This disclosure relates generally to power supply systems. In particular, but not by way of limitation, this disclosure relates to the interoperation of power system components.
Power supply systems, including power supplies and match networks, are used in a variety of contexts including semiconductor processing. Semiconductor processing and other advanced material processing rely on increasingly sophisticated plasma processes. Such plasma processes, in turn, require increasingly sophisticated power systems and control systems, to subject inherently unstable and nonlinear plasmas to increasing precision and consistency. Such plasmas are used for processes such as plasma etch processes, plasma-enhanced chemical vapor deposition (CEPVD) processes, plasma-enhanced atomic layer deposition (PEALD) processes, plasma-assisted atomic-layer deposition (PA-ALD), RF sputtering deposition, and other plasma processing applications.
In some plasma processing recipes, it is desirable to apply a pulsed and/or a multi-level power waveform having multiple states and/or levels, such as exemplary pulsed waveform 50 of
It is noted that in a power waveform such as that shown in
Power generators need to support power waveforms such as waveform 50 having multiple states, with each state having independent control parameters such as power setpoint and frequency. Power generators are commonly used with match networks to optimize delivery of the power waveform to the plasma processing chamber. The match network is typically coupled between the power generator and the plasma processing chamber and adjusts its impedance as needed to reduce reflected power. It is important that the matching network be synchronized to any changes in the power signal, such as the state changes that occur in a pulsed waveform having multiple cycles comprised of multiple sequences having multiple states.
Process results may be degraded if the system components (such as generators and match networks) are not coordinated and synchronized. A tune point may be characterized as the frequency at which the input impedance of the match network matches the output impedance of the power generator. If not coordinated and synchronized, the match network can oscillate between optimal tune points for different states. Current match functionality supports only a single-wire signal to support two pulse states. Process results may be degraded in a multilevel pulsing system if the impedance is tuned to one state only. Moreover, match networks in typical systems are unable to report information on a state-by-state basis because match networks typically do not know when each state starts and stops.
One aspect of this disclosure is a power generator that comprises a power generation component configured to generate a power waveform for transmission to a secondary component and a synchronization component configured to generate a synchronization signal for transmission to the secondary component. The synchronization signal is formed with pulses having varying durations, and a duration of a pulse in the synchronization signal conveys information to the secondary component about an event in the power waveform.
In one implementation, the secondary component is a matching network interposed between the power generator and a plasma processing chamber.
In another implementation, the duration of the pulse in the synchronization signal conveys information about a change in a state of the power waveform.
In a further implementation, a first pulse of a first duration in the synchronization signal indicates that the state is ending and that a next state in a same sequence of a same cycle of the power waveform is beginning.
In a further implementation, a second pulse of a second duration in the synchronization signal indicates that a last state of a particular repeating sequence is ending and that a first state in the same particular repeating sequence of the same cycle of the power waveform is beginning.
In a further implementation, a third pulse of a third duration indicates that the state is ending and that the next state in a first sequence of a next cycle of the power waveform is beginning.
In a further implementation, a threshold time of inactivity after a pulse is initiated signals the power is off.
Another aspect of this disclosure is a match network that has an input configured to receive a power waveform from a primary component, and a synchronization component configured to receive a synchronization signal from the primary component. The synchronization signal is formed with pulses having varying durations, and a duration of a pulse in the synchronization signal conveys information to the match network about an event in the power waveform.
A further aspect of this disclosure is a plasma processing system comprising at least one match network and at least one power generator. The power generator is configured to generate and transmit a power waveform to the match network. The system also comprises a synchronization component configured to generate a synchronization signal for transmission to the power generator and/or the match network. The synchronization signal is formed with pulses having varying durations, and a duration of a pulse in the synchronization signal conveys information about an event in the power waveform to the match network.
Further aspects of this disclosure are depicted in the accompanying drawings and description and will be apparent based thereon.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” should not be construed as preferred or advantageous over other embodiments.
Preliminary note: the flowcharts and block diagrams in the following drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, some blocks in the flowcharts and block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). In some implementations, the functions noted in the block may occur out of the order set forth in the drawings. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or be executed in the reverse order, depending upon the functionality involved. It will also be understood that each block and combinations of blocks in the flowcharts and block diagrams can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
Although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, it will be understood that these elements, components, regions, layers and/or sections are not limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of this disclosure.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes all combinations of one or more of the associated listed items and may be abbreviated as “/”.
Other components depicted in
As shown, a centralized controller 101 comprises an interface to receive and process the input signal 106 and a control section 112 to provide one or more control signals based upon the input signal 106. As shown, the control section 112 includes a primary synchronization module (“Sync”) 124 that is coupled to a synchronization line 302, and the synchronization line 302 may be coupled to the components in the system 100A to provide a synchronization signal as described further herein. In some embodiments, at a physical layer, the synchronization line 302 may be a single wireline connection, but this is not required.
According to one aspect of this disclosure, the synchronization signal disclosed herein conveys information that enables the components of the system 100A to quickly respond to changing events within the system 100A. For example, the synchronization signals disclosed herein may convey information about events occurring in a power waveform applied by the generator 102. More specifically, the synchronization signal applied to the synchronization line may be formed with pulses having varying durations, wherein the duration of the pulse conveys information about events such as, for example and without limitation, a change of state within a sequence, a completion of a sequence and the beginning of a new state in the next sequence, or a completion of a cycle and the beginning of a new state in the next cycle.
Although the primary synchronization module 124 may be implemented in a centralized controller 101 as shown in
As shown, the control section 112 of generator 102 comprises primary synchronization module (“Sync”) 124 coupled to secondary synchronization module (“Sync”) 126 of match network 116 via the synchronization line 302, which propagates the synchronization signal to provide the synchronization signal to match network 116. Coordination between match network 116 and generator 102 is thereby enabled to prevent or mitigate against oscillation of match network 116 between optimal tune points for the power states that are applied to plasma load 104. Moreover, in some implementations the synchronization signal may enable the impedance of match network 116 to be changed on a per-state basis, thereby enabling the impedance of match network 116 to be separately tuned during multiple states and enabling increasingly faster embodiments of match network 116 to be realized. In this regard, some embodiments of match network 116 may be realized by solid-state switching components that may be switched at very high speeds to enable the impedance of match network 116 to be changed at very high speeds, utilizing synchronization signal 302, on a per-pulse basis. But the match network 116 may be implemented utilizing variable vacuum capacitors in some embodiments.
According to one aspect of this disclosure, the synchronization signal conveys information to match network 116 about the power waveform generated by generator 102. In particular, synchronization signal conveys information about events occurring in the power waveform. More particularly, synchronization signal may be formed with pulses having varying widths or durations, wherein the width or duration of the pulse conveys information about events such as a change of state within a sequence, a completion of a sequence and the beginning of a new state in the next sequence, or a completion of a cycle and the beginning of a new state in the next cycle.
It should be recognized that
The power waveform represented by states 304 (“psyncState”) of
Synchronization signal 302 (“psync”) generally has two levels: a first level that indicates that a power waveform is active or on; and a second level that conveys information about events occurring in the power waveform. The first level is shown generally and for non-limiting purposes of illustration in
Synchronization signal 302 of
As previously described, first cycle w0 of the waveform has three sequences, with each sequence having four states: w0_0, w0_1, w0_2, and w0_3. Thus, synchronization signal 302 communicates each upcoming state change within the first cycle w0 except for the last state change (third occurrence of w0_3) using pulse S1, thereby communicating to match network 116 that a change to a new state within the same cycle of repeating sequences is upcoming. Near the end of the last state (third occurrence of w0_3) within the first cycle w0, synchronization signal 302 communicates the upcoming state change to transition state t0_0 using pulse S2, thereby communicating to match network 116 that a change to a new state within a new cycle is upcoming.
Transition state t0_0 is a cycle having a single state, so near the end of transition state t0_0, synchronization signal 302 communicates another upcoming state change to the second cycle w1 using pulse S2, thereby communicating that a change to a new state within a new cycle is upcoming. Second cycle w1 has two sequences, with each sequence having two states: w1_0 and w1_1. Thus, synchronization signal 302 communicates each upcoming state change within second cycle w1 except for the last state change (second occurrence of w1_1) using pulse S1, thereby communicating that a change to a new state within the same cycle of repeating sequences is upcoming. Near the end of the last state (second occurrence of w1_1) within second cycle w1, synchronization signal 302 communicates the upcoming state change back to first cycle w0 (no transition state in this example) using pulse S2, thereby communicating to match network 116 that a change to a new state within a new cycle is upcoming. First cycle w0 then begins again with state changes within first cycle w0 being indicated by pulse S1.
First synchronization signal 402 is configured to synchronize a first component (a match network or another generator, for example) to a first power waveform represented by states 404 (“PSync_1”). Second synchronization signal 412 is configured to synchronize a second component (a match network or another generator, for example) to a second power waveform represented by states 414 (“PSync_2”). Third synchronization signal 422 is configured to synchronize a third component (a match network or another generator, for example) to a third power waveform represented by states 424 (“PSync_3”). Although the frequency of the first, second and third waveforms may vary in some use cases the frequency of these waveforms is a radio frequency (RF) frequency (for example and without limitation, 13.56 MHz).
Each of the power waveforms represented by states 404, 414, 424 of
The first power waveform represented by states 404 (“PSync_1”) has one state P1 in the repeating sequences of its first cycle (
In a similar manner as described with reference to
Synchronization signals 402, 412, 422 of
As mentioned above, each of the three waveforms respectively depicted by states 404, 414, 424 has a first cycle comprising two repeating sequences, with the first repeating sequence being shown in
With reference to
With reference to
With reference to
If a number of states changes on the secondary component that receives the synchronization signal (e.g., match network 116) for the sequence that is active, that number of states may be latched and then later applied when the sequence completes (this helps avoid issues for sequences such as when the primary component (e.g., synchronization module 124 of generator 102) is told to toggle waveforms, but there is a delay for the actual toggle in order for the in-process waveform to be completed.
The secondary synchronization component (e.g., match network 116) can detect loss of synchronization, and if the primary synchronization component (e.g., generator 102) is constrained to not change duration while running, the secondary component can detect if the same state is received with a different duration. In addition, the secondary component can detect if an ending pulse was not received during the last state of a sequence (e.g., pulses S2, S12). For states that are indefinite, there is a predetermined delay (in one example, 10 μs) from exit stimulus until the state changes. Also, if a waveform switch request is received within a predetermined time (in one example, 10 μs) of the end of the last state, that request will be delayed until the next repetition of the sequence is completed.
The methods described in connection with the embodiments disclosed herein may be embodied directly in hardware, in processor-executable code encoded in a non-transitory tangible processor readable storage medium, or in a combination of the two. Referring to
As shown, nonvolatile memory 4220 is coupled to bus 4222 that is also coupled to random access memory (“RAM”) 4224, processing portion 4226 that includes N processing components, field programmable gate array (FPGA) 4227, and transceiver component 4228 that includes N transceivers. None of these components are required, and any combination of these may be included in the systems disclosed herein. For instance, where FPGA 4227 is implemented, processing portion 4226 may not be used, and vice versa. Although the components depicted in
In general, nonvolatile memory 4220 is non-transitory memory that functions to store (e.g., persistently store) data and processor-executable code (including executable code that is associated with effectuating the methods described herein). In some embodiments, nonvolatile memory 4220 includes bootloader code, operating system code, file system code, and non-transitory processor-executable code to facilitate the execution of a method to coordinate operation of generator 102 and match network 116 as described herein.
In many implementations, nonvolatile memory 4220 is realized by flash memory (e.g., NAND or ONENAND memory), but it is contemplated that other memory types may be utilized as well. Although it may be possible to execute the code from nonvolatile memory 4220, the executable code in the nonvolatile memory is typically loaded into RAM 4224 and executed by one or more of the N processing components in processing portion 4226.
The N processing components in connection with RAM 4224 generally operate to execute the instructions stored in nonvolatile memory 4220 to enable a method for coordinating operation of generator 102 and match network 116. For example, non-transitory, processor-executable code to effectuate the methods described herein may be persistently stored in nonvolatile memory 4220 and executed by the N processing components in connection with RAM 4224. As one of ordinarily skill in the art will appreciate, processing portion 4226 may include a video processor, digital signal processor (DSP), micro-controller, graphics processing unit (GPU), or other hardware processing components or combinations of hardware and software processing components (e.g., an FPGA or an FPGA including digital logic processing portions).
In general, input component 4230 operates to receive signals such as synchronization signal 302 corresponding to a multi-level pulsed power waveform applied by generator 102. The signals received at input component 4230 may include, for example, signals depicted in
Transceiver component 4228 includes N transceiver chains, which may be used for communicating with external devices via wireless or wireline networks. Each of the N transceiver chains may represent a transceiver associated with a particular communication scheme (e.g., WiFi, Ethernet, Profibus, etc.).
Some portions are presented in terms of algorithms or symbolic representations of operations on data bits or binary digital signals stored within a computing system memory, such as a computer memory. These algorithmic descriptions or representations are examples of techniques used by those of ordinary skill in the data processing arts to convey the substance of their work to others skilled in the art. An algorithm is a self-consistent sequence of operations or similar processing leading to a desired result. In this context, operations or processing involves physical manipulation of physical quantities. Typically, although not necessarily, such quantities may take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numerals, or the like. It should be understood, however, that all of these and similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, it is appreciated that throughout this specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” and “identifying” or the like refer to actions or processes of a computing device, such as one or more computers or a similar electronic computing device or devices, that manipulate or transform data represented as physical electronic or magnetic quantities within memories, registers, or other information storage devices, transmission devices, or display devices of the computing platform.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method, or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
As used herein, the recitation of “at least one of A, B and C” or “at least one of A, B or C” is intended to mean “either A, B, C or any combination of A, B and C.” This description is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the scope of this disclosure is not limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This disclosure is provided to enable any person skilled in the art to make or use the embodiments described herein. Various modifications will be readily apparent to those skilled in the art, and the principles disclosed herein may be applied to other embodiments without departing from the spirit or scope of this disclosure. While certain embodiments are described herein, these embodiments are presented by way of example only and do not limit the scope of this disclosure.
This application claims the benefit of priority of provisional application No. 63/332,139, entitled Multi-Level Pulsing System filed on Apr. 18, 2022, which is incorporated herein by reference.
Number | Date | Country | |
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63332139 | Apr 2022 | US |