse repetition rate, and the hold-off time associated with the state, as shown in equation (2) below.

[0089]

number

[0090] however, T Pulse This is the pulse period, which is equal to 1 over the pulse repetition rate. The duty cycle is the ratio of the state width over the entire pulse. Holdoff_Time is the duration during which the tuner remains idle during pulse state transitions.

[0091] For example, with a pulse repetition rate of 2 kHz, and a 20% duty cycle and a 50-microsecond hold-off time for one of the pulse states, the tuner will see a significant frequency component (apparent frequency) at 20 kHz from the pulse train itself. If the duty cycle is changed from 20% to 15%, the apparent pulse frequency shifts to 40 kHz.

[0092] For example, Figures 5A and 5B show plots 500A and 500B, illustrating the calculated apparent pulse frequency (Y-axis) as a function of pulse repetition rate (X-axis), duty cycle, and holdoff time, according to equation (2) above. In the example of Figures 5A and 5B, the holdoff time is constant, the holdoff time in Figure 5A is shorter than the holdoff time in Figure 5B, and the pulse repetition rate ranges between values ​​X1 and X2. Additionally, the apparent pulse frequency in Figure 5A ranges between values ​​y1 (e.g., 0Hz) and y2, and the apparent pulse frequency in Figure 5B ranges between values ​​y1 and y3. In this example, the value y3 in Figure 5B is greater than the value y2 in Figure 5A. Lines 502, 504, 506, 508, 510, 512, 514, and 516 in Figures 5A and 5B represent the apparent pulse frequency as it changes with respect to pulse repetition rate while implementing different duty cycles. For example, lines 502 and 510 represent the apparent pulse frequency as a function of the pulse repetition rate and the first duty cycle; lines 504 and 512 represent the apparent pulse frequency as a function of the pulse repetition rate and the second duty cycle; lines 506 and 514 represent the apparent pulse frequency as a function of the pulse repetition rate and the third duty cycle; and lines 508 and 516 represent the apparent pulse frequency as a function of the pulse repetition rate and the fourth duty cycle.

[0093] As seen in Figures 5A and 5B, the data suggest that high perturbation frequencies may be acceptable for a number of repetition rate and duty cycle combinations. However, if the repetition rate is shifted to a higher rate, for example, this perturbation frequency may become too close to the apparent pulse frequency, resulting in a loss of the desired gradient measurement. In practice, in various embodiments, the apparent pulse frequency may be just at the perturbation frequency. Therefore, the data in Figures 5A and 5B may suggest that selecting a relatively higher perturbation frequency may provide some assurance of avoiding the effects of the pulse repetition rate, but small setup changes can dramatically affect the resulting apparent pulse frequency. Thus, for example, only small changes to the holdoff time, duty cycle, and / or repetition rate can significantly affect the resulting apparent pulse frequency and cause interference with the perturbation frequency.

[0094] Additionally, in some embodiments, selecting a high perturbation frequency can lead to other problems in the control system. For example, a frequency tuner constantly modulates the load impedance along with its sinusoidal perturbation signal, and a power controller, such as power controller 416 in Figure 4, may rely on the parameters sensed from the load to control the power amplifier. If the power controller (more specifically, the power control loop) does not have sufficient bandwidth, this disturbance will flow into the power supplied to the load and affect it. Thus, in many cases, a higher perturbation frequency for the frequency tuning loop can result in a reduced ability of the power control loop to reject this disturbance. This is shown in Figure 6.

[0095] For example, Figure 6 shows various waveforms 602, 604, 606, 608, 610, and 612 representing forward power, measured supply power, actual power setpoint, gamma squared, power drive signal, and sinusoidal frequency modulated signal. As seen in Figure 6, the effect of 40 kHz sinusoidal frequency modulation (waveform 612) is clearly visible in the measured supply power (waveform 604). For example, it is desirable to supply constant power to the load. However, 40 kHz sinusoidal frequency modulation causes a + / - 5% supply power fluctuation (e.g., wiggle or ripple) to the supply power. This is because the power control loop does not have sufficient bandwidth to handle 40 kHz sinusoidal frequency modulation. However, if the perturbation frequency is within the controller's bandwidth, the controller can compensate for the impedance fluctuations caused by the frequency tuning loop and maintain constant supply power.

[0096] In view of the above, it is desirable to select a perturbation frequency for the perturbation signal that satisfies various design constraints, as recognized by the inventors. For example, as further described herein, the perturbation frequency is within a window that avoids other signal components (frequencies) that would interfere with the gradient measurement. In other words, the selected perturbation frequency is isolated from other frequency tones in the system (e.g., frequency tones associated with RF generators that utilize the perturbation signal, other RF generators in the system, load components such as plasma chamber components, controllers in the system, etc.). Furthermore, the perturbation frequency is small enough to avoid disturbances to the power control loop (e.g., below the bandwidth limit) and / or large enough to avoid low-frequency components not associated with the perturbation signal.

[0097] This disclosure provides various solutions for selecting and / or adjusting the perturbation frequency of a perturbed signal to satisfy one or more of these various design constraints. For example, the selection and adjustment of the perturbation frequency may be performed dynamically so that the perturbation frequency is below the bandwidth limit of the power control loop while being sufficiently isolated from other frequency tones, such as apparent pulse frequencies and harmonics, within the system. This may be done based on current operating conditions while the system is in use (e.g., online) rather than during the design phase. Doing so improves the tuning performance for ESC-based automatic frequency tuning systems in that the signals in question may be reliable and usable (e.g., undamaged).

[0098] In addition, as will be further described herein, perturbation frequencies may be selected for various scenarios. For example, based on operating conditions, a single perturbation frequency may be selected for each state of a pulse, a single perturbation frequency may be selected for the entire pulse, or a single perturbation frequency may be selected for each corresponding state of multiple pulses (e.g., one perturbation frequency for state S1 of each pulse, another perturbation frequency for state S2 of each pulse, etc.).

[0099] Figure 7 shows an example of a power supply system 700 including an RF generator 710 that implements an ESC-based technique in which the perturbation frequency may be preferably selected according to the teachings herein. As shown, the power supply system 700 includes the match network 412 and load 414 of Figure 4 and the RF generator 710 for providing output to the load 414. The RF generator 710 includes the power controller 416 of Figure 4, a power amplifier 418, a sensor 420, a control block 422 (e.g., including a scaling or calibration module), a mixer 423, an adder 424, a control block 425 (e.g., including an integrator), a control block 426 (e.g., including a high-pass filter), a signal combiner or adder 427, and a perturbation signal source 429. These components function and interact in the same manner as described above. In addition, the RF generator 710 receives the perturbation signal generated by the signal source 429.

[0100]

number

[0101] Includes a frequency selector control block (or module) 702 for selecting a desired perturbation frequency.

[0102] According to various embodiments, various parts of the RF generator 710 may be considered to cooperate to define a frequency controller, such as an extreme-finding frequency controller. For example, in various embodiments, the frequency controller may include all or part of the mixer 423, control block 425, adder 427, perturbation signal source 429, and / or frequency selector block 702. In other embodiments, the frequency controller may include, for example, the control block 425 and receive a perturbation signal-based signal from the signal source 429. In addition, according to various embodiments, various or all of the control elements in Figure 7 may be implemented using controllers such as controllers 20a, 20b, 20' in Figure 1. For example, in Figure 7, all or part of the power controller 416, control block 422, mixer 423, adder 424, control block 425, control block 426, adder 427, perturbation signal source 429, and / or frequency selector control block 702 may be implemented as controllers 20a, 20b, 20' in Figure 1.

[0103] In various embodiments, the frequency selector block 702 may determine one or more frequency tones associated with RF generator 710 and / or other RF generators in system 700, and then select a perturbation frequency to be separated from the frequency tone. For example, the frequency selector block 702 may take in or optionally receive various known operating parameters, and then select a desired perturbation frequency based on the operating parameters. For example, operating parameters may include pulse repetition rate, state duty cycle, and / or hold-off time associated with RF generator 710, operating frequencies associated with one or more other RF generators in RF generator 710 and / or system 700, harmonic aliases, etc. In various embodiments, the operating frequencies of the RF generators may generate a beat frequency tone (e.g., the difference between the operating frequencies of the RF generators). Based on this data or a portion thereof, the frequency selector block 702 may calculate an apparent frequency (e.g., a frequency tone) associated with a particular state of the pulse as described above, and then select an appropriate perturbation frequency to avoid that apparent frequency, any related frequencies (e.g., harmonics of the apparent frequency), and other frequency tones (e.g., a beat frequency tone). In other words, the perturbation frequency may be selected to ensure robust isolation from the apparent frequency, its related frequencies, and / or other known frequency tones.

[0104] The operating parameters may include information for a single state of a pulse, for multiple states of a single pulse, for multiple states of multiple pulses, and so on. Therefore, the frequency selector block 702 may, depending on the provided operating parameters, calculate, or possibly determine, the apparent frequency associated with a single state in a pulse, and / or the apparent frequency associated with multiple states in a pulse (or multiple pulses). In some examples, the apparent frequency for one state may be the same as, or different from, the apparent frequency for another state.

[0105] Once the apparent frequencies for a single state or for multiple states are determined, the frequency selector block 702 may select an appropriate perturbation frequency. For example, the frequency selector block 702 may select a single perturbation frequency for each distinct state in a pulse. This may be necessary, for example, if the determined apparent frequencies for multiple states are such that there are no suitable frequencies available to avoid each apparent frequency. In other examples, the same perturbation frequency may be selected and used for multiple states of a pulse (if possible) or multiple corresponding states of multiple pulses (if possible), based on operating parameters. For example, the frequency selector block 702 may determine that multiple states in one or more pulses have apparent frequencies that are similar enough to allow the selection of a single perturbation frequency that avoids each of their apparent frequencies.

[0106] In other embodiments, as further described below, the frequency selector block 702 may determine one or more frequency tones associated with the RF generator 710 based on the measured feedback and an analysis of that feedback. For example, the frequency selector block 702 may perform a transformation (e.g., a fast Fourier transform (FFT)) to analyze data from one or more feedback signals, such as gamma squared, reflected power, etc., and determine one or more frequency tones based on the analyzed data. Once the frequency tones are determined, the frequency selector block 702 may select appropriate perturbation frequencies to avoid the frequency tones.

[0107] Additionally, in selecting the perturbation frequency, the frequency selector block 702 may take into account the bandwidth limit of the power controller 416. For example, the frequency selector block 702 may select a frequency that is below a known control bandwidth limit while also avoiding frequency tones (e.g., apparent pulse frequencies for each state).

[0108] Figures 8A and 8B illustrate exemplary methods of such selection. For example, as shown in Figures 8A and 8B, the frequency selector block 702 may receive, or possibly determine, a bandwidth limit 804 of a control loop, such as a power control loop associated with the power controller 416. After determining the frequency tone, such as the apparent frequency, the frequency selector block 702 may select an optimal perturbation frequency to avoid both the frequency tone and the bandwidth limit 804.

[0109] For example, in Figure 8A, it is determined that the apparent frequency 806 is closer to the bandwidth limit 804 than the bandwidth DC value (0Hz) 802. In other words, delta 1 between the DC value 802 and the apparent frequency 806 is greater than delta 2 between the apparent frequency 806 and the bandwidth limit 804. In such an example, the frequency selector block 702 selects the perturbation frequency 808 so that it falls within delta 1 (the larger of the two deltas in Figure 8A). In other words, the perturbation frequency 808 is set to be equal to a frequency value or point within delta 1.

[0110] However, in Figure 8B, it is determined that the apparent frequency 816 is closer to the DC value 802 than to the bandwidth limit 804. Therefore, the delta 2 between the apparent frequency 816 and the bandwidth limit 804 is greater than the delta 1 between the DC value 802 and the apparent frequency 816. Thus, in this example, the frequency selector block 702 selects the perturbation frequency 818 so that it falls within delta 2 (the larger of the two deltas in Figure 8B). In other words, the perturbation frequency 818 is set to be equal to a frequency value or point within delta 2.

[0111] In various embodiments, the frequency selector block 702 selects the perturbation frequency so that it lies at the midpoint of a larger delta. For example, in Figure 8A, the perturbation frequency 808 is selected so that it lies at the midpoint of delta 1, whereas in Figure 8B, the perturbation frequency 818 is selected so that it lies at the midpoint of delta 2. This can ensure that the perturbation frequency is sufficiently far from the bandwidth limit 804, the DC value 802, and the apparent frequency 816. Thus, this can ensure that the perturbation frequency is sufficiently small (e.g., below the bandwidth limit) to avoid disturbances to the power control loop, sufficiently large to avoid low-frequency components not associated with the perturbation signal, and isolated from the apparent frequency 816. Otherwise, if the perturbation frequency is too close to the apparent frequency 816, the frequency controller may not be able to tune to the minimum or maximum of the cost function (or gamma absolute value squared) and instead may tune to another, less desirable value.

[0112] In other embodiments, the frequency selector block 702 may select a different perturbation frequency that is not necessarily at the midpoint of the maximum delta, but still maintains a sufficient distance from the bandwidth limit 804, the DC value 802, and the apparent frequency 816. For example, the frequency selector block 702 may select the lowest possible perturbation frequency at any delta (larger or smaller delta) that is at least a minimum distance from the apparent pulse frequency 816 (e.g., + / -2.5kHz, + / -5kHz, etc.) but also maintains a defined distance from the DC value 802 or the bandwidth limit 804 (e.g., 5kHz, 10kHz, etc., depending on other frequency tones in the system, the value of the bandwidth limit, etc.).

[0113] In various embodiments, the frequency selector block 702 may select an initial perturbation frequency such that it is at a point or frequency value (e.g., midpoint, not midpoint, etc.) in one of deltas 1, 2, and then adjust the perturbation frequency to another point or frequency value in delta. For example, once the initial perturbation frequency is determined by the frequency selector block 702, data from a feedback signal (e.g., the absolute value squared of gamma or another signal) may be observed and analyzed. If the feedback signal indicates that the operating parameters of system 700 and / or RF generator 710 meet a threshold (e.g., the quibble of the supplied power is below a defined threshold), the frequency selector block 702 may adjust the perturbation frequency to another point further away from the apparent pulse frequency 816, for example. The adjustment of the perturbation frequency may be repeated until the feedback signal indicates that the threshold is not met (e.g., the quibble of the supplied power is at the defined threshold). Therefore, in such examples, the distance from the apparent pulse frequency 816 can be increased while still maintaining a sufficient distance from the bandwidth limit 804 and the DC value 802.

[0114] In some embodiments, it may be desirable to use the same perturbation frequency for multiple pulse states. This may allow for the reuse of some common elements (e.g., high-pass filters in a feedback loop) across multiple pulse states. As a result, improved resource utilization efficiency can be achieved in some implementations, such as FPGA implementations that utilize at least some common elements. In these embodiments, it then becomes necessary to select a single perturbation frequency.

[0115] For example, along with pulse state holdoff, a known pulsing setup can be analyzed to calculate the apparent pulse frequencies that the tuner will see for each state. Using this information, a desired exclusion zone (e.g., a bandwidth of frequencies close to each apparent pulse frequency) can be identified as an area of ​​operation that should be avoided.

[0116] Figures 9 and 10 illustrate exemplary methods of such selection. For example, Figure 9 shows a plot 900 illustrating apparent pulse frequency curves for a pulsed configuration with a defined holdoff time and for four different pulsed duty cycle values. As shown, exclusion zone 902 centers on the apparent pulse frequency curve at the first duty cycle value, exclusion zone 904 centers on the apparent pulse frequency curve at the second duty cycle value, exclusion zone 906 centers on the apparent pulse frequency curve at the third duty cycle value, and exclusion zone 908 centers on the apparent pulse frequency curve at the fourth duty cycle value. In this embodiment, each exclusion zone 902, 904, 906, and 908 represents a 5 kHz region on each side of its corresponding apparent frequency curve.

[0117] Once an exclusion zone is identified, the frequency selector block 702 may select a single perturbation frequency for multiple pulse states, for example, based on the pulse repetition rate. For example, the exclusion zones or regions in Figure 9 may be overlaid using a specific pulse repetition rate to identify possible perturbation frequencies to avoid each of the exclusion zones or regions.

[0118] For example, Figure 10A shows a plot 1000A of the obtained overlay of exclusion zones or regions in Figure 9 with respect to a first pulse repetition rate. As shown in the figure, line 1002 has a value of 0 from frequency value x0 (e.g., 0 Hz (DC)) to frequency value x1, indicating that the perturbation frequency is unsuitable in this region. This represents exclusion zones 908, 906, and 904 in Figure 9 at the first pulse repetition rate. Next, line 1002 has a value of 1 from frequency value x1 to frequency value x2, indicating that the perturbation frequency is suitable in this second region. This represents exclusion zones 904 and 902 in Figure 9. Line 1002 again has a value of 0 from frequency value x2 to frequency value x3, indicating that the perturbation frequency is unsuitable in this region. This represents exclusion zone 902 in Figure 9. Next, line 1002 again has a value of 1 from frequency value x3 to frequency value x4, indicating that the perturbation frequency may be suitable in this region. This represents the region between the exclusion zone 902 in Figure 9 and the bandwidth limit of the power control loop. In such an example, the frequency selector block 702 may identify the most favorable region (e.g., between frequency values ​​x1 and x2) and select a perturbation frequency within that region (e.g., at the midpoint between frequency values ​​x1 and x2) for a plurality of pulse states having a first pulse repetition rate.

[0119] Figure 10B is similar to plot 1000A, but shows plot 1000B with the obtained overlay of the exclusion zones or regions from Figure 9 for a second pulse repetition rate that is greater than the first pulse repetition rate. As shown in the figure, line 1004 has values ​​of 0 from frequency value x0 (e.g., 0 Hz (DC)) to frequency value x5 (representing exclusion zones 908 and 906 in Figure 9 at the second pulse repetition rate), values ​​of 1 from frequency value x5 to frequency value x6 (representing the region between exclusion zones 906 and 904), values ​​of 0 from frequency value x6 to frequency value x7 (representing exclusion zone 904), and values ​​of 1 from frequency value x7 to frequency value x8 (representing the region between exclusion zone 904 and the bandwidth limit of the power control loop). In such an example, the frequency selector block 702 may again identify the most suitable region (between frequency values ​​x7 and x8) and select a perturbation frequency within that region (for example, at the midpoint between frequency values ​​x7 and x8) for a plurality of pulse states having a second pulse repetition rate.

[0120] In various embodiments, the frequency selector block 702 may take into account the entire set of pulsing conditions to select the most appropriate single perturbation frequency for multiple pulses. For example, calculating the logical AND of the two profiles shown in Figures 10A and 10B would indicate a particular operating perturbation frequency as the most appropriate.

[0121] In various embodiments, the acceptable operating region (or, conversely, the undesirable exclusion zone) may vary with the pulse repetition rate and duty cycle. For example, Figure 10C shows plot 1000C of the obtained overlay of the exclusion zone or region in Figure 9 for three different repetition rates (represented by lines 1006, 1008, and 1010) and four different duty cycles for four pulse states. Using the data from plot 1000C, the frequency selector block 702 may calculate the logical AND of the three profiles shown in Figure 10C to generate plot 1000D in Figure 10D. As shown, plot 1000D includes line 1012, which has values ​​of 0 from frequency value x0 (e.g., 0 Hz (DC)) to frequency value x9, indicating an undesirable region for the perturbation frequency, and values ​​of 1 from frequency value x9 to frequency value x10, indicating a suitable region for the perturbation frequency. In such an example, the frequency selector block 702 may select a perturbation frequency within a suitable region (for example, at the midpoint between frequency values ​​x9 and x10) for a plurality of pulses having any one of three different pulse repetition rates.

[0122] In some cases, overlapping constraints may prevent a single perturbation frequency from occurring across the entire set of pulses. Therefore, in such examples, the frequency selector block 702 can iteratively identify the minimum set of suitable operating perturbation frequencies. In such scenarios, instead of calculating the logical AND of the three profiles shown in Figure 10C, the frequency selector block 702 can calculate the sum of the profiles. The frequency that produces the largest sum indicates the frequency that satisfies the most overlapping pulse constraints. By selecting the frequency with the largest sum, the frequency selector block 702 can then exclude these pulsating conditions and recalculate the sum across the remaining (not included) pulsating conditions. Thus, by selecting the frequency with the largest sum, the frequency selector block 702 can iteratively identify the minimum set of perturbation frequencies required to satisfy all the pulsating conditions in a given recipe.

[0123] In various embodiments, the frequency selector block 702 may also take into account other frequency tones that may be present in the system (e.g., other than the apparent pulse frequency) when selecting a perturbation frequency. In other words, the frequency selector block 702 may determine other frequency tones that should be avoided. For example, the frequency selector block 702 may take into account known harmonic aliases for one of the RF frequencies (e.g., harmonics of the apparent pulse frequency), beat frequencies occurring between two RF carrier frequencies, and / or, for example, perturbation frequencies associated with another RF generator when an RF generator is harmoniously pulsed. These additional frequency tones may take the form of a single frequency or an exclusion zone (a set of frequencies that will be avoided), as described above. For example, using the frequency selection method described above, the frequency selector block 702 may select appropriate perturbation frequencies that are isolated from (e.g., avoided) such frequency tones or constraints by selecting perturbation frequencies through overlapping constraints.

[0124] In some embodiments, potentially interfering signal components, including apparent pulse frequencies and other frequency tones, can be determined via online frequency analysis. This allows for the identification of potentially unexpected signal components (e.g., strong harmonics) that may impair gradient measurements. For example, the frequency selector block 702 may collect a set of feedback data (e.g., gamma squared, reflected power) over a given operating pulse, state in the pulse, etc., and perform a transformation (e.g., Fast Fourier Transform (FFT)) to analyze the data. Based on this transformation analysis, the frequency selector block 702 can determine possible interfering signal components (e.g., interfering frequency tones).

[0125] For example, Figure 11A shows plot 1100A, which displays the spectrum (amplitude and frequency) of data for operating conditions based on feedback data analyzed using FFT. As shown in the figure, plot 1100A includes several potentially interfering frequency tones 1102, 1104, 1106A-I. In detail, in Figure 11A, frequency tone 1102 represents an identified apparent pulse frequency, frequency tone 1104 represents an identified harmonic of the apparent pulse frequency 1102, and frequency tones 1106A-I represent other potentially interfering signals (which are not identifiable). Once the potentially interfering signal components are determined, the frequency selector block 702 may identify one or more preferred regions (e.g., the maximum region) among the frequency tones 1102, 1104, 1106A-I, and then select perturbation frequencies for each state, multiple states in a pulse, or multiple corresponding states in multiple pulses in one of the regions. For example, based on the determined signal components, the frequency selector block 702 may select a perturbation frequency such that it falls within the region between frequency tones 1106C to D (for example, at the midpoint between frequency tones 1106C to D) or within the region between frequency tones 1106E to F (for example, at the midpoint between frequency tones 1106E to F).

[0126] Furthermore, in some embodiments, the perturbation frequency may be selected first (for example, by the frequency selector block 702), and the frequency selector block 702 may collect and analyze (for example, by performing an FFT) a set of feedback data over a given operating pulse, state in the pulse, etc., based on the output response of the perturbation frequency. In doing so, the frequency selector block 702 may determine potentially interfering signal components close to the perturbation frequency.

[0127] For example, Figure 11B shows plot 1100B, which is similar to plot 1100A in Figure 11A, but shows the spectrum (amplitude and frequency) of the data based on the output response of the selected perturbation frequency. In detail, plot 1100B includes the frequency tones 1102, 1104, 1106A-I and the perturbation frequency 1108 from Figure 11A. Based on the data in plot 1100B, it can be seen that the perturbation frequency 1108 is located near several frequency tones, such as tones 1104, 1106D, E, etc. Therefore, in this example, the frequency selector block 702 may select a different perturbation frequency or adjust the perturbation frequency 1108 based on the output response. For example, similar to Figure 11A, the frequency selector block 702 may select a different perturbation frequency or adjust the perturbation frequency 1108 so that it falls within the region between frequency tones 1106C-D or between frequency tones 1106E-F. In various embodiments, a data spectrum (amplitude and frequency) can be generated based on the output response of a newly selected perturbation frequency, ensuring that the new frequency does not strongly overlap with another signal source.

[0128] In various embodiments, a desired perturbation frequency may be determined during the online learning / training phase. For example, during the online learning / training phase, the determination and selection of perturbation frequency values ​​may be performed for different setups (e.g., different pulsation conditions). In some examples, the perturbation frequency values ​​may be selected based on data provided by the transformation, as described herein. In this way, one or more specific perturbation frequency values ​​may be applied each time a particular setup is implemented in the future. Furthermore, when a new setup with different operating conditions is developed, one or more perturbation frequency values ​​may be selected for each new setup.

[0129] In various embodiments, the systems and methods herein may implement various control processes after selecting a perturbation frequency. For example, after selecting a perturbation frequency, the systems and methods herein may implement any one of the control processes / systems described in U.S. Patent No. 10,741,363 with respect to Figures 17 to 22.

[0130] Figure 12 shows the control module 1200. The control module 1200 incorporates various components from Figures 1, 4, and 7. The control module 1200 may include an amplitude control module 1202, a frequency control module 1204, a match network control module 1206, a perturbation module 1208, a frequency tuning module 1210, and a cost determination module 1212. As shown, the perturbation module 1208 includes a frequency selector module 1214. In various embodiments, the control module 1200 includes one or more processors that execute code associated with modules 1202, 1204, 1206, 1208, 1210, 1212, and 1214. Operation using one or more of modules 1202, 1204, 1206, 1208, 1210, 1212, and 1214 is described below with respect to the methods shown in Figures 13 to 16. In addition, in various embodiments, operation using one or more of modules 1202, 1204, 1206, 1208, 1210, and 1212 is described in U.S. Patent No. 10,741,363 with respect to the methods shown in Figures 17 to 22.

[0131] For further defined structures of controllers 20a, 20b, and 20' in Figure 1, and / or the various control elements in Figures 4 and 7, see the flowcharts in Figures 13–16 provided below, the flowcharts in Figures 17–22 of U.S. Patent No. 10,741,363, and the definition for the term “module” provided below. The systems disclosed herein may be operated using numerous methods, examples, and various control system methods, some of which are shown in Figures 13–16. The following operations are primarily described with respect to the implementations in Figures 1, 4, and 7, but the operations can be readily modified to apply to other implementations of the disclosure. The operations may be performed iteratively. The following operations are shown and primarily described as being performed sequentially, but one or more of the following operations may be performed while one or more of the other operations are being performed.

[0132] Figure 13 shows a flowchart of the control process 1300 for perturbation frequency selection in an RF generator, such as the RF generator 710 in Figure 7. The control starts in block 1302, where initialization takes place. The control then proceeds to block 1304.

[0133] In block 1304, the control receives operating parameters associated with the RF generator. In various embodiments, the operating parameters may include the duty cycle of a pulse state, the pulse repetition rate, and the holdoff time associated with a state. In other embodiments, the operating parameters may include, for example, the duty cycle of multiple states of a pulse, the pulse repetition rate, and the holdoff time associated with a pulse state, and / or the duty cycle of multiple states of multiple pulses, the pulse repetition rate, and the holdoff time associated with multiple pulse states. The control then proceeds to block 1306.

[0134] In block 1306, the control determines, or optionally identifies, one or more potentially interfering frequency tones. For example, a potentially interfering frequency tone may be determined according to any of the methods described herein, such as determining one or more apparent pulse frequencies, determining one or more exclusion zones associated with the apparent pulse frequencies, etc. Once the potentially interfering frequency tone has been determined, the control proceeds to block 1308.

[0135] In block 1308, the control selects one or more suitable perturbation frequencies that are far from the determined frequency tone. In other words, the control selects suitable perturbation frequencies that are sufficiently isolated from the frequency tone. This selection of one or more perturbation frequencies may be carried out according to any one of the methods described herein. For example, the control may select perturbation frequencies that fall within a region (e.g., the midpoint of a region) such as between frequency tones, between exclusion zones, between frequency tones and bandwidth limits, or between DC values ​​and frequency tones. Once the control has selected one or more perturbation frequencies in block 1308, the control may proceed to block 1310, thereby ending process 1300 (as shown in Figure 13), or, if desired, return to block 1304.

[0136] Figure 14 shows a flowchart of another exemplary control process 1400 for perturbation frequency selection in an RF generator, such as the RF generator 710 in Figure 7. The control starts in block 1402, where initialization takes place. The control proceeds to block 1404. In block 1404, the control receives one or more feedback signals associated with the RF generator. For example, feedback data associated with the absolute value squared of gamma, reflected power, and / or other relevant data may be provided by or derived from the feedback signals. The control then proceeds to block 1406.

[0137] In block 1406, the control performs a transformation to analyze data in or derived from the feedback signal. For example, the control may perform an FFT or another suitable transformation to analyze such data. The control then proceeds to block 1408.

[0138] In block 1408, the control determines, or optionally identifies, one or more potentially interfering frequency tones. For example, potentially interfering frequency tones may be determined according to any of the methods described herein, such as by determining frequency tones across the spectrum for operating conditions based on analyzed feedback data. The control then proceeds to block 1410.

[0139] In block 1410, the control selects one or more preferred perturbation frequencies away from the determined frequency tone. This selection may be carried out in a manner similar to that of block 1308 in Figure 13. Once the control has selected one or more perturbation frequencies in block 1410, the control proceeds to block 1412, thereby ending process 1400 (as shown in Figure 14), or, if desired, returning to block 1404.

[0140] Figure 15 shows a flowchart of another exemplary control process 1500 for perturbation frequency selection in an RF generator, such as the RF generator 710 in Figure 7. The control starts in block 1502, where initialization takes place. The control proceeds to block 1504. In block 1504, the control receives, or possibly determines, the bandwidth of a power controller associated with the RF generator, such as the power controller 416 in Figure 7. The control proceeds to block 1506.

[0141] In block 1506, the control determines, or possibly identifies, one or more potentially interfering frequency tones. This determination of potentially interfering frequency tones can be carried out in the same manner as in blocks 1306 and 1408 in Figures 13 and 14. The control then proceeds to block 1508.

[0142] In block 1508, the control determines the delta between the lower or minimum bandwidth limit (e.g., DC or 0 Hz) and one of the frequency tones, and between the same or different frequency tones and the upper or maximum bandwidth limit. This can be done, for example, by taking the difference between the lower bandwidth limit and the frequency tone, and the difference between the upper bandwidth limit and the frequency tone. The control then proceeds to block 1510, where the largest of the deltas is identified. The control then proceeds to block 1512.

[0143] In block 1512, the control selects a perturbation frequency at the midpoint of the maximum delta. For example, after determining the maximum delta, the control may divide the value of the delta by 2 and then select a perturbation frequency to place at the divided value. Alternatively, the control may select a perturbation frequency at another preferred point (e.g., a frequency value) within the maximum delta, as described herein. The control then proceeds to block 1514, where it generates a perturbation signal based on the selected perturbation frequency (e.g., at the midpoint of the maximum delta or another frequency value). The control then proceeds to blocks 1516 and 1518.

[0144] In block 1516, the control analyzes feedback response data associated with the selected perturbation frequency, as described herein. In block 1518, the control determines whether the data indicates that a defined threshold is met (for example, that the small fluctuations in the supplied power are below the defined threshold). If not, the control proceeds to block 1520. If yes, the control proceeds to block 1522, thereby terminating process 1500 (as shown in Figure 15), or, if desired, returning to block 1504.

[0145] In block 1520, the control adjusts the selected perturbation frequency at another point (e.g., a frequency value) in the maximum delta, or selects a different perturbation frequency. The control then returns to block 1514.

[0146] Figure 16 shows a flowchart of another exemplary control process 1600 for perturbation frequency selection in an RF generator, such as the RF generator 710 in Figure 7. The control starts in block 1602, where initialization is performed. The control proceeds to block 1604. In block 1604, the control receives one or more feedback signals associated with the RF generator, from which feedback data associated with, for example, the absolute value squared of gamma, reflected power, and / or other relevant data may be provided or derived. The control then proceeds to blocks 1606, 1608, and 1610. In block 1606, the control performs transformations to analyze data in or derived from the feedback signals, for example, in a manner similar to that described in block 1406 of Figure 14. In block 1608, the control determines, or possibly identifies, one or more potentially interfering frequency tones, for example, in a manner similar to that described in block 1408 of Figure 14. In block 1610, the control selects one or more preferred perturbation frequencies away from the determined frequency tone, for example, in a manner similar to that described in block 1410 of Figure 14. The control then proceeds to blocks 1612, 1614, and 1616.

[0147] In block 1612, the control generates a perturbation signal based on the selected perturbation frequency. For example, in block 1614, in a manner similar to that described in blocks 1516 and 1518 of Figure 15, the control analyzes the feedback response data associated with the selected perturbation frequency, and in block 1616, the control determines whether the data indicates that a defined threshold is met. If the threshold is not met in block 1616, the control proceeds to block 1618. Otherwise, the control proceeds to block 1620, thereby terminating process 1600 (as shown in Figure 16), or, if desired, returning to block 1604.

[0148] In block 1618, the control adjusts the selected perturbation frequency at another point (e.g., a frequency value) away from the determined frequency tone, or selects a different perturbation frequency. The control then returns to block 1612.

[0149] The systems and methods described herein may, in various configurations, provide one or more of the following advantages. For example, the systems and methods described herein may enable dynamic optimization of perturbation frequencies for ESC-based frequency tuning control. As a result, the robustness of perturbation-based signal extraction (e.g., gradient measurement) may be improved, thereby improving ESC-based frequency tuning control with respect to known pulsing artifacts and other signal components occurring within the system. In addition, the systems and methods described herein may enable optimization over a single pulsing condition or over an entire pulsing recipe. Thus, the number of perturbation frequency changes required within the system may be minimized. Furthermore, the systems and methods described herein may improve efficiency through online adjustment of perturbation frequencies based on current or previous operating conditions, setup, etc., as described herein.

[0150] The above description is essentially illustrative and is not intended to limit the Disclosure, its application, or its use. The broad teachings of this Disclosure can be implemented in various forms. Therefore, although this Disclosure includes certain examples, the true scope of this Disclosure should not be limited in this way, as other variations become apparent when considering the drawings, specification, and the claims below. In the specification and claims, one or more steps within a method may be performed in a different order (or in parallel) without altering the principles of this Disclosure. Similarly, one or more instructions stored on a non-temporary computer-readable medium may be performed in a different order (or in parallel) without altering the principles of this Disclosure. Unless otherwise specified, the numbering or other labeling of instructions or method steps is for convenient reference only, and not to indicate a fixed order.

[0151] Furthermore, while each embodiment has been described above as having several features, any one or more of those features described in relation to any embodiment of the Disclosure may be implemented in and / or combined with any feature of any other embodiment, even if such combination is not explicitly described. In other words, the embodiments described are not mutually exclusive, and any rearrangement of one or more embodiments remains within the scope of the Disclosure.

[0152] The spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using a variety of terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as “direct,” when a relationship between a first element and a second element is described in the above disclosure, that relationship may be a direct relationship in which no other intervening elements exist between the first element and the second element, or it may be an indirect relationship in which one or more intervening elements (either spatially or functionally) exist between the first element and the second element.

[0153] The phrase "at least one of A, B, and C" should be interpreted as meaning a logic (A OR B OR C) using non-exclusive logic OR, and not as meaning "at least one of A, at least one of B, and at least one of C". The term "set" does not necessarily exclude empty sets—in other words, in some situations a "set" can have zero elements. The term "non-empty set" can be used to indicate the exclusion of empty sets—in other words, a non-empty set will always have one or more elements. The term "subset" does not necessarily require a suitable subset. In other words, a "subset" of a first set can be identifiable (equal) to the first set. Furthermore, the term "subset" does not necessarily exclude empty sets—in some situations a "subset" can have zero elements.

[0154] In the diagram, the direction of the arrowhead generally indicates the flow of information (such as data or instructions) related to the example. For example, if elements A and B exchange various pieces of information, and the information sent from element A to element B is related to the example, the arrow may point from element A to element B. This unidirectional arrow does not imply that there is no other information sent from element B to element A. Furthermore, in response to information sent from element A to element B, element B may send a request for the information or an acknowledgment of receipt of the information to element A.

[0155] In this application, the term “module” may be replaced by the term “controller” or “circuit,” including the following definitions. In this application, the term “controller” may be replaced by the term “module.” The term “module” refers to, is part of, or may include, some or all of the above, such as application-specific integrated circuits (ASICs), digital, analog, or mixed analog / digital discrete circuits, digital, analog, or mixed analog / digital integrated circuits, combinational logic circuits, field-programmable gate arrays (FPGAs), processor hardware (shared, dedicated, or group) that executes code, memory hardware (shared, dedicated, or group) that stores code executed by the processor hardware, other suitable hardware components that provide the described functionality, or a system on a chip.

[0156] A module may include one or more interface circuits. In some examples, the interface circuits may implement wired or wireless interfaces that connect to a local area network (LAN) or a wireless personal area network (WPAN). Examples of LANs include IEEE standard 802.11-2020 (also known as the WIFI wireless networking standard) and IEEE standard 802.3-2018 (also known as the ETHERNET wired networking standard). Examples of WPANs include IEEE standard 802.15.4 (including the ZIGBEE standard from the ZigBee® Alliance) and the BLUETOOTH® wireless networking standard from the Bluetooth Special Interest Group (SIG) (including core specification versions 3.0, 4.0, 4.1, 4.2, 5.0, and 5.1 from the Bluetooth SIG).

[0157] Modules can communicate with other modules using interface circuits. While modules may be shown in this disclosure as communicating directly and logically with other modules, in various implementations, modules can actually communicate via a communication system. The communication system includes physical and / or virtual networking devices, such as hubs, switches, routers, and gateways. In some implementations, the communication system connects to or traverses a wide area network (WAN), such as the Internet. For example, the communication system may include multiple LANs connected to each other over the Internet or over point-to-point dedicated lines using technologies including Multiprotocol Label Switching (MPLS) and Virtual Private Networks (VPNs).

[0158] In various implementations, the functionality of a module can be distributed among multiple modules connected via a communication system. For example, multiple modules may implement the same functionality distributed by a load balancing system. In a further example, the functionality of a module can be divided between a server (also known as a remote or cloud) module and a client (or user) module. For example, a client module may include a native or web application that runs on a client device and communicates with the server module over a network.

[0159] Some or all of the module's hardware features may be defined using a hardware description language, such as IEEE standard 1364-2005 (commonly known as "Verilog") and IEEE standard 1076-2008 (commonly known as "VHDL"). Hardware description languages ​​may be used to manufacture and / or program hardware circuits. In some implementations, some or all of the module's features may be defined by a language such as IEEE 1666-2005 (commonly known as "SystemC"), which encompasses both the code and hardware description described below.

[0160] The term "code" as used above may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. Shared processor hardware encompasses a single microprocessor that executes some or all of the code from multiple modules. Group processor hardware encompasses a microprocessor, in combination with additional microprocessors, that executes some or all of the code from one or more modules. References to multiple microprocessors include multiple microprocessors on a discrete die, multiple microprocessors on a single die, multiple cores in a single microprocessor, multiple threads in a single microprocessor, or a combination of the above.

[0161] Memory hardware can store data along with or separately from code. Shared memory hardware encompasses a single memory device that stores some or all of the code from multiple modules. An example of shared memory hardware might be a level 1 cache on or near a microprocessor die, which can store code from multiple modules. Another example of shared memory hardware might be persistent storage, such as a solid-state drive (SSD), which can store code from multiple modules. Group memory hardware encompasses a memory device, in combination with other memory devices, that stores some or all of the code from one or more modules. An example of group memory hardware is a storage area network (SAN), which can store the code of a particular module across multiple physical devices. Another example of group memory hardware is the random access memory of each server in a set, which, in combination, stores the code of a particular module.

[0162] The term "memory hardware" is a subset of the term "computer-readable media." As used herein, the term "computer-readable media" does not encompass transient electrical or electromagnetic signals that propagate through a medium (such as on a carrier wave), and therefore, the term "computer-readable media" is considered tangible and non-transient. Non-exclusive examples of non-transient computer-readable media include non-volatile memory devices (such as flash memory devices, erasable programmable read-only memory devices, or mask read-only memory devices), volatile memory devices (such as static random-access memory devices or dynamic random-access memory devices), magnetic storage media (such as analog or digital magnetic tape, or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0163] The apparatus and methods described in this application may be partially or entirely implemented by a dedicated computer, which is created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. Such apparatus and methods may be described as computerized apparatus and computerized methods. The functional blocks and flowchart elements described above serve as software specifications, which can be converted into computer programs through the routine work of a skilled technician or programmer.

[0164] A computer program includes processor-executable instructions stored on at least one non-temporary computer-readable medium. A computer program may also include or rely on stored data. A computer program may encompass a basic input / output system (BIOS) that interacts with the hardware of a dedicated computer, device drivers that interact with specific devices of the dedicated computer, one or more operating systems, user applications, background services, background applications, and the like.

[0165] A computer program may include (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, and (v) source code for compilation and execution by a just-in-time compiler. As a simple example, source code can be written using syntax from languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, JavaScript®, HTML5 (Hypertext Markup Language, 5th Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB®, SIMULINK®, and Python®. [Explanation of Symbols]

[0166] 10 RF generator or power supply system, power supply system 12, 410, 710 RF Generator 12a Radio frequency (RF) generator or power supply, RF generator, source RF generator, RF power generator 12b Radio frequency (RF) generators or power supplies, RF generators, bias RF generators, RF power generators 14a RF power source or amplifier, RF power source, power amplifier, power source, source RF power source 14b RF power source or amplifier, RF power source, power amplifier, power source, bias RF power source 16a sensor, source sensor 16b sensor, bias sensor 18a Matched network, source matched network 18b Harmonized networks, biased harmonized networks 20a Processor, controller, or control module, power controller or control module, control module, local controller, source controller 20b Processor, controller, or control module, power controller or control module, control module, local controller, bias controller 20" controller, external or common controller 22a, 22b RF power signal 24a, 24b X signal 26a, 26b Y signal 28a, 28b Feedforward or feedback control signal, control signal, feedback control signal, signal 29a, 29b Control signals 30 Control signals, synchronous or trigger signals, trigger signals, trigger or synchronous signals, signals 30' Control signal, sync or trigger signal, trigger or sync signal, signal 32,414 load 34 Synchronized Bias Detector Links 36 and 38 40 pulse-synchronous output ports 42, 50 Digital communication ports 44 RF output ports 48 RF input ports 52 pulse synchronous input ports 56. Pulse synchronization signal 57 Digital Communication Links 58RF control signal 60 control signal ports 70 pulse signals 80 RF signals 300A, 300B, 500A, 500B, 900, 1000A, 1000B, 1000C, 1000D, 1100A, 1100B plot 302, 310 Quadratic cost function, cost function 304 maximum 306, 308, 314, 316 positions 312 min 400, 700 power supply systems, systems 412 Match Network 416 Power Controller 418 Power Amplifier 420 sensors Blocks 422 and 426, control blocks 423 Mixer 424 Adder 425 Integrator D esc (z), control block 427 Signal combiner or adder, adder 429 Signal source, perturbation signal source 502, 504, 506, 508, 510, 512, 514, 516, 1002, 1004, 1006, 1008, 1010, 1012 lines 602, 604, 606, 608, 610, 612 waveform 702 Frequency selector control block (or module), frequency selector block, frequency selector control block 802 DC value (0Hz), DC value 804 Bandwidth Limit 806 Apparent frequency 808, 818 perturbation frequencies 816 Apparent frequency, apparent pulse frequency 902, 904, 906, 908 Exclusion Zones 1102 Potentially interfering frequency tone, frequency tone, apparent pulse frequency 1104 Potentially interfering frequency tone, frequency tone, tone 1106A~I Potentially interfering frequency tones, frequency tone 1106D, E tone 1108 Perturbation frequency 1200 Control Module 1202 Amplitude control module, module 1204 Frequency control module, module 1206 Match Network Control Module, Module 1208 Perturbation module, module 1210 Frequency Tuning Module, Module 1212 Cost Determination Module, Module 1214 Frequency Selector Module, Module

Claims

1. A power supply system for supplying power to a load, A radio frequency (RF) power source configured to generate an output signal at the output frequency, A signal source configured to generate a perturbation signal, An extreme value search frequency controller configured to generate a frequency control signal based on the perturbation signal, wherein the frequency control signal causes the output frequency of the RF power source to vary. A frequency selector configured to select a perturbation frequency of the perturbation signal, which is isolated from at least one frequency tone associated with the power supply system, and A power supply system equipped with the following features.

2. The power supply system according to claim 1, further comprising a power controller coupled to the RF power source, wherein the power controller is configured to generate pulses to modulate the output signal of the RF power source, the pulses comprising a first state and a second state.

3. The aforementioned perturbation frequency is the first perturbation frequency, The frequency selector is configured to select a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state. The power supply system according to claim 2, wherein the first perturbation frequency and the second perturbation frequency are different.

4. The power supply system according to claim 2, wherein the frequency selector is configured to select the perturbation frequencies for the first and second states of the pulse.

5. The power supply system further comprises a power controller coupled to the RF power source, the power controller configured to generate at least two pulses to modulate the output signal of the RF power source, each of the at least two pulses comprising a first state and a second state, The aforementioned perturbation frequency is the first perturbation frequency, The frequency selector is configured to select a first perturbation frequency for each of the first states of the at least two pulses, and a second perturbation frequency for each of the second states of the at least two pulses. The power supply system according to claim 1, wherein the first perturbation frequency and the second perturbation frequency are different.

6. The power supply system according to claim 1, further comprising a power controller coupled to the RF power source, wherein the power controller is configured to generate pulses to modulate the output signal of the RF power source, and the frequency selector is configured to select the perturbation frequency based on the bandwidth of the power controller.

7. The frequency selector, Determining a first delta between the minimum value of the bandwidth and the at least one frequency tone, and a second delta between the at least one frequency tone and the maximum value of the bandwidth, Selecting the perturbation frequency such that it is equal to the frequency value of the larger of the first delta and the second delta. The power supply system according to claim 6, configured to perform the following:

8. The power supply system according to claim 7, wherein the frequency value is the midpoint of the larger of the first delta and the second delta.

9. The power supply system according to claim 7, wherein the frequency selector is configured to analyze data indicating the operating parameters of the power supply system based on the selected perturbation frequency, and, if the operating parameters fall below a defined threshold, to adjust the perturbation frequency to the larger of the first delta and the second delta.

10. The power supply system according to claim 9, wherein the frequency selector is configured to analyze data indicating the operating parameters of the power supply system with respect to the adjusted perturbation frequency, and, if the operating parameters fall below a defined threshold, to readjust the perturbation frequency to the larger of the first delta and the second delta.

11. The power supply system according to claim 1, wherein the frequency selector is configured to determine the at least one frequency tone.

12. The power supply system according to claim 11, further comprising a power controller coupled to the RF power source, wherein the power controller is configured to generate pulses to modulate the output signal of the RF power source, and the at least one frequency tone includes an apparent frequency associated with the state of the pulse.

13. The power supply system according to claim 12, wherein the apparent frequency is determined based on the duty cycle of the state, the repetition rate of the pulse, and the hold-off time associated with the state.

14. The state of the pulse is a first state, and the apparent frequency is a first apparent frequency associated with the first state. The at least one frequency tone includes a second apparent frequency associated with the second state of the pulse, The power supply system according to claim 12, wherein the frequency selector is configured to select the perturbation frequencies for the first and second states, which are separated from the first apparent frequency and the second apparent frequency.

15. The power supply system according to claim 1, wherein the frequency selector is configured to perform a conversion to analyze data of one or more feedback signals and to determine the at least one frequency tone based on the analyzed data.

16. The power supply system according to claim 15, wherein the frequency selector is configured to select the perturbation frequency based on the analyzed data.

17. The power supply system according to claim 1, wherein the frequency selector is configured to perform a conversion based on the output response of the perturbation frequency and analyze data of one or more feedback signals.

18. The power supply system according to claim 17, wherein the frequency selector is configured to adjust the perturbation frequency based on the analyzed data.

19. The power supply system according to claim 17, wherein the data indicates the operating parameters of the power supply system, and the frequency selector is configured to adjust the perturbation frequency if the operating parameters fall below a defined threshold.

20. The power supply system according to claim 19, wherein the frequency selector is configured to analyze data indicating the operating parameters of the power supply system based on the adjusted perturbation frequency, and to readjust the perturbation frequency if the operating parameters fall below a defined threshold.

21. A method for controlling a radio frequency (RF) generator in a power system, wherein the RF generator includes an RF power source, and the method The steps include selecting a perturbation frequency of a perturbation signal that is separated from at least one frequency tone associated with the power supply system, The steps include generating the perturbation signal having the selected perturbation frequency, A step of generating a frequency control signal based on the perturbation signal, wherein the frequency control signal causes the output frequency of the RF power source to vary. Methods that include...

22. The method according to claim 21, wherein the method further comprises the step of generating a pulse for modulating the output signal of the RF power source, wherein the pulse includes a first state and a second state, and the step of selecting the perturbation frequency of the perturbation signal includes the step of selecting a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state which is different from the first perturbation frequency.

23. The method according to claim 21, wherein the method further comprises the step of generating a pulse for modulating the output signal of the RF power source, wherein the pulse comprises a first state and a second state, and the step of selecting the perturbation frequency of the perturbation signal comprises the step of selecting the perturbation frequency for the first state and the second state of the pulse.

24. The method according to claim 21, further comprising the step of generating at least two pulses to modulate the output signal of the RF power source, wherein each of the at least two pulses includes a first state and a second state, and the step of selecting the perturbation frequency of the perturbation signal includes selecting a first perturbation frequency for each of the at least two pulses for the first state and a second perturbation frequency for each of the at least two pulses for the second state, which is different from the first perturbation frequency.

25. The method according to claim 21, further comprising the step of generating pulses using a power controller to modulate the output signal of the RF power source, wherein the step of selecting the perturbation frequency of the perturbation signal includes the step of selecting the perturbation frequency based on the bandwidth of the power controller.

26. The method according to claim 25, further comprising the step of determining a first delta between the minimum value of the bandwidth and the at least one frequency tone, and a second delta between the at least one frequency tone and the maximum value of the bandwidth, wherein the step of selecting the perturbation frequency of the perturbation signal includes the step of selecting the perturbation frequency such that it is equal to the frequency value of the larger of the first delta and the second delta.

27. The method according to claim 26, wherein the frequency value is the midpoint of the larger of the first delta and the second delta.

28. The method according to claim 26, further comprising the steps of: analyzing data indicating the operating parameters of the power supply system based on the selected perturbation frequency; and adjusting the perturbation frequency within the larger of the first delta and the second delta if the operating parameters fall below a defined threshold.

29. The method of claim 28, further comprising the steps of: analyzing data indicating the operating parameters of the power supply system with respect to the adjusted perturbation frequency; and, if the operating parameters fall below a defined threshold, readjusting the perturbation frequency to the larger of the first delta and the second delta.

30. The method according to claim 21, further comprising the step of determining the at least one frequency tone.

31. The method according to claim 30, wherein the at least one frequency tone includes an apparent frequency associated with the pulse state.

32. The method according to claim 31, wherein the step of determining the at least one frequency tone includes the step of determining the apparent frequency of the pulse associated with the state, based on the duty cycle of the state, the repetition rate of the pulse, and the hold-off time associated with the state.

33. The state of the pulse is a first state, and the apparent frequency is a first apparent frequency associated with the first state. The at least one frequency tone includes a second apparent frequency associated with the second state of the pulse, The method according to claim 31, wherein the step of selecting the perturbation frequency of the perturbation signal includes the step of selecting the perturbation frequencies for the first state and the second state, which are separated from the first apparent frequency and the second apparent frequency.

34. The method according to claim 21, further comprising the steps of performing a conversion and analyzing data of one or more feedback signals, and determining the at least one frequency tone based on the analyzed data.

35. The method according to claim 34, wherein the step of selecting the perturbation frequency of the perturbation signal includes the step of selecting the perturbation frequency based on the analyzed data.

36. The method according to claim 21, further comprising the step of performing a conversion based on the output response of the perturbation frequency and analyzing the data of one or more feedback signals.

37. The method according to claim 36, further comprising the step of adjusting the perturbation frequency based on the analyzed data.

38. The aforementioned data indicates the operating parameters of the power supply system. The method according to claim 36, further comprising the step of adjusting the perturbation frequency if the operating parameter falls below a defined threshold.

39. The method according to claim 38, further comprising the steps of: analyzing data indicating the operating parameters of the power supply system with respect to the adjusted perturbation frequency; and readjusting the perturbation frequency if the operating parameters fall below a defined threshold.

40. A non-temporary computer-readable medium for storing processor-executable instructions for controlling a radio frequency (RF) generator of a power system, wherein the RF generator includes an RF power source, and the processor-executable instructions are Selecting a perturbation frequency of a perturbation signal that is isolated from at least one frequency tone associated with the power supply system, To generate the perturbation signal having the selected perturbation frequency, The process involves generating a frequency control signal based on the perturbation signal, wherein the frequency control signal causes the output frequency of the RF power source to vary or generate. A non-temporary computer-readable medium that stores processor-executable instructions, including those mentioned above.

41. A non-temporary computer-readable medium storing a processor-executable instruction according to claim 40, further comprising using a power controller to generate a pulse to modulate the output signal of the RF power source, and selecting the perturbation frequency of the perturbation signal comprising selecting the perturbation frequency based on the bandwidth of the power controller.

42. A non-temporary computer-readable medium storing a processor-executable instruction according to claim 41, further comprising determining a first delta between the minimum value of the bandwidth and the at least one frequency tone, and a second delta between the at least one frequency tone and the maximum value of the bandwidth, and selecting the perturbation frequency of the perturbation signal such that the perturbation frequency is equal to the frequency value of the larger of the first delta and the second delta.

43. A non-temporary computer-readable medium for storing processor-executable instructions according to claim 42, wherein the frequency value is the midpoint of the larger of the first delta and the second delta.

44. A non-temporary computer-readable medium for storing a processor-executable instruction according to claim 42, further comprising analyzing data indicating the operating parameters of the power supply system at the selected perturbation frequency, and adjusting the perturbation frequency at the larger of the first delta and the second delta if the operating parameters fall below a defined threshold.

45. A non-temporary computer-readable medium for storing a processor-executable instruction according to claim 44, further comprising analyzing data indicating the operating parameters of the power supply system by the adjusted perturbation frequency, and if the operating parameters fall below a defined threshold, readjusting the perturbation frequency by the larger of the first delta and the second delta.

46. A non-temporary computer-readable medium for storing a processor-executable instruction according to claim 40, further comprising determining the at least one frequency tone.

47. The at least one frequency tone includes an apparent frequency associated with the pulse state, A non-temporary computer-readable medium for storing processor-executable instructions according to claim 46, wherein determining the at least one frequency tone includes determining the apparent frequency of the pulse associated with the state based on the duty cycle of the state, the repetition rate of the pulse, and the hold-off time associated with the state.

48. The at least one frequency tone includes a first apparent frequency associated with a first state of the pulse and a second apparent frequency associated with a second state of the pulse, A non-temporary computer-readable medium for storing processor-executable instructions according to claim 46, wherein selecting the perturbation frequency of the perturbation signal includes selecting the perturbation frequency for the first state and the second state, which are separated from the first apparent frequency and the second apparent frequency.

49. A non-temporary computer-readable medium for storing a processor-executable instruction according to claim 40, further comprising: performing a conversion based on the output response of the perturbation frequency to analyze data of one or more feedback signals such that the data indicates the operating parameters of the power supply system; and adjusting the perturbation frequency if the operating parameters fall below a defined threshold.

50. A non-temporary computer-readable medium for storing a processor-executable instruction according to claim 49, further comprising analyzing data indicating the operating parameters of the power supply system with respect to the adjusted perturbation frequency, and readjusting the perturbation frequency if the operating parameters fall below a defined threshold.

51. A control system for controlling a radio frequency (RF) generator of a power supply system, wherein the RF generator includes an RF power source configured to generate an output signal at an output frequency, and the control system A signal source configured to generate a perturbation signal, An extreme value search frequency controller configured to generate a frequency control signal based on the perturbation signal, wherein the frequency control signal causes the output frequency of the RF power source to vary. A frequency selector configured to select a perturbation frequency of the perturbation signal, which is isolated from at least one frequency tone associated with the power supply system, and A control system equipped with the following features.

52. The control system further comprises a power controller configured to generate pulses to modulate the output signal of the RF power source, wherein the pulses include a first state and a second state. The aforementioned perturbation frequency is the first perturbation frequency, The frequency selector is configured to select a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state. The control system according to claim 51, wherein the first perturbation frequency and the second perturbation frequency are different.

53. The control system according to claim 51, further comprising a power controller configured to generate pulses for modulating the output signal of the RF power source, wherein the pulses include a first state and a second state, and the frequency selector is configured to select the perturbation frequencies for the first state and the second state of the pulse.

54. The control system further comprises a power controller configured to generate at least two pulses to modulate the output signal of the RF power source, each of the at least two pulses comprising a first state and a second state. The aforementioned perturbation frequency is the first perturbation frequency, The frequency selector is configured to select a first perturbation frequency for each of the first states of the at least two pulses, and a second perturbation frequency for each of the second states of the at least two pulses. The control system according to claim 51, wherein the first perturbation frequency and the second perturbation frequency are different.

55. The control system according to claim 51, further comprising a power controller configured to generate pulses for modulating the output signal of the RF power source, wherein the frequency selector is configured to select the perturbation frequency based on the bandwidth of the power controller.

56. The frequency selector, Determining a first delta between the minimum value of the bandwidth and the at least one frequency tone, and a second delta between the at least one frequency tone and the maximum value of the bandwidth, Selecting the perturbation frequency such that it is equal to the frequency value of the larger of the first delta and the second delta. The control system according to claim 55, configured to perform the following:

57. The control system according to claim 51, wherein the frequency selector is configured to determine the at least one frequency tone.

58. The control system according to claim 57, wherein the frequency selector is configured to perform a conversion to analyze data of one or more feedback signals, determine the at least one frequency tone based on the analyzed data, and select the perturbation frequency based on the at least one frequency tone.

59. The control system according to claim 51, wherein the frequency selector is configured to perform a conversion based on the output response of the perturbation frequency to analyze data of one or more feedback signals, and to adjust the perturbation frequency based on the analyzed data.

60. The aforementioned data indicates the operating parameters of the power supply system. The control system according to claim 59, wherein the frequency selector is configured to adjust the perturbation frequency when the operating parameter falls below a defined threshold.

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