Automatic Impedance Matching Method, Device, System, Electronic Device and Storage Medium

Abstract

This application relates to the field of semiconductor manufacturing. Specifically, it relates to an automatic impedance matching method, device, system, electronic device, and storage medium for matching the impedance in a reaction chamber. The automatic impedance matching method includes the following steps: obtaining the impedance information of the plasma; obtaining the impedance standard table of the plasma, the impedance standard table including a plurality of working state intervals divided according to the change of the plasma impedance, and the impedance standard table being generated according to the previous activation process of the plasma; obtaining the current working state of the plasma according to the impedance standard table and the impedance information; adjusting the impedance of the impedance matching box according to the current working state for impedance matching. This application realizes the adaptive and rapid matching of impedance through the method of first collecting and then matching. At the same time, this adaptive matching method can be applied to multiple platforms.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing, and more particularly, to an automatic impedance matching method, apparatus, system, electronic device, and storage medium. Background Art

[0002] With the development of technology and modern industry, radio frequency (RF) power supplies are increasingly widely used and have now penetrated into multiple fields such as vacuum coating, plasma equipment cleaning, and semiconductor etching, including applications in RF discharge, RF heating, etc. The role of the RF power supply is to provide high-frequency energy for the backend reaction chamber, and after plasmaizing the input gas, active molecules are obtained. Since the impedance characteristics of the gas in the reaction chamber change drastically before and after plasmaization, if there is impedance mismatch, a large amount of RF power will be reflected from the chamber back to the RF power supply, causing damage to the RF power supply. Therefore, an impedance matching box must be set between the RF power supply and the reaction chamber to perform impedance matching between the two, so as to feed the power into the reaction chamber with high efficiency.

[0003] The existing automatic impedance matching methods generally detect the impedance value of the plasma during operation, and then change the operating frequency to adapt to the current resonance frequency, so that the impedance can be matched with the impedance in the impedance box. However, this method has a long matching time and requires multiple iterations to complete the impedance matching process, resulting in low efficiency.

[0004] In view of the above problems, there is currently no effective technical solution. Summary of the Invention

[0005] The purpose of the present application is to provide an automatic impedance matching method, apparatus, system, electronic device, and storage medium, aiming to solve the problems of large computational amount and low efficiency in automatic impedance matching.

[0006] In a first aspect, the present application provides an automatic impedance matching method for matching the impedance in a reaction chamber. The automatic impedance matching method includes the following steps:

[0007] Obtain the impedance information of the plasma;

[0008] Obtain an impedance standard table of the plasma, where the impedance standard table includes multiple working state intervals divided according to the change of the plasma impedance, and the impedance standard table is generated according to the previous activation process of the plasma;

[0009] Obtain the current working state of the plasma according to the impedance standard table and the impedance information;

[0010] Adjust the impedance of the impedance matching box according to the current working state to perform impedance matching.

[0011] The automatic impedance matching method provided by this application first performs a pre-activation process of the plasma before impedance matching. By obtaining the impedance information of the plasma during the pre-activation process, an impedance standard table with different working state intervals is generated. During the working stage, according to the impedance information of the plasma, the corresponding working state interval in the impedance standard table is matched, so that the plasma can quickly complete impedance matching. This application uses a method of first collecting and then matching. An impedance standard table is established during the pre-activation process, so that during the working process, the working state intervals in the impedance standard table can be directly automatically matched by obtaining impedance information, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, due to the setting of the pre-activation process, corresponding impedance standard tables can be established according to different parameters of different platforms, so that this automatic impedance matching method can be applied to multiple platforms.

[0012] Optionally, for an automatic impedance matching method provided by this application, the steps of obtaining the impedance information of the plasma include:

[0013] Obtain voltage information, current information, and phase angle information;

[0014] Generate the impedance information of the plasma according to the voltage information, current information, and phase angle information.

[0015] Optionally, for an automatic impedance matching method provided by this application, the generation process of the impedance standard table includes:

[0016] Use a radio frequency power supply to perform pre-activation on the plasma;

[0017] Obtain the reference impedance information of the plasma during the pre-activation process;

[0018] Establish an impedance standard table according to the reference impedance information;

[0019] Divide the impedance standard table into multiple working state intervals according to the slope change of the reference impedance information in the impedance standard table with respect to time.

[0020] This application obtains the reference impedance information through a pre-activation process before working, establishes an impedance standard table according to the reference impedance information, and divides the impedance into multiple working state intervals in the impedance standard table, so that the impedance can generate an impedance standard table adapted to different machines and different parameters, facilitating subsequent automatic impedance matching.

[0021] Optionally, for an automatic impedance matching method provided by this application, the steps of establishing an impedance standard table according to the reference impedance information include:

[0022] Establish multiple impedance information matrix tables according to the reference impedance information generated by multiple runs of the radio frequency power supply;

[0023] Calculate the root mean square of multiple impedance information matrix tables to obtain the impedance standard value table.

[0024] In this application, multiple impedance information matrix tables are established through multiple measurements, and the root mean square is calculated between the multiple impedance matrix tables to obtain the impedance standard table, which is the basis for judging the working state of the plasma.

[0025] Optionally, for an automatic impedance matching method provided by this application, different working state intervals have corresponding target impedance information. The steps of adjusting the impedance of the impedance matching box according to the current working state for impedance matching include:

[0026] Obtain the target impedance information that matches the current working state;

[0027] Adjust the impedance of the impedance matching box according to the target impedance information that matches the current working state for impedance matching.

[0028] Optionally, for an automatic impedance matching method provided by this application, the steps of obtaining the current working state of the plasma according to the impedance standard table and the impedance information include:

[0029] Obtain the instantaneous impedance slope of the impedance of the plasma changing with time according to the impedance information;

[0030] Obtain the current working state of the plasma according to the instantaneous impedance slope and the working state interval of the impedance standard table.

[0031] In a second aspect, this application also provides an automatic impedance matching device for matching the impedance in a reaction chamber. The automatic impedance matching device includes:

[0032] The first acquisition module is used to acquire the impedance information of the plasma;

[0033] The second acquisition module is used to acquire the impedance standard table of the plasma. The impedance standard table includes multiple working state intervals divided according to the impedance change of the plasma, and the impedance standard table is generated according to the previous activation process of the plasma;

[0034] The third acquisition module is used to obtain the current working state of the plasma according to the impedance standard table and the impedance information;

[0035] The matching module is used to adjust the impedance of the impedance matching box according to the current working state for impedance matching.

[0036] The automatic impedance matching device provided by this application first performs a pre-activation process of the plasma before impedance matching. By obtaining the impedance information of the plasma during the pre-activation process, an impedance standard table with different working state intervals is generated. During the working stage, according to the impedance information of the plasma, the corresponding working state interval in the impedance standard table is matched, so that the plasma can quickly complete impedance matching. This application uses the method of first collecting and then matching to establish an impedance standard table during the pre-activation process, enabling the automatic matching of each working state interval in the impedance standard table directly by obtaining impedance information during the working process, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, due to the pre-activation process being set, corresponding impedance standard tables can be established according to different parameters of different platforms, making this automatic impedance matching device applicable to multiple platforms.

[0037] In a third aspect, this application also provides an automatic impedance matching system for matching the impedance in a reaction chamber, including:

[0038] A reaction chamber for providing a reaction space for plasma activation;

[0039] A radio frequency power supply for providing energy for plasma activation;

[0040] An impedance matching box for adjusting the impedance change by adjusting the internal adjustable capacitor;

[0041] The automatic impedance matching system further includes:

[0042] A real-time impedance detector for real-time collecting the impedance information of the plasma in the reaction chamber;

[0043] An impedance storage unit for storing the impedance standard table, which includes multiple working state intervals divided according to the change of plasma impedance, and the impedance standard table is generated according to the pre-activation process of the plasma;

[0044] A controller, which is electrically connected to the radio frequency power supply, the impedance matching box, the real-time impedance detector, and the impedance storage unit;

[0045] The controller is used to obtain the impedance information of the plasma;

[0046] The controller is also used to obtain the impedance standard table of the plasma;

[0047] The controller is also used to obtain the current working state of the plasma according to the impedance standard table and the impedance information;

[0048] The controller is also used to adjust the impedance of the impedance matching box according to the current working state for impedance matching.

[0049] The automatic impedance matching system provided by this application first performs a pre-activation process of the plasma before impedance matching. By obtaining the impedance information of the plasma during the pre-activation process, an impedance standard table with different working state intervals is generated. During the working stage, according to the impedance information of the plasma, the corresponding working state interval in the impedance standard table is matched, so that the plasma can quickly complete impedance matching. This application uses the method of first collecting and then matching to establish an impedance standard table during the pre-activation process, enabling the automatic matching of each working state interval in the impedance standard table directly by obtaining impedance information during the working process, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, due to the pre-activation process being set, corresponding impedance standard tables can be established according to different parameters of different platforms, making this automatic impedance matching system applicable to multiple platforms.

[0050] In a fourth aspect, this application also provides an electronic device, including a processor and a memory. The memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the steps of the automatic impedance matching method provided in the first aspect above are run: obtaining the impedance information of the plasma; obtaining the impedance standard table of the plasma, where the impedance standard table includes multiple working state intervals divided according to the impedance change situation of the plasma, and the impedance standard table is generated according to the pre-activation process of the plasma; obtaining the current working state of the plasma according to the impedance standard table and the impedance information; adjusting the impedance of the impedance matching box according to the current working state to perform impedance matching.

[0051] In a fifth aspect, this application also provides a storage medium, on which a computer program is stored. When the computer program is executed by the processor, the steps of the automatic impedance matching method provided in the first aspect above are run: obtaining the impedance information of the plasma; obtaining the impedance standard table of the plasma, where the impedance standard table includes multiple working state intervals divided according to the impedance change situation of the plasma, and the impedance standard table is generated according to the pre-activation process of the plasma; obtaining the current working state of the plasma according to the impedance standard table and the impedance information; adjusting the impedance of the impedance matching box according to the current working state to perform impedance matching.

[0052] As can be seen from the above, the automatic impedance matching method, device, system, electronic device and storage medium provided by the present application first perform a pre-activation process of the plasma before impedance matching, generate an impedance standard table with different working state intervals by obtaining the impedance information of the plasma during the pre-activation process, and during the working stage, match the corresponding working state intervals in the impedance standard table according to the impedance information of the plasma, so as to enable the plasma to quickly complete impedance matching. The present application establishes an impedance standard table during the pre-activation process by the method of first collecting and then matching, so that during the working process, the working state intervals in the impedance standard table can be directly automatically matched by obtaining the impedance information, thereby realizing fast adaptive impedance matching of the impedance, improving the matching efficiency. At the same time, due to the setting of the pre-activation process, corresponding impedance standard tables can be established according to different parameters of different platforms, so that the automatic impedance matching method can be applied to multiple platforms.

[0053] Other features and advantages of the present application will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing the present application. The objectives and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written specification and the drawings. Brief Description of the Drawings

[0054] Figure 1 It is a flowchart of the steps of an automatic impedance matching method provided by an embodiment of the present application.

[0055] Figure 2 It is a schematic structural diagram of an impedance matching box provided by this embodiment.

[0056] Figure 3 It is a schematic structural diagram of an automatic impedance matching device provided by an embodiment of the present application.

[0057] Figure 4 It is a schematic structural diagram of an automatic impedance matching system provided by an embodiment of the present application.

[0058] Figure 5 It is an electronic device provided by an embodiment of the present application.

[0059] Reference numerals: 1, radio frequency power supply; 2, real-time impedance detector; 3, controller; 4, impedance matching box; 5, impedance storage unit; 6, reaction chamber; 100, first acquisition module; 200, second acquisition module; 300, third acquisition module; 400, matching module; 91, processor; 92, memory; 93, communication bus. Detailed Embodiment

[0060] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0061] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0062] In the existing impedance matching method, generally, the impedance value of the plasma is detected during operation, and then the switching frequency of the inverter circuit is changed to adapt to the current resonance frequency, so that the impedance can be matched with the impedance in the impedance box. However, this method has a long matching time and low efficiency.

[0063] In the first aspect, referring to Figure 1 , Figure 1 is a flowchart of the steps of an automatic impedance matching method provided by an embodiment of the present application. Figure 1 As shown, an automatic impedance matching method for matching the impedance in the reaction chamber 6 includes the following steps:

[0064] S1. Obtain the impedance information of the plasma;

[0065] S2. Obtain the impedance standard table of the plasma. The impedance standard table includes multiple working state intervals divided according to the change of the plasma impedance, and the impedance standard table is generated according to the previous activation process of the plasma;

[0066] S3. Obtain the current working state of the plasma according to the impedance standard table and the impedance information;

[0067] S4. Adjust the impedance of the impedance matching box 4 according to the current working state to perform impedance matching.

[0068] Specifically, this method can be applied to the automatic impedance matching system shown in Figure 4 . The system includes a reaction chamber 6, a radio frequency power supply 1, an impedance matching box 4, a real-time impedance detector 2, an impedance storage unit 5, and a controller 3.

[0069] Specifically, the impedance information is the magnitude of the impedance value of the plasma formed after being energized by the input gas radio frequency power supply 1 in the reaction chamber 6.

[0070] Specifically, the impedance matching process is divided into a pre-activation process and an operating process. When the plasma is in the pre-activation process, the radio frequency power supply 1 outputs energy to the reaction chamber 6 to activate the plasma in the reaction chamber 6, and the impedance information of the plasma in the reaction chamber 6 is obtained in real time. An impedance standard table is obtained based on the variation relationship of the real-time impedance information with time, and the impedance standard value table is divided into multiple operating state intervals according to the slope relationship between the impedance and time in the impedance standard table. Subsequently, the operating process is entered. Specifically, the operating process is the current activation process of the input gas. During the operating process, according to the slope relationship between the impedance information obtained in real time and time, the operating state interval of the plasma in the impedance standard table is judged, and the plasma is moved to the corresponding operating state interval to achieve matching.

[0071] Specifically, the operating process is a process in which the input gas forms a plasma in the matching reaction chamber 6 after being energized by the radio frequency power supply 1.

[0072] Preferably, during the operating process, the impedance information of the plasma is still continuously obtained, and an impedance standard table is obtained based on the variation relationship of the real-time impedance information with time for subsequent impedance matching. At the same time, after the impedance standard table is generated, the impedance standard table will be stored in the impedance storage unit 5.

[0073] Specifically, in this embodiment, the operating state of the plasma is divided into three states: a power rising process, an ignition process, and a sustained discharge process. The slope relationships between the impedance and time in the three states are different. Specifically, in the power rising process, the impedance of the plasma has a positive volt-ampere characteristic, that is, the impedance decreases at this time, and the impedance shows a downward trend with time. In the ignition process, the impedance of the plasma decreases rapidly within a short time and reaches the minimum impedance value. At this time, the impedance slope is less than the impedance slope in the power rising process. In the sustained discharge process, the plasma has been formed at this time, and a stable excitation needs to be provided externally. At this time, the impedance slope rises slightly but the change is not large, and it is relatively stable as a whole. Therefore, the impedance slopes in the three stages are different, and the operating state of the current plasma can be judged according to the impedance slope.

[0074] In the automatic impedance matching method in the embodiments of the present application, a pre-activation process of the plasma is first performed before impedance matching. An impedance standard table with different working state intervals is generated by obtaining the impedance information of the plasma during the pre-activation process. During the working process, the corresponding working state interval in the impedance standard table is matched according to the impedance information of the plasma, so that the plasma can quickly complete impedance matching. The present application establishes an impedance standard table during the pre-activation process by the method of first collecting and then matching, so that each working state interval in the impedance standard table can be directly automatically matched by obtaining the impedance information during the working process, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, due to the setting of the pre-activation process, corresponding impedance standard tables can be established according to different parameters of different platforms, so that the automatic impedance matching method can be applied to multiple platforms.

[0075] In some preferred embodiments, the steps of obtaining the impedance information of the plasma include:

[0076] Obtaining voltage information, current information, and phase angle information;

[0077] Generating the impedance information of the plasma according to the voltage information, current information, and phase angle information.

[0078] Specifically, in this embodiment, the impedance information of the plasma can be generated by obtaining the voltage information, current information, and phase angle information of the plasma. The generation process is as follows:

[0079] If the current flowing through the plasma is , then the voltage across the plasma is: Where R is the impedance of the plasma, V is the voltage across the plasma, I is the current passing through the plasma, and both represent the angle of the phase angle, but their forms of expression are different. For example: =π / 3, then =60°, represents the amplitude of the current, represents the scaling coefficient of the trigonometric function graph curve, , where freq represents the frequency of the radio frequency power supply 1 at this time. Only by knowing three of the impedance, voltage, current amplitude, and phase angle of the plasma can the other quantity be calculated. In this embodiment, the voltage information, current information, and phase angle information of the plasma are measured by a detection device, and the impedance information of the plasma can be calculated through the voltage across the plasma. The obtained impedance information is instantaneous impedance information.

[0080] In some preferred embodiments, the generation process of the impedance standard table generated according to the pre-activation process of the plasma includes:

[0081] The plasma is pre-activated by using the radio frequency power supply 1;

[0082] Obtain the reference impedance information during the pre-activation of the plasma;

[0083] Establish an impedance standard table according to the reference impedance information;

[0084] Divide the impedance standard table into multiple working state intervals according to the slope change of the reference impedance information in the impedance standard table with respect to time.

[0085] Specifically, the impedance standard table is a curve graph of impedance versus time. By establishing an impedance standard table with different working state intervals, during the working process, the impedance information can be obtained and automatically matched with each working state interval in the impedance standard table, thereby reducing the calculation time of the matching and improving the matching efficiency. Optionally, the pre-activation process can be carried out according to the radio frequency power supply 1 with different powers to generate impedance standard tables under different powers, so that the automatic impedance matching method can be applied to match radio frequency power supplies 1 with different frequencies, improving the adaptability of the automatic impedance matching method.

[0086] In some preferred embodiments, the steps of establishing an impedance standard table according to the reference impedance information include:

[0087] Establish multiple impedance information matrix tables according to the reference impedance information generated by the multiple operations of the radio frequency power supply 1;

[0088] Perform root mean square measurement on the multiple impedance information matrix tables to obtain an impedance standard value table.

[0089] Specifically, in this embodiment, 3 impedance information matrix tables are collected: A1, A2, A3. A1, A2, A3 are impedance information matrix tables collected under different powers, where , , , are the real part values of three continuously collected impedances within the first time period, , , are the imaginary part values of three continuously collected impedances within the first time period. According to , , , the standard deviation k1 of the real part of the impedance can be calculated. According to , , The standard deviation n1 of the imaginary part of the impedance can be calculated; similarly, the standard deviation k2 of the real part of the impedance continuously collected in the second time period, the standard deviation n2 of the imaginary part of the impedance continuously collected in the second time period, and the standard deviation k3 of the real part of the impedance continuously collected in the third time period, and the standard deviation n3 of the imaginary part of the impedance continuously collected in the third time period can be calculated. The average value of the standard deviations k1, k2, and k3 of the real part of the impedance collected in the three time periods is obtained as p1, and the average value of the standard deviations n1, n2, and n3 of the imaginary part of the impedance collected in the three time periods is obtained as p2. In actual operation, according to different matching scenarios and different matching parameters of the impedance matching that has been completed, different preset empirical coefficient values will be obtained. The preset empirical coefficient values include the real part j1 and the imaginary part j2. If p1 < j1 and p2 < j2, then it can be determined that one of the three impedance information matrix tables that meet the conditions is the impedance standard value table. If the above conditions are not met, then this impedance information matrix table is not the impedance standard value table, and it is necessary to continue to obtain the three impedance information matrix tables obtained in the next three time periods and compare them with the preset empirical coefficient values for judgment.

[0090] In some preferred embodiments, different working state intervals have corresponding target impedance information. The steps of adjusting the impedance of the impedance matching box 4 for impedance matching according to the current working state include:

[0091] Obtain the target impedance information that matches the current working state;

[0092] Adjust the impedance of the impedance matching box 4 according to the target impedance information that matches the current working state for impedance matching.

[0093] In some preferred embodiments, the steps of obtaining the current working state of the plasma according to the impedance standard table and the impedance information include:

[0094] Obtain the instantaneous impedance slope of the impedance of the plasma changing with time according to the impedance information;

[0095] Obtain the current working state of the plasma according to the instantaneous impedance slope and the working state interval of the impedance standard table.

[0096] Generally, in the semiconductor field, the power level of the RF power supply 1 reaches kilowatts. Therefore, the requirement for the capacitive voltage resistance ability of the impedance matching box 4 is very high. In this embodiment, vacuum capacitors are selected to form the adjustable elements of the impedance matching box 4.

[0097] Specifically, the impedance matching box 4 is used to adjust the impedance magnitude to achieve impedance matching. Generally, the impedance matching box 4 usually achieves impedance matching by adjusting the resonance frequency. Since the impedance variation characteristic of the impedance load may be several times or even more than a dozen times the initial impedance amplitude, the method of adjusting the resonance frequency has great limitations. Preferably, referring to Figure 2 , Figure 2 is a schematic structural diagram of an impedance matching box provided in this embodiment. Figure 2 The shown impedance matching box 4 adopts a π-type matching circuit. The impedance matching box 4 includes a fixed capacitor , , a fixed inductor L, variable capacitors , . By adjusting the capacitance values of the variable capacitors , , impedance matching can be achieved. Specifically, the capacitance value is adjusted by adjusting the facing area of the capacitor plates. The facing area of the capacitor plates is proportional to the capacitance value. The capacitor plates are driven by a motor to change the facing area of the capacitor plates, and thus change the capacitance value.

[0098] Specifically, since there are obvious differences in the slopes of the linear relationships between impedance and time in different working states, the working state of the plasma at a certain moment can be judged according to the instantaneous impedance slope at different moments. Specifically, the working state of the plasma at this moment is determined by combining the similarity between the instantaneous impedance slope and the slopes of the working state intervals in the impedance standard table.

[0099] Specifically, it is necessary to obtain the impedance slope based on the impedance information obtained in real time. Specifically, multiple impedance value points at different time periods can be obtained to calculate the impedance slope. In some embodiments, it may happen that the two time points taken happen to be in different working state intervals. Therefore, to improve the accuracy of obtaining the impedance slope, the time interval for obtaining different time points can be reduced. However, if the time interval is too short, it is easy to cause a large calculation error in the impedance slope. Therefore, to reduce the slope error and prevent the sampling points from being in different working state intervals, multiple groups of data can be collected. The time interval between two adjacent sampling points in each group of data is less than the time interval between multiple groups of data, and the time interval cannot be too small. Multiple impedance slopes are obtained through multiple groups of data. Exclude the data that is significantly inconsistent with other impedance slope data, and calculate the average value of the remaining impedance slope values. Compare the averaged impedance slope value with the impedance slopes in different working state intervals in the impedance standard table, and match the plasma to the corresponding working state interval in the impedance standard table to complete the matching. In this embodiment, three groups of sampling data are set. Two sampling points are set in each group of sampling data, and the two sampling points are separated by 1 - 2 seconds. The interval between each group of data is 5 - 10 seconds. After obtaining the impedance slopes of the three groups of data, average the impedance slopes with similar data, and then compare with the information in the impedance standard table to match to the corresponding working state interval in the impedance standard table.

[0100] Specifically, a preset point is set in each working state interval. By adjusting the variable capacitor and to the preset point, automatic impedance matching of the plasma can be achieved. In this embodiment, taking a certain IPC machine as an example, assume that the power is rising in the 0 - t1 period. At this time, the impedance characteristic of the plasma is: the imaginary part is positive, and the impedance gradually decreases from more than 200 ohms. In the t1 - t2 period, it is the ignition process. At this time, the impedance characteristic of the plasma is: the imaginary part gradually decreases to near 0, and the real part value is stable at around 50 ohms. After t2, it is the process of maintaining discharge. At this time, the impedance characteristic of the plasma is: the real part and the imaginary part remain stable, and the change value is small.

[0101] Furthermore, the preset point needs to be calculated based on the impedance value of the plasma and the frequency of the RF power supply 1 in each working state interval. In this embodiment, assume that the current impedance value of the plasma is (m1 + n1j) Ω, and the impedance value of the current impedance matching network is (m2 + n2j) Ω. By adjusting the variable capacitor the real part of the impedance can be changed. By adjusting the imaginary part of the impedance can be changed. Specifically, in this embodiment, the difference in the real part is m1 - m2. According to the capacitance impedance formula , the value of can be obtained. The difference in the imaginary part is n1 - n2. According to the capacitance impedance formula , the value can be obtained , where freq represents the frequency of the radio frequency power supply 1 at this time.

[0102] For example, if the plasma is in the process of power increase, the point at 0.9t1 during the power increase process is selected as the matching target. Since the impedance of the plasma gradually decreases to 50 ohms at this time, in this embodiment, it is assumed that the impedance is 70 ohms at 0.9t1, that is, 70 ohms is the matching target at this time. According to the formula, the preset points of the variable capacitor and are 52 pF and 174 pF respectively to achieve impedance matching. If the plasma is in the ignition process, since the plasma is stable near 50 ohms at this time, the matching target during the ignition process is selected as 50 ohms. According to the formula, the preset points of the variable capacitor and are 98 pF and 42 pF respectively to achieve impedance matching. If the plasma is in the process of maintaining discharge, since the imaginary part and the real part of the impedance remain stable at this time, the stable value is selected as the matching target during the process of maintaining discharge. According to the formula, the preset points of the variable capacitor and are 80 pF and 59 pF respectively to achieve impedance matching.

[0103] The automatic impedance matching method provided in this embodiment first performs the pre-activation process of the plasma before impedance matching, generates an impedance standard table with different working state intervals by obtaining the impedance information of the plasma during the pre-activation process. During the working stage, according to the impedance information of the plasma, the corresponding working state interval in the impedance standard table is matched, so that the plasma can quickly complete impedance matching. This application uses the method of first collecting and then matching to establish an impedance standard table during the pre-activation process, so that during the working process, the impedance information can be directly obtained to automatically match each working state interval in the impedance standard table, thereby realizing the automatic and rapid matching of impedance, improving the matching efficiency. At the same time, due to the setting of the pre-activation process, the corresponding impedance standard table can be established according to the different parameters of different platforms, so that this automatic impedance matching method can be applied to multiple platforms.

[0104] Second, referring to Figure 3 , Figure 3 is a schematic structural diagram of an automatic impedance matching device provided in an embodiment of the present application. Figure 3 As shown in the automatic impedance matching device for matching the impedance in the reaction chamber 6, the automatic impedance matching device includes:

[0105] The first acquisition module 100 is used to acquire the impedance information of the plasma;

[0106] The second acquisition module 200 is configured to acquire an impedance standard table of the plasma. The impedance standard table includes multiple working state intervals divided according to the change of the plasma impedance. The impedance standard table is generated according to the previous activation process of the plasma.

[0107] The third acquisition module 300 is configured to acquire the current working state of the plasma according to the impedance standard table and the impedance information.

[0108] The matching module 400 is configured to adjust the impedance of the impedance matching box 4 according to the current working state to perform impedance matching.

[0109] In the automatic impedance matching device provided in this embodiment, the previous activation process of the plasma is performed before impedance matching. By acquiring the impedance information of the plasma during the previous activation process, an impedance standard table with different working state intervals is generated. During the working stage, according to the impedance information of the plasma, the corresponding working state interval in the impedance standard table is matched, so that the plasma can quickly complete impedance matching. In this application, by the method of first acquisition and then matching, an impedance standard table is established during the previous activation process, so that during the working process, the corresponding working state intervals in the impedance standard table can be directly automatically matched by acquiring the impedance information, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, because it is set in the previous activation process, corresponding impedance standard tables can be established according to different parameters of different platforms, so that the automatic impedance matching device can be applied to multiple platforms.

[0110] In the third aspect, referring to Figure 4 , Figure 4 is a schematic structural diagram of an automatic impedance matching system provided in an embodiment of the present application. Figure 4 An automatic impedance matching system shown is used to match the impedance in the reaction chamber 6 and includes:

[0111] The reaction chamber 6 is configured to provide a reaction space for plasma activation.

[0112] The radio frequency power supply 1 is configured to provide energy for plasma activation.

[0113] The impedance matching box 4 is configured to complete the adjustment and change of the impedance by adjusting the internal adjustable capacitor.

[0114] The automatic impedance matching system further includes:

[0115] The real-time impedance detector 2 is configured to collect the impedance information of the plasma in the reaction chamber 6 in real time.

[0116] The impedance storage unit 5 is configured to store an impedance standard table. The impedance standard table includes multiple working state intervals divided according to the change of the plasma impedance. The impedance standard table is generated according to the previous activation process of the plasma.

[0117] A controller 3, which is electrically connected to a radio frequency power supply 1, an impedance matching box 4, a real-time impedance detector 2, and an impedance storage unit 5;

[0118] The controller 3 is used to obtain the impedance information of the plasma;

[0119] The controller 3 is further used to obtain an impedance standard table of the plasma;

[0120] The controller 3 is further used to obtain the current working state of the plasma according to the impedance standard table and the impedance information;

[0121] The controller 3 is further used to adjust the impedance of the impedance matching box 4 according to the current working state for impedance matching.

[0122] In the automatic impedance matching system provided by the embodiment of the present application, a pre-activation process of the plasma is first performed before impedance matching. An impedance standard table with different working state intervals is generated by obtaining the impedance information of the plasma during the pre-activation process. During the working stage, the corresponding working state interval in the impedance standard table is matched according to the impedance information of the plasma, so that the plasma can quickly complete impedance matching. Through the method of first collecting and then matching, the present application establishes an impedance standard table during the pre-activation process, enabling the automatic matching of each working state interval in the impedance standard table directly by obtaining impedance information during the working process, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, due to the setting of the pre-activation process, corresponding impedance standard tables can be established according to different parameters of different platforms, making the automatic impedance matching system applicable to multiple platforms.

[0123] Fourthly, referring to Figure 5 , Figure 5 An electronic device provided by the present application includes: a processor 91 and a memory 92. The processor 91 and the memory 92 are interconnected and communicate with each other through a communication bus 93 and / or other forms of connection mechanisms (not marked). The memory 92 stores a computer program executable by the processor 91. When the electronic device runs, the processor 91 executes the computer program to perform any optional implementation manner of the above embodiments to achieve the following functions: obtaining the impedance information of the plasma; obtaining an impedance standard table of the plasma, the impedance standard table including multiple working state intervals divided according to the change of the plasma impedance, and the impedance standard table is generated according to the pre-activation process of the plasma; obtaining the current working state of the plasma according to the impedance standard table and the impedance information; adjusting the impedance of the impedance matching box 4 according to the current working state for impedance matching.

[0124] Fifth aspect, the present application provides a storage medium, on which a computer program is stored. When the computer program is executed by a processor 91, it executes the method in any optional implementation manner of the above embodiments to implement the following functions: obtaining impedance information of the plasma; obtaining an impedance standard table of the plasma, the impedance standard table including a plurality of working state intervals divided according to the change of the plasma impedance, and the impedance standard table is generated according to the previous activation process of the plasma; obtaining the current working state of the plasma according to the impedance standard table and the impedance information; adjusting the impedance of the impedance matching box 4 according to the current working state to perform impedance matching.

[0125] As can be seen from the above, for the automatic impedance matching method, device, system, electronic device and storage medium provided by the present application, the previous activation process of the plasma is carried out before impedance matching. By obtaining the impedance information of the plasma during the previous activation process, an impedance standard table with different working state intervals is generated. During the working stage, according to the impedance information of the plasma, the corresponding working state interval in the impedance standard table is matched, so that the plasma can quickly complete impedance matching. The present application establishes an impedance standard table during the previous activation process by the method of first collecting and then matching, so that during the working process, the working state intervals in the impedance standard table can be directly automatically matched by obtaining the impedance information, thereby realizing automatic and rapid impedance matching, improving the matching efficiency. At the same time, due to the setting in the previous activation process, the corresponding impedance standard table can be established according to different parameters of different platforms, so that the automatic impedance matching method can be applied to multiple platforms.

[0126] In the embodiments provided by the present application, it should be understood that the disclosed device and method can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0127] In addition, the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0128] Furthermore, in each embodiment of the present application, each functional module may be integrated together to form an independent part, or each module may exist alone, or two or more modules may be integrated to form an independent part.

[0129] In this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0130] The above are only embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An automatic impedance matching method for matching the impedance in a reaction chamber (6), characterized in that, The described automatic impedance matching method includes the following steps: Obtain the impedance information of the plasma; Obtain the impedance standard table of the plasma, where the impedance standard table includes multiple working state intervals divided according to the impedance change of the plasma, and the impedance standard table is generated according to the previous activation process of the plasma; Obtain the current working state of the plasma according to the impedance standard table and the impedance information; Adjust the impedance of the impedance matching box (4) according to the current working state for impedance matching; The step of obtaining the current working state of the plasma according to the impedance standard table and the impedance information includes: Obtain the instantaneous impedance slope of the impedance of the plasma changing with time according to the impedance information; Obtain the current working state of the plasma according to the instantaneous impedance slope and the working state intervals of the impedance standard table; The generation process of the impedance standard table includes: Use the radio frequency power supply (1) to perform previous activation on the plasma; Obtain the reference impedance information of the plasma during the previous activation process; Establish the impedance standard table according to the reference impedance information; Divide the impedance standard table into multiple working state intervals according to the slope change of the reference impedance information with respect to time in the impedance standard table; The step of establishing the impedance standard table according to the reference impedance information includes: Establish multiple impedance information matrix tables according to the reference impedance information generated by the multiple operations of the radio frequency power supply (1); Perform root mean square measurement on the multiple impedance information matrix tables to obtain the impedance standard table.

2. The automatic impedance matching method according to claim 1, wherein The step of obtaining the impedance information of the plasma includes: Obtain voltage information, current information, and phase angle information; Generate the impedance information of the plasma according to the voltage information, the current information, and the phase angle information.

3. An automatic impedance matching method according to claim 1, characterized in that, Different working state intervals have corresponding target impedance information. The step of adjusting the impedance of the impedance matching box (4) according to the current working state for impedance matching includes: ​ ​ 4. An automatic impedance matching device for matching the impedance in a reaction chamber (6), characterized in that, ​ ​ ​ ​ ​ ​ ​ Obtain the current working state of the plasma according to the instantaneous impedance slope and the working state interval of the impedance standard table; The generation process of the impedance standard table includes: Use the radio frequency power supply (1) to pre-activate the plasma; Obtain the reference impedance information of the plasma during the pre-activation process; Establish the impedance standard table according to the reference impedance information; Divide the impedance standard table into multiple working state intervals according to the slope change of the reference impedance information in the impedance standard table with respect to time; The establishing the impedance standard table according to the reference impedance information includes: Establish multiple impedance information matrix tables according to the reference impedance information generated by multiple runs of the radio frequency power supply (1); Perform root mean square measurement on multiple impedance information matrix tables to obtain the impedance standard table.

5. An automatic impedance matching system for matching the impedance in a reaction chamber (6), comprising: A reaction chamber (6) for providing a reaction space for plasma activation; A radio frequency power supply (1) for providing energy for the plasma activation; An impedance matching box (4) for adjusting the impedance by adjusting the internal adjustable capacitor; Characterized in that the automatic impedance matching system further includes: A real-time impedance detector (2) for real-time collecting the impedance information of the plasma in the reaction chamber (6); An impedance storage unit (5) for storing an impedance standard table, the impedance standard table including multiple working state intervals divided according to the impedance change situation of the plasma, and the impedance standard table is generated according to the pre-activation process of the plasma; A controller (3), the controller (3) is electrically connected to the radio frequency power supply (1), the impedance matching box (4), the real-time impedance detector (2) and the impedance storage unit (5); The controller (3) is used to obtain the impedance information of the plasma; The controller (3) is further used to obtain the impedance standard table of the plasma; The controller (3) is further used to obtain the current working state of the plasma according to the impedance standard table and the impedance information; The controller (3) is further used to adjust the impedance of the impedance matching box (4) according to the current working state for impedance matching; The obtaining the current working state of the plasma according to the impedance standard table and the impedance information includes: Obtain the instantaneous impedance slope of the impedance change of the plasma with respect to time according to the impedance information; Obtain the current working state of the plasma according to the instantaneous impedance slope and the working state interval of the impedance standard table; The generation process of the impedance standard table includes: Use the radio frequency power supply (1) to pre-activate the plasma; Obtain the reference impedance information of the plasma during the pre-activation process; Establish the impedance standard table according to the reference impedance information; Divide the impedance standard table into multiple working state intervals according to the slope change of the reference impedance information in the impedance standard table with respect to time; The establishing the impedance standard table according to the reference impedance information includes: Establish a plurality of impedance information matrix tables based on the reference impedance information generated by multiple runs of the radio frequency power supply (1); Perform root mean square measurement on the plurality of impedance information matrix tables to obtain the impedance standard table.

6. An electronic device, characterized in that, It includes a processor (91) and a memory (92), and the memory (92) stores computer-readable instructions. When the computer-readable instructions are executed by the processor (91), the steps in the method according to any one of claims 1-3 are run.

7. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor (91), the steps in the method according to any one of claims 1-3 are run.

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