Output performance feedback microwave ion source adaptive impedance matching method and device

Abstract

The application discloses an output performance feedback microwave ion source self-adaptive impedance matching method and device, and belongs to the field of ion source technology. The output performance feedback microwave ion source self-adaptive impedance matching device comprises a microwave matching mechanism, an ion source output monitoring unit and an intelligent decision controller. The microwave matching mechanism comprises a microwave transmission line, a pin, a reflected power detection unit and a driving mechanism. The intelligent decision controller is configured to execute the output performance feedback microwave ion source self-adaptive impedance matching method. The application introduces the screen-grid current as a high-level optimization target into the matching control closed loop by configuring a plurality of pins capable of coordinated motion on the microwave transmission line, a reflected power detection unit capable of automatically detecting the reflected power and an intelligent decision controller capable of executing the output performance feedback microwave ion source self-adaptive impedance matching method. When the system falls into a 'high efficiency and low power' state, the original matching point can be actively jumped out, and a global optimal working point capable of simultaneously satisfying low reflection and high screen-grid current is searched again.

Description

Technical Field

[0001] This invention relates to an adaptive impedance matching method and apparatus for output performance feedback microwave ion sources. Background Technology

[0002] In equipment used for ion implantation and thin film deposition, the microwave ion source is a key component, and its core performance indicators are the stable output of the set grid voltage and grid current. The grid current originates from the plasma formed by the ionization of the process gas by microwave energy in the ionization chamber. Microwave energy is fed in through a transmission line, and the impedance matching state directly affects the energy coupling efficiency.

[0003] Existing technologies aim to minimize reflected power. The basic principle is that the lower the reflected power, the higher the net power incident on the plasma, which should theoretically generate a larger grid current. However, in actual complex operating conditions, an anomaly of "high efficiency and low energy" has been found: even when the matching network adjusts the microwave reflected power to near zero (e.g., <1W), indicating extremely high energy transfer efficiency, the grid current is still far below the expected value.

[0004] The root cause of this phenomenon is: 1. Energy coupling position deviation: The optimal impedance matching point may only guarantee the maximum transmission of microwave energy from the generator to the transmission line, but it does not guarantee that the energy is most effectively coupled to the optimal region in the ionization chamber to generate high-density plasma. The energy may be absorbed or dissipated in the non-core region of the cavity.

[0005] 2. Influence of Plasma Modes: Different matching states may excite different electromagnetic field modes or plasma resonance modes. Although some modes have low reflection, their ionization efficiency (electron temperature and density distribution) is not optimal.

[0006] 3. Non-uniqueness of matching points: On the Smith chart, there are multiple matching points (local optima) that can achieve low reflection, but the corresponding electromagnetic field distributions in the cavity are different, thus contributing differently to the grid current. Summary of the Invention

[0007] The purpose of this invention is to provide an adaptive impedance matching method for microwave ion sources with output performance feedback, in order to solve the problem that the current matching strategy that uses reflected power as the sole optimization target may cause the system to converge to a local operating point that is optimal for "transmission efficiency" but suboptimal for "ionization efficiency", thus failing to guarantee the final output performance of the ion source.

[0008] This invention is achieved through the following technical solution: The adaptive impedance matching method for output performance feedback microwave ion sources comprises the following steps: S1: Set the target value I_target or the target range [I_min, I_max] of the screen grid current I_actual, and set the target threshold P_thresh of the reflected power P_refl; S2: Execute the reflected power optimization process to reduce the reflected power P_refl below P_thresh or converge it to a local minimum; S3: After completing the reflected power optimization process, obtain the screen grid current I_actual; S4: If I_actual >= I_target or I_actual >= I_min, end the process; If I_actual < I_target or I_actual < I_min), and P_refl <= P_thresh, then enter the re-search process; The re-search process is as follows: S5: Set the maximum number of re-searches; S6: Enter the re-search, and several pins are controlled to move to a group of new initial positions that are significantly different from the current position; S7: Perform a new round of reflected power optimization process, obtain the pin position Pos and the reflected power value P_refl and the screen grid current I_actual corresponding to the pin position Pos, and record the pin position Pos that takes into account the lower reflected power value P_refl and the higher screen grid current I_actual; Or perform a new round of reflected power optimization process, search with the screen grid current I_actual as the optimization objective function, and at the same time constrain the reflected power P_refl to be less than the absolute threshold; S8: In the current re-search, if a state that satisfies I_actual >= I_target and P_refl <= P_thresh is found, end the re-search; If a state that satisfies I_actual >= I_target and P_refl <= P_thresh is not found in the current re-search, then enter the next round of re-search and repeat steps S6 - S8; If a state that satisfies I_actual >= I_target and P_refl <= P_thresh is not found even after reaching the maximum number of re-searches, then output the relevant parameters matching the maximum screen grid current I_actual and give an alarm prompt.

[0009] Furthermore, the reflected power optimization process is as follows: S9: Several pins are controlled to move to the initial position; S10: Set the maximum number of outer loops; S11: Enter the first external circulation. During the first external circulation, each pin moves in sequence according to a preset order. S12: Obtain the pin position Pos and the corresponding reflection power value P_refl; S13: Based on the obtained pin position Pos and reflected power value P_refl, obtain the trend curve of reflected power changing with pin position, obtain the minimum power value P_min based on the trend curve, and lock the pin at the pin position Pos_min corresponding to the minimum power value P_min. S14: In the first external cycle, if the lowest power value P_min that occurs when a pin moves is lower than the absolute threshold, the matching is considered successful and the adjustment ends. In the first outer loop, if the minimum power value P_min that occurs when all pins move is higher than the absolute threshold, then a new round of outer loop is entered. S15: In the new round of external circulation, each pin moves in sequence according to the preset order; S16: Obtain the pin position Pos and the corresponding reflection power value P_refl; S17: Based on the obtained pin position Pos and reflected power value P_refl, obtain the trend curve of reflected power changing with pin position, obtain the minimum power value P_min based on the trend curve, and lock the pin at the pin position Pos_min corresponding to the minimum power value P_min. S18: In the new round of external circulation, if the lowest power value P_min that occurs when a pin moves is lower than the absolute threshold, the matching is determined to be successful and the adjustment ends. In a new round of external circulation, if the minimum power value P_min that occurs when all pins move is higher than the absolute threshold, then enter a new round of external circulation again, repeating steps S7-S10 until the minimum power value P_min that occurs when a pin moves is lower than the absolute threshold or the maximum number of external circulations is reached, then end the adjustment.

[0010] Furthermore, the target threshold P_thresh is 0 to 5W.

[0011] Furthermore, in step S6, each pin is either returned to 50% of its travel or randomly assigned to one of three different intervals.

[0012] Further, in steps S13 and S17, if the trend curve first decreases and then increases, the minimum power value P_min and its corresponding pin position Pos_min are recorded, and the pin is driven to the pin position Pos_min corresponding to the minimum power value P_min; if the trend curve continues to increase or decreases, the pin is stopped at the current stroke end point or at the pin position Pos_min corresponding to the minimum power value P_min.

[0013] Further, in steps S11 and S15, each pin moves continuously or stepwise within its entire or part of its effective stroke; in steps S12 and S16, the reflected power value P_refl and the pin position Pos are recorded at a fixed sampling interval; in steps S13 and S17, either in real time or after a period of movement, the trend curve of the reflected power changing with the pin position is fitted or analyzed based on the recorded reflected power value P_refl and the pin position Pos.

[0014] Furthermore, there are 3 pins; and / or the maximum number of outer loops is at least 2; and / or the maximum number of re-searches is at least 3.

[0015] Furthermore, the absolute threshold is 0–10W.

[0016] To address the problem that current matching strategies that solely optimize reflected power may cause the system to converge to a local operating point that is optimal for "transmission efficiency" but suboptimal for "ionization performance," thus failing to guarantee the final output performance of the ion source, this invention provides an adaptive impedance matching method for an output performance feedback microwave ion source. Correspondingly, an adaptive impedance matching device for an output performance feedback microwave ion source is provided, comprising a microwave matching mechanism, an ion source output monitoring unit, and an intelligent decision controller. The microwave matching mechanism includes a microwave transmission line, pins, a reflected power detection unit, and a driving mechanism. Several pins are present, each with one end inserted into the microwave transmission line and its insertion depth adjusted by the driving mechanism. Each pin moves independently. The reflected power detection unit detects reflected power from the plasma load direction. The ion source output monitoring unit monitors the output parameters of the ion source, including the grid current. The intelligent decision controller is configured to execute the adaptive impedance matching method for an output performance feedback microwave ion source.

[0017] Furthermore, the ion source output monitoring unit includes a current sensor and a signal conditioning circuit; and / or the reflection power detection unit includes a directional coupler and a detector; and / or the driving mechanism includes a plurality of driving modules corresponding one-to-one with the plurality of pins, and each pin is driven by the corresponding driving module to adjust the insertion depth.

[0018] The advantages of this technical solution are: 1. Breaking through local optima and pursuing global optima: By introducing grid current feedback, the system has the ability to identify and escape the suboptimal operating point of "minimum reflection power but low ionization efficiency", and actively seek the optimal matching point that is truly beneficial to the final process output.

[0019] 2. Performance-oriented, intelligent and reliable: The ultimate goal of matching is corrected from intermediate variable (reflection power) to final result (grid current), so that the matching process directly serves the core performance of the ion source, and the level of intelligence is significantly improved.

[0020] 3. Enhance process stability and repeatability: Ensure that after each startup or change in process parameters, the system can automatically converge to a stable operating point that guarantees both energy transmission efficiency and high output current, greatly improving the consistency of equipment process results.

[0021] 4. Strong adaptability: It can automatically cope with the problem of "optimal matching point drift" caused by grid contamination, magnetic field drift, and slight changes in gas composition, and always maintain the best output performance.

[0022] 5. The method has strong versatility: This "performance feedback re-search" idea can be extended to other plasma source matching systems that take output parameters as the final goal. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0025] Figure 1 This is a flowchart of the adaptive impedance matching method for output performance feedback microwave ion source according to an embodiment of the present invention; Figure 2 This is a flowchart of the reflection power optimization process in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the adaptive impedance matching device for the microwave ion source with output performance feedback according to an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example: Figure 3 As shown, the output performance feedback microwave ion source adaptive impedance matching device includes a microwave matching mechanism 1, an ion source output monitoring unit 2, and an intelligent decision controller 3. The microwave matching mechanism 1 includes a microwave transmission line 101, pins 102, a reflection power detection unit 103, and a drive mechanism 104. Several pins 102 are present, each with one end inserted into the microwave transmission line 101 and driven by the drive mechanism 104 to adjust the insertion depth. Each pin 102 moves independently. The reflection power detection unit 103 detects the reflected power from the plasma load direction. The ion source output monitoring unit 2 monitors the output parameters of the ion source, including the grid current. The intelligent decision controller 3 is configured to execute the output performance feedback microwave ion source adaptive impedance matching method. The microwave transmission line 101 is connected to the vacuum cavity 5 via an antenna 4. The microwave transmission line 101 can be, but is not limited to, a waveguide.

[0028] In this embodiment of the invention, the microwave transmission line 101 has an inner cavity 105, and a plurality of pins 102 are inserted into the inner cavity 105 in the radial direction of the microwave transmission line 101 and arranged side by side in the axial direction of the microwave transmission line 101.

[0029] In this embodiment of the invention, the ion source output monitoring unit 2 includes a current sensor (not shown in the figure) and a signal conditioning circuit (not shown in the figure). The signal conditioning circuit is a conventional signal conditioning circuit and will not be described in detail here.

[0030] In this embodiment of the invention, the reflection power detection unit 103 includes a directional coupler (not shown in the figure) and a detector (not shown in the figure). The reflection power detection unit 103 is used to detect the reflection power from the direction of the plasma load and output the corresponding analog or digital detection signal.

[0031] In this embodiment of the invention, the driving mechanism 104 includes a plurality of driving modules 106 corresponding one-to-one with a plurality of pins 102, and each pin 102 is driven by the corresponding driving module 106 to adjust the insertion depth. Specifically, the driving module 106 is a stepper motor or a servo motor in conjunction with a lead screw mechanism.

[0032] like Figure 1 As shown, the adaptive impedance matching method for output performance feedback microwave ion sources has the following steps: S1: Set the target value I_target or the target range [I_min, I_max] of the screen grid current I_actual, and set the target threshold P_thresh of the reflected power P_refl; S2: Execute the reflected power optimization process to reduce the reflected power P_refl below P_thresh or converge to a local minimum; S3: After completing the reflected power optimization process, obtain the screen grid current I_actual; S4: If I_actual >= I_target or I_actual >= I_min, end the process; If I_actual < I_target or I_actual < I_min), and P_refl <= P_thresh, then enter the re-search process; The re-search process is as follows: S5: Set the maximum number of re-searches; S6: Enter the re-search, break the current state, and a number of pins 102 are controlled to move to a new initial position significantly different from the current position; S7: Conduct a new round of reflected power optimization process, obtain the pin position Pos and the reflected power value P_refl and the screen grid current I_actual corresponding to the pin position Pos, and record the pin position Pos that takes into account the lower reflected power value P_refl and the higher screen grid current I_actual; Or conduct a new round of reflected power optimization process, search with the screen grid current I_actual as the optimization objective function, and at the same time constrain the reflected power P_refl to be less than the absolute threshold; S8: During the current re-search, if a state that satisfies I_actual >= I_target and P_refl <= P_thresh is found, end the re-search; If a state that satisfies I_actual >= I_target and P_refl <= P_thresh is not found during the current re-search, then enter the next round of re-search and repeat steps S6 - S8; If a state that satisfies I_actual >= I_target and P_refl <= P_thresh is still not found after reaching the maximum number of re-searches, output the relevant parameters matching the maximum screen grid current I_actual, and the relevant parameters include the reflected power P_refl and the pin position Pos, and give an alarm prompt.

[0033] In summary, this embodiment provides an adaptive impedance matching method and apparatus for an output performance feedback microwave ion source. This addresses the problem that current matching strategies that solely optimize reflected power may cause the system to converge to a local operating point that is optimal for "transmission efficiency" but suboptimal for "ionization efficiency," failing to guarantee the final output performance of the ion source. The solution primarily involves configuring several co-moving pins 102 on the microwave transmission line 101, a reflected power detection unit 103 that automatically detects reflected power, and an intelligent decision controller 3 that executes the adaptive impedance matching method for the output performance feedback microwave ion source. By introducing the grid current as a higher-level optimization objective into the matching control closed loop, when the system falls into a "high efficiency, low energy" state, it can actively jump out of the original matching point and re-search for a globally optimal operating point that simultaneously satisfies low reflection and high grid current, achieving the following effects: 1. Breaking through local optima and pursuing global optima: By introducing grid current feedback, the system has the ability to identify and escape the suboptimal operating point of "minimum reflection power but low ionization efficiency", and actively seek the optimal matching point that is truly beneficial to the final process output.

[0034] 2. Performance-oriented, intelligent and reliable: The ultimate goal of matching is corrected from intermediate variable (reflection power) to final result (grid current), so that the matching process directly serves the core performance of the ion source, and the level of intelligence is significantly improved.

[0035] 3. Enhance process stability and repeatability: Ensure that after each startup or change in process parameters, the system can automatically converge to a stable operating point that guarantees both energy transmission efficiency and high output current, greatly improving the consistency of equipment process results.

[0036] 4. Strong adaptability: It can automatically cope with the problem of "optimal matching point drift" caused by grid contamination, magnetic field drift, and slight changes in gas composition, and always maintain the best output performance.

[0037] 5. The method has strong versatility: This "performance feedback re-search" idea can be extended to other plasma source matching systems that take output parameters as the final goal.

[0038] like Figure 2 As shown, the reflection power optimization process has the following steps: S9: Several pins 102 are moved to their initial positions under control; S10: Set the maximum number of outer loop iterations; S11: Enter the first external circulation. In the first external circulation, each pin 102 moves in sequence according to a preset order. S12: Obtain the pin position Pos and the corresponding reflection power value P_refl; S13: Based on the obtained pin position Pos and reflected power value P_refl, obtain the trend curve of reflected power changing with the position of pin 102, obtain the minimum power value P_min based on the trend curve, and lock pin 102 at the pin position Pos_min corresponding to the minimum power value P_min. S14: In the first external cycle, if the lowest power value P_min that occurs when a pin 102 moves is lower than the absolute threshold, the matching is determined to be successful and the adjustment ends. In the first outer loop, if the minimum power value P_min that occurs when all pins 102 move is higher than the absolute threshold, then a new round of outer loop is entered. S15: In the new round of external circulation, each pin 102 moves sequentially in a preset order; S16: Obtain the pin position Pos and the corresponding reflection power value P_refl; S17: Based on the obtained pin position Pos and reflected power value P_refl, obtain the trend curve of reflected power changing with the position of pin 102, obtain the minimum power value P_min based on the trend curve, and lock pin 102 at the pin position Pos_min corresponding to the minimum power value P_min. S18: In the new round of external circulation, if the lowest power value P_min that occurs when a pin 102 moves is lower than the absolute threshold, the matching is determined to be successful and the adjustment ends. In a new round of external circulation, if the minimum power value P_min that occurs when all pins 102 move is higher than the absolute threshold, then a new round of external circulation is entered again, and steps S7-S10 are repeated until the minimum power value P_min that occurs when one pin 102 moves is lower than the absolute threshold or the maximum number of external circulations is reached, and then the adjustment ends.

[0039] The above settings allow each of the pins 102 to perform a local optimal search, and iterate multiple times until the system is globally optimal, ultimately suppressing the reflected power to the lowest level, achieving fast automatic matching and dynamic tracking, and dynamically maintaining the best matching state during operation.

[0040] Steps S12 and S13 are performed one by one on each of the pins 102.

[0041] In step S14, during the first outer loop, if the lowest power value P_min that occurs when a pin 1022 moves is lower than the absolute threshold, then the matching is determined to be successful and the adjustment ends. This means that if the reflected power value P_refl detected when a pin 102 moves is lower than the absolute threshold, then the reflected power value P_refl is defined as the lowest power value P_min of the pin 102, and the entire adjustment ends immediately (other pins 102 that have not moved do not need to be moved either).

[0042] Steps S16 and S17 are performed one by one on each of the pins 102.

[0043] In step S18, if the lowest power value P_min that occurs when a pin 1022 moves is lower than the absolute threshold in the new outer loop, the matching is determined to be successful and the adjustment ends. This means that if the reflected power value P_refl detected when a pin 102 moves is lower than the absolute threshold, then the reflected power value P_refl is defined as the lowest power value P_min of the pin 102, and the entire adjustment ends immediately (other pins 102 that have not moved do not need to be moved either).

[0044] Since each pin is moved to a new initial position that is significantly different from its current position in step S6, step S9 is not executed again when the reflection power optimization process is executed again in step S7.

[0045] In this embodiment of the invention, the target threshold P_thresh is 0 to 5W.

[0046] In this embodiment of the invention, in step S6, each pin 102 is retracted to 50% of its travel, or randomly assigned to one of three different intervals. This arrangement causes the system to move away from its current local optimal attraction region.

[0047] In this embodiment of the invention, in steps S13 and S17, if the trend curve first decreases and then increases, the minimum power value P_min and its corresponding pin position Pos_min are recorded, and the pin 102 is driven to the pin position Pos_min corresponding to the minimum power value P_min. If the trend curve first decreases and then increases, a local minimum point is determined, and the pin 102 is driven to the pin position Pos_min corresponding to the minimum power value P_min, which helps to quickly lock the pin position Pos_min.

[0048] In this embodiment of the invention, in steps S13 and S17, if the trend curve continues to rise or fall, the pin 102 is stopped at the current travel endpoint or at the pin position Pos_min corresponding to the lowest power value P_min. If the pin 102 does not detect a "falling then rising" trend throughout its movement, the pin 102 is stopped at the current travel endpoint or at the position with the lowest reflected power, which is beneficial for quickly locking the pin position Pos_min.

[0049] In this embodiment of the invention, in steps S11 and S15, each pin 102 moves continuously or in steps within its entire or part of its effective stroke. This arrangement ensures stable movement of the pin 102 and improves the accuracy of detection.

[0050] In this embodiment of the invention, in steps S12 and S16, the reflected power value P_refl and the pin position Pos are recorded at a fixed sampling interval. In steps S13 and S17, either in real time or after a period of movement, the trend curve of the reflected power changing with the position of the pin 102 is fitted or analyzed based on the recorded reflected power value P_refl and the pin position Pos.

[0051] In this embodiment of the invention, there are 3 pins 102, the maximum number of outer loops is at least 2, and the maximum number of re-searches is at least 3.

[0052] In this embodiment of the invention, the absolute threshold is 0 to 10W.

[0053] It should be understood that the terms "first," "second," etc., are used in this invention to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information. In addition, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0054] The above description provides one or more embodiments in conjunction with specific content, and does not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered as protected by the present invention.

Claims

1. An adaptive impedance matching method for output performance feedback microwave ion sources, characterized in that, The steps are as follows: S1: Set the target value I_target or target range [I_min, I_max] of the screen grid current I_actual, and set the target threshold P_thresh of the reflected power P_refl; S2: Execute the reflection power optimization process to reduce the reflection power P_refl to below P_thresh or converge to a local minimum. S3: After completing the reflection power optimization process, obtain the screen grid current I_actual; S4: If I_actual >= I_target or I_actual >= I_min, end the process; If I_actual < I_target or I_actual < I_min), and P_refl <= P_thresh, then proceed with the re-search process; The re-search process involves the following steps: S5: Set the maximum number of re-searches; S6: Enter re-search, several pins are controlled to move to a new initial position that is significantly different from the current position; S7: Perform a new round of reflection power optimization process, obtain the pin position Pos and the reflection power value P_refl and the screen current I_actual corresponding to the pin position Pos, and record the pin position Pos that takes into account both the lower reflection power value P_refl and the higher screen current I_actual. Alternatively, a new round of reflection power optimization process can be carried out, using the screen current I_actual as the optimization objective function for the search, while constraining the reflection power P_refl to be less than the absolute threshold. S8: If a state satisfying I_actual >= I_target and P_refl <= P_thresh is found within the current re-search, the re-search ends; If no state satisfying I_actual >= I_target and P_refl <= P_thresh is found in the current re-search, then proceed to the next round of re-search and repeat steps S6-S8; If the maximum number of re-searches is reached and a state satisfying I_actual >= I_target and P_refl <= P_thresh is still not found, then the relevant parameters matching the maximum screen current I_actual will be output, and an alarm will be triggered.

2. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 1, characterized in that, The reflection power optimization process consists of the following steps: S9: Several pins are moved to their initial positions under control; S10: Set the maximum number of outer loop iterations; S11: Enter the first external circulation. During the first external circulation, each pin moves in sequence according to a preset order. S12: Obtain the pin position Pos and the corresponding reflection power value P_refl; S13: Based on the obtained pin position Pos and reflected power value P_refl, obtain the trend curve of reflected power changing with pin position, obtain the minimum power value P_min based on the trend curve, and lock the pin at the pin position Pos_min corresponding to the minimum power value P_min. S14: In the first external cycle, if the lowest power value P_min that occurs when a pin moves is lower than the absolute threshold, the matching is considered successful and the adjustment ends. In the first outer loop, if the minimum power value P_min that occurs when all pins move is higher than the absolute threshold, then a new round of outer loop is entered. S15: In the new round of external circulation, each pin moves in sequence according to the preset order; S16: Obtain the pin position Pos and the corresponding reflection power value P_refl; S17: Based on the obtained pin position Pos and reflected power value P_refl, obtain the trend curve of reflected power changing with pin position, obtain the minimum power value P_min based on the trend curve, and lock the pin at the pin position Pos_min corresponding to the minimum power value P_min. S18: In the new round of external circulation, if the lowest power value P_min that occurs when a pin moves is lower than the absolute threshold, the matching is determined to be successful and the adjustment ends. In a new round of external circulation, if the minimum power value P_min that occurs when all pins move is higher than the absolute threshold, then enter a new round of external circulation again, repeating steps S7-S10 until the minimum power value P_min that occurs when a pin moves is lower than the absolute threshold or the maximum number of external circulations is reached, then end the adjustment.

3. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 1, characterized in that, The target threshold P_thresh is 0 to 5W.

4. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 1, characterized in that, In step S6, each pin is either returned to 50% of its travel or randomly assigned to one of three different intervals.

5. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 2, characterized in that, In steps S13 and S17, if the trend curve first decreases and then increases, the minimum power value P_min and its corresponding pin position Pos_min are recorded, and the pin is driven to the pin position Pos_min corresponding to the minimum power value P_min. If the trend curve continues to rise or continue to fall, then stop the pin at the current travel endpoint or at the pin position Pos_min corresponding to the minimum power value P_min.

6. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 2, characterized in that, In steps S11 and S15, each pin moves continuously or stepwise within its entire or part of its effective stroke. In steps S12 and S16, the reflected power value P_refl and the pin position Pos are recorded at a fixed sampling interval; In steps S13 and S17, either in real time or after a movement is completed, the trend curve of the reflected power changing with the pin position is fitted or analyzed based on the recorded reflected power value P_refl and the pin position Pos.

7. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 2, characterized in that, There are 3 pins; and / or the maximum number of outer loops is at least 2; and / or the maximum number of re-searches is at least 3.

8. The adaptive impedance matching method for output performance feedback microwave ion source according to claim 1, characterized in that, The absolute threshold is 0 to 10W.

9. An adaptive impedance matching device for a microwave ion source with output performance feedback, characterized in that, The system includes a microwave matching mechanism, an ion source output monitoring unit, and an intelligent decision controller. The microwave matching mechanism includes a microwave transmission line, pins, a reflection power detection unit, and a driving mechanism. There are several pins, one end of which is inserted into the microwave transmission line and the insertion depth is adjusted by the driving mechanism. Each pin moves independently. The reflection power detection unit is used to detect the reflection power from the direction of the plasma load. The ion source output monitoring unit is used to monitor the output parameters of the ion source, including the grid current. The intelligent decision controller is configured to perform the output performance feedback microwave ion source adaptive impedance matching method according to any one of claims 1-8.

10. The output performance feedback microwave ion source adaptive impedance matching device according to claim 9, characterized in that, The ion source output monitoring unit includes a current sensor and a signal conditioning circuit; and / or the reflection power detection unit includes a directional coupler and a detector; and / or the driving mechanism includes a plurality of driving modules corresponding one-to-one with the plurality of pins, and each pin is driven by the corresponding driving module to adjust the insertion depth.

Images