Radio frequency power supply impedance matching method and device, electronic equipment and storage medium

Abstract

The invention provides a radio frequency power supply impedance matching method and device, electronic equipment and a storage medium, and relates to the technical field of semiconductor device manufacturing. The method comprises the following steps: acquiring association information between substrate temperature dynamic change and plasma load impedance of a multilayer film structure under different process steps; acquiring current process step information and real-time temperature information of a substrate in the process of performing plasma etching on the multilayer film structure; according to the current process step information and the real-time temperature information of the substrate, determining a plasma load impedance target value corresponding to the real-time temperature information of the substrate by using the associated information; and adjusting an adjustable element of a radio frequency energy transmission matching network in the radio frequency power supply according to the plasma load impedance target value. According to the method, the dynamic drift of the plasma load impedance caused by the dynamic change of the actual surface temperature of the substrate is effectively dealt with, and the effect of maintaining efficient and stable transmission of radio frequency energy is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor device manufacturing, and in particular to a radio frequency power supply impedance matching method, device, electronic equipment and storage medium. Background Art

[0002] In the semiconductor device manufacturing process, plasma etching is one of the key processes for achieving pattern transfer. A plasma etching system typically includes an RF power supply, a reaction chamber, and a support table for carrying and controlling the temperature of the substrate. The RF energy generated by the RF power supply is coupled into the reaction chamber through an impedance matching network, and is excited to form a plasma under a specific process gas environment. The active particles in the plasma undergo chemical or physical reactions with the surface material of the substrate placed on the support table, thereby achieving selective removal of the material, i.e., etching. The impedance matching network plays a vital role in this. Its main function is to adjust the complex impedance presented by the plasma load so that it matches the output impedance of the RF power supply to maximize the transmission of RF energy to the plasma while minimizing the power reflected back to the RF power supply. Efficient and stable RF energy coupling is the basis for obtaining a stable plasma state and repeatable etching results.

[0003] However, in the actual plasma etching process, especially when etching multi-layer film structures composed of different material layers that are common in semiconductor devices, the situation becomes more complicated. Multi-layer film etching usually requires etching different material layers in multiple steps according to a preset process flow. Each layer of material has unique physical and chemical properties, such as thermal conductivity, heat capacity, and interaction characteristics with plasma. During the etching process, the temperature of the substrate is not constant, but is affected by a combination of factors, including the energy bombardment of the plasma on the substrate, the temperature control setting of the substrate support table, the differences in the thermophysical properties of different material layers, and the exothermic or endothermic chemical reactions that occur during the etching process.

[0004] As plasma etching progresses from one material layer to the next, the energy coupling between the plasma and the substrate surface and its efficiency change significantly due to changes in material properties. This switching of process steps and the replacement of material layers directly affects the rate and distribution of energy absorbed by the substrate, leading to dynamic changes in the actual operating temperature of the substrate surface. The rate of change and the resulting steady-state temperature may be completely different from the previous stage.

[0005] Furthermore, the dynamic changes in the substrate surface temperature will profoundly affect the physical and chemical reaction processes occurring on the substrate surface. The etching reaction rate, the volatility of the etching products, and the deposition rate of the by-products are all highly sensitive to the surface temperature. For example, an increase in temperature may accelerate the reaction rate or enhance product volatility, while a decrease in temperature may cause by-products to deposit more easily. This product deposition or change in the substrate surface state will in turn affect the characteristics of the plasma-substrate boundary layer, change the plasma sheath structure and the parameters of the plasma itself. These changes in plasma characteristics will ultimately be reflected in the dynamic drift of the plasma load impedance. Therefore, when etching a multilayer film structure with different material layers that requires process step switching, the plasma load impedance caused by surface reactions, product behavior, and plasma boundary effects will exhibit complex dynamic drift characteristics as the process steps are switched and the actual surface temperature of the substrate changes dynamically.

[0006] In existing technologies, sensors used to monitor substrate temperature may have inherent limitations. For example, temperature sensors installed inside or on the surface of the substrate support primarily measure the support temperature, with inevitable delays and discrepancies between the actual substrate surface temperature. While non-contact temperature measurement methods (such as infrared thermometry) can measure surface temperature, they can be affected by the plasma's own emission spectrum, deposits on the cavity window, or changes in the substrate surface state. This can lead to noise, drift, or errors in the measurement signal, making it inaccurate and inaccurate to reflect the true substrate surface temperature.

[0007] Traditional RF power supply impedance matching control typically employs a feedback control strategy based on minimizing reflected power. Based on the real-time reflected power signal, the matching network adjusts its adjustable parameters (such as capacitance and inductance) through a feedback loop to minimize reflected power. However, when the plasma impedance drift caused by substrate temperature changes is a relatively slow but continuous process, the reflected power feedback system may experience response lag, failing to accurately track this dynamic change. This lag is particularly pronounced in multilayer etching, where rapid process switching leads to rapid changes in substrate temperature and impedance, potentially leading to transient or persistent impedance mismatches. Even attempts to utilize inaccurate or delayed substrate temperature measurement signals for auxiliary control still struggle to accurately predict and compensate for the plasma impedance drift caused by the dynamic changes in the actual substrate surface temperature. This unacceptable dynamic impedance mismatch can lead to reduced RF energy transmission efficiency, increased reflected power, and compromised plasma parameter stability (such as plasma density, electron temperature, and ion energy). This in turn directly impacts etch rate, selectivity, and uniformity, ultimately affecting device performance and process yield.

[0008] Therefore, when plasma etching a multi-layer film structure with different material layers that requires switching process steps, how to effectively deal with the dynamic drift of plasma load impedance caused by the dynamic changes in the actual surface temperature of the substrate to achieve efficient and stable transmission of RF energy and overcome the shortcomings of existing methods based on reflected power feedback or limited temperature monitoring is an important technical challenge facing the current semiconductor manufacturing field. Summary of the Invention

[0009] The purpose of the present invention is to provide a radio frequency power supply impedance matching method, device, electronic device and storage medium to overcome the response lag and error influence of existing methods based on reflected power feedback or limited temperature monitoring, effectively deal with the dynamic drift of plasma load impedance caused by the dynamic change of the actual surface temperature of the substrate, and achieve the effect of maintaining efficient and stable transmission of radio frequency energy.

[0010] In a first aspect, the present invention provides a radio frequency power supply impedance matching method, which is applied to a plasma etching system and comprises the following steps: S1. Obtaining correlation information between the dynamic change of substrate temperature and plasma load impedance at different process steps of a multilayer film structure; S2. During the plasma etching process of the multilayer film structure, obtaining the current process step information and the real-time temperature information of the substrate; S3. Based on the current process step information and the real-time substrate temperature information, and using the associated information, determine the target value of the plasma load impedance corresponding to the real-time substrate temperature information; S4. Adjust the adjustable elements of the RF energy transmission matching network in the RF power supply according to the target value of the plasma load impedance.

[0011] The RF power supply impedance matching method provided by the present invention pre-acquires and utilizes the dynamic correlation data between substrate temperature and impedance under specific process steps, and dynamically adjusts the impedance matching according to the current step and substrate temperature during real-time etching to cope with the impedance drift caused by dynamic temperature changes in multilayer film etching.

[0012] In a second aspect, the present invention provides a radio frequency power supply impedance matching device, which is applied to a plasma etching system, comprising: The first acquisition module is used to obtain the correlation information between the dynamic change of substrate temperature and plasma load impedance in different process steps of the multilayer film structure; The second acquisition module is used to obtain the current process step information and the real-time temperature information of the substrate during the plasma etching process of the multi-layer film structure; a determination module for determining a plasma load impedance target value corresponding to the real-time substrate temperature information based on current process step information and the real-time substrate temperature information and utilizing associated information; The adjustment module is used to adjust the adjustable elements of the radio frequency energy transmission matching network in the radio frequency power supply according to the target value of the plasma load impedance.

[0013] The radio frequency power supply impedance matching device provided by the present invention can effectively deal with the problem of complex impedance drift caused by dynamic changes in substrate temperature, and achieve more timely and accurate tracking of dynamic changes in impedance.

[0014] In a third aspect, the present invention provides an electronic device comprising a processor and a memory, wherein the memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the steps in the RF power supply impedance matching method provided in the first aspect are executed.

[0015] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the RF power supply impedance matching method provided in the first aspect are executed.

[0016] As can be seen from the above, the RF power supply impedance matching method provided by the present invention can effectively deal with the dynamic drift of the plasma load impedance caused by the dynamic change of the actual surface temperature of the substrate when plasma etching a multilayer film structure with different material layers and the need to switch process steps. By pre-acquiring and utilizing the dynamic correlation data between the substrate temperature and the plasma impedance under specific process steps, the impedance matching is dynamically adjusted according to the current process step and the real-time substrate temperature during real-time etching, overcoming the shortcomings of the existing response lag based on reflected power feedback control and the delay and error of the limited temperature monitoring method. This enables RF energy to be transmitted to the plasma more efficiently and stably, reducing the reflected power, thereby stabilizing the plasma parameters and improving the etching rate, etching selectivity, etching uniformity and process repeatability.

[0017] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the embodiments of the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of a radio frequency power supply impedance matching method provided in an embodiment of the present invention.

[0019] Figure 2 A schematic structural diagram of a radio frequency power supply impedance matching device provided in an embodiment of the present invention.

[0020] Figure 3 A schematic structural diagram of an electronic device provided by an embodiment of the present invention.

[0021] Description of labels: 100. First acquisition module; 200. Second acquisition module; 300. Determination module; 400. Adjustment module; 13. Electronic device; 1301. Processor; 1302. Memory; 1303. Communication bus. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are used only to distinguish the description and should not be understood as indicating or implying relative importance.

[0024] Reference Attachment Figure 1 The present invention provides a radio frequency power supply impedance matching method, which is applied to a plasma etching system and includes the following steps: S1. Obtaining correlation information between the dynamic change of substrate temperature and plasma load impedance at different process steps of a multilayer film structure; S2. During the plasma etching process of the multilayer film structure, obtaining the current process step information and the real-time temperature information of the substrate; S3. Based on the current process step information and the real-time substrate temperature information, and using the associated information, determine the target value of the plasma load impedance corresponding to the real-time substrate temperature information; S4. Adjust the adjustable elements of the RF energy transmission matching network in the RF power supply according to the target value of the plasma load impedance.

[0025] The correlation information between the dynamic changes in substrate temperature and plasma load impedance at different process steps of a multilayer film structure refers to a set or model that reflects the relationship between the dynamic changes in substrate temperature and plasma load impedance at specific process steps. This information can be implemented using experimental measurement data, simulation models, or historical process data analysis, primarily to provide a basis for temperature-based impedance prediction. Real-time substrate temperature information refers to the real-time substrate temperature measurement obtained during the etching process. This information can be implemented using thermocouples, infrared sensors, or fiber optic thermometers, primarily serving as input for determining the real-time impedance target value. The plasma load impedance target value refers to the complex impedance value expected to be exhibited by the plasma load at the current process step and substrate temperature. This information can be derived from the correlation information using table lookup, model calculation, or interpolation, primarily serving as a basis for adjusting the matching network. The adjustable element of the RF energy transmission matching network refers to an electronic component whose electrical parameters can be modified within the matching network. This information can be implemented using adjustable capacitors or adjustable inductors, primarily to change the total impedance of the matching network to achieve matching with the load impedance.

[0026] This solution operates on the principle of "offline calibration, online compensation." During the offline data preparation phase, experiments or simulations are used to record in detail the dynamic changes in substrate temperature over time and / or during each etching step for a specific multilayer film structure. The corresponding plasma load impedance at these temperature points is also recorded. This dynamic correlation data is stored in a database, capturing the inherent dynamic relationship between temperature and impedance for this specific process scenario. During the online, real-time execution phase, the system identifies the current etching step and measures the substrate temperature in real time. Using this information and the real-time temperature value, the system searches or calculates the target impedance corresponding to the current temperature in a pre-stored database. This target value is then sent to the matching controller, driving the matching network to adjust. This approach eliminates the reliance on the delayed real-time reflected power feedback signal. Instead, matching network adjustments are based on pre-identified dynamic patterns, using the real-time temperature as an index for dynamic feedforward or compensation. This allows for more timely and accurate tracking and response to plasma impedance drift caused by dynamic substrate temperature changes.

[0027] The core innovation of this application lies in that, by pre-acquiring and utilizing the correlation information between the dynamic changes in substrate temperature and the plasma load impedance of the multilayer film structure at different process steps, combined with the real-time temperature information of the substrate during the etching process, the real-time target impedance value of the plasma load is predicted or determined, and this is used to guide the adjustment of the RF energy transmission matching network, thereby overcoming the problem in the existing technology that only relies on reflected power feedback or limited temperature measurement to effectively deal with the complex impedance drift caused by dynamic changes in substrate temperature, and achieving more timely and accurate tracking of dynamic impedance changes.

[0028] Specifically, the method first establishes the correlation information between the dynamic changes in substrate temperature and the plasma load impedance of the multilayer film structure under different process steps. This information captures the influence of temperature changes on impedance. During the actual etching process, the system obtains the current process step and the real-time temperature of the substrate in real time. Then, using the pre-established correlation information, combined with the current process step and real-time temperature, the impedance target value that the plasma load should present at the current moment is determined. This target value reflects the expected impedance of the load under the current temperature state. Finally, according to the determined impedance target value, the adjustable elements in the RF energy transmission matching network in the RF power supply are adjusted so that the matching network can match the output impedance of the RF power supply with the target impedance, thereby maximizing energy transmission. The entire process forms a matching control loop based on dynamic temperature prediction, which can actively respond to impedance drift caused by changes in substrate temperature.

[0029] As an embodiment, the solution of the present application is specifically implemented as follows: when etching a multilayer film structure, first, through offline experiments or simulations, for each layer of material and its corresponding process steps, a typical curve of the substrate temperature changing with time is recorded, and the curve of the plasma load impedance changing with time is synchronously measured to establish a temperature-impedance dynamic correlation database. During the actual etching process, the system monitors the current process step and reads the thermocouple temperature inside the substrate support table in real time. According to the current process step and the real-time temperature, the target impedance value corresponding to the current temperature is obtained by searching in the database or by interpolation calculation. For example, if the current step is to etch the second layer of material and the real-time temperature is 150°C, the system will find the impedance value corresponding to 150°C in the associated data of the second layer of material as the target impedance. Then, the matching control algorithm calculates the specific capacitance and inductance values ​​of the two adjustable capacitors and one adjustable inductor in the matching network based on this target impedance value, and drives the corresponding actuators to adjust the positions of these components until the calculated values ​​are reached, thereby achieving impedance matching.

[0030] Through the above scheme, the present application utilizes the correlation information between the dynamic changes in substrate temperature and the plasma load impedance, and combines it with real-time temperature information to predict or determine the target impedance, which can more promptly predict and respond to the impedance drift caused by substrate temperature changes. This enables the RF energy transmission matching network to more accurately track the changes in load impedance, maintain efficient coupling of RF energy, and reduce reflected power. Stable energy coupling helps maintain the stability of plasma parameters, thereby improving the stability and repeatability of the etching process, and increasing the etching rate, selectivity, and uniformity.

[0031] In some embodiments, the specific steps in step S3 include: S31 obtains substrate temperature trend information; S32. Determine whether a process step switch is currently occurring based on the current process step information, and obtain process step switching information when a process step switch occurs; S33. According to the process step switching information, dynamic association data related to the process step switching process is extracted from the associated information; S34. Determine the target value of the plasma load impedance based on the real-time temperature information of the substrate, the temperature change trend information of the substrate, and the dynamic correlation data.

[0032] Obtaining substrate temperature change trend information refers to analyzing continuously collected real-time substrate temperature data, such as calculating the rate or direction of temperature change over time, to obtain information reflecting the current state of substrate temperature change. Process step switching information refers to the relevant information generated when the etching process transitions from one preset step to another, and may include the process step identifiers before and after the switch, the time point when the switch occurs, etc. Dynamic correlation data refers to pre-stored data that describes the relationship between the dynamic change of substrate temperature and the dynamic change of plasma load impedance during the switching of specific process steps. This data can be collected and established in pre-conducted experiments or simulations, and reflects the typical trajectory, function or lookup table of the impedance change with temperature or time under specific switching scenarios.

[0033] The RF power supply impedance matching method of this application, which determines the target plasma load impedance based on the current process step information, real-time substrate temperature information, and related information, aims to more quickly and accurately determine the target plasma load impedance or the target parameters of the RF energy transmission matching network by refining this determination step. This allows for faster and more accurate determination of the target plasma load impedance or the target values ​​of the RF energy transmission matching network parameters, thereby addressing the rapid dynamic changes in substrate temperature and plasma load impedance caused by process step switching, avoiding matching lags during the initial switching phase, and maintaining stable RF energy transmission. First, information on substrate temperature change trends is obtained. This complements the limitations of only real-time temperature information. By understanding whether the temperature is rising, falling, or stabilizing, as well as its rate of change, a more comprehensive understanding of the substrate's current thermal state and future direction of change can be obtained, providing richer and more forward-looking information for predicting dynamic changes in the plasma load impedance. Next, based on the current process step information, it is determined whether a process step switch has occurred. If a process step switch occurs, process step switch information is obtained. A process step switch is a critical moment that causes significant dynamic changes in substrate temperature and plasma load impedance. By identifying this event and obtaining specific switching information, the system can specifically address the unique dynamics of the switching process, providing important context for subsequent steps. Then, based on the process step switching information, dynamic correlation data related to the process step switching process is extracted from the correlation information. This correlation information includes the overall correlation between the dynamic changes in substrate temperature and plasma load impedance. This proposal further states that when a specific process step switching occurs, it is necessary to utilize previously acquired switching information to extract dynamic correlation data specifically describing the switching process. This data may reflect the typical dynamic trajectories of substrate temperature and plasma load impedance changes over time or temperature under specific switching scenarios. By extracting dynamic data more relevant to the actual switching process, more targeted predictions can be obtained, better capturing the rapid dynamic changes during the switching process and overcoming the limitations of using general correlation information. Finally, the target value of the plasma load impedance is determined by combining the real-time substrate temperature information, substrate temperature trend information, and dynamic correlation data. This step comprehensively utilizes the current real-time substrate temperature, substrate temperature trend information, and dynamic correlation data extracted specifically for the current state (particularly the process switching state). Real-time substrate temperature provides an instant snapshot of the current state; substrate temperature trend information provides a forecast of future temperature trends; and dynamic correlation data provides a reference model for the dynamic relationship between temperature and impedance in specific current scenarios (especially switching scenarios). By combining these three types of information, a more comprehensive and accurate prediction of the impedance value that the plasma load will exhibit at the current moment can be achieved, thereby determining a more precise impedance target value. This effectively addresses the complex impedance drift caused by dynamic substrate temperature changes, especially process switching, and improves the accuracy and stability of impedance matching.This refined scheme for determining the target value of the plasma load impedance cooperates with the step of adjusting the adjustable elements of the RF energy transmission matching network in the RF power supply according to the target value of the plasma load impedance. This enables the entire RF power supply impedance matching method to provide more accurate target values ​​when facing the rapid dynamic changes of substrate temperature and plasma load impedance caused by switching process steps, thereby guiding the matching network to make more timely and precise adjustments, effectively avoiding matching lag in the initial stage of switching, and maintaining stable RF energy transmission.

[0034] In one embodiment, substrate temperature trend information can be obtained by configuring a temperature sensor to continuously collect substrate temperature data. A processing unit periodically reads this data and calculates the difference or rate of change between the current temperature and the temperature over a previous period, thereby obtaining substrate temperature trend information. Determining process step switching and obtaining switching information can be achieved by monitoring the current process step identifier output by the etching process control system. When the identifier changes, the step identifiers and time points before and after the switch are recorded as process step switching information. Extracting dynamic correlation data can pre-establish a database that stores substrate temperature dynamic trajectories and plasma load impedance dynamic trajectories corresponding to different process step switching types. After obtaining process step switching information, the system queries the database based on the switching type and extracts the corresponding dynamic trajectories as dynamic correlation data. When determining the target plasma load impedance value, the processing unit can search or interpolate a preliminary target value based on the extracted plasma load impedance dynamic trajectory based on the real-time substrate temperature information. The preliminary target value can then be modified based on the substrate temperature trend information, for example, based on the temperature change rate, to ultimately obtain the target plasma load impedance value used to guide matching network adjustment.

[0035] Through the above scheme, the target value of plasma load impedance can be determined more quickly and accurately, effectively responding to the rapid dynamic changes of substrate temperature and plasma load impedance caused by switching process steps, avoiding matching lag in the initial switching stage, and maintaining the stability of RF energy transmission.

[0036] In some embodiments, the specific steps in step S33 include: S331. Obtaining plasma parameter information when process step switching occurs; S332. According to the process step switching information, typical dynamic correlation data related to the process step switching process is initially extracted from the associated information; the typical dynamic correlation data includes a typical substrate temperature dynamic trajectory and a corresponding typical plasma load impedance dynamic trajectory; S333. Based on the real-time substrate temperature information, plasma parameter information, and typical dynamic correlation data, evaluate the first deviation between the current actual substrate temperature and the typical substrate temperature dynamic trajectory, and the second deviation between the current actual plasma parameter and the typical plasma load impedance dynamic trajectory; S334. According to the first deviation and the second deviation, the typical plasma load impedance dynamic trajectory is corrected to obtain a plasma load impedance dynamic trajectory that better matches the current actual switching state and serves as the final dynamic correlation data.

[0037] Plasma parameter information is obtained when a process step switch occurs. This plasma parameter information may include, but is not limited to, RF voltage, RF current, RF power, reflected power, and plasma emission spectrum information. These parameters can reflect the instantaneous state of the plasma and can be obtained using sensors installed in the RF path or in the reaction chamber. Typical dynamic correlation data related to the process step switch is initially extracted. This typical dynamic correlation data is established based on a large amount of historical process data or previously conducted experimental data and stored in the correlation information. It represents the expected pattern of substrate temperature and plasma load impedance changes over time during a specific process step switch under standard or typical conditions. A first deviation between the current actual substrate temperature and the typical substrate temperature dynamic trajectory, as well as a second deviation between the current actual plasma parameters and the typical plasma load impedance dynamic trajectory, are evaluated. This deviation can be assessed using various methods, such as calculating the difference, integrated difference, or mean square error between the actual value and the typical trajectory at a specific time point or time period. The first deviation reflects the degree to which the actual substrate temperature change deviates from the expected one, while the second deviation indirectly reflects the degree to which the actual plasma state deviates from the expected impedance trajectory through the plasma parameters. Based on the first deviation and the second deviation, the dynamic trajectory of the typical plasma load impedance is corrected. The correction process aims to adjust the typical impedance trajectory to make it more consistent with the current actual process switching state. The correction can be achieved through additive or multiplicative methods, or by applying a correction function based on the deviation information.

[0038] The present application addresses the aforementioned issues by further utilizing real-time information during process step switching, including real-time substrate temperature and plasma parameters, based on the initial acquisition of representative dynamic correlation data. By comparing this real-time information with representative temperature and impedance dynamic trajectories, the deviation between the current actual state and the preset representative state can be quantified. This dual deviation assessment (substrate temperature deviation and plasma parameter deviation) enables the system to more comprehensively perceive the actual state of the current process switch, including deviations that may be caused by initial state differences or other unmodeled factors. Based on this assessed deviation information, the representative plasma load impedance dynamic trajectory is corrected to generate customized dynamic correlation data that better reflects the current actual temperature changes and plasma state. Compared to simple representative data, this corrected dynamic correlation data can more accurately predict the actual dynamic changes in plasma load impedance during the switching process, providing a more precise basis for subsequently determining the target plasma load impedance value. Consequently, applying this corrected dynamic correlation data to determine the target plasma load impedance value enables impedance matching adjustments of the RF power supply to more timely and accurately track actual plasma impedance drift, especially during the dynamic and critical process step switching phase. This real-time correction and optimization of dynamic correlation data significantly improves the accuracy of the entire impedance matching method and its adaptability to actual process changes, thereby helping to maintain the stability of the plasma state and improve the repeatability and yield of the etching results.

[0039] As a preferred embodiment, in a specific implementation, obtaining plasma parameter information at the time of process step switching can be accomplished by measuring RF voltage, current, and phase with an RF sensor and calculating the instantaneous impedance of the plasma load, or by monitoring the intensity of specific spectral lines in the plasma with an optical emission spectrometer. Based on the process step switching information, representative dynamic correlation data is initially extracted from the correlation information. This correlation information can be stored in a database containing pre-recorded or simulated time-varying curves of substrate temperature and plasma impedance for different material layer switching (e.g., from silicon oxide to silicon nitride). When evaluating the first and second deviations, the average or maximum difference between the real-time substrate temperature and a typical substrate temperature trajectory at the current time point or over a period of time can be used as a quantitative indicator of the first deviation. Simultaneously, the currently measured plasma parameters (e.g., the real and imaginary parts of the instantaneous plasma impedance) can be compared with the expected impedance values ​​corresponding to the typical plasma load impedance trajectory at the current time point, and the difference or relative difference can be calculated as a quantitative indicator of the second deviation. To correct the typical plasma load impedance dynamic trajectory based on the first and second deviations, a correction model or lookup table can be pre-established. This model or lookup table takes the first and second deviation values ​​as input and outputs a correction value or correction function for the typical impedance trajectory. For example, if the first deviation indicates that the actual temperature rise is faster than typical, and the second deviation indicates that the real part of the plasma impedance is too high, the correction model can output a real part impedance correction value that increases over time. This correction value is added to the typical plasma load impedance trajectory to obtain a corrected trajectory. This corrected trajectory serves as the final dynamic correlation data for subsequent determination of the impedance target value.

[0040] Through the above-mentioned technical means, the present application can effectively deal with the problem that even if the same process step is switched, the initial state at the time of the actual occurrence may be different, resulting in a deviation between the actual temperature-impedance dynamic trajectory and the pre-stored typical associated data. By obtaining real-time plasma parameters and substrate temperature information and comparing them with the typical dynamic associated data initially extracted, the deviation between the actual state and the typical substrate temperature trajectory and plasma load impedance trajectory is evaluated. Based on these deviation information, the typical plasma load impedance dynamic trajectory is corrected to obtain a plasma load impedance dynamic trajectory that better reflects the current actual switching state. Thus, a more accurate and practical basis is provided for the subsequent determination of the plasma load impedance target value, the accuracy of impedance matching and the adaptability to process changes are improved, and it is helpful to maintain the stability of the plasma state and improve the performance and yield of the etching process.

[0041] In some embodiments, the specific steps in step S334 include: S3341. According to the type and size of the first deviation and the second deviation, a correction amount or correction function for the typical plasma load impedance dynamic trajectory is determined from a pre-established correction mapping relationship; the correction mapping relationship reflects the influence of different deviation combinations on the plasma load impedance dynamic trajectory; S3342. Apply the correction amount or correction function to the typical plasma load impedance dynamic trajectory to correct the impedance value on the trajectory corresponding to the real-time temperature information of the substrate or the current etching time point, and obtain the corrected plasma load impedance dynamic trajectory as the final dynamic correlation data.

[0042] A correction mapping relationship refers to a pre-established data structure or model that establishes a correspondence between input deviations (type and magnitude of the first and second deviations) and output correction information (correction value or correction function). This can be implemented using a lookup table, mathematical model, empirical formula, or machine learning model. The correction value or correction function refers to a specific numerical value or mathematical expression used to adjust the dynamic trajectory of a typical plasma load impedance. The correction value can be a fixed offset value or scaling factor, and the correction function can be a mathematical expression that changes with time, temperature, or deviation. It can be implemented using a constant, linear function, polynomial function, or nonlinear function.

[0043] This solution introduces a correction mapping relationship, providing a systematic approach to determining the correction method. First, based on the type and magnitude of the first deviation (the deviation between the actual substrate temperature and the typical substrate temperature dynamic trajectory) and the second deviation (the deviation between the actual plasma parameters and the typical plasma load impedance dynamic trajectory) obtained from the current actual assessment, a specific correction value or correction function is determined by searching or calculating from a pre-established correction mapping relationship. This determination, based on pre-defined rules, avoids ambiguous judgments, making the correction process repeatable and potentially automated. Subsequently, the determined correction value or correction function is applied to the typical plasma load impedance dynamic trajectory, adjusting the impedance value corresponding to the real-time substrate temperature information or the current etching time point on the trajectory. This means that corrections can be made based on the actual current temperature conditions or etching progress. By applying the deviation-based correction value or correction function to the typical trajectory, this solution achieves precise adjustment of the typical trajectory, ensuring that it more accurately reflects the dynamic changes in plasma load impedance under the current process switching conditions. This corrected trajectory serves as the final dynamic correlation data, more accurately guiding the subsequent determination of impedance target values ​​and matching network adjustments. Based on the assessment of the deviation between the current actual situation and the typical situation, this solution further provides a method for determining specific correction rules based on the deviation and applying the correction. This makes the correction of the typical trajectory no longer a simple offset or scaling, but can be fine-tuned according to the type and size of the deviation, thereby improving the accuracy and adaptability of the correction, and can more effectively deal with the impedance drift caused by dynamic changes in substrate temperature, thereby improving the stability and efficiency of RF energy transmission.

[0044] In one embodiment, the correction mapping relationship can be implemented as a multi-dimensional lookup table. The input dimensions of the lookup table include the type of first deviation (e.g., above typical, below typical) and magnitude range (e.g., 0-5°C, 5-10°C, etc.), and the type of second deviation (e.g., plasma density above typical, below typical) and magnitude range (e.g., ±10%, ±20%, etc.). The output value of the lookup table can be a correction value for the typical plasma load impedance dynamic trajectory. For example, when the first deviation is "5-10°C above typical" and the second deviation is "plasma density below typical, ±10%," the lookup table can return a correction value. This correction value can be a fixed impedance offset (e.g., +0.5 ohms) or a scaling factor (e.g., multiplied by 1.05). After the correction value or correction function is determined, it is applied to the typical plasma load impedance dynamic trajectory. For example, if a fixed impedance offset is determined, it is added to the impedance value corresponding to the current substrate real-time temperature or the current etching time point on the typical trajectory to obtain the corrected impedance value. If a correction function, such as a linear function, is determined, the current substrate temperature or etching time is used as an input to calculate a correction value, which is then applied to the corresponding impedance value on the representative trajectory. The corrected plasma load impedance dynamic trajectory is then used as the basis for determining the target plasma load impedance value.

[0045] By determining a correction value or correction function for a typical plasma load impedance dynamic trajectory from a pre-established correction mapping relationship based on the type and magnitude of the first and second deviations, and applying this correction function to the typical plasma load impedance dynamic trajectory, this solution can accurately determine a correction rule or function for deviations in the temperature-impedance dynamic trajectory caused by differences in actual initial states during the switching process of the same process step. This ensures that the corrected trajectory has high accuracy throughout the entire switching transition period, thereby more accurately reflecting the actual dynamic changes in plasma load impedance and improving the stability and efficiency of RF energy transmission.

[0046] In some embodiments, the specific steps in step S34 include: S341. Preliminarily determine the target value of the original plasma load impedance based on the real-time substrate temperature information, substrate temperature trend information, and dynamic correlation data; S342. Obtaining current process step information, preset smoothing weight determination rules, and historical plasma load impedance target values; S343. Determine the smoothing weight at the current moment based on the current process step information, substrate temperature trend information, and smoothing weight determination rules; S344. According to the original plasma load impedance target value, the historical plasma load impedance target value and the smoothing weight, the original plasma load impedance target value and the historical plasma load impedance target value are weighted to obtain a smoothed plasma load impedance target value as the final plasma load impedance target value.

[0047] The preset smoothing weight determination rule refers to a set of criteria or algorithms used to calculate the smoothing weight. It can dynamically adjust the smoothing strength based on different input conditions (such as process steps and temperature change trends). The rule can be implemented using a lookup table, mathematical function, or machine learning-based model. The smoothing weight is a numerical factor used to balance the influence of the original plasma load impedance target value and the historical plasma load impedance target value in the weighted processing. Its value determines whether the current smoothed target value relies more on the newly calculated original value or the past stable value.

[0048] This solution improves the stability of the initially determined plasma load impedance target value by smoothing it. First, a raw plasma load impedance target value is calculated based on current etching state information (substrate real-time temperature and temperature trend) and pre-acquired dynamic correlation data. This value reflects the theoretically matched impedance at the current moment. Simultaneously, information about the current process step, the rules guiding the smoothing process, and historical plasma load impedance target values ​​from the previous moment or period are obtained. Next, a smoothing weight appropriate for the current state is dynamically calculated based on the current process step and substrate temperature trend, and according to pre-set smoothing weight determination rules. For example, when the process step is stable and the temperature changes slowly, a higher weight can be assigned to the historical value to enhance the smoothing effect. When the process step switches and the temperature changes rapidly, a higher weight can be assigned to the raw value to improve response speed. Finally, using this dynamically determined smoothing weight, a weighted average is performed on the initially determined raw target value and the historical target value to obtain a smoothed plasma load impedance target value. This smoothed value serves as the final plasma load impedance target value and is used to guide the adjustment of the adjustable components of the RF energy transmission matching network. This dynamic smoothing process ensures that the final target value sequence remains smooth and continuous even when the original target value experiences transient fluctuations. Compared to relying solely on real-time calculated raw values, this approach effectively combines current state information with historical stability information, making the determined target value more robust. This approach can better cope with plasma impedance drift caused by dynamic changes in substrate temperature during the etching process, especially during process step switching, and provides a more stable and reliable basis for subsequent matching network adjustments.

[0049] In one embodiment, the process of determining the plasma load impedance target value can be implemented as follows: First, based on the substrate temperature obtained in real time, its change trend and the pre-established dynamic correlation model, an original plasma load impedance target value is calculated. Then, the system reads the process step identifier currently being executed, obtains the preset smoothing weight determination rule table from the memory, and obtains the smoothed plasma load impedance target value calculated at the previous moment as a historical value. Then, based on the current process step identifier and the substrate temperature change trend, the smoothing weight determination rule table is consulted to find the corresponding smoothing weight value. Finally, the original plasma load impedance target value and the historical plasma load impedance target value are weighted averaged according to the smoothing weight obtained by looking up the table. For example, a linear weighted average formula can be used: smoothed target value = smoothing weight * original target value + (1-smoothing weight) * historical target value. The calculated smoothed value is used as the final plasma load impedance target value at the current moment.

[0050] The above technical solution dynamically smooths the initially determined plasma load impedance target value, ensuring smoothness and continuity in the final sequence of plasma load impedance target values. This effectively prevents frequent or drastic adjustments to the adjustable components of the RF energy transmission matching network due to target value fluctuations, thereby maintaining stable RF energy transmission and improving the stability and repeatability of the plasma etching process.

[0051] In some embodiments, the specific steps in step S4 include: S41. Get the current status information of the adjustable component; S42 obtains the actual impedance information of the current RF energy transmission matching network; S43. Based on the plasma load impedance target value, the current state information of the adjustable element, and the current actual impedance information of the RF energy transmission matching network, combined with the preset adjustment path generation rules, an adjustment path for each adjustable element is generated from the current state to the target state corresponding to the plasma load impedance target value; S44. Adjust the adjustable element according to the adjustment path.

[0052] The current state information of the adjustable element refers to the value reflecting the current physical position or electrical parameters of the adjustable element. For example, for an adjustable capacitor, it can be the relative position of the electrode plates; for an adjustable inductor, it can be the position of the magnetic core or the connection state of the winding. The current actual impedance information of the RF energy transmission matching network refers to the complex impedance value of the matching network at the current operating frequency obtained in real time by the impedance measuring device. The preset adjustment path generation rule refers to the logic or algorithm established based on the matching network model, historical adjustment data, optimization algorithm or lookup table, etc., which is used to calculate a series of intermediate adjustment points between the current adjustable element state and the target adjustable element state. The adjustment path refers to a sequence consisting of a series of ordered intermediate adjustable element states, which describes the trajectory of the adjustable element from the current state to the target state. The target state refers to the ideal physical position or electrical parameter combination that the adjustable element of the RF energy transmission matching network should achieve when matching the target value of the plasma load impedance.

[0053] This solution provides a specific method for adjusting the adjustable components of an RF energy transmission matching network. It aims to coordinate the adjustment of multiple adjustable components, achieving fast, smooth, and oscillation-free matching adjustments while effectively tracking the dynamically changing plasma load impedance. This solution achieves this goal by planning and executing an adjustment path from the current state to the target state. First, the current state information of the adjustable components is obtained. This provides the starting point for the adjustment process—the actual position or value of the current adjustable component. Understanding the current state is fundamental to planning how to reach the target state. Next, the current actual impedance information of the RF energy transmission matching network is obtained, reflecting the actual electrical characteristics of the matching network in its current state. Combining the current state information of the adjustable components with the actual impedance information allows for a more accurate understanding of the current electrical operating point of the system, providing more comprehensive information about the current system for subsequent adjustment path generation. Then, based on the target plasma load impedance value, the current state information of the adjustable components, and the current actual impedance information of the RF energy transmission matching network, combined with pre-defined adjustment path generation rules, an adjustment path is generated for each adjustable component from the current state to the target state corresponding to the target plasma load impedance value. This step comprehensively considers the final adjustment target and starting point, and utilizes pre-set adjustment path generation rules to plan a specific, executable adjustment sequence or trajectory. These pre-set adjustment path generation rules, which may be based on modeling or optimization algorithms for the matching network's characteristics, aim to plan an adjustment path that achieves a smooth, rapid, and stable target state. Generating an adjustment path means breaking the entire adjustment process into a series of steps or a continuous trajectory, rather than simply performing it in one step. This helps improve the stability and accuracy of the adjustment process. Finally, the adjustable element is actually controlled to adjust according to the generated adjustment path. This step executes the previously planned adjustment scheme, ensuring that the adjustable element changes according to the predetermined trajectory, thereby achieving stable and precise adjustment of the matching network to the target impedance, thereby improving the efficiency and stability of RF energy transmission. By further planning the adjustment path for the adjustable element based on the target value of the plasma load impedance, this scheme enables more precise control of the matching process, effectively addressing plasma impedance drift caused by dynamic changes in substrate temperature, and thus achieving efficient and stable RF energy transmission.

[0054] In one embodiment, the adjustable element includes an adjustable capacitor and an adjustable inductor. The current state information of the adjustable element can be obtained by reading the electrode plate position of the adjustable capacitor and the core position of the adjustable inductor through a sensor. The current actual impedance information of the RF energy transmission matching network can be obtained by real-time calculation using an RF voltage / current sensor and a calculation unit connected to the input end of the matching network. The preset adjustment path generation rule can be an optimization algorithm based on the S-parameter model of the matching network. The algorithm receives the target impedance, the current capacitor position, the current inductor position and the current actual impedance as input, and calculates a trajectory of the capacitor position and the inductor position changing over time. The trajectory is designed to minimize the reflected power fluctuation during the adjustment process and quickly reach the target matching state. The generated adjustment path can be a series of discrete combination points of the capacitor position and the inductor position. According to the adjustment path, the capacitor plate and the inductor core can be gradually moved according to the calculated position sequence by controlling the stepper motor connected to the adjustable capacitor and the adjustable inductor, thereby achieving adjustment of the matching network.

[0055] By obtaining the current state of the adjustable element and the actual impedance of the matching network, and planning the adjustment path in combination with preset rules, this solution can achieve coordinated adjustment of the adjustable element, avoiding the oscillation and overshoot that may be caused by direct jump or simple feedback control, making the matching adjustment process smoother and faster, and can effectively track the dynamically changing plasma impedance, improving the efficiency and stability of RF energy transmission.

[0056] In some embodiments, the tunable element includes a tunable capacitor and a tunable inductor.

[0057] Please refer to Figure 2 , Figure 2 In some embodiments of the present invention, a radio frequency power supply impedance matching device is applied to a plasma etching system. The radio frequency power supply impedance matching device is integrated into a back-end control device in the form of a computer program, and includes: The first acquisition module 100 is used to obtain the correlation information between the dynamic change of substrate temperature and plasma load impedance in different process steps of the multilayer film structure; The second acquisition module 200 is used to obtain the current process step information and the real-time temperature information of the substrate during the plasma etching process of the multi-layer film structure; A determination module 300 is configured to determine a target plasma load impedance value corresponding to the real-time substrate temperature information based on the current process step information and the real-time substrate temperature information and using the associated information; The adjustment module 400 is used to adjust the adjustable elements of the radio frequency energy transmission matching network in the radio frequency power supply according to the target value of the plasma load impedance.

[0058] In some embodiments, when determining the target plasma load impedance value corresponding to the real-time substrate temperature information based on the current process step information and the real-time substrate temperature information and utilizing the associated information, the determination module 300 performs: S31 obtains substrate temperature trend information; S32. Determine whether a process step switch is currently occurring based on the current process step information, and obtain process step switching information when a process step switch occurs; S33. According to the process step switching information, dynamic association data related to the process step switching process is extracted from the associated information; S34. Determine the target value of the plasma load impedance based on the real-time temperature information of the substrate, the temperature change trend information of the substrate, and the dynamic correlation data.

[0059] In some embodiments, when the determination module 300 is used to extract dynamic association data related to the process step switching process from the association information according to the process step switching information, the following steps are executed: S331. Obtaining plasma parameter information when process step switching occurs; S332. According to the process step switching information, typical dynamic correlation data related to the process step switching process is initially extracted from the associated information; the typical dynamic correlation data includes a typical substrate temperature dynamic trajectory and a corresponding typical plasma load impedance dynamic trajectory; S333. Based on the real-time substrate temperature information, plasma parameter information, and typical dynamic correlation data, evaluate the first deviation between the current actual substrate temperature and the typical substrate temperature dynamic trajectory, and the second deviation between the current actual plasma parameter and the typical plasma load impedance dynamic trajectory; S334. According to the first deviation and the second deviation, the typical plasma load impedance dynamic trajectory is corrected to obtain a plasma load impedance dynamic trajectory that better matches the current actual switching state and serves as the final dynamic correlation data.

[0060] In some embodiments, when the determination module 300 is used to correct the typical plasma load impedance dynamic trajectory based on the first deviation and the second deviation to obtain a plasma load impedance dynamic trajectory that better matches the current actual switching state and serves as the final dynamic correlation data, the following steps are executed: S3341. Determine a correction amount or correction function for a typical plasma load impedance dynamic trajectory from a pre-established correction mapping relationship according to the type and size of the first deviation and the second deviation; S3342. Apply the correction amount or correction function to the typical plasma load impedance dynamic trajectory to correct the impedance value on the trajectory corresponding to the real-time temperature information of the substrate or the current etching time point, and obtain the corrected plasma load impedance dynamic trajectory as the final dynamic correlation data.

[0061] In some embodiments, the determination module 300 performs the following when determining the target value of the plasma load impedance based on the real-time substrate temperature information, the substrate temperature change trend information, and the dynamic correlation data: S341. Preliminarily determine the target value of the original plasma load impedance based on the real-time substrate temperature information, substrate temperature trend information, and dynamic correlation data; S342. Obtaining current process step information, preset smoothing weight determination rules, and historical plasma load impedance target values; S343. Determine the smoothing weight at the current moment based on the current process step information, substrate temperature trend information, and smoothing weight determination rules; S344. According to the original plasma load impedance target value, the historical plasma load impedance target value and the smoothing weight, the original plasma load impedance target value and the historical plasma load impedance target value are weighted to obtain a smoothed plasma load impedance target value as the final plasma load impedance target value.

[0062] In some embodiments, the adjustment module 400 performs the following when adjusting the adjustable element of the RF energy transmission matching network in the RF power supply according to the target plasma load impedance: S41. Get the current status information of the adjustable component; S42 obtains the actual impedance information of the current RF energy transmission matching network; S43. Based on the plasma load impedance target value, the current state information of the adjustable element, and the current actual impedance information of the RF energy transmission matching network, combined with the preset adjustment path generation rules, an adjustment path for each adjustable element is generated from the current state to the target state corresponding to the plasma load impedance target value; S44. Adjust the adjustable element according to the adjustment path.

[0063] Please refer to Figure 3 , Figure 3The present invention provides a structural schematic diagram of an electronic device provided in an embodiment of the present invention. The present invention provides an electronic device 13, comprising: a processor 1301 and a memory 1302. The processor 1301 and the memory 1302 are interconnected and communicate with each other via a communication bus 1303 and / or other forms of connection mechanisms (not shown). The memory 1302 stores computer-readable instructions executable by the processor 1301. When the electronic device is in operation, the processor 1301 executes the computer-readable instructions to perform the RF power supply impedance matching method in any optional implementation of the above-mentioned embodiment, thereby achieving the following functions: obtaining correlation information between dynamic changes in substrate temperature and plasma load impedance at different process steps of a multi-layer film structure; obtaining current process step information and real-time substrate temperature information during plasma etching of the multi-layer film structure; determining a target plasma load impedance value corresponding to the real-time substrate temperature information based on the current process step information and the real-time substrate temperature information and utilizing the correlation information; and adjusting an adjustable element of a RF energy transmission matching network in the RF power supply based on the target plasma load impedance value.

[0064] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the RF power supply impedance matching method in any optional implementation of the above-mentioned embodiment is executed to achieve the following functions: obtaining correlation information between the dynamic change of substrate temperature and plasma load impedance under different process steps of a multilayer film structure; obtaining current process step information and real-time substrate temperature information during plasma etching of the multilayer film structure; determining a plasma load impedance target value corresponding to the real-time substrate temperature information based on the current process step information and the real-time substrate temperature information and utilizing the correlation information; and adjusting an adjustable element of an RF energy transmission matching network in an RF power supply based on the plasma load impedance target value.

[0065] Among them, the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0066] In the embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, the indirect coupling or communication connection of the device or unit may be electrical, mechanical or other forms.

[0067] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0068] Furthermore, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0069] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0070] The foregoing description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A radio frequency power supply impedance matching method, applied to a plasma etching system, characterized in that: The following steps are involved: S1. Obtaining correlation information between the dynamic change of substrate temperature and plasma load impedance at different process steps of a multilayer film structure; S2. During the plasma etching process of the multilayer film structure, obtaining the current process step information and the real-time temperature information of the substrate; S3. Based on the current process step information and the real-time substrate temperature information, and using the associated information, determine the target value of the plasma load impedance corresponding to the real-time substrate temperature information; S4. Adjust the adjustable elements of the RF energy transmission matching network in the RF power supply according to the target value of the plasma load impedance.

2. The radio frequency power supply impedance matching method according to claim 1, wherein: The specific steps in step S3 include: S31 obtains substrate temperature trend information; S32. Determine whether a process step switch is currently occurring based on the current process step information, and obtain process step switching information when a process step switch occurs; S33. According to the process step switching information, dynamic association data related to the process step switching process is extracted from the associated information; S34. Determine the target value of the plasma load impedance based on the real-time temperature information of the substrate, the temperature change trend information of the substrate, and the dynamic correlation data.

3. The radio frequency power supply impedance matching method according to claim 2, wherein: The specific steps in step S33 include: S331. Obtaining plasma parameter information when process step switching occurs; S332. According to the process step switching information, typical dynamic correlation data related to the process step switching process is initially extracted from the associated information; the typical dynamic correlation data includes a typical substrate temperature dynamic trajectory and a corresponding typical plasma load impedance dynamic trajectory; S333. Based on the real-time substrate temperature information, plasma parameter information, and typical dynamic correlation data, evaluate the first deviation between the current actual substrate temperature and the typical substrate temperature dynamic trajectory, and the second deviation between the current actual plasma parameter and the typical plasma load impedance dynamic trajectory; S334. According to the first deviation and the second deviation, the typical plasma load impedance dynamic trajectory is corrected to obtain a plasma load impedance dynamic trajectory that better matches the current actual switching state and serves as the final dynamic correlation data.

4. The radio frequency power supply impedance matching method according to claim 3, wherein: The specific steps in step S334 include: S3341. Determine a correction amount or correction function for a typical plasma load impedance dynamic trajectory from a pre-established correction mapping relationship according to the type and size of the first deviation and the second deviation; S3342. Apply the correction amount or correction function to the typical plasma load impedance dynamic trajectory to correct the impedance value on the trajectory corresponding to the real-time temperature information of the substrate or the current etching time point, and obtain the corrected plasma load impedance dynamic trajectory as the final dynamic correlation data.

5. The radio frequency power supply impedance matching method according to claim 2, wherein: The specific steps in step S34 include: S341. Preliminarily determine the target value of the original plasma load impedance based on the real-time substrate temperature information, substrate temperature trend information, and dynamic correlation data; S342. Obtaining current process step information, preset smoothing weight determination rules, and historical plasma load impedance target values; S343. Determine the smoothing weight at the current moment based on the current process step information, substrate temperature trend information, and smoothing weight determination rules; S344. According to the original plasma load impedance target value, the historical plasma load impedance target value and the smoothing weight, the original plasma load impedance target value and the historical plasma load impedance target value are weighted to obtain a smoothed plasma load impedance target value as the final plasma load impedance target value.

6. The radio frequency power supply impedance matching method according to claim 1, wherein: The specific steps in step S4 include: S41. Get the current status information of the adjustable component; S42 obtains the actual impedance information of the current RF energy transmission matching network; S43. Based on the plasma load impedance target value, the current state information of the adjustable element, and the current actual impedance information of the RF energy transmission matching network, combined with the preset adjustment path generation rules, an adjustment path for each adjustable element is generated from the current state to the target state corresponding to the plasma load impedance target value; S44. Adjust the adjustable element according to the adjustment path.

7. The radio frequency power supply impedance matching method according to claim 6, characterized in that: Adjustable components include adjustable capacitors and adjustable inductors.

8. A radio frequency power supply impedance matching device, used in a plasma etching system, characterized in that: include: The first acquisition module is used to obtain the correlation information between the dynamic change of substrate temperature and plasma load impedance in different process steps of the multilayer film structure; The second acquisition module is used to obtain the current process step information and the real-time temperature information of the substrate during the plasma etching process of the multi-layer film structure; a determination module for determining a plasma load impedance target value corresponding to the real-time substrate temperature information based on current process step information and the real-time substrate temperature information and utilizing associated information; The adjustment module is used to adjust the adjustable elements of the radio frequency energy transmission matching network in the radio frequency power supply according to the target value of the plasma load impedance.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the steps in the radio frequency power supply impedance matching method according to any one of claims 1 to 7 are executed.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the radio frequency power supply impedance matching method according to any one of claims 1 to 7 are executed.

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