Non-transitory computer-readable medium for RF power generators and stored instructions

Abstract

An RF generator having a fixed power generation section. The fixed power generation section includes a plurality of first power amplifiers, each configured to receive a power supply voltage and output a corresponding first voltage. The RF power generator also includes a weighted power generation section comprising a plurality of weighted power amplifier modules. Each weighted power amplifier module includes a weighted power amplifier and an associated transformer. Each weighted power amplifier in the weighted power amplifier module receives a corresponding weighted power supply voltage. The voltage across the transformer of each weighted power amplifier module is a fraction of the first voltage.

Description

Pulsed RF plasma generator with high dynamic range This disclosure claims the benefit of U.S. Provisional Application No. 63 / 441,616, filed January 27, 2023. The entire disclosure of the above application is incorporated herein by reference. The present disclosure relates to RF generator systems and control of RF generators. Plasma processing is frequently used in semiconductor manufacturing. In plasma processing, ions are accelerated by an electric field to etch material from or deposit material onto the surface of a substrate. In a basic embodiment, the electric field is generated based on an RF or DC power signal generated by a corresponding RF or DC generator in a power delivery system. The power signal generated by the generator must be precisely controlled to effectively perform plasma etching. The background description provided here is for the purpose of generally presenting the context of the present disclosure. The work of the presently named inventors within the scope described in this background section and aspects of the description that may not qualify as prior art at the time of filing are neither explicitly nor implicitly admitted to be prior art against the present disclosure. A system of one or more computers can be configured to perform specific operations or actions by installing software, firmware, hardware, or a combination thereof on the system, which, when in operation, causes the system to perform the actions. One or more computer programs can be configured to perform specific operations or actions by including instructions that, when executed by a data processing device, cause the device to perform the actions. One general aspect includes an RF power generator. The RF power generator also includes: a fixed power generation section comprising a first plurality of power amplifiers, each configured to receive a power supply voltage and output a first voltage. The generator also includes: a weighted power generation section comprising a plurality of weighted power amplifier modules, each weighted power amplifier module comprising a weighted power amplifier and a transformer, wherein each weighted power amplifier of the plurality of weighted power amplifier modules receives a corresponding weighted power supply voltage, and the voltage across the transformer of each weighted power amplifier module is a fraction of the first voltage. 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. Implementations may include one or more of the following features. An RF power generator, wherein at least one of the plurality of weighted power amplifier modules receives a fraction of a supply voltage and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of a first voltage. The at least one of the plurality of weighted power amplifier modules is configured to output a different fraction of the first voltage from another of the plurality of weighted power amplifier modules. More than one of the plurality of weighted power amplifier modules receives the same fraction of the supply voltage. A transformer associated with one of the more than one of the plurality of weighted power amplifier modules has a different turns ratio than another of the more than one of the plurality of weighted power amplifier modules. At least one of the plurality of weighted power amplifier modules receives the supply voltage and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of the first voltage. The transformer associated with at least one of the plurality of weighted power amplifier modules has a different turns ratio such that at least one of the plurality of weighted power amplifier modules outputs a voltage that is a fraction of the first voltage. More than one weighted power amplifier module in a plurality of weighted power amplifier modules receives a power supply voltage, and the more than one weighted power amplifier module in the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of a first voltage. A transformer associated with the more than one weighted power amplifier module in the plurality of weighted power amplifier modules has a turns ratio that is different from another of the more than one weighted power amplifier module in the plurality of weighted power amplifier modules. A weighted power supply voltage is input to the weighted power amplifiers of the plurality of weighted power amplifier modules. Each weighted power supply voltage is input to a corresponding weighted power amplifier in the plurality of weighted power amplifier modules. The weighted power supply voltage is a binary fraction of the power supply voltage. The RF power generator may include a harmonic filter configured to convert the impedance of each power amplifier into an inductive impedance. The inductive impedance is located above the horizontal axis of the Smith chart. The first plurality of power amplifiers in the fixed power generation section are connected in series. Each of the first plurality of power amplifiers in the fixed power generation section is configured to output a corresponding first voltage to a corresponding transformer, and the corresponding transformers are connected in series. The weighted power amplifier modules of the weighted power generation section are connected in series. Each of the plurality of weighted power amplifier modules of the weighted power generation section is configured to output a fraction of the first voltage to a respective associated transformer, and the respective associated transformers are connected in series. Each power amplifier of the fixed power generation section and each power amplifier module of the weighted power generation section are connected in series, and the fixed power generation section and the weighted power generation section are connected in series. Fewer than all of the first plurality of power amplifiers of the fixed power generation section generate a primary output voltage, and the first plurality of power amplifiers switch between generating the output voltage and being cut off.The fraction of the first voltage is a binary fraction of the first voltage. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium. A system of one or more computers can be configured to perform specific operations or actions by installing software, firmware, hardware, or a combination thereof on the system, which software, firmware, hardware, or a combination thereof causes the system to perform actions during operation. One or more computer programs can be configured to perform specific operations or actions by including instructions that, when executed by a data processing device, cause the device to perform actions. A general aspect includes an RF power generator. The RF power generator also includes: a fixed power generation portion, including a first plurality of power amplifiers, each of which is configured to receive a power supply voltage and output a first voltage. The generator also includes: a weighted power generation portion, including a plurality of weighted power amplifier modules, each weighted power amplifier module is configured to receive a corresponding weighted power supply voltage, and the voltage across the output of each weighted power amplifier module is a fraction of the first voltage. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each of which is configured to perform the actions of the method. Embodiments may include one or more of the following features. An RF power generator, wherein at least one of the plurality of weighted power amplifiers of the plurality of weighted power amplifier modules receives a fraction of a power supply voltage and at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of a first voltage. At least one of the plurality of weighted power amplifier modules receives a power supply voltage and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of the first voltage. The weighted power supply voltage is input to the weighted power amplifiers of the plurality of weighted power amplifier modules. The weighted power supply voltage is a binary fraction of the power supply voltage. The RF power generator may include a harmonic filter configured to convert the impedance of each power amplifier into an inductive impedance. The first plurality of power amplifiers of the fixed power generation section are connected in series. Each of the first plurality of power amplifiers of the fixed power generation section is configured to output a corresponding first voltage to a corresponding transformer, and the corresponding transformers are connected in series. The weighted power amplifier modules of the weighted power generation section are connected in series. Each of the plurality of weighted power amplifier modules of the weighted power generation section is configured to output a fraction of the first voltage to a respective associated transformer, and the respective associated transformers are connected in series. Each power amplifier of the fixed power generation section and each power amplifier module of the weighted power generation section are connected in series, and the fixed power generation section and the weighted power generation section are connected in series. Fewer than all of the first plurality of power amplifiers of the fixed power generation section generate a primary output voltage, and the first plurality of power amplifiers switch between generating the output voltage and being disabled. Implementation of the described techniques may include hardware, methods, or processes, or computer software on a computer-accessible medium. One general aspect includes a non-transitory computer-readable medium storing instructions. The non-transitory computer-readable medium storing instructions further includes receiving a command output voltage. The instructions further include determining a number of power amplifiers among a plurality of power amplifiers that will produce the command output voltage when activated. The instructions further include generating a control word based on the number of power amplifiers and controlling the number of power amplifiers based on the control word to produce the output voltage. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs stored on one or more computer storage devices, each configured to perform the actions of a method. Implementations may include one or more of the following features. The instructions on a non-transitory computer-readable medium may include comparing an output voltage to a commanded output voltage and adjusting the number of power amplifiers based on a difference between the output voltage and the commanded output voltage. The plurality of power amplifiers may include a first plurality of power amplifiers configured to receive a supply voltage and output a first voltage and a second plurality of power-weighted power amplifiers configured to receive corresponding weighted supply voltages and output fractions of the first voltage. Implementations of the described techniques may include hardware, methods, or processes, or computer software on a computer-accessible medium. Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.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. A power system can include a DC or RF power generator, or a DC or RF generator, a matching network, and a load (e.g., a processing chamber, plasma chamber, or reactor with fixed or variable impedance). The power generator generates a DC or RF power signal that is received by a matching network or impedance optimization controller or circuit. The matching network or impedance optimization controller or circuit converts the load impedance to the characteristic impedance of the transmission line between the power generator and the matching network. Impedance matching helps maximize the amount of power delivered to the load ("forward power") and minimize the amount of power reflected from the load back to the power generator ("reverse power" or "reflected power"). When the input impedance of the matching network matches the characteristic impedance of the transmission line and the generator, the output power to the load can be maximized by minimizing the reflected power. In the field of power supplies, there are two common methods for applying a power signal to a load. The first, more traditional method, applies 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 continuously output by the power supply to the load. In this continuous mode method, the power signal is a constant DC or sinusoidal output, and the amplitude and / or frequency (of the RF power signal) of the power signal can be varied to change the output power applied to the load. A second method of applying a power signal to a load involves pulsing the RF signal, rather than applying a continuous RF signal to the load. In a pulsed or pulsed operating mode, the RF signal is modulated by a modulating signal to define the envelope of the modulated power signal. The RF signal can be, for example, a sinusoidal RF signal or other time-varying signal. Typically, the power delivered to the load is varied by varying the modulating signal. In a typical power supply configuration, the output power applied to the load is determined using sensors that measure forward and reflected power, or the voltage and current of the RF signal applied to the load. Any of these signals is analyzed in a control loop. This analysis typically determines the power level used to adjust the output of the power supply to change the power applied to the load. In power delivery systems where the load is a process chamber or other nonlinear or time-varying load, since the applied power is partially a function of the load's impedance, a changing impedance of the load causes a corresponding change in the power applied to the load. In systems where the manufacture of various devices relies on introducing power into a load to control the manufacturing process, power is typically delivered in one of two configurations. In the first configuration, the power source is capacitively coupled to the load. This system is referred to as a capacitively coupled plasma (CCP) system. In the second configuration, the power source is inductively coupled to the load. This system is often referred to as an inductively coupled plasma (ICP) system. Power coupling to the plasma can also be achieved via wave coupling at microwave frequencies. This approach typically uses electron cyclotron resonance (ECR) or microwave sources. Helicon sources are another form of wave-coupled source and typically operate at RF frequencies similar to those of traditional ICP and CCP systems. The power delivery system can 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 the ions in the sheath formulation. Depending on various design considerations, the bias and source can share the same electrode or use separate electrodes. When a power delivery system drives a time-varying or nonlinear load, such as a processing chamber or plasma chamber, the power absorbed by the bulk plasma and plasma sheath results in an ion density over a range of ion energies. A 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 in a system where multiple RF power signals are applied to a load is by varying the multiple RF signals, which are related by at least one of amplitude, frequency, and phase. The at least one of the amplitude, frequency, and phase of the multiple RF power signals can also be related by a Fourier series and associated coefficients. The frequencies of the multiple RF power signals can be locked, and the relative phases of the multiple RF signals can also be locked. Examples of such systems can be found in U.S. Patent Nos. 7,602,127, 8,110,991, and 8,395,322, all of which are assigned to the assignee of the present disclosure and incorporated herein by reference. Time-varying or nonlinear loads may 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 processing chamber, such as a plasma chamber or reactor. A typical plasma chamber or reactor used in a plasma processing system, such as that used for thin film manufacturing, may utilize a dual power supply system. One power generator (source) controls plasma generation, while another power generator (bias) controls ion energy. Examples of dual power supply systems include those described in U.S. Patent Nos. 7,602,127, 8,110,991, and 8,395,322, cited above. The dual power supply systems described in the patents cited above employ closed-loop control systems that adapt power supply operation to control ion density and its corresponding ion energy distribution function (IEDF). There are various approaches for controlling a process chamber, such as one that can be used to generate a plasma. For example, in an RF power delivery 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. For RF-driven plasma sources, the periodic waveforms and corresponding ion energies that influence the plasma sheath dynamics are generally known and controlled by the frequency and associated phase interactions of the periodic waveforms. Another approach in RF power delivery systems involves dual-frequency control. That is, two RF frequency sources operating at different frequencies are used to power the plasma chamber, providing essentially independent control of ion density and electron density. Another approach utilizes a broadband RF power source to drive the plasma chamber. Broadband approaches present certain challenges. One challenge is coupling the power to the electrodes. A second challenge is developing a transfer function from the generated waveform to the actual sheath voltage required for the IEDF across a wide process window to support material-surface interaction. In a similar approach in inductively coupled plasma systems, controlling the power applied to the source electrode controls the plasma density, while controlling the power applied to the bias electrode modulates the ions to control the IEDF, thereby providing control over the etch rate and etch feature profile. By using both the source and bias electrode controls, the etch rate and various other etch characteristics are controlled via ion density and energy. As integrated circuit and device manufacturing continues to advance, so too do the power requirements for the processes controlling their fabrication. For example, with the fabrication of memory devices, bias power requirements continue to increase. Increased power produces higher-order and more energetic ions for improved directional or anisotropic etch feature profiles and faster surface interactions, thereby increasing etch rates and enabling etching of higher aspect ratio features. In RF systems, increased ion energy is sometimes accompanied by lower bias frequency requirements and an increase in the power and number of bias supplies coupled to the plasma sheath generated in the plasma chamber. The increased power and increased number of bias supplies at lower bias frequencies result in intermodulation distortion (IMD) emissions from sheath modulation. IMD emissions can significantly reduce the power delivered by the source generating the plasma. U.S. Patent No. 10,821,542, issued on November 3, 2020, and entitled "Pulse Synchronization by Monitoring Power in Another Frequency Band," assigned to the assignee of the present disclosure and incorporated herein by reference, describes a method for pulse synchronization by monitoring power in another frequency band. In the referenced U.S. patent application, pulses of a second RF generator are controlled based on detection of pulses of a first RF generator at the second RF generator, thereby synchronizing the pulses between the two RF generators. The fabrication of modern high-performance memory devices, such as nonvolatile flash memory (3D NAND flash) and dynamic random access memory (DRAM), in which memory cells are vertically stacked in multiple layers, requires the precise etching of extremely high aspect ratio (HAR) features with aspect ratios greater than approximately 50:1. As described in more detail below, an RF bias generator operating in pulsed mode is a key component in meeting the challenging requirements of semiconductor processing systems for HAR etching. The pulsing of the bias RF generator alternates between high-energy ion-assisted etching of the memory structure and low-energy polymer formation to protect the HAR feature sidewalls. Current RF bias generators provide multi-level pulses with a power range of 200 W to approximately 50 kW at pulse widths approaching 100 microseconds. However, emerging device manufacturing technologies require a wider power range (approximately 50 W to >200 kW) and narrower pulse widths of less than approximately 25 microseconds. Existing RF bias generator designs typically control power using pulse-width modulation (PWM) or out-of-phase (Chireix) power amplifier drive schemes. These drive schemes limit the usable dynamic range to approximately 20 dB and a minimum pulse width of approximately 20 RF cycles. Furthermore, conventional PWM and Chireix drive schemes are inefficient when operating RF generators to meet HAR manufacturing requirements, including generating pulse waveforms at low duty cycles, such as less than approximately 5% of the pulse duration, and generating low power for greater than approximately 95% of the pulse duration. Furthermore, floor space in typical wafer fabrication equipment is expensive, and increasing bias power requirements have led to increased space requirements for wafer fabrication equipment. Therefore, there is a need for RF generators that output higher power over an improved dynamic range and with increased power density. With regard to RF bias generators in particular, the evolving requirements of wafer fabrication call for RF bias generators that meet these capabilities. FIG1 depicts an RF generator or power supply system 110. Power supply system 110 includes a pair of radio frequency (RF) generators or power supplies 112a, 112b, matching networks 118a, 118b, and a load 132, such as a nonlinear load, which can be a plasma chamber, plasma reactor, or processing chamber. In various configurations, RF generator 112a is referred to as the source RF generator or power supply, and matching network 118a is referred to as the source matching network. Furthermore, in various configurations, RF generator 112b is referred to as the bias RF generator or power supply, and matching network 118b is referred to as the bias matching network. It will be understood that reference numerals with or without alphabetical subscripts or primes may be used to refer to components, individually or collectively. In various configurations, one or both matching networks 118a, 118b may be implemented as RF blocking filters rather than impedance matching, such as may be the case for matching networks receiving pulsed DC or non-sinusoidal signals. In various other configurations, one or both matching networks 118a, 118b may be omitted. In various configurations, the source RF generator 112a receives a control signal 130 from the matching network 118b, the generator 112b, or a control signal 130′ from the bias RF generator 112b. The control signal 130 or 130′ represents an input signal to the source RF generator 112a that indicates one or more operating characteristics or parameters of the bias RF generator 112b. In various configurations, a synchronization bias detector 134 senses the RF signal output from the matching network 118b to the load 132 and outputs a synchronization or trigger signal 130 to the source RF generator 112a. In various configurations, the synchronization or trigger signal 130′ may be output from the bias RF generator 112b to the source RF generator 112a instead of the trigger signal 130. The difference between the trigger or synchronization signals 130 and 130' can result from the effect of the matching network 118b, which can adjust the phase between the input signal to the matching network and the output signal from the matching network. Signals 130 and 130' are included in various configurations to provide information about the operation of the biased RF generator 112b that enables predictive responsiveness to account for periodic fluctuations in the impedance of the plasma chamber or load 132 caused by the biased RF generator 112b. When the control signals 130 or 130' are absent, the RF generators 112a and 112b operate autonomously. The RF generators 112a, 112b include respective RF power supplies or amplifiers 114a, 114b, sensors 116a, 116b, and processors, controllers, or control modules 120a, 120b. The RF power supplies 114a, 114b generate respective RF power signals 122a, 122b that are output to the respective sensors 116a, 116b. The RF power signals 122a, 122b pass through the sensors 116a, 116b and serve as the corresponding RF power signals. and is provided to matching networks 118a, 118b. Sensors 116a, 116b output signals that vary according to various parameters sensed from load 132. Although sensors 116a, 116b are shown within respective RF generators 112a, 112b, sensors 116a, 116b can be located external to RF generators 112a, 112b. Such external sensing can occur at the output of the RF generator, at the input of an impedance matching device disposed between the RF generator and the load, or between the output of the impedance matching device (included within the impedance matching device) and the load. Sensors 116a, 116b detect various command parameters and output signals X and Y. Sensors 116a, 116b may include voltage, current, and / or directional coupler sensors. Sensors 116a, 116b may detect (i) voltage V and current I output from each power amplifier 114a, 114b and / or RF generator 112a, 112b and / or (ii) forward power and the reverse or reflected power received from each matching network 118a, 118b or load 132 connected to each sensor 116a, 116b. . Voltage V, current I, forward power and reverse power The signals X and Y can be scaled, filtered, or scaled and filtered versions of the actual voltage, current, forward power, and reverse power associated with each power source 114a, 114b. The sensors 116a, 116b can be analog or digital sensors, or a combination thereof. In a digital implementation, the sensors 116a, 116b can include analog-to-digital (A / D) converters and signal sampling components with corresponding sampling rates. The signals X and Y can represent the voltage V and current I or the forward (or source) power and reverse (or reflected) power Any one of . Sensors 116a, 116b generate sensor signals X, Y, which are received by corresponding controllers or control modules 120a, 120b. Control modules 120a, 120b process respective X, Y signals 124a, 126a and 124b, 126b and generate one or more feedforward or feedback control signals 128a, 128b for respective power supplies 114a, 114b. Power supplies 114a, 114b adjust RF power signals 122a, 122b based on the received one or more feedback or feedforward control signals. In various configurations, power control modules 120a, 120b can control matching networks 118a, 118b, respectively, based on, for example, X, Y signals 124a, 126a and 124b, 126b, via respective control signals 129a, 129b. The power control modules 120a, 120b may include one or more proportional-integral (PI), proportional-integral-derivative (PID), linear-quadratic regulator (LQR) controllers or subsets thereof and / or direct digital synthesis (DDS) components and / or any of the various components described below in connection with the modules. In various configurations, the power control modules 120a, 120b can include functions, processes, processors, or submodules. The control signals 128a, 128b can be control signals or actuator drive signals and can convey DC offset or rail voltage, voltage amplitude or current amplitude, frequency and phase components, etc. In various configurations, the feedback control signals 128a, 128b can be used as inputs to one or more control loops. In various configurations, the multiple control loops can include proportional-integral (PI), proportional-integral-derivative (PID) controllers, linear-quadratic regulator (LQR) control loops, or subsets thereof, for the RF drive and rail voltages. In various configurations, the control signals 128a, 128b can be used in one or both of single-input single-output (SISO) or multiple-input multiple-output (MIMO) control schemes. Examples of MIMO control schemes can be found in U.S. Patent No. 10,546,724, issued on January 28, 2020, entitled “Pulsed Bidirectional Radio Frequency Source / Load,” assigned to the assignee of the present disclosure and incorporated herein by reference. In other configurations, signals 128a, 128b can provide feedforward control as described in U.S. Patent No. 10,049,857, issued on August 14, 2018, entitled “Adaptive Periodic Waveform Controller,” assigned to the assignee of the present disclosure and incorporated herein by reference. In various configurations, the power system 110 can include a controller 120'. The controller 120' can be external to one or both of the RF generators 112a, 112b and can be referred to as an external or common controller 120'. In various configurations, the controller 120' can implement one or more functions, processes, or algorithms described herein with respect to one or both of the controllers 120a, 120b. Accordingly, the controller 120' communicates with each of the RF generators 112a, 112b via a pair of corresponding links 136, 138 that enable appropriate exchange of data and control signals between the controller 120' and the RF generators 112a, 112b. For various configurations, the controllers 120a, 120b, 120' can provide analysis and control of the RF generators 112a, 112b in a decentralized and collaborative manner. In various other configurations, the controller 120 ′ can provide control of the RF generators 112 a , 112 b , thereby eliminating the need for separate local controllers 120 a , 120 b . In various configurations, the RF power supply 114a, sensor 116a, controller 120a, and matching network 118a may be referred to as the source RF power supply 114a, source sensor 116a, source controller 120a, and source matching network 118a, respectively. Similarly, in various configurations, the RF power supply 114b, sensor 116b, controller 120b, and matching network 118b may be referred to as the bias RF power supply 114b, bias sensor 116b, bias controller 120b, and bias matching network 118b, respectively. In various configurations and 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 tunes the ion potential and ion energy distribution function (IEDF) of the plasma. In various configurations, the source RF power supply and the bias RF power supply 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 RF power supply and the bias RF power supply operate at the same frequency or substantially the same frequency. According to various configurations, the source RF generator 112a and the bias RF generator 112b include multiple ports for external communication. The source RF generator 112a includes a pulse synchronization output port 140, a digital communication port 142, an RF output port 144, and a control signal port 160. The bias RF generator 112b includes an RF input port 148, a digital communication port 150, and a pulse synchronization input port 152. The pulse synchronization output port 140 outputs a pulse synchronization signal 156 to the pulse synchronization input port 152 of the bias RF generator 112b. The digital communication port 142 of the source RF generator 112a and the digital communication port 150 of the bias RF generator 112b communicate via a digital communication link 157. The control signal port 160 of the source RF generator 112a receives one or both of the control signals 130 and 130′. The RF output port 144 generates an RF control signal 158 that is input to the RF input port 148. In various configurations, the RF control signal 158 is substantially identical to the RF control signal that controls the source RF generator 112a. In various other configurations, the RF control signal 158 is identical to the RF control signal that controls the source RF generator 112a, but is phase-shifted within the source RF generator 112a according to a requested phase shift generated by the bias RF generator 112b. Thus, in various configurations, the source RF generator 112a and the bias RF generator 112b are driven by substantially the same RF control signal or by substantially the same RF control signal that is phase-shifted by a predetermined amount. In various configurations, the power supply system 110 may include a plurality of RF source generators 112a and a plurality of RF bias generators 112b. As non-limiting examples, the plurality of source RF generators 112a, 112a', 112a", ..., 112a nThe plurality of bias RF generators 112b, 112b', 112b", ..., 112b are arranged to provide a plurality of output power signals to one or more source electrodes of the load 132. Similarly, the plurality of bias RF generators 112b, 112b', 112b", ..., 112b n Multiple output power signals can be provided to multiple bias electrodes of load 132. When source RF generator 112a and bias RF generator 112b are configured to include multiple corresponding source RF generators or bias RF generators, each RF generator will output a separate signal in a one-to-one correspondence to a corresponding plurality of matching networks 118a, 118b configured to operate as described above. In various other configurations, there may not be a one-to-one correspondence between each RF generator and the matching network. In various configurations, multiple source electrodes can refer to multiple electrodes that cooperate to define a composite source electrode. Similarly, multiple bias electrodes can refer to multiple connections to multiple electrodes that cooperate to define a composite bias electrode. FIG2 depicts a graph of voltage versus time for describing a pulsed or pulsed mode of operation for delivering power to a load, such as load 132 of FIG1 . More specifically, FIG2 depicts two multi-state pulses P1 and P2 of a pulse signal 212 having respective multiple states S1-S4 and S1-S3. In FIG2 , an RF signal 210 is modulated by pulses P1 and P2. As shown in states S1-S3 of P1 and S1-S2 of P2, when the pulse is ON, RF generator 112 outputs RF signal 210 having an amplitude defined by the pulse amplitude in each state. Conversely, during state S4 of P1 and state S3 of P2, the pulse is OFF, and RF generator 112 does not output RF signal 210. Pulses P1 and P2 can repeat with a constant duty cycle or a variable duty cycle, and each state S1-S4 and S1-S3 of pulses P1 and P2 can have the same or variable amplitude and width. In various configurations, RF signal 210 need not be implemented as a sinusoidal waveform as shown in FIG. 2 . As described above with reference to FIG. 2 , in various configurations, RF signal 210 may have a non-sinusoidal waveform in addition to a sinusoidal waveform. As a non-limiting example, RF signal 210 may be a rectangular waveform or a piecewise linear waveform pulsed in a repetitive or intermittent manner as described in US Pat. No. 10,396,601. In various configurations, pulse signal 212 may not be a square wave as shown in FIG. 2 . Furthermore, as a non-limiting example, the envelope or pulse signal 212 may be rectangular, trapezoidal, triangular, sawtooth, Gaussian, or other shapes that define the envelope or modulation envelope of a basic, modulated RF signal. In various configurations, the pulse signal may occur and reoccur within a fixed or variable period or time. In various other configurations, the pulse signal may change shape between each occurrence. In various other configurations, the pulse signal may occur and reoccur within a fixed or variable period and change shape between each occurrence. Furthermore, pulses P1 and P2 can have multiple states S1, ..., Sn with varying amplitudes, durations, and shapes. States S1, ..., Sn can repeat over fixed or variable time periods and can include all or a portion of the various shapes described above. Furthermore, as shown in FIG2 , RF signal 210 can operate at a frequency that varies between multiple states or within a single state. FIG3A shows an RF generator 310 arranged in accordance with the principles of the present disclosure. The RF generator 310 includes a plurality of fixed voltage power amplifiers 314 and weighted voltage power amplifiers 326 shown coupled in series to obtain a composite output voltage at the input of a harmonic filter 334. The fixed power generation section 312 includes a plurality of fixed voltage power amplifiers 314 and a weighted voltage power amplifier 326, also referred to as PAs, respectively. F1 、……、PA F （ n-1 ） 、PA Fn Multiple fixed power supplies or power amplifiers 314a, ..., 314 (n-1), 314n. Fixed power amplifier PA F1 、……、PA F （ n-1 ） 、PA FnEach outputs a voltage signal or voltage V to a corresponding transformer 324, all of which are arranged in series. The weighted power generation section 322 includes a weighted power generation section also referred to as a PA. W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Multiple weighted power supplies or power amplifiers 326a, 326b, ..., 326(m-1), 326m. Weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Each of them will have its own voltage signal or voltage output to the corresponding transformer 324, where Subscripts (1, 2, ..., m-1, m) indicate the corresponding power amplifiers, all of which are also arranged in series. It should be noted that although all transformers shown in FIG3A are substantially identical or can vary in terms of turns ratio and are arranged in series, only one transformer 324 is labeled in FIG3A . In various configurations, the weighted power amplifiers 326 and associated transformers 324 can be referred to as a weighted power amplifier module. The voltage signals or voltages output from the respective fixed power generation sections 312 and weighted power generation sections 322 are summed via a series connection of transformers 324. The voltage generated by the series connection of transformers 324 is transmitted to the input of a harmonic filter 334. Harmonic filter 334 is configured to remove selected harmonics from the voltage signal input thereto. The output of harmonic filter 334 is input to a matching network 318, which is arranged similarly to matching networks 118a and 118b of FIG. 1 . Matching network 318 operates as described above and generates a matched voltage signal that is transmitted to load 332, which can be configured similarly to load 132 described above in FIG. Sensors (not shown in FIG. 3A , but configured similarly to sensors 116a and 116b of FIG. 1 ) generate one or more feedback signals that vary based on one or more corresponding electrical parameters (e.g., voltage and current, in one non-limiting example) that are transmitted to controller 320. The controller 320 is configured to operate generally similarly to the controllers 120 , 120 ′ described above with reference to FIG. 1 and as further described below. Controller 320 receives one or more feedback signals and other command inputs and generates enable and drive signals for each of the power amplifiers in fixed power generation section 312 and weighted power generation section 322. Controller 320 outputs a plurality of (n+m) enable signals, one of which is input to a corresponding power amplifier 314 or 326 to enable operation of the corresponding power amplifier. In various configurations, controller 320 outputs the plurality of (n+m) enable signals via a bus structure. Controller 320 also outputs one or more drive signals applied to each power amplifier to control the frequency and phase of the voltage signal output by the corresponding power amplifier according to the phase and frequency of the drive signals. The one or more feedback signals input to controller 320 are analyzed by controller 320, and controller 320 may modify the enable signals to modify one or more detected electrical parameters to generate the one or more feedback signals. In various configurations, the enable signal is a separate signal applied to the corresponding power amplifier. In various configurations, the drive signal is a common signal that is buffered individually to each power amplifier. As shown in FIG3A , a power supply voltage signal or power supply voltage Vd, which may be a stable, non-isolated power supply voltage, is generated internally in the RF generator 310 or received from an external source. d The voltage input is directly provided to the fixed power amplifier 314 of the fixed power generation part 312. Each power amplifier of the fixed power generation part 312 outputs a voltage signal or voltage V when turned on, and outputs 0V when turned off. The power supply voltage V dis also input to one or more DC / DC converters 328. In various configurations, the DC / DC converter 328 receives an input voltage V d And V which can be called weighted voltage signal or weighted voltage d The fractional output is fed to the weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Therefore, the power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Receive respective fractional voltage signals or voltages and output corresponding fractions of V. Each power amplifier of the weighted power generation section 322 outputs 0V when turned off. W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The weighted voltage output provides The step size control is the minimum step size of some fraction of . In a different configuration, the DC / DC converter 328 receives an input voltage V d and represented as a binary, weighted voltage signal or voltage V d The binary fraction is output to the weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The corresponding power amplifier in which The subscripts (1, 2, ..., m-1, m) of the corresponding weighted power amplifiers are represented. W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Receive respective binary weighted voltage signals or voltage , and the output is represented as a binary weighted voltage signal or voltage The binary fraction of V, where The subscripts (1, 2, ..., m-1, m) of the corresponding weighted power amplifiers are shown. Each power amplifier of the weighted power generating section 322 outputs 0V when it is turned off. W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The binary weighted voltage output provides The controller 320 determines which amplifiers to enable based on the amplitude set point. The arrangement of the fixed power generation section 312 and the weighted power generation section 322 realizes the PA F1 、……、PA F （ n-1 ） 、PA Fn and PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The series connection of the power generating section 312 generates a combined series voltage input to the harmonic filter 334. The combined voltage of the fixed power generating section 312 is determined according to the power amplifier PA started. F1 、……、PA F （ n-1 ） 、PA Fn As a non-limiting example, if the power amplifier PA F1 、……、PA F （ n-1 ） 、PA Fn If one of the power amplifiers PA is enabled, the voltage output from the weighted power generating portion 322 is V. Similarly, as a non-limiting example, if the power amplifier PA F1 、……、PA F （ n-1 ） 、PA Fn If two of the power amplifiers PA are enabled, the voltage output from the weighted power generating section 312 is 2 V. In addition, as a non-limiting example, if the power amplifier PA F1 、……、PA F （ n-1 ） 、PA Fn If n of the fixed power generating portions 312 are enabled, the voltage output from the fixed power generating portion 312 is nV. In a similar manner, the output voltage V of each power amplifier of the weighted power generating section 322 is equal to The binary fraction of , where The subscripts (1, 2, ..., m-1, m) representing the power amplifiers are 0V when turned on and 0V when turned off. The following indications are from the respective power amplifiers PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Voltage output: PA W1 ; PA W2 ; ... PA W （ m-1 ） ; PA Wm The combined voltage of the weighted power generating section 322 is determined according to which power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm As a non-limiting example, if only the power amplifier PA W is started, the voltage output from the weighted power generating section 322 is Similarly, as a non-limiting example, if the power amplifier PA W1 and PA W2 is started, the voltage output from the weighted power generating section 322 is Furthermore, as a non-limiting example, if two power amplifiers PA W1 and PA Wm (where m=6) is activated, the voltage output from the weighted power generating portion 322 is . In one non-limiting example, the weighted power generation section 322 can include six power supplies or power amplifiers PA W1 、PA W2 、PA W3 、PA W4 、PA W5 、PA W6 (m = 6). Power amplifier PA W1 、PA W2 、PA W3 、PA W4 、PA W5 、PA W6Generate V / 2, V / 4, V / 8, V / 16, V / 32, V / 64 respectively ( ,in, The addition of binary weighted voltage power amplifiers provides fine step control of the minimum step size of V / 64 for the weighted power generation section 322 having six power amplifiers. The controller 320 determines which amplifiers to enable based on the amplitude set point. This power control scheme can achieve a power output of V / 64 with a minimum step size of V / 64. Volt resolution, generating a range from 0 volts to Volts output quantized step voltage (where = Maximum number of active power amplifiers). This allows the AC voltage to be converted to a DC input voltage (V d The AC / DC front-end power supply is a fixed-voltage, non-isolated buck converter. This configuration reduces the size of the RF generator and increases power density. FIG3B shows one of the various configurations of the weighted power generating section 322. In FIG3B , the weighted power amplifiers PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The associated transformers 324 output the same voltage as the corresponding transformers across the weighted power amplifiers of FIG3A. However, in the weighted power generation section 322 of FIG3B, the voltage generated across each transformer 324 varies according to the power supply voltage input to each weighted power amplifier and the turns ratio of the transformer at the output of each weighted power amplifier. This configuration can reduce the number of DC / DC converters required to implement the weighted power generation section 322. As a non-limiting example, a weighted power amplifier PA W1 、PA W2 Each receives the same supply voltage . Weighted Power Amplifier PA W1 The transformer at the output has a 1:1 (input:output) turns ratio, and the weighted power amplifier PA W2 The transformer at the output of has a turns ratio of 2:1. Therefore, assuming the input to the weighted power amplifier PA W1 、PA W2 The supply voltage is , weighted power amplifier PA W1 、PA W2 The output is . Due to the weighted power amplifier PA W1 、PA W2 The different turns ratios of the associated transformers weighted the power amplifier PA W1 The voltage across the transformer at the output is , and the weighted power amplifier PA W2 The voltage across the transformer at the output is Similarly, the weighted power amplifier PA W （ m-1 ） 、PA Wm Each receives the same supply voltage . Weighted Power Amplifier PA W （ m-1 ） The transformer at the output has a 1:1 turns ratio, and the weighted power amplifier PA Wm The output of has a turns ratio of 2:1. Therefore, assuming the input to the weighted power amplifier PA W （ m-1 ） 、PA Wm The supply voltage is , then the weighted power amplifier PA W1 、PA W2 The output is . Due to the different turns ratio, PA W （ m-1 ） The voltage across the transformer at the output is , and PA Wm The voltage across the transformer at the output is . FIG3C shows one of the various configurations of the weighted power generating section 322. In FIG3C, the weighted power amplifiers PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The associated transformer 324 outputs the same voltage as the corresponding transformer across the weighted power amplifier of FIG3A. However, in the weighted power generation section 322 of FIG3C, each weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Receives the same supply voltage V d , so that each weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The output voltage V. The output across each transformer 324 associated with the corresponding weighted power amplifier varies in accordance with the turns ratio of each transformer. This configuration can reduce the number of DC / DC converters required to implement the weighted power generation section 322. As a non-limiting example, a weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Each receives the same supply voltage . Weighted Power Amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The output of transformer 324 has ) of the corresponding turns ratio, where is the subscript of each weighted power amplifier. Therefore, with the corresponding weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA WmThe corresponding turns ratio of each transformer is associated with ( 、( 、……、( 、 Therefore, assuming that the input to each weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The supply voltage is , then the weighted power amplifier PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm The output is 、 、……、 、 . In various configurations, the weighted power generation section 322 can include a hybrid of FIG3A and FIG3B. In the hybrid configuration, a first group or plurality of weighted power amplifiers PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Capable of receiving a first power supply voltage signal or voltage or Since each weighted power amplifier in the first group or plurality of weighted power amplifiers receives the same supply voltage, the voltage across each transformer associated with a corresponding weighted power amplifier in the first plurality of weighted power amplifiers is determined according to the turns ratio of each transformer. Similarly, the second group or plurality of weighted power amplifiers PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm Capable of receiving a second power supply voltage signal or voltage or , wherein the second power supply voltage signal or voltage is different from the first power supply voltage signal or voltage. Since each weighted power amplifier in the second group or second plurality of weighted power amplifiers receives the same power supply voltage, the voltage across each transformer associated with a corresponding weighted power amplifier in the second plurality of weighted power amplifiers is determined according to the turns ratio of each transformer. In various configurations, the third group or third plurality of weighted power amplifiers PA W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm In various configurations, the voltage across each transformer of the power generating portion 322 is weighted to provide a uniform step size as described above. In various other configurations, the voltage across each transformer can be a unique binary fraction of the output voltage V. In wafer fabrication, plasma loads are highly nonlinear and prone to fast load transients during plasma ignition, arcing, and pulsing. The plasma load is represented as a complex impedance The impedance Z is converted back to the fixed power amplifier 314 and the weighted power amplifier 326 of the RF generator 310 through the functions of the matching network 118a, 118b or 318 described above and the harmonic filter 334. In various configurations, if the load impedance of the RF generator 310 and its power amplifier is inductive, this is This is usually desirable. If the impedance is capacitive, this When this occurs, the power amplifier suffers from higher losses, lower efficiency, and lower reliability. The optimal RF power amplifier load impedance is inductive, , which is where the power amplifier achieves peak performance and highest efficiency. Accordingly, the harmonic filter 334 in various configurations is designed to add a large inductor with a positive phase angle to shift the power amplifier load impedance toward a more inductive phase angle. This configuration improves the efficiency of the RF generator 310 and advantageously modifies the plasma impedance lobe. FIG4 illustrates a Smith chart 410, which will be used to further describe the operation of an RF power amplifier having impedance transformation to the inductive portion of the Smith chart 410. Impedance circle 414 illustrates the typical impedance of a power amplifier driving a plasma load, such as provided by harmonic filter 334, without inductive load offset. Impedance circle 414 may also be referred to as a plasma impedance lobe. Using harmonic filter 334, the RF power amplifier is shifted from impedance circle 414 to impedance circle 412 along impedance transformation path 416. Impedance circle 412 represents the inductive region of operation of RF generator 310. As shown in FIG4 , impedance circle 412 is generally cylindrical in shape. Furthermore, impedance transformation path 416 represents a seventh-order or seventh-pole transformation. Thus, harmonic filter 334 shifts the operation of fixed power amplifier 314 and weighted power amplifier 326 of RF generator 310 to an inductive mode of operation by shifting the power amplifier impedance from low impedance to the upper half of Smith chart 410 (above the horizontal axis). Figures 5 through 7 illustrate graphs of example control schemes in which the drive actuators of a feedback, feedforward, or MIMO controller are switched so that the output power is linear with the linear variation of the drive actuator, and the output voltage follows the square root of the output power. Figure 5 shows a graph 510 including a plot of output power 512 versus the drive actuator or drive word, and a plot of output voltage 514 versus the drive actuator or drive word. The drive word indicates which power amplifiers, such as those shown in Figures 3A through 3C, are turned on and off. In Figure 5, the output power 512 is linear with respect to the drive word, while the output voltage 514 is shown as the square root of the output power 512. In various configurations, to achieve smooth, monotonic, and linear power characteristics, a controller, such as controller 320 of Figures 3A through 3C, activates the fixed-voltage power amplifiers of the fixed power generation section 312 and the binary-weighted power amplifiers of the weighted power generation section 322 to provide the desired output power. FIG6 shows a graph 610 including a curve 612 plotting the relationship between the drive word and the power amplifier count. The power amplifier count indicates the number of power amplifiers of the fixed power generation section 312 that are enabled to provide a coarse voltage step. FIG7 shows a graph 710 including a curve 712 plotting the drive word versus the weighted power amplifier output voltage output by the weighted power generation section 322. The voltage output by the weighted power generation section 322 provides a fine voltage step. In the non-limiting examples of FIG5-7, each power amplifier of the fixed power generation section 312 is configured for a given supply voltage. Output 98 V. Similarly, in the non-limiting examples of Figures 5 to 7, each power amplifier of the weighted power generation section 322 is configured to output 98 V according to the power supplied by the DC / DC converter 328 for a given power supply voltage. Output power supply voltage Outputting a binary fraction of 98 V, where there are six weighted power amplifiers. Thus, according to Figures 5 to 6, a coarse voltage step is created by activating the correct number of fixed voltage power amplifiers, as shown in Figure 6, and a fine voltage step is provided by activating the correct combination of weighted power amplifiers, as shown in Figure 7. Figures 8 through 10 illustrate graphs of example control schemes in which the drive actuator of a feedback, feedforward, or MIMO controller is switched so that the output voltage is linear with respect to the drive actuator and the output power follows the square of the output voltage. Figure 8 shows a graph 810 including a plot of output voltage 812 versus the drive actuator or drive word and a plot of output power 814 versus the drive actuator or drive word. The drive word indicates which power amplifiers, such as those shown in Figures 3A through 3C, are turned on and off. In Figure 8, the output voltage 812 is linear with respect to the drive word, while the output power 814 is shown as the square of the output voltage 812. In various configurations, to achieve a smooth, monotonic, and linear voltage characteristic, a controller, such as controller 320 of Figures 3A through 3C, activates the fixed-voltage power amplifier of the fixed power generation section 312 and the binary-weighted power amplifier of the weighted power generation section 322 to provide the desired output power. FIG9 shows a graph 912 including a curve 910 plotting the relationship between a drive word and a power amplifier count. The power amplifier count indicates the number of power amplifiers of the fixed power generation section 312 that are enabled to provide a coarse voltage step. FIG10 shows a graph 1010 including a curve 1012 plotting the drive word versus the weighted power amplifier output voltage output by the weighted power generation section 322. The voltage output by the weighted power generation section 322 provides a fine voltage step. In the non-limiting examples of FIG8-10, each power amplifier of the fixed power generation section 312 is configured for a given supply voltage. Output 98 V. Similarly, in the non-limiting examples of Figures 8-10, each power amplifier of the weighted power generation section 322 is configured to generate 98 V of power according to the power supplied by the DC / DC converter 328 for a given power supply voltage. Output power supply voltage Outputting a binary fraction of 98 V, where there are six weighted power amplifiers. Thus, according to Figures 8 to 10, a coarse voltage step is created by activating the correct number of fixed voltage power amplifiers as shown in Figure 9, and a fine voltage step is provided by activating the correct combination of weighted power amplifiers as shown in Figure 10. FIG11 shows a graph 1110 having a curve or waveform 1112 depicting a linearly ramped pulse envelope. The pulse envelope of FIG11 shows two pulses P1, P2, each having a repetition rate of 10 kHz. Feedforward control can be used to adjust the pulse shape during the rapid impedance changes that occur while driving the plasma. Additionally, MIMO control can be used to simultaneously control the drive actuator and the frequency actuator to adjust the pulse shape and minimize reflected power. Current semiconductor etching and deposition processes require bias generators capable of generating complex amplitude-modulated envelopes (also known as multi-state pulses). Because the output voltage amplitude can be changed almost instantaneously at the zero crossing of the RF output, the RF generators described in this disclosure offer higher performance than existing RF generators. FIG12 combines various components of FIG1 through FIG11 . A control module 1210 may include a power generation module 1212 and an impedance matching module 1218, including an amplitude control module portion 1214 and a frequency control module portion 1216. The amplitude control module portion 1214 includes a DC voltage generator module 1220, an amplitude adjustment module 1222, and an amplitude update module 1224. The frequency control module portion 1216 includes a frequency adjustment module 1226 and a frequency update module 1228. In various configurations, the control module 1210 includes one or more processors that execute code associated with the module portions or modules 1210, 1212, 1214, 1216, 1218, 1220, 1222, 1224, 1226, and 1228. The operation of module portions or modules 1210 , 1212 , 1214 , 1216 , 1218 , 1220 , 1222 , 1224 , 1226 , and 1228 is described below with reference to the method of FIG. 13 . For further defined structures of the controllers 120a, 120b, and 120' of Figure 1, see the flowchart of Figure 13 provided below and the definition of the term "module" provided below. The system disclosed herein can operate using the various methods, examples, and various control system methods illustrated in Figure 1. Although the following operations are described primarily with respect to the embodiment of Figure 1, these operations can be easily modified to apply to other embodiments of the present disclosure. These operations can be performed iteratively. Although the following operations are shown and described primarily as being performed sequentially, one or more of the following operations can be performed while one or more other operations are being performed. FIG13 shows a flow chart of a control system 1310 for performing mode-based impedance control on the power delivery system of FIG1 , in a non-limiting example. Control begins at a start / initialization block 1312 . Control proceeds to block 1314 , where a commanded output voltage is received. Control proceeds to block 1316 , where a determination is made as to the number of power amplifiers of the fixed power generation section 312 and which power amplifiers of the weighted power generation section 322 are required to generate the commanded output voltage. Control proceeds to block 1318 , where a control word is generated based on the number of power amplifiers required to generate the commanded output voltage. Control proceeds to block 1320 , where the output voltage is generated in accordance with the control word by generating drive signals and enable signals to each power amplifier. Control proceeds to block 1322 , where a determination is made as to whether the commanded output voltage has been generated. If the commanded output voltage has not yet been achieved, control passes to block 1316 and repeatedly updates the power amplifier control signal to progress toward the commanded output voltage. If the commanded output voltage has been achieved, control passes to block 1324, which ends the process but continues to monitor the output voltage. Plasma loads are highly nonlinear and prone to rapid load transients during plasma ignition, arcing, and pulsing. The RF generator described in this disclosure can be configured to protect the circuit from mismatched loads by switching the power amplifier of the fixed power generation section 312 into and out of operation to prevent overheating. The switching occurs at the zero crossing of the PA module output waveform and does not interfere with the overall output of the RF generator 310. In the above RF generator, the fixed power generation section 312 is described as having a PA module, a fixed power generation section, and a fixed power generation section. F1 、……、PA F （ n-1 ） 、PA Fn of, Fixed power amplifiers 314a, ..., 314(n-1), 314n. Similarly, the weighted power generation section 322 is described as having a PA also referred to as W1 、PA W2 、……、PA W （ m-1 ） 、PA Wm m power amplifiers 326a, 326b, ..., 326(m-1), 326m. In various configurations, if and , then the RF generator 310 can be Output between volts. In various configurations, the total output voltage can be limited to an output voltage that is less than the total number of power amplifiers that can output it. As a non-limiting example, if , the fixed power generation section 312 may include power amplifiers, but only a fixed power generation portion of 312 can be started at a time. In this configuration, it is possible to convert The operation of each power amplifier makes all Each power amplifier has an on period and an off period to prevent overheating. In this configuration, the switching occurs at the zero crossing of the power amplifier output waveform so as not to interfere with the overall output of the RF generator 310. In a conventional phase-shifted Class D power amplifier, such as may be implemented in the power amplifiers of FIG3A through FIG3C , a typical failure involves the main power amplifier device shorting to ground, resulting in a loss of control and power. When such an event occurs during wafer fabrication, it is possible that the wafer may need to be scrapped. In the disclosed RF plasma generator, the increased number of independent, identical amplifiers can produce increased redundancy subtlety. As a non-limiting example, the above Each power amplifier creates The additional inventory of individual power amplifiers allows a power amplifier to be omitted from the conversion if it has failed. Accordingly, if a power amplifier has failed, since the power amplifiers are combined using the series transformer 324, the failed amplifier does not affect the remaining amplifiers. In various configurations, a fault sensor can be associated with each power amplifier to provide an indication of the failure of the corresponding power amplifier when a fault occurs. In addition, in various configurations, each power amplifier is individually fused to isolate that particular power amplifier from the main voltage source in the event of a short circuit in the power amplifier. This allows the voltage to remain uninterrupted for other RF power amplifiers. In addition, at the next zero crossing, the failed power amplifier is identified and switched out in favor of the replacement power amplifier to minimize any output interference. The RF power generator described herein may provide one or more of the following benefits. Since a non-isolated, fixed voltage buck regulator may be used to generate V d The RF power generator described herein offers higher power density due to its smaller voltage regulator than an isolated agile rail voltage source. The RF power generator described herein offers improved pulse performance because it can generate narrower pulses, higher peak-to-average power ratios, and complex envelopes due to faster actuation rates. Because power amplifier modules are either on or off, and unneeded power amplifiers are disabled, no power is wasted during the low-power portion of the pulse envelope. The RF power generator described herein offers higher power efficiency during multi-level pulses. Because the inherent symmetry of the output waveform reduces even harmonics and simplifies harmonic output filtering, the RF power generator described herein provides low harmonic distortion at even harmonic frequencies. The RF power generator described herein offers a higher dynamic range of approximately >60 dB. Because the power amplifier inherently drives amplitude variations that align with pulse state changes, the RF power generator described herein achieves alignment of power variations with pulse state, which improves plasma stability in pulsed operation. The RF power generator described herein offers fast response time. The fast response time is derived from the constant voltage power supply that powers all power amplifiers. This eliminates the power supply control loop and the resulting response time, and eliminates the turn-on delay used in other designs. When there are six weighted power amplifiers, the power amplifiers in the series combination are synchronously enabled / disabled on each RF clock cycle and are switched on / off at each step size. Volt resolution produces values ​​from zero volts to Volts (where = maximum number of active fixed power amplifiers) output quantized step voltage. The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses. The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited since other modifications will become apparent upon study of the drawings, the specification, and the following claims. In the written description and the claims, one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure. Similarly, one or more instructions stored in a non-transitory computer-readable medium may be executed in a different order (or simultaneously) without altering the principles of the present disclosure. Unless otherwise noted, numbering or other labeling of instructions or method steps is for ease of reference and does not indicate a fixed order. Furthermore, while each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure may be implemented in and / or combined with features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments for one another is still within the scope of the present disclosure. Various terms including “connected,” “engaged,” “coupled,” “adjacent,” “proximate,” “on,” “directly over,” “under,” and “disposed” are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.). Unless explicitly described as “direct,” when describing a relationship between first and second elements in the above disclosure, the relationship may be a direct relationship in which there are no other intervening elements between the first and second elements, but may also be an indirect relationship in which one or more intermediate elements (spatially or functionally) are present between the first and second elements. The phrase "at least one of A, B, and C" should be interpreted as meaning a logical (A or B or C) using a non-exclusive logical OR, and should not be interpreted 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 the empty set; in other words, in some cases, a "set" can have zero elements. The term "non-empty set" can be used to indicate the exclusion of the empty set; in other words, a non-empty set will always have one or more elements. The term "subset" does not necessarily require a proper subset. In other words, a "subset" of a first set can be coextensive with (equal to) the first set. Furthermore, the term "subset" does not necessarily exclude the empty set; in some cases, a "subset" can have zero elements. In a diagram, the direction of the arrow, indicated by an arrowhead, generally illustrates the flow of information (e.g., data or instructions) of interest in the diagram. For example, when components A and B exchange various information, but the information transmitted from component A to component B is relevant to the diagram, the arrow may point from component A to component B. This unidirectional arrow does not mean that no other information is transmitted from component B to component A. In addition, for information sent from component A to component B, component B may send a request for the information or an acknowledgment of receipt of the information to component A. In this disclosure, including the definitions below, the term "module" can be replaced with the term "controller" or the term "circuit." In this disclosure, the term "controller" can be replaced with the term "module." The term "module" can refer to, be part of, or include: an application-specific integrated circuit (ASIC); 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 combination of some or all of the foregoing, such as in a system-on-chip. The module may include one or more interface circuits. In some examples, the interface circuits may implement a wired or wireless interface to a local area network (LAN) or a wireless personal area network (WPAN). Examples of LANs are Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11-2020 (also known as the Wi-Fi wireless network standard) and IEEE Standard 802.3-2018 (also known as the Ethernet wired network standard). Examples of WPANs are IEEE Standard 802.15.4 (including the ZIGBEE standard from the ZigBee Alliance) and the Bluetooth wireless network 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. Modules can communicate with other modules using interface circuitry. Although modules may be described in this disclosure as being in direct logical communication with other modules, in various embodiments, modules may actually communicate via a communication system. The communication system includes physical and / or virtual network devices such as hubs, switches, routers, and gateways. In some embodiments, 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 via the Internet or point-to-point leased lines using technologies including Multiprotocol Label Switching (MPLS) and Virtual Private Networks (VPNs). In various embodiments, module functionality can be distributed across multiple modules connected via a communication system. For example, multiple modules can implement the same functionality distributed by a load balancing system. In another example, module functionality can be split between a server (also known as a remote or cloud) module and a client (or user) module. For example, a client module can include a local or network application that executes on a client device and communicates with a server module over a network. Some or all of a module's hardware features can be defined using a language for hardware description, such as IEEE Standard 1364-2005 (commonly referred to as "Verilog") and IEEE Standard 1076-2008 (commonly referred to as "VHDL"). Hardware description languages ​​can be used to create and / or program hardware circuits. In some embodiments, some or all of a module's features can be defined using a language such as IEEE 1666-2005 (commonly referred to as "SystemC"), which includes both code and hardware descriptions, as described below. As used above, the term "code" can include software, firmware, and / or microcode, and can also refer to software, routines, functions, classes, data structures, and / or objects. Shared processor hardware includes a single microprocessor that executes some or all code from multiple modules. Group processor hardware includes a microprocessor that cooperates with additional microprocessors to execute some or all code from one or more modules. References to multiple microprocessors include multiple microprocessors on discrete dies, multiple microprocessors on a single die, multiple cores of a single microprocessor, multiple threads of a single microprocessor, or combinations of the above. Memory hardware can also store data alongside or separately from code. Shared memory hardware includes a single memory device that stores some or all code from multiple modules. One example of shared memory hardware might be a level 1 cache memory on or near the microprocessor die that can store code from multiple modules. Another example of shared memory hardware might be persistent memory, such as a solid-state drive (SSD), that can store code from multiple modules. Group memory hardware includes a memory device that works in conjunction with other memory devices to store some or all code from one or more modules. One example of group memory hardware is a storage area network (SAN) that can store code for a particular module across multiple physical devices. Another example of group memory hardware is the random access memory of each of a group of servers that jointly stores code for a particular module. The term memory hardware is a subset of the term computer-readable media. As used herein, the term computer-readable media does not include transient electrical or electromagnetic signals propagated through a medium (e.g., on a carrier wave); thus, the term computer-readable media is considered tangible and non-transitory. Non-limiting examples of non-transitory computer-readable media are 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 tapes or hard drives), and optical storage media (such as CDs, DVDs, or Blu-ray Discs). The apparatus and methods described in this disclosure can be implemented in part or in whole by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. Such apparatus and methods can be described as computerized apparatus and computerized methods. The functional blocks and flow chart elements described above serve as software specifications that can be converted into computer programs through routine work by a skilled technician or programmer. A computer program includes processor-executable instructions stored on at least one non-transitory computer-readable medium. A computer program may also include stored data or rely on stored data. A computer program may include a basic input / output system (BIOS) for interacting with the hardware of a special-purpose computer, device drivers for interacting with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc. 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 by a compiler from source code; (iv) source code to be executed by an interpreter; (v) source code to be compiled and executed by a just-in-time compiler, etc. By way of example only, source code may be written in languages ​​including C, C++, C#, Objective C, Swift, Haskell, Go, SQL, R, Lisp, Java, etc. ® , Fortran, Perl, Pascal, Curl, OCaml, JavaScript ® , HTML5 (Hypertext Markup Language Version 5), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash ® 、Visual Basic ® , Lua, MATLAB, SIMULINK, and Python ® The grammar of the language is written. 110: Power supply system 112: RF generators 112a, 112a', 112a", ..., 112a n :RF generator, source RF generator 112b, 112b', 112b'', ..., 112b n:RF generator, bias RF generator 114a, 114b: RF power supply or amplifier, power amplifier 116a, 116b: sensor 118a, 118b: matching network 120', 120a, 120b: controller 122a, 122b: RF power signal 124a, 124b: X signal 126a, 126b: Y signal 128a, 128b: feedforward or feedback control signal 129a, 129b: control signal 130, 130': control signal 132: load 134: synchronous bias detector 136, 138: link 140: pulse synchronization output port 142: digital communication connection port 144: RF output port 148: RF input port 150: digital communication Port 152: Pulse synchronization input port 156: Pulse synchronization signal 157: Digital communication link 158: RF control signal 160: Control signal port 210: RF signal 212: Pulse signals P1, P2: Pulses S1-Sn: Status 310: RF generator 312: Fixed power generation section 314, 314a, ..., 314 (n-1), 314n: Fixed power supply or power amplifier 318: Matching network 320: Controller 322: Weighted power generation section 324: Transformer 326, 326a, 326b, ..., 326 (m-1), 326m: Weighted power supply or power amplifier 328: DC / DC converter 332: Load 334: Harmonic filter PA W1 、PA W2 、PA W （ m-1 ） 、PA Wm: Weighted power amplifier 410: Smith charts 412, 414: Impedance circle 416: Impedance transformation paths 510, 610, 710, 710, 810, 910, 1010, 1110: Curve 512: Output power 514: Output voltage 612, 712, 912, 1012, 1112: Curve 812: Output voltage 814: Output power 1210: Control module 1212: Power generation module 1214: Amplitude control module portion 1216: Frequency control module portion 1218: Impedance matching module 1220: DC voltage generator module 1222: Amplitude adjustment module 1224: Amplitude update module 1226: Frequency adjustment module 1228: Frequency update module 1310: Control system 1312-1324: Blocks The present disclosure will become more fully understood from the detailed description and accompanying drawings. FIG1 is a schematic block diagram of a power delivery system having multiple power sources arranged in accordance with various configurations of the present disclosure; FIG2 shows waveforms of an RF signal and a pulse modulating the RF signal to illustrate the pulse operation mode; FIG3A illustrates an RF generator having multiple power amplifiers arranged in various configurations according to the present disclosure; FIG3B illustrates a weighted power generation portion of the RF generator of FIG3A arranged in accordance with various configurations of the present disclosure; FIG3C illustrates a weighted power generation portion of the RF generator of FIG3A arranged in accordance with various configurations of the present disclosure; FIG4 shows a Smith chart depicting regions of inductive operation of RF generators arranged in accordance with various configurations of the present disclosure; 5 shows a graph of power output and voltage output of an RF generator in response to drive words controlling various power amplifiers of the RF generator for a square root scaling control configuration; FIG6 shows a graph of the number of power amplifiers of a fixed power generating portion that are enabled in response to a drive word for a square root scaling control configuration; 7 shows a graph of the weighted voltage output of a power amplifier of a RF generator in response to a weighted power generating portion of the RF generator controlling the drive word of the power amplifier for a square root scaling control configuration; FIG8 shows a graph of the number of power amplifiers of a fixed power generating portion that are enabled in response to a drive word for a linear scaling control configuration; FIG9 shows a graph of the number of power amplifiers enabled for a fixed power generation portion of a drive word for a linear scaling control configuration; FIG10 shows a graph of the weighted voltage output of a power amplifier of a RF generator in response to a weighted power generating portion of the RF generator controlling the drive word of the power amplifier for a linear scaling control configuration; FIG11 shows an example of envelope modulation with a linear voltage ramp output by an RF generator arranged in accordance with the present disclosure; FIG12 illustrates a functional block diagram of an example control module according to various configuration arrangements of the present disclosure; and 13 shows a flow chart illustrating the operation of a control system arranged according to the principles of the present disclosure. Among the drawings, reference numbers may be reused to identify similar and / or identical elements. 1310: Control System 1312~1324: Blocks

Claims

1. An RF power generator, comprising: The fixed power generation section includes a plurality of first power amplifiers, each configured to receive a power supply voltage and output a first voltage. The weighted power generation section includes multiple weighted power amplifier modules, each weighted power amplifier module including a weighted power amplifier and a transformer, wherein each weighted power amplifier of the multiple weighted power amplifier modules receives a corresponding weighted power supply voltage, and the voltage across the transformer of each weighted power amplifier module is a fraction of the first voltage.

2. The RF power generator according to claim 1, wherein, At least one of the weighted power amplifiers in the plurality of weighted power amplifier modules receives a fraction of the power supply voltage, and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of the first voltage.

3. The RF power generator according to claim 2, wherein, At least one of the plurality of weighted power amplifier modules is configured to output a different fraction of the first voltage from another of the plurality of weighted power amplifier modules.

4. The RF power generator according to claim 1, wherein, More than one of the multiple weighted power amplifier modules receives the same fraction of the power supply voltage.

5. The RF power generator according to claim 4, wherein, The transformer associated with one of the plurality of weighted power amplifier modules has a different turns ratio than that of the other of the plurality of weighted power amplifier modules.

6. The RF power generator according to claim 1, wherein, At least one of the plurality of weighted power amplifier modules receives the power supply voltage, and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of the first voltage.

7. The RF power generator according to claim 6, wherein, The transformer associated with at least one of the plurality of weighted power amplifier modules has a different turns ratio, such that the output of at least one of the plurality of weighted power amplifier modules is a fraction of the first voltage.

8. The RF power generator according to claim 1, wherein, More than one of the plurality of weighted power amplifier modules receives the power supply voltage, and the plurality of weighted power amplifier modules are configured to output a voltage that is a fraction of the first voltage.

9. The RF power generator according to claim 8, wherein, The transformer associated with more than one of the plurality of weighted power amplifier modules has a different turns ratio than that of another of the plurality of weighted power amplifier modules.

10. The RF power generator according to claim 1, further comprising: A DC / DC converter configured to receive the power supply voltage and generate a weighted power supply voltage, wherein the weighted power supply voltage is input to the weighted power amplifier of the plurality of weighted power amplifier modules.

11. The RF power generator according to claim 1, further comprising: A plurality of DC / DC converters, each DC / DC converter being configured to receive the power supply voltage and generate the corresponding weighted power supply voltage, wherein each weighted power supply voltage is input to a corresponding weighted power amplifier of the plurality of weighted power amplifier modules.

12. The RF power generator according to claim 11, wherein, The weighted power supply voltage is a binary fraction of the power supply voltage.

13. The RF power generator according to claim 1, further comprising: Harmonic filters are configured to convert the impedance of each power amplifier into inductive impedance.

14. The RF power generator according to claim 13, wherein, The inductive impedance is located above the horizontal axis of the Smith chart.

15. The RF power generator according to claim 1, wherein, The first plurality of power amplifiers in the fixed power generation section are connected in series.

16. The RF power generator according to claim 1, wherein, Each of the first plurality of power amplifiers in the fixed power generation section is configured to output a corresponding first voltage to a corresponding transformer, and the corresponding transformers are connected in series.

17. The RF power generator according to claim 1, wherein, The weighted power amplifier module of the weighted power generation section is connected in series.

18. The RF power generator according to claim 1, wherein, Each of the plurality of weighted power amplifier modules in the weighted power generation section is configured to output the fraction of the first voltage to a respective associated transformer, and the respective associated transformers are connected in series.

19. The RF power generator according to claim 1, wherein, Each power amplifier in the fixed power generation section and each power amplifier module in the weighted power generation section are connected in series, and the fixed power generation section and the weighted power generation section are connected in series.

20. The RF power generator according to claim 1, wherein, The fixed power generating section generates a single output voltage from fewer than all of the first plurality of power amplifiers, and the first plurality of power amplifiers switch between generating an output voltage and being cut off.

21. The RF power generator according to claim 1, wherein, The fraction of the first voltage is a binary fraction of the first voltage.

22. An RF power generator, comprising: The fixed power generation section includes a plurality of first power amplifiers, each configured to receive a power supply voltage and output a first voltage. The weighted power generation section includes multiple weighted power amplifier modules, each of which is configured to receive a corresponding weighted power supply voltage, and the voltage at the output terminals of each weighted power amplifier module is a fraction of the first voltage.

23. The RF power generator according to claim 22, wherein, At least one of the weighted power amplifiers in the plurality of weighted power amplifier modules receives a fraction of the power supply voltage, and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of the first voltage.

24. The RF power generator according to claim 22, wherein, At least one of the plurality of weighted power amplifier modules receives the power supply voltage, and the at least one of the plurality of weighted power amplifier modules is configured to output a voltage that is a fraction of the first voltage.

25. The RF power generator according to claim 22, further comprising: At least one DC / DC converter is configured to receive the power supply voltage and generate a weighted power supply voltage, wherein the weighted power supply voltage is input to the weighted power amplifier of the plurality of weighted power amplifier modules.

26. The RF power generator according to claim 22, wherein, The weighted power supply voltage is a binary fraction of the power supply voltage.

27. The RF power generator according to claim 22, further comprising: Harmonic filters are configured to convert the impedance of each power amplifier into inductive impedance.

28. The RF power generator according to claim 22, wherein, The first plurality of power amplifiers in the fixed power generation section are connected in series.

29. The RF power generator according to claim 22, wherein, Each of the first plurality of power amplifiers in the fixed power generation section is configured to output a corresponding first voltage to a corresponding transformer, and the corresponding transformers are connected in series.

30. The RF power generator according to claim 22, wherein, The weighted power amplifier module of the weighted power generation section is connected in series.

31. The RF power generator according to claim 22, wherein, Each of the plurality of weighted power amplifier modules in the weighted power generation section is configured to output the fraction of the first voltage to a respective associated transformer, and the respective associated transformers are connected in series.

32. The RF power generator according to claim 22, wherein, Each power amplifier in the fixed power generation section and each power amplifier module in the weighted power generation section are connected in series, and the fixed power generation section and the weighted power generation section are connected in series.

33. The RF power generator according to claim 22, wherein, The fixed power generating section generates a single output voltage from fewer than all of the first plurality of power amplifiers, and the first plurality of power amplifiers switch between generating an output voltage and being cut off.

34. A non-transitory computer-readable medium storing instructions, the instructions comprising: Receive command output voltage; determine the number of power amplifiers among a plurality of power amplifiers that will generate the command output voltage when activated; The method includes generating a control word according to the number of power amplifiers and controlling the number of power amplifiers according to the control word to generate an output voltage, wherein the plurality of power amplifiers includes a first plurality of power amplifiers configured to receive a power supply voltage and output a first voltage and a second plurality of power-weighted power amplifiers configured to receive a corresponding weighted power supply voltage and output a fraction of the first voltage.

35. The non-transitory computer-readable medium according to claim 34, wherein the instructions include comparing the output voltage with the instruction output voltage and adjusting the number of the power amplifiers according to the difference between the output voltage and the instruction output voltage.

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