Plasma cavity arc suppression method, device, and radio frequency power system

Abstract

The present application relates to a plasma cavity arc suppression method, apparatus, and radio frequency power system. The method comprises the steps of: obtaining a reflection coefficient within a plasma cavity through arc detection sampling—the reflection coefficient includes an instantaneous reflection coefficient and an average reflection coefficient—; comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold; if it is determined that an arc has occurred within the plasma cavity based on the comparison result, freezing the operating parameters of the final corresponding reduction node of the radio frequency power system via a state machine, stopping the arc detection sampling, and instructing the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity via the control module of the PID controller; and, after the arc within the plasma cavity has disappeared, instructing the control module of the PID controller to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters. High-precision arc suppression processing within the cavity has been achieved.

Description

Technology Field

[0001] This application relates to the field of radio frequency system measurement and control technology, and in particular to a plasma cavity arc suppression method, apparatus, and radio frequency power system. Background Technology

[0002] As radio frequency power technology has advanced, its application fields have also evolved, expanding from the previous vacuum sector to other areas, such as semiconductors and even cosmetics. A typical radio frequency power system generally includes a radio frequency power source and a plasma chamber; the radio frequency power source serves as an auxiliary power source for the plasma chamber and is primarily used in equipment for radio frequency sputtering, PECVD chemical vapor deposition, and reactive ion etching. In actual applications, arc generation in the plasma chamber can reduce product yield and additionally cause electromagnetic interference (EMI) problems. Currently, regarding arc generation within the plasma chamber, existing suppression technology is primarily based on judgment methods that detect the instantaneous rate of change of voltage and current, whereas arc extinction technology performs arc extinction through hardware equipment and suppresses the arc by designing an arc suppressor. However, during the implementation process, the inventor discovered that existing technologies have technical problems, at least in terms of low arc suppression accuracy.

[0003] Based on this, it is necessary to provide a plasma cavity arc suppression method, a plasma cavity arc suppression device, a radio frequency power system, and a computer-readable storage medium that can significantly improve the accuracy of arc suppression within a chamber in response to the technical challenges mentioned above.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solution.

[0005] In one embodiment, a method for suppressing a plasma cavity arc is provided, and the method,

[0006] Step of obtaining reflection coefficients within the plasma cavity through arc detection sampling - the reflection coefficients include instantaneous reflection coefficients and average reflection coefficients - ;

[0007] A step of comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold;

[0008] If it is determined that an arc has occurred within the plasma cavity based on the comparison result, the step of freezing the operating parameters of the final corresponding reduction node of the radio frequency power system via the state machine, stopping arc detection sampling, and instructing the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity;

[0009] After the arc in the plasma cavity disappears, the method includes the step of instructing the control module of the PID controller to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters.

[0010] In one embodiment, the process of determining whether an arc occurs within the plasma cavity based on a comparison result is,

[0011] It includes determining whether there is an arc in the plasma cavity or not, depending on whether the absolute value of the difference is smaller than the set reflection coefficient threshold, thereby satisfying the set analysis judgment condition.

[0012] In one embodiment, the set analysis judgment condition is,

[0013] It includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference is smaller than the set reflection coefficient threshold N times consecutively; N is a positive integer greater than or equal to 2.

[0014] In one embodiment, the set analysis judgment condition is,

[0015] It includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference value within the set period is greater than the set reflection coefficient threshold number of times M is not continuous; M is a positive integer greater than or equal to 1.

[0016] In one embodiment, the set analysis judgment condition is,

[0017] It includes determining that there is an arc in the plasma cavity when the absolute value of the difference reaches one time greater than the set reflection coefficient threshold.

[0018] In one embodiment, the set analysis judgment condition is,

[0019] It includes determining that there is an arc in the plasma cavity if the absolute value of the difference is greater than the set reflection coefficient threshold N times consecutively; N is a positive integer greater than or equal to 2.

[0020] In one embodiment, the detection time interval of the arc detection sampling includes a plurality of detection time intervals from small to large, and the set reflection coefficient threshold is a manually set coefficient threshold or a coefficient threshold that is self-adaptively set by the system;

[0021] The above method is,

[0022] A step of extending the detection time to the next larger detection time if, starting from the minimum detection time, the frequency at which an arc occurs within the plasma cavity is smaller than a set frequency threshold;

[0023] Otherwise, it further includes the step of maintaining the detection time so that it does not change, and the system self-adaptively increasing the coefficient threshold using a method of multiple increase or fixed increase.

[0024] In one embodiment, the method is,

[0025] If it is determined based on the comparison result that there is no arc generation within the plasma cavity, the method further includes the step of maintaining the PID controller to operate in a normal control state.

[0026] Here, the general control state is,

[0027] Maintaining the current operating state of the control module;

[0028] Continuously performing arc detection sampling to obtain the reflection coefficient within the plasma cavity;

[0029] Recording the average reflection coefficient under current normal operating conditions;

[0030] Recording operating parameters for the control module;

[0031] It includes recording the operating variable parameters of the unit element of the output stage, setting the time node currently in normal operation as the reduction node, and continuously updating it.

[0032] In one embodiment, the process of instructing the final corresponding reduction node of a radio frequency power system to freeze operating parameters through a state machine is,

[0033] It includes instructing the state machine to freeze the last average reflection coefficient of the normal operating state, instructing the control module to freeze the operating parameters, and instructing the output stage to freeze the operating variable parameters of each unit element.

[0034] In one embodiment, the step of obtaining the reflection coefficient within the plasma cavity through arc detection sampling is,

[0035] A step of acquiring instantaneous reflection coefficients using a timing pointing sampling method;

[0036] It includes the step of calculating and obtaining an average reflection coefficient using all instantaneous reflection coefficients obtained from the current sampling; wherein each sampling, average value calculation, and threshold comparison is a synchronized multi-threaded process with a single time interval.

[0037] In another embodiment, a plasma cavity arc suppression device is provided, and the device,

[0038] Detection sampling module for obtaining reflection coefficients within a plasma cavity through arc detection sampling - reflection coefficients include instantaneous reflection coefficients and average reflection coefficients - ;

[0039] A coefficient comparison module that compares the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold;

[0040] An arc removal module that, upon determining that an arc has occurred within the plasma cavity based on a comparison result, freezes the operating parameters of the final corresponding reduction node of the radio frequency power system via a state machine, stops arc detection sampling, and instructs the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity;

[0041] It includes an output restoration module that, after the arc in the plasma cavity disappears, instructs the control module of the PID controller to restore the power output of the output stage and restore arc detection sampling according to operating parameters.

[0042] In another embodiment, a radio frequency power system is provided, wherein the radio frequency power system comprises a radio frequency power source, a PID controller, and a plasma chamber, and the radio frequency power source is electrically connected to the plasma chamber through the PID controller;

[0043] The PID controller is,

[0044] Step of obtaining reflection coefficients within the plasma cavity through arc detection sampling - the reflection coefficients include instantaneous reflection coefficients and average reflection coefficients - ;

[0045] A step of comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold;

[0046] If it is determined that an arc has occurred within the plasma cavity based on the comparison result, the step of freezing the operating parameters of the final corresponding reduction node of the radio frequency power system, stopping arc detection sampling, and cutting off the power output of the output terminal docked to the plasma cavity;

[0047] An arc suppression processing step is implemented, comprising the step of restoring the power output of the output terminal and restoring the arc detection sampling according to operating parameters after the arc in the plasma cavity has disappeared.

[0048] In another embodiment, a computer-readable storage medium storing a computer program is provided, and when the computer program is executed by a processor, the step of any one of the plasma cavity arc suppression methods described above is implemented.

[0049] One of the above technical solutions has the following advantages and beneficial effects.

[0050] The above-described plasma cavity arc suppression method, device, and radio frequency power system obtains instantaneous and average reflection coefficients within the plasma cavity through arc detection sampling, compares them with a set reflection coefficient threshold to accurately determine whether an arc has occurred within the plasma cavity, and if it is determined that an arc has occurred within the plasma cavity, freezes the operating parameters of the final corresponding reduction node of the radio frequency power system through a state machine, stops arc detection sampling, and instructs the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity, i.e., the radio frequency power supply stops the power output to the plasma chamber; and after the arc within the plasma cavity disappears, instructs the control module of the PID controller to restore the power output of the output terminal and restore arc detection sampling according to the operating parameters, i.e., by restoring the power output to the plasma chamber, high-precision suppression of the arc within the plasma cavity is achieved.

[0051] Compared to existing methods, the aforementioned approach significantly improves the accuracy of determining whether an arc has occurred through a comparison mechanism between the average reflection coefficient (also known as the gamma average) and a threshold value. When determining arc occurrence, the operating parameters of the system's final response reduction node are frozen via a state machine, arc detection is halted, and power output is stopped. Consequently, power output can be restored accurately and rapidly based on the frozen operating parameters after the arc within the cavity has disappeared, enabling high-precision arc suppression processing within the cavity. Furthermore, arc suppression is less expensive, more efficient, and more adaptable. Brief explanation of the drawing

[0052] In order to more clearly explain the embodiments of the present application or the technical methods of the prior art, the drawings necessary for explaining the embodiments or prior art are briefly introduced below. The drawings described below are merely some embodiments of the present application, and it is obvious to those skilled in the art that other drawings can be obtained based on these attached drawings without performing any creative work. Figure 1 is a schematic flowchart of a plasma cavity arc suppression method of one embodiment. Figure 2 is a schematic diagram of the sampling of instantaneous values ​​in one embodiment. Figure 3 is a schematic diagram of the ARC suppression step of one embodiment. Figure 4 is a schematic diagram of the flow of ARC monitoring and suppression treatment in one embodiment. FIG. 5 is a block diagram of the modular structure of a plasma cavity arc suppression device of one embodiment. Figure 6 is a schematic diagram of the structural frame of a radio frequency power system of one embodiment. Figure 7 is a schematic diagram of the structure of an ARC processing module of one embodiment. Specific details for implementing the invention

[0053] To clarify the purpose, technical solution, and advantages of the present application, the application is described in more detail below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are used solely to illustrate the present application and are not intended to limit the application.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as generally understood by a person skilled in the art of this application. The terms used herein in the description of this application are for the purpose of describing specific embodiments and are not intended to limit this application.

[0055] It should be noted that references to "Examples" in this specification mean that specific features, structures, or characteristics described together with the Examples may be included in at least one Example of the present invention. Where such words or phrases appear in each place in the specification, they are not necessarily all the same Example, nor are they independent or alternative Examples mutually exclusive from other Examples.

[0056] A person skilled in the art will understand that the embodiments described herein may be combined with other embodiments. The term “and / or” as used in the specification and appended claims of the present invention means any combination of one or more of the related listed items and all possible combinations, and includes such combinations.

[0057] In actual research, the inventors discovered that determining whether an arc has occurred by detecting only the rate of change of current and voltage can lead to misjudgment and affect the normal operation of the system. Furthermore, while the use of a dedicated arc extinguishing device can effectively suppress arc phenomena, it can increase system complexity and manufacturing costs, and the need for an arc extinguishing device is not high when only small arcs occur. Additionally, arc extinguishing devices must be designed for specific scenarios, and since there are many types of arcs within the plasma cavity, it is difficult to achieve an effect with a single arc extinguishing device. Therefore, this application proposes a novel plasma cavity arc suppression method capable of implementing high-precision cavity arc suppression, which addresses the technical problem of low arc suppression accuracy in existing technologies.

[0058] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings in the embodiments of the present invention.

[0059] In one embodiment, as illustrated in FIG. 1, a plasma cavity arc suppression method applicable to each type of radio frequency power system is provided, and the method may include steps (S12) to (S18).

[0060] Step (S12), obtaining reflection coefficients within the plasma cavity through arc detection sampling; the reflection coefficients include instantaneous reflection coefficients and average reflection coefficients.

[0061] It can be understood that arc detection sampling refers to a detection means that calculates the reflection coefficient (also referred to as the gamma value in this specification) within the plasma cavity based on measurement information sampling performed on the plasma chamber using the system's existing sensor system or external sensor device. The sampled measurement information may be a combination of one or more of voltage values, current values, power values, chamber impedance values, and power supply impedance values, provided that the reflection coefficient within the plasma cavity can be accurately measured. The instantaneous reflection coefficient refers to the real-time reflection coefficient within the plasma cavity sampled at the present time, and the average reflection coefficient refers to the average coefficient value calculated using all reflection coefficients sampled up to the present time.

[0062] Specifically, during the operation of a radio frequency power system, arc detection and sampling of the system (mainly the relevant electrical parameters of the plasma chamber therein) are performed to obtain the instantaneous reflection coefficient within the plasma cavity and calculate the corresponding average reflection coefficient.

[0063] Step (S14), the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient is compared with the set reflection coefficient threshold.

[0064] What can be understood is that, to facilitate the explanation, the instantaneous reflection coefficient Γ cur Record as, and the average reflection coefficient Γ aver It is recorded as, and the aforementioned comparison process is |Γ cur -Γaver |<Γ th It can be explained as determining whether [condition] is established; if it is established, it means that the system is currently operating normally and no arc is occurring within the cavity, otherwise it means that the system is operating abnormally and an arc is occurring.

[0065] The process of accurately determining whether an arc has occurred in the cavity through the aforementioned arc detection sampling, calculation of the gamma average value, and comparison of the processed parts is also called ARC (arc) monitoring.

[0066] Step (S16), if it is determined that an arc has occurred in the plasma cavity based on the comparison result, the operating parameters of the final corresponding reduction node of the radio frequency power system are frozen via the state machine, arc detection sampling is stopped, and the power output of the output terminal docked to the plasma cavity is cut off via the control module of the PID controller.

[0067] In a system, a state machine can be understood as a state control unit that instructs each module of the system to freeze and / or thaw operating parameters. In the system operation process, a PID controller may include normal control states and off control states. The PID controller obtains gamma instantaneous values ​​through sampling, calculates their average values, and |Γ cur -Γ aver |<Γ th When comparing with the gamma instantaneous value and the result of the comparison is obtained, if it is determined that there is no arc, that is, a normal control state, the PID controller maintains the current operation of the control module and continuously detects the gamma value, and also records various operating parameters of the system operating normally at the current time node, and the time node can be considered as a reduction node, and each data of this reduction node is continuously updated in the normal control state.

[0068] When it is determined that an arc has occurred within the plasma cavity, the PID controller switches to an off-control state, and in that state, on the one hand, the state machine also switches to an operating state, instructing each module to freeze the operating parameters of the final corresponding reduction node, stop arc detection, and perform sampling (ARC monitoring) for a certain time (X) (the length of the said time (X) can be set according to the plasma cavity potential drop time + zero potential time + potential rise time); on the other hand, the control module of the PID controller remains in an operating state and cuts off the power output of the output terminal docked to the plasma cavity, thereby cutting off the radio frequency power output to the plasma chamber, and from the time the power output is cut off, the plasma chamber undergoes a potential drop, a certain time stop (potential zero time), and a potential rise time after subsequent power recovery (potential rise time).

[0069] Step (S18), after the arc in the plasma cavity disappears, the control module of the PID controller is instructed to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters.

[0070] It can be understood that after the control module of the PID controller cuts off the power output of the output terminal docked to the plasma cavity, the potential of the plasma chamber is lowered and maintained at zero potential for a set time to eliminate the arc generated within the cavity. After stopping for the set time (the length of the time may be set by the statistical law of the shortest time for arc elimination / arc extinction time in actual application), the arc is eliminated, at which point the state machine may switch the operating state to instruct each module to restore to a normal operating state according to the operating parameters of the reduction node that was last frozen before the arc extinction, the control module of the PID controller reconnects the power output docked to the output terminal of the plasma chamber, and the PID controller reactivates ARC monitoring, thereby entering the next round of arc monitoring and suppression operations. To a person of ordinary knowledge in the art, it will be understood that if arc generation within the cavity is still monitored after operations are restored, the above-described operations can be repeated for arc suppression, and optionally, the zero potential time can be extended to obtain a better arc extinction effect.

[0071] In the above plasma cavity arc suppression method, after obtaining the instantaneous and average reflection coefficients within the plasma cavity through arc detection sampling, the presence of an arc within the plasma cavity is accurately determined by comparing them with a set reflection coefficient threshold; if it is determined that an arc is present within the plasma cavity, the operating parameters of the final corresponding reduction node of the radio frequency power system are frozen via a state machine, arc detection sampling is stopped, and the control module of the PID controller is instructed to cut off the power output of the output terminal docked to the plasma cavity, i.e., the radio frequency power supply stops the power output to the plasma chamber; and after the arc within the plasma cavity disappears, the control module of the PID controller is instructed to restore the power output of the output terminal and restore arc detection sampling according to the operating parameters, i.e., by restoring the power output to the plasma chamber of the radio frequency power supply, high-precision suppression of the arc within the plasma cavity is achieved.

[0072] Compared to existing methods, the aforementioned approach significantly improves the accuracy of determining whether an arc has occurred through a comparison mechanism between the average reflection coefficient (also known as the gamma average) and a threshold value. When determining arc occurrence, the operating parameters of the system's final response reduction node are frozen via a state machine, arc detection is halted, and power output is stopped. Consequently, power output can be restored accurately and rapidly based on the frozen operating parameters after the arc within the cavity has disappeared, enabling high-precision arc suppression processing within the cavity. Furthermore, arc suppression is less expensive, more efficient, and more adaptable.

[0073] In one embodiment, the method for determining whether an arc in a plasma cavity has been extinguished may be as follows, but is not limited thereto. It may be determined whether the arc has been extinguished by detecting energy in the cavity to determine whether the residual energy in the cavity returns to zero or falls below a set energy threshold (if the residual energy in the cavity returns to zero or is lower than the set energy threshold, it may be determined that the arc has been extinguished, and otherwise, it may be determined that it has not been extinguished); or it may be confirmed that the arc in the cavity has been extinguished after waiting for a set time after cutting off the power output; or it may be determined whether the arc in the cavity has already been extinguished through artificial visual observation (if it is observed that there is no arc in the cavity, the arc is considered to have disappeared, and otherwise, it is considered not to have disappeared). Other determination methods are also possible as long as they can accurately determine whether the arc in the cavity has been extinguished. Through the above method, the arc state within the cavity can be determined to accurately instruct the state machine to switch its operating state in a timely manner, and each module can be instructed to restore to its pre-freezing operating state, thereby reducing the power cutoff time and improving the overall arc suppression processing efficiency.

[0074] In one embodiment, regarding the above-described step (S12), specifically,

[0075] A step of acquiring instantaneous reflection coefficients using a timing pointing sampling method;

[0076] It may include a step of calculating and obtaining an average reflection coefficient using all instantaneous reflection coefficients obtained from the current sampling; wherein each sampling, average value calculation, and threshold comparison is a synchronized multi-threaded process with a single time interval.

[0077] Specifically, the detection and sampling of instantaneous reflection coefficients adopt a timing point sampling method, and all sampling values ​​are available values ​​and are all used to calculate the average value of gamma. In addition, for each sampling, coefficient and average value calculation and threshold comparison process, in this embodiment, the PID controller adopts synchronized multi-thread processing with a single time interval to synchronize multiple workstations as shown in FIG. 2 to achieve the same purpose, thereby further improving the reliability of reflection detection and arc determination within the cavity.

[0078] In one embodiment, regarding the above-described step (S16), the process of determining whether an arc occurs in the plasma cavity based on the comparison result may include the following judgment.

[0079] It includes determining whether there is an arc in the plasma cavity or not, depending on whether the absolute value of the difference is smaller than the set reflection coefficient threshold, thereby satisfying the set analysis judgment condition.

[0080] In the above-described embodiment, |Γ cur -Γ aver |<Γ th It can be understood that the occurrence of an arc within the cavity can be directly determined by judging whether the condition is established. In this embodiment, to further improve the accuracy of determining arc occurrence, |Γ cur -Γ aver |<Γ th By determining whether the establishment of the arc occurs and simultaneously determining whether the set analysis judgment conditions are satisfied, the occurrence of an arc within the cavity is determined more accurately.

[0081] In one embodiment, optionally, the set analysis judgment condition may include the following conditions.

[0082] It includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference is smaller than the set reflection coefficient threshold N times consecutively; N is a positive integer greater than or equal to 2.

[0083] Specifically, |Γ cur -Γ aver |<Γ th If it is determined that it has been reached N times consecutively, it can be determined that there is no arc generation in the current plasma cavity.

[0084] In one embodiment, optionally, the set analysis judgment condition may further include the following conditions.

[0085] It includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference value within the set period is greater than the set reflection coefficient threshold number of times M is not continuous; M is a positive integer greater than or equal to 1.

[0086] Specifically, |Γ cur -Γ aver |>Γ th If, within a set period of time (i.e., a set period, the specific length may be determined based on actual applied monitoring experience or statistics of past monitoring data), the number of times M is less than the limit (including 1 time) and is not continuous, it can be determined that there is no arc generation in the current plasma cavity.

[0087] In one embodiment, optionally, the set analysis judgment condition may further include the following conditions.

[0088] It includes determining that there is an arc in the plasma cavity when the absolute value of the difference reaches one time greater than the set reflection coefficient threshold.

[0089] Specifically, |Γ cur -Γ aver |>Γ th If it occurs once, it can be determined that there is an arc in the plasma cavity.

[0090] In one embodiment, optionally, the set analysis judgment condition may further include the following conditions.

[0091] It includes determining that there is an arc in the plasma cavity if the absolute value of the difference is greater than the set reflection coefficient threshold N times consecutively; N is a positive integer greater than or equal to 2.

[0092] Specifically, |Γ cur -Γ aver |>Γ th If it occurs several times in succession (including 2 times), it can be determined that an arc has occurred within the plasma cavity.

[0093] It should be noted that the aforementioned established analysis judgment conditions may be used in combination, provided that mutually exclusive conditions do not form a combination.

[0094] In one embodiment, the detection time interval of the arc detection sampling includes a plurality of detection time intervals from small to large. The set reflection coefficient threshold is a manually set coefficient threshold or a coefficient threshold that is self-adaptively set by the system. The plasma cavity arc suppression method is,

[0095] A step of extending the detection time to the next larger detection time if, starting from the minimum detection time, the frequency at which an arc occurs within the plasma cavity is smaller than a set frequency threshold;

[0096] Otherwise, it may further include a step of maintaining the detection time as unchanged and self-adaptively increasing the system using a method of multiple increase or fixed increase for a self-adaptively set coefficient threshold.

[0097] Specifically, the set reflection coefficient threshold Γ thIt can be set manually (e.g., based on work experience or historical monitoring data, etc.) or set autonomously by the system. Here, when the system sets it autonomously, it first sets an initial value Γ th By setting, |Γ cur -Γ aver |<Γ th Initial comparison processing can be introduced, and the corresponding initial value Γ th It can be artificially set, or Γ cur and Γ aver It can be generated through calculation using dynamic data or historical data.

[0098] In actual monitoring, multiple inspection time intervals can be used as defined, ranging from small to large; for example, 8us, 16us, 32us, etc., although this is not limited thereto. A minimum detection time interval, such as 8us, is set first, and during that minimum detection time, |Γ cur -Γ aver |<Γ th The arc occurrence frequency is evaluated, and if the arc occurrence frequency is below a preset frequency threshold, the detection period is extended to the next larger detection period, such as 16 µs or 32 µs, and the self-adaptively set coefficient threshold of the system may be maintained. If the arc occurrence frequency during the corresponding minimum detection period is higher than the preset frequency threshold, a multiplier increase, a fixed value increase, or |Γ cur -Γ aver First, obtain the dynamic maximum value of |, then adjust Γ through a multiple or fixed-value increase. th It is used as.

[0099] Through the steps described above, it is possible to adjust the coefficient threshold for system adaptation, thereby further improving the accuracy of determining arc occurrence.

[0100] In one embodiment, the plasma cavity arc suppression method is,

[0101] If it is determined based on the comparison result that there is no arc generation within the plasma cavity, the method further includes the step of maintaining the PID controller to operate in a normal control state. Here, the normal control state is,

[0102] Maintaining the current operating state of the control module;

[0103] Continuously performing arc detection sampling to obtain the reflection coefficient within the plasma cavity;

[0104] Recording the average reflection coefficient under current normal operating conditions;

[0105] Recording operating parameters for the control module;

[0106] It includes recording the operating variable parameters of the unit element of the output stage, setting the time node currently in normal operation as the reduction node, and continuously updating it.

[0107] Specifically, in the normal control state of the PID controller, the PID controller acquires the gamma instantaneous value, calculates its average value, and |Γ cur -Γ aver |<Γ th When it is determined that there is no arc generation in comparison, a normal control state is maintained, and at this time, the PID controller maintains the operation of the current control module and continuously monitors the gamma value, and additionally records the next operating parameters of the current time node: (a) the average gamma value of normal operation; (b) the operating parameters of the control module of the output stage for which the PID controller operates; (c) the operating variable parameters of the unit element that executes power output at the output stage; and considers the corresponding time node as a reduction node, and the data of this reduction node is continuously updated in the normal control state.

[0108] In one embodiment, with respect to the above-described step (S16), the process of instructing the state machine to freeze the operating parameters of the final corresponding reduction node of the radio frequency power system is specifically,

[0109] It may include instructing the state machine to freeze the last average reflection coefficient of the normal operating state, instructing the control module to freeze the operating parameters, and instructing the output terminal to freeze the operating variable parameters of each unit element.

[0110] Specifically, when arc generation is determined, the PID controller switches to an off-control state, and the state machine also switches to an operating state to instruct each module to freeze the operating parameters of the final corresponding reduction node, for example, the module responsible for calculating the average gamma value is instructed to freeze the average gamma value, the control module of the PID controller is instructed to freeze its operating parameters, and the output terminal docked to the plasma cavity is instructed to freeze the operating variable parameters of its unit element; additionally, the state machine instructs the PID controller to stop monitoring the gamma value for a certain period (X) (including potential drop time + zero potential + potential rise).

[0111] As shown in FIG. 3, the schematic diagram of ARC suppression for each stage can divide the entire ARC generation process into seven stages, A through G, and the meaning and processing method of each stage are as shown in Table 1. Through the aforementioned stages, the parameter freezing control mechanism provided by the state machine can ensure that the system can be restored to a normal operating state as quickly as possible after arc removal.

[0112] [Table 1]

[0113]

[0114] As shown in Fig. 4, one schematic diagram of the ARC processing flow shows that the entire process can be divided into two parts: a Gamma average calculation and comparison part and a PID storage and retention part. Through this processing method, high-precision detection and suppression of the ARC can be achieved, while the system can be restored most quickly after the arc is extinguished, and the cost of arc extinguishing is low.

[0115] Each step of the flowcharts in FIGS. 1 and FIGS. 4 is shown sequentially according to the direction of the arrows, but it should be understood that these steps are not necessarily performed sequentially according to the direction of the arrows. Unless otherwise clearly stated in this specification, the execution of these steps may be performed in a different order, and there are no strict restrictions on the order. Additionally, at least some steps of FIGS. 1 and FIGS. 4 may include several sub-steps or multiple steps, and these sub-steps or steps do not necessarily have to be performed simultaneously but may be performed at different times, and the execution order of these sub-steps or steps does not necessarily proceed sequentially but may be performed alternately or alternately with other steps or at least some of the sub-steps or steps of other steps.

[0116] In one embodiment, as illustrated in FIG. 5, a plasma cavity arc suppression device (100) is provided, said suppression device (100) includes a detection sampling module (11), a coefficient comparison module (13), an arc removal module (15), and an output restoration module (17). Herein: the detection sampling module (11) obtains a reflection coefficient within the plasma cavity through arc detection sampling; the reflection coefficient includes an instantaneous reflection coefficient and an average reflection coefficient. The coefficient comparison module (13) compares the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold. If the arc removal module (15) determines that an arc has occurred within the plasma cavity based on the comparison result, it freezes the operating parameters of the final corresponding reduction node of the radio frequency power system via a state machine, stops arc detection sampling, and instructs the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity. The output restoration module (17) instructs the control module of the PID controller to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters after the arc in the plasma cavity disappears.

[0117] The above plasma cavity arc suppression device (100) obtains the instantaneous and average reflection coefficients within the plasma cavity through arc detection sampling, compares them with a set reflection coefficient threshold to accurately determine whether an arc has occurred within the plasma cavity, and if it is determined that an arc has occurred within the plasma cavity, freezes the operating parameters of the final corresponding reduction node of the radio frequency power system through a state machine, stops arc detection sampling, and instructs the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity, that is, the radio frequency power supply stops the power output to the plasma chamber, and after the arc within the plasma cavity disappears, instructs the control module of the PID controller to restore the power output of the output terminal and restore arc detection sampling according to the operating parameters, that is, by restoring the power output to the plasma chamber of the radio frequency power supply, thereby achieving high-precision suppression of the arc within the plasma cavity.

[0118] Compared to existing methods, the aforementioned approach significantly improves the accuracy of determining whether an arc has occurred through a comparison mechanism between the average reflection coefficient (also known as the gamma average) and a threshold value. When determining arc occurrence, the operating parameters of the system's final response reduction node are frozen via a state machine, arc detection is halted, and power output is stopped. Consequently, power output can be restored accurately and rapidly based on the frozen operating parameters after the arc within the cavity has disappeared, enabling high-precision arc suppression processing within the cavity. Furthermore, arc suppression is less expensive, more efficient, and more adaptable.

[0119] In one embodiment, the process of determining whether an arc occurs within the plasma cavity based on a comparison result is,

[0120] It includes determining whether there is an arc in the plasma cavity or not, depending on whether the absolute value of the difference is smaller than the set reflection coefficient threshold, thereby satisfying the set analysis judgment condition.

[0121] In one embodiment, the set analysis judgment condition is,

[0122] It includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference is smaller than the set reflection coefficient threshold N times consecutively; N is a positive integer greater than or equal to 2.

[0123] In one embodiment, the set analysis judgment condition is,

[0124] It includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference value within the set period is greater than the set reflection coefficient threshold number of times M is not continuous; M is a positive integer greater than or equal to 1.

[0125] In one embodiment, the set analysis judgment condition is,

[0126] It includes determining that there is an arc in the plasma cavity when the absolute value of the difference reaches one time greater than the set reflection coefficient threshold.

[0127] In one embodiment, the set analysis judgment condition is,

[0128] It includes determining that there is an arc in the plasma cavity if the absolute value of the difference is greater than the set reflection coefficient threshold N times consecutively; N is a positive integer greater than or equal to 2.

[0129] In one embodiment, the detection time interval of the arc detection sampling includes a plurality of detection time intervals from small to large, and the set reflection coefficient threshold is a manually set coefficient threshold or a coefficient threshold that is self-adaptively set by the system;

[0130] The above method is,

[0131] A step of extending the detection time to the next larger detection time if, starting from the minimum detection time, the frequency at which an arc occurs within the plasma cavity is smaller than a set frequency threshold;

[0132] Otherwise, it further includes the step of maintaining the detection time so that it does not change, and the system self-adaptively increasing the coefficient threshold using a method of multiple increase or fixed increase.

[0133] In one embodiment, the method is,

[0134] If it is determined based on the comparison result that there is no arc generation within the plasma cavity, the method further includes the step of maintaining the PID controller to operate in a normal control state.

[0135] Here, the general control state is,

[0136] Maintaining the current operating state of the control module;

[0137] Continuously performing arc detection sampling to obtain the reflection coefficient within the plasma cavity;

[0138] Recording the average reflection coefficient under current normal operating conditions;

[0139] Recording operating parameters for the control module;

[0140] It includes recording the operating variable parameters of the unit element of the output stage, setting the time node currently in normal operation as the reduction node, and continuously updating it.

[0141] In one embodiment, the process of instructing the final corresponding reduction node of a radio frequency power system to freeze operating parameters through a state machine is,

[0142] It includes instructing the state machine to freeze the last average reflection coefficient of the normal operating state, instructing the control module to freeze the operating parameters, and instructing the output stage to freeze the operating variable parameters of each unit element.

[0143] In one embodiment, the step of obtaining a reflection coefficient within a plasma cavity through arc detection sampling is,

[0144] A step of acquiring instantaneous reflection coefficients using a timing pointing sampling method;

[0145] It includes the step of calculating and obtaining an average reflection coefficient using all instantaneous reflection coefficients obtained from the current sampling; wherein each sampling, average value calculation, and threshold comparison is a synchronized multi-threaded process with a single time interval.

[0146] Specific limitations regarding the plasma cavity arc suppression device (100) may refer to the limitations regarding the plasma cavity arc suppression method above and are not repeated here. Each module of the plasma cavity arc suppression device (100) may be implemented in whole or in part by software, hardware, or a combination thereof. Each module may be embedded in the PID controller or processor of the radio frequency power system in the form of hardware or may be independent, or may be stored in the memory of the radio frequency power system in the form of software so that the PID controller or processor can easily perform the task corresponding to the above module.

[0147] In one embodiment, as illustrated in FIG. 6, a radio frequency power system (200) is provided, said radio frequency power system (200) includes a radio frequency power source (22), a PID controller (24), and a plasma chamber (26). The radio frequency power source (22) is electrically connected to the plasma chamber (26) through the PID controller (24). The PID controller (24) is,

[0148] Step of obtaining reflection coefficients within the plasma cavity through arc detection sampling - the reflection coefficients include instantaneous reflection coefficients and average reflection coefficients - ;

[0149] A step of comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold;

[0150] If it is determined that an arc has occurred within the plasma cavity based on the comparison result, the operating parameters of the final corresponding reduction node of the radio frequency power supply (22) system are frozen, arc detection sampling is stopped, and the power output of the output terminal docked to the plasma cavity is cut off;

[0151] An arc suppression processing step is implemented, comprising the step of restoring the power output of the output terminal and restoring the arc detection sampling according to operating parameters after the arc in the plasma cavity has disappeared.

[0152] For understanding, specific limitations regarding the functions implemented by the above PID controller (24) can be described by referring to the corresponding limitations regarding the plasma cavity arc suppression method above, and are not repeated here. Specific electrical connection relationships and mechanical structures between each component of the above radio frequency power system (200) can all be understood by referring to the electrical and mechanical structures of existing radio frequency power systems (22) in the field, and are not described repeatedly in this specification.

[0153] FIG. 7 shows the structure of an ARC processing module classified according to implementation functions. The PID controller (24) can be divided into a control module that controls the output terminal docked to the plasma chamber (26) and an ARC processing module as shown in FIG. 7. The ARC processing module includes an average value calculation unit, a comparison unit, an ARC detection unit, and a state machine. The average value calculation unit can be used to calculate the instantaneous reflection coefficient from real-time detection and sampled measurement information and to calculate the corresponding average reflection coefficient. The comparison unit is |Γ cur -Γ aver | and Γ th It can be used to perform a comparison. An ARC detection unit can be used to determine whether an arc has occurred in the cavity based on the comparison result. A state machine can be used to implement the corresponding instruction control function shown in the above-described embodiment.

[0154] To those skilled in the art, FIGS. 6 and 7 are merely block diagrams of some product entities and functional structures related to the present application and do not constitute detailed limitations on the radio frequency power system applicable to the present application. It will be understood that the specific radio frequency power system may include more or fewer members than shown in the drawings above, combine some members, or have different arrangements of members, and specifically can be determined according to the actual type of radio frequency power system.

[0155] The above radio frequency power system (200) obtains the instantaneous and average reflection coefficients within the plasma cavity through arc detection sampling, and then compares them with a set reflection coefficient threshold to accurately determine whether an arc has occurred within the plasma cavity. If it is determined that an arc has occurred within the plasma cavity, the system freezes the operating parameters of the final corresponding reduction node of the radio frequency power system through a state machine, stops the arc detection sampling, and instructs the control module of the PID controller (24) to cut off the power output of the output terminal docked to the plasma cavity, that is, the radio frequency power supply stops the power output to the plasma chamber. After the arc within the plasma cavity (26) disappears, the system instructs the control module of the PID controller (24) to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters, that is, by restoring the power output to the plasma chamber, the radio frequency power supply implements high-precision suppression of the arc within the plasma cavity (26).

[0156] Compared to existing methods, the aforementioned approach significantly improves the accuracy of determining whether an arc has occurred through a comparison mechanism between the average reflection coefficient (also known as the gamma average) and a threshold value. When determining arc occurrence, the operating parameters of the system's final response reduction node are frozen via a state machine, arc detection is halted, and power output is stopped. Consequently, power output can be restored accurately and rapidly based on the frozen operating parameters after the arc within the cavity has disappeared, enabling high-precision arc suppression processing within the cavity. Furthermore, arc suppression is less expensive, more efficient, and more adaptable.

[0157] In one embodiment, a computer-readable storage medium storing a computer program is further provided, and when the computer program is executed by a processor, a processing step comprising: obtaining a reflection coefficient within a plasma cavity through arc detection sampling—the reflection coefficient includes an instantaneous reflection coefficient and an average reflection coefficient—; comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold; if it is determined that an arc has occurred within the plasma cavity based on the comparison result, a step of instructing, through a state machine, to freeze the operating parameters of the final corresponding reduction node of the radio frequency power system, stop arc detection sampling, and cut off the power output of the output terminal docked to the plasma cavity through the control module of the PID controller; and after the arc within the plasma cavity disappears, a step of instructing the control module of the PID controller to restore the power output of the output terminal and restore arc detection sampling according to the operating parameters.

[0158] In one embodiment, when a computer program is executed by a processor, the additional steps or substeps in each embodiment of the plasma cavity arc suppression method may be implemented.

[0159] It will be understood by those skilled in the art that the method of the above-described embodiment may be implemented in whole or in part and completed by commanding the relevant hardware through a computer program, said computer program may be stored on a non-volatile computer-readable storage medium and said computer program may include the process of each embodiment of the above-described method. Herein, any reference to memory, storage, database, or other medium used in each embodiment provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electro-programmable ROM (EPROM), electro-erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As a description rather than a limitation, RAM can be implemented in various forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0160] Each technical feature of the above embodiments can be combined in any way, and for the sake of brevity, not all possible combinations of each technical feature of the above embodiments have been described; however, as long as there is no contradiction in such combinations of technical features, they should be considered within the scope described in this specification.

[0161] The embodiments described above represent only a few embodiments of the present application, and while the description is more specific and detailed, it should not be understood as a limitation on the scope of the patent application. Those skilled in the art should note that various modifications and improvements may be made without departing from the spirit of the present application, and that all such modifications and improvements fall within the scope of protection of the present application. Accordingly, the scope of protection of the patent of the present application is based on the appended claims.

Claims

Claim 1 A method for suppressing a plasma cavity arc comprises: a step of obtaining a reflection coefficient within the plasma cavity through arc detection sampling, wherein the reflection coefficient includes an instantaneous reflection coefficient and an average reflection coefficient; a step of comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold; a step of, if it is determined that an arc has occurred within the plasma cavity based on the comparison result, freezing the operating parameters of the final corresponding reduction node of the radio frequency power system via a state machine, stopping the arc detection sampling, and instructing the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity via the control module of the PID controller; and a step of, after the arc within the plasma cavity has disappeared, instructing the control module of the PID controller to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters; wherein the detection time interval of the arc detection sampling includes a plurality of detection time intervals from small to large, and the set reflection coefficient threshold is a manually set coefficient threshold or a coefficient threshold set self-adaptively by the system; and from the minimum detection time interval, the frequency at which the arc occurs within the plasma cavity is a set frequency A plasma cavity arc suppression method characterized by further comprising: a step of extending the detection time to a next larger detection time if it is smaller than a threshold; otherwise, maintaining the detection time unchanged and self-adaptively increasing it using a method of multiple increase or fixed increase with respect to a self-adaptively set coefficient threshold. Claim 2 A plasma cavity arc suppression method according to claim 1, wherein the process of determining whether an arc occurs within the plasma cavity based on the comparison result includes determining whether an arc occurs or not within the plasma cavity when the absolute value of the difference value is smaller than the set reflection coefficient threshold value, thereby satisfying a set analysis judgment condition. Claim 3 A plasma cavity arc suppression method according to claim 2, wherein the set analysis judgment condition includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference value is smaller than the set reflection coefficient threshold value N times consecutively; and wherein N is a positive integer greater than or equal to 2. Claim 4 A plasma cavity arc suppression method according to paragraph 2, wherein the set analysis judgment condition includes determining that there is no arc generation in the plasma cavity if the absolute value of the difference value within a set period is greater than the set reflection coefficient threshold number M times and is not continuous; and wherein M is a positive integer greater than or equal to 1. Claim 5 A plasma cavity arc suppression method according to claim 2, characterized in that the set analysis judgment condition includes determining that an arc has occurred in the plasma cavity when the absolute value of the difference value reaches one time greater than the set reflection coefficient threshold. Claim 6 A plasma cavity arc suppression method according to claim 2, wherein the set analysis judgment condition includes determining that there is an arc in the plasma cavity if the absolute value of the difference value is greater than the set reflection coefficient threshold value N times consecutively; and wherein N is a positive integer greater than or equal to 2. Claim 7 delete Claim 8 A method for suppressing a plasma cavity arc according to claim 1, further comprising the step of maintaining the PID controller to operate in a normal control state when it is determined that there is no arc generation in the plasma cavity according to the comparison result; wherein the normal control state comprises: maintaining the current operating state of the control module; continuously performing arc detection sampling to obtain the reflection coefficient in the plasma cavity; recording the average reflection coefficient in the current normal operating state; recording the operating parameters for the control module; recording the operating variable parameters of the unit element of the output terminal, setting the time node currently in normal operation as the reduction node, and continuously updating it. Claim 9 A plasma cavity arc suppression method according to claim 8, wherein the process of instructing the final corresponding reduction node of the radio frequency power system to freeze the operating parameters through the state machine includes instructing the last average reflection coefficient of the normal operating state to freeze through the state machine, instructing the control module to freeze the operating parameters, and instructing the output terminal to freeze the operating variable parameters of each unit element. Claim 10 A plasma cavity arc suppression method according to claim 1, wherein the step of obtaining a reflection coefficient within the plasma cavity through the arc detection sampling comprises: a step of obtaining the instantaneous reflection coefficient using a timing point sampling method; and a step of calculating and obtaining the average reflection coefficient using all instantaneous reflection coefficients obtained from the current sampling, wherein each sampling, average value calculation, and threshold comparison is a synchronized multi-threaded process with a single time interval. Claim 11 A plasma cavity arc suppression device comprises: a detection sampling module for obtaining a reflection coefficient within a plasma cavity through arc detection sampling, wherein the reflection coefficient includes an instantaneous reflection coefficient and an average reflection coefficient; a coefficient comparison module for comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold; an arc removal module that, if it is determined that an arc has occurred within the plasma cavity according to the comparison result, freezes the operating parameters of the final corresponding reduction node of the radio frequency power system via a state machine, stops the arc detection sampling, and instructs the control module of the PID controller to cut off the power output of the output terminal docked to the plasma cavity; and an output restoration module that, after the arc within the plasma cavity disappears, instructs the control module of the PID controller to restore the power output of the output terminal and restore the arc detection sampling according to the operating parameters; wherein the detection time period of the arc detection sampling includes a plurality of detection time periods ranging from small to large, and the set reflection coefficient threshold is a manually set coefficient threshold or a coefficient threshold set self-adaptively by the system; and from the minimum detection time period, the plasma cavity A plasma cavity arc suppression device characterized by extending the detection time to the next larger detection time if the frequency at which an arc occurs within is smaller than a set frequency threshold, otherwise maintaining the detection time unchanged, and self-adaptively increasing the system using a method of multiple increase or fixed increase with respect to a self-adaptively set coefficient threshold. Claim 12 A radio frequency power system comprises a radio frequency power source, a PID controller, and a plasma chamber, wherein the radio frequency power source is electrically connected to the plasma chamber through the PID controller; the PID controller comprises the steps of: obtaining a reflection coefficient within a plasma cavity through arc detection sampling—wherein the reflection coefficient includes an instantaneous reflection coefficient and an average reflection coefficient—; comparing the absolute value of the difference between the instantaneous reflection coefficient and the average reflection coefficient with a set reflection coefficient threshold; if it is determined that an arc has occurred within the plasma cavity based on the comparison result, freezing the operating parameters of the final corresponding reduction node of the radio frequency power system, stopping the arc detection sampling, and cutting off the power output of the output terminal docked to the plasma cavity; and after the arc within the plasma cavity disappears, restoring the power output of the output terminal and restoring the arc detection sampling according to the operating parameters; wherein the detection time interval of the arc detection sampling includes a plurality of detection time intervals from small to large, and the set reflection coefficient threshold is a manually set coefficient threshold or a coefficient threshold set self-adaptively by the system; and from the minimum detection time interval, A radio frequency power system characterized by implementing an arc suppression processing step further comprising: a step of extending the detection time to a next larger detection time if the frequency at which an arc occurs within the plasma cavity is smaller than a set frequency threshold; otherwise, a step of maintaining the detection time unchanged and self-adaptively increasing it using a method of multiple increase or fixed increase with respect to a self-adaptively set coefficient threshold. Claim 13 A computer-readable storage medium in which a computer program is stored, wherein when the computer program is executed by a processor, the step of a plasma cavity arc suppression method according to any one of claims 1 to 6 and 8 to 10 is implemented.

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