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CN-121984468-A - Matching method for automatic matcher equipment

CN121984468ACN 121984468 ACN121984468 ACN 121984468ACN-121984468-A

Abstract

The invention discloses a matching method for automatic matcher equipment, which relates to the technical field of radio frequency impedance matching, and is applied to radio frequency impedance matching equipment. The matching method for the automatic matcher device performs parameter scanning on two adjustable vacuum capacitors through a two-dimensional optimizing scanning algorithm, finds target matching parameters in advance and stores the target matching parameters in a nonvolatile memory module, when a plasma generating device is started, a central processing unit can directly call pre-stored parameters without re-executing full-range scanning, a capacitor driving mechanism is controlled to be quickly adjusted to a target state, even if initial matching parameters are called in an extreme scene and secondary fine adjustment is started, the problem of unstable power caused by scanning hysteresis in the existing scheme is avoided, and the severe requirement of a high-precision process on ignition stability is met.

Inventors

  • LI XIN
  • PENG JIE

Assignees

  • 苏州纳飞卫星动力科技有限公司

Dates

Publication Date
20260505
Application Date
20251219

Claims (10)

  1. 1. The matching method for the automatic matcher equipment is applied to radio frequency impedance matching equipment, the radio frequency impedance matching equipment is used for connecting a radio frequency output device and a plasma load, and controlling the output power of the radio frequency output device to be effectively transmitted to the plasma load, and is characterized by comprising the following steps: starting a radio frequency output device, outputting according to preset power, and enabling the radio frequency output device and a plasma load to be in an impedance mismatch state in a plasma non-generation stage; Running an optimizing scanning flow, scanning and adjusting all capacitance parameters of a first adjustable capacitor and a second adjustable capacitor contained in a matching network in radio frequency impedance matching equipment, and adjusting the parameters of the two adjustable capacitors to minimum parameter values in an initial state; performing incremental adjustment on the current parameter of the second adjustable capacitor to obtain an adjusted second adjustable capacitor parameter; According to the accumulated adjustment times of the second adjustable capacitor, adjusting the parameter scanning direction of the first adjustable capacitor, and scanning the parameter of the first adjustable capacitor from one limit parameter value to the other limit parameter value according to the scanning direction; In the parameter scanning process of the first adjustable capacitor, continuously detecting the reflected power in a circuit loop and judging whether the reflected power is reduced, if the reflected power is reduced, stopping scanning, taking the parameters of the two adjustable capacitors at the moment as target matching parameters to be stored, and exiting the optimizing scanning process; After the plasma is generated, the radio frequency impedance matching equipment invokes the stored target matching parameters to perform impedance matching between the radio frequency output device and the plasma load, so that the power output by the radio frequency output device is transmitted to the plasma load, and the matching process does not enter a matching point dead zone.
  2. 2. The matching method for an automatic matcher apparatus of claim 1, wherein the preset power of the rf output device is adjusted according to the plasma process, the reflected power in the circuit loop is collected in real time by a power detection component built in the rf impedance matching apparatus, and the power detection component is connected in series between the rf output device and the matching network, for continuously capturing the power reflection data in the loop.
  3. 3. The matching method for an automatic matcher apparatus of claim 1, wherein the matching network is of an L-type structure, and the optimizing scanning process is performed by a central control unit of the radio frequency impedance matching apparatus; The first adjustable capacitor and the second adjustable capacitor are vacuum capacitors, and the minimum capacity range corresponding to the minimum parameter value corresponds to the matching network.
  4. 4. The matching method for an automatic matcher apparatus of claim 1 wherein the preset parameter increment is a fixed value, the fixed value being set according to the matching accuracy; After parameter adjustment of the second adjustable capacitor is completed each time, keeping stable time, and collecting stable reflected power data through the power detection component; The parameter adjustment of the second adjustable capacitor is completed by sending a control instruction to a matched driving mechanism through a central control unit, the driving mechanism changes the distance between capacitor plates through mechanical transmission, the capacitance is adjusted, the maximum parameter can be adjusted to the maximum parameter value, and the maximum capacitance range corresponding to the parameter value is matched with a matching network.
  5. 5. The matching method for an automatic matcher apparatus of claim 1, wherein the cumulative adjustment number of the second adjustable capacitance is counted as one adjustment per execution of the parameter adjustment operation of the second adjustable capacitance with an initial minimum parameter value as a statistical starting point; When the accumulated adjustment times are odd, the scanning direction of the first adjustable capacitor is from the minimum parameter value to the maximum parameter value, and when the accumulated adjustment times are even, the scanning direction is from the maximum parameter value to the minimum parameter value; the maximum upper limit of the accumulated adjustment times is obtained by a preset parameter increment and a maximum parameter value, and the second adjustable capacitor is adjusted from the minimum parameter value to the maximum parameter value.
  6. 6. The matching method for an automatic matcher apparatus according to claim 1, wherein the reflected power is detected in real time by a power separating means for separating forward power from reflected power of the loop, the means transmitting the separated reflected power data to the central control unit; The judgment standard of the reduction of the reflected power is that the value of the currently detected reflected power is smaller than the value of the reflected power detected last time, the detection time interval is opposite to the parameter adjustment precision of the first adjustable capacitor, and the change of the reflected power is captured.
  7. 7. The matching method for an automatic matcher apparatus according to claim 1, wherein the save carrier of the target matching parameters is a nonvolatile memory means provided for the central control unit, which can keep the saved parameter data from being lost after the radio frequency impedance matching apparatus is powered off.
  8. 8. The matching method for automatic matcher apparatus of claim 1, wherein if the parameter of the second adjustable capacitor has been adjusted to the maximum parameter value and no reflected power decrease has been detected after the corresponding scan of the first adjustable capacitor is completed, stopping the repeated operation, saving the maximum parameter values of the two adjustable capacitors as initial matching parameters, and exiting the optimizing scanning flow; After the plasma is generated, the radio frequency impedance matching device starts a secondary fine tuning operation based on the initial matching parameter, the fine tuning parameter increment is smaller than the preset parameter increment until the reflected power is reduced below a preset minimum threshold value, and the secondary fine tuning process does not enter a matching point dead zone.
  9. 9. The matching method for an automatic matcher apparatus of claim 1 wherein the decision criteria for substantially all transmission of power is that the reflected power falls below a preset proportion of the output power of the radio frequency output device; the radio frequency impedance matching equipment is suitable for the related industries of plasma process, including the semiconductor industry, the solar industry or the aerospace propulsion industry; the plasma load maintains a stable state of the plasma by receiving the power output by the radio frequency output device.
  10. 10. The matching method for an automatic matcher apparatus of claim 1 wherein the method combines the reverse scan logic for determining the scan direction of the first tunable capacitance based on the second tunable capacitance adjustment times by a full scan of all parameters of both tunable capacitances.

Description

Matching method for automatic matcher equipment Technical Field The invention relates to the technical field of radio frequency impedance matching, in particular to a matching method for automatic matcher equipment. Background In the core plasma processes of semiconductor chip etching, solar cell coating, aerospace plasma thruster ignition and the like, a radio frequency source is connected with a plasma load through automatic radio frequency impedance matching equipment so as to eliminate impedance difference between the radio frequency source and the load; The automatic matching methods commonly used in the current industry mainly have two types, and obvious defects exist in practical application: The first is a single-capacitor scanning matching scheme, which is used as an early mainstream technology, and the implementation logic is that parameter scanning is carried out on a single adjustable capacitor in a matching network, the other capacitor parameter is kept fixed, an optimal matching point is found by detecting the change of reflected power, the capacitor parameter is adjusted point by point according to a fixed direction after equipment is started, the reflected power is collected once every time after the equipment is adjusted, and the parameter with the minimum reflected power is selected as the matching point after the scanning is finished, but the scheme ignores the synergistic effect of the two capacitor parameters, and the optimal matching point under the double-capacitor combination is easily omitted, so that the matching precision is seriously insufficient, and the requirement of a high-precision technology on the power stability cannot be met; The second type is a fixed step length full-range scanning scheme, in order to solve the precision problem of single-capacitor scanning, the scheme carries out full-range scanning on two adjustable capacitors, namely, a first capacitor parameter is fixed, a second capacitor is adjusted according to a fixed step length, the full parameter range of the first capacitor is scanned once every time the second capacitor is adjusted, the full-range scanning is completed until the second capacitor completes, but the matching time is overlong, the whole process requires a large amount of parameter adjustment and reflected power detection operation, the time consumption is excessively high in proportion to the total process time length, the production efficiency is seriously influenced, the scanning direction is fixed, a better matching point of a reverse interval is easy to miss, and potential precision hazards still exist. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention provides a matching method for automatic matcher equipment, which solves the problems of insufficient matching precision, overlong matching time, easiness in entering a matching point dead zone, poor adaptability and the like of the existing automatic matching method. (II) technical scheme In order to achieve the above purpose, the invention is realized by the following technical scheme: the matching method for the automatic matcher equipment is applied to radio frequency impedance matching equipment, the radio frequency impedance matching equipment is used for connecting a radio frequency output device and a plasma load, and effective transmission of output power of the radio frequency output device to the plasma load is realized, and the matching method comprises the following steps: step 1, starting a radio frequency output device to output preset power, wherein the radio frequency output device and a plasma load are in an impedance mismatch state in a non-generation stage of plasma, and a power reflection phenomenon exists in a circuit loop; Step 2, running an optimizing scanning flow, scanning and adjusting all capacitance parameters of two adjustable capacitors (respectively called a first adjustable capacitor and a second adjustable capacitor) contained in a matching network in the radio frequency impedance matching equipment, and adjusting the parameters of the two adjustable capacitors to minimum parameter values in an initial state; Step 3, adjusting the current parameters of the second adjustable capacitor according to the preset parameter increment to obtain adjusted second adjustable capacitor parameters; Step 4, determining a parameter scanning direction of the first adjustable capacitor according to the accumulated adjustment times of the second adjustable capacitor, and scanning the parameter of the first adjustable capacitor from one limit parameter value to the other limit parameter value according to the scanning direction; Step 5, continuously detecting the reflected power in the circuit loop and judging whether the reflected power is reduced or not in the parameter scanning process of the first adjustable capacitor, immediately stopping scanning if the reflected power is reduced, taking the parameters of t