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EP-4736212-A1 - TRANSFORMATION SYSTEM FOR CONNECTING A PLASMA PROCESS CONTROL SYSTEM TO AN IMPEDANCE MATCHING CIRCUIT, PLASMA-GENERATING SYSTEM HAVING SUCH A TRANSFORMATION SYSTEM, AND METHOD FOR GENERATING A TRANSFORMATION TABLE AND/OR A TRANSFORMATION FUNCTION

EP4736212A1EP 4736212 A1EP4736212 A1EP 4736212A1EP-4736212-A1

Abstract

A transformation system (10) is used for connecting a plasma process control system (2) to an impedance matching circuit A (9), wherein the impedance matching circuit A (9) is connectable to an RF generator (3) and a plasma chamber (5). A first transformation device (10a) and a communication device (14) are provided, wherein the communication device (14) is connectable to the plasma process control system (2). The communication device (14) is designed to receive control data B for an impedance matching circuit B (4) from the plasma process control system (2). The first transformation device (10a) is designed to transform the control data B for the impedance matching circuit B (4) into control data A for the impedance matching circuit A (9). The transformation system (10) is designed to provide the control data A for the control of the impedance matching circuit A (9). Additionally or alternatively, information data A may also be received from the impedance matching circuit A (9) and transformed into information data B for an impedance matching circuit B (4) and transmitted to the plasma process control system (2).

Inventors

  • MAIER, FLORIAN

Assignees

  • TRUMPF Hüttinger GmbH + Co. KG

Dates

Publication Date
20260506
Application Date
20240630

Claims (16)

  1. 1. Transformation system (10) for connecting a plasma process control system (2) to an impedance matching circuit A (9), wherein the impedance matching circuit A (9) is connectable to an RF generator (3) and a plasma chamber (5), wherein the transformation system (10) comprises the following features: - a first transformation device (10a) and a communication device are provided, wherein the communication device (14) is connectable to the plasma process control system (2); wherein: a) - the communication device (14) is designed to receive control data B for an impedance matching circuit B (4), in particular to receive it from the plasma process control system (2); - the first transformation device (10a) is designed to transform the control data B for the impedance matching circuit B (4) into control data A for the impedance matching circuit A (9); and - the transformation system (10) is designed to provide the control data A for controlling the impedance matching circuit A (9); and/or b) - the transformation system (10) is designed to receive information data A from the impedance matching circuit A (9); - the first transformation device (10a) is designed to transform the received information data A from the impedance matching circuit A (9) into information data B of the impedance matching circuit B (4); and - the communication device (14) is designed to provide the information data B, in particular to transmit it to the plasma process control system (2).
  2. 2. Transformation system (10) according to claim 1, characterized by the following feature: - the transformation system (10) is designed to transmit the control data A to the impedance matching circuit A (9) and thereby control the impedance matching circuit A (9).
  3. 3. Transformation system (10) according to claim 1 or 2, characterized by the following feature: - the first transformation device (10a) comprises a transformation table and/or a transformation function in order to transform the control data B for the impedance matching circuit B (4) into control data A for the impedance matching circuit A (9).
  4. 4. Transformation system (10) according to one of the preceding claims, characterized by the following feature: - the control data B for the impedance matching circuit B (4) comprise manipulated variables for at least one mechanically, in particular motor-driven, adjustable reactance in the impedance matching circuit B (4); - the control data A for the impedance matching circuit A (9) comprise manipulated variables for at least one mechanically, in particular motor-driven, adjustable reactance (52, 53) for the impedance matching circuit A (9).
  5. 5. Transformation system (10) according to one of the preceding claims, characterized by the following features: - the control data B for the impedance matching circuit B (4) comprise: a) position information; and/or b) capacitance information; for at least one mechanically, in particular motor-driven, adjustable reactance which is arranged in the impedance matching circuit B (4) in order to to provide a certain impedance target value at the output terminal (4b) of the impedance matching circuit B (4); - the first transformation device (10a) is designed to transform the control data B for the impedance matching circuit B (4) into control data A for the impedance matching circuit A (9), wherein the control data A for the impedance matching circuit A (9) comprises position information for at least one mechanically, in particular motor-driven, adjustable reactance (52, 53) which is arranged in the impedance matching circuit A (9), by means of which the same impedance target value can be provided at the output terminal (9b) of the impedance matching circuit A (9) as at the output terminal (4b) of the impedance matching circuit B (4).
  6. 6. Transformation system (10) according to one of the preceding claims, characterized by the following feature: - the information data A comprise at least one of the following values: a) current position information for at least one mechanically, in particular motor-adjustable reactance (52, 53) in the impedance matching circuit A (9); b) current capacitance information for at least one mechanically, in particular motor-adjustable reactance (52, 53) in the impedance matching circuit A (9); c) a currently set transformation ratio in the impedance matching circuit A (9); d) a current efficiency of the impedance matching circuit A (9); e) at least one current value for a voltage and/or current at or in the impedance matching circuit A (9).
  7. 7. Transformation system (10) according to one of the preceding claims, characterized by the following feature: - the first transformation device (10a) comprises a transformation table and/or a transformation function in order to transform the information data A for the impedance matching circuit A (9) into information data B for the impedance matching circuit B (4).
  8. 8. Transformation system (10) according to one of the preceding claims, characterized by the following features: - the communication device is designed to receive a target generator power B for the RF generator (3) for use with the impedance matching circuit B (4) from the plasma process control system (2); - a second transformation device (10b) is provided, wherein the second transformation device (10b) is designed to transform the target generator power B for use of the impedance matching circuit B (4) into a target generator power A for use of the impedance matching circuit A (9); - the second transformation device (10b) is designed to transmit the target generator power A to the RF generator (3).
  9. 9. Transformation system (10) according to claim 8, characterized by the following feature: - the second transformation device (10b) is designed to transform the target generator power B received from the plasma process control system (2) as a function of a variable, wherein the variable can describe an efficiency difference between the impedance matching circuit A (9) and the impedance matching circuit B (4).
  10. 10. Transformation system (10) according to claim 8 or 9, characterized by the following features: - the second transformation device (10b) is designed to transform the target generator power B received from the plasma process control system (2) as a function of an efficiency difference between an efficiency of the impedance matching circuit A (9) and an efficiency of the impedance matching circuit B (4), wherein the efficiency of the impedance matching circuit A (9) results when operating with the manipulated variable A and wherein the efficiency of the impedance matching circuit B (4) results when operating with the manipulated variable B.
  11. 11. Transformation system (10) according to one of claims 8 to 10, characterized by the following feature: - the second transformation device (10b) is designed to reduce the target generator power B received from the plasma process control system (2) if the efficiency of the impedance matching circuit A (9) is greater than the efficiency of the impedance matching circuit B (4).
  12. 12. Transformation system (10) according to one of claims 8 to 11, characterized by the following features: - the second transformation device (10b) is designed to receive an actual generator power from the RF generator (3) with connected impedance matching circuit A (9); wherein: a) the second transformation device (10b) is designed to increase the actual generator power if the efficiency of the impedance matching circuit A (9) is greater than the efficiency of the impedance matching circuit B (4); the communication device is designed to transmit the increased actual generator power to the plasma process control system (2); and/or b) the second transformation device (10) is designed to reduce the actual generator power if the efficiency of the impedance matching circuit A (9) is less than the efficiency of the impedance matching circuit B (4); the communication device is designed to transmit the reduced actual generator power to the plasma process control system (2).
  13. 13. Transformation system (10) according to one of the preceding claims, characterized by the following features: - the communication device (14) is designed to receive a frequency setpoint for the RF generator (3) from the higher-level plasma process control system (2); - the second transformation device (10b) is designed to transmit the frequency target value to the RF generator (3) without changing the frequency.
  14. 14. Plasma generation system (1) with a transformation system (10) according to one of the preceding claims, an RF generator (3), an impedance matching circuit A (9) and a plasma process control system (2), wherein the plasma generation system (1) comprises the following features: - the plasma process control system (2) is connected to the transformation system; - the RF generator (3) is connected to the impedance matching circuit A (9); - the plasma process control system (2) is connected to the transformation system (10).
  15. 15. Plasma generation system (1) according to claim 14, characterized by the following features: - the transformation system (10) is: a) designed as a separate system between the RF generator (3), the impedance matching circuit A (9) and the plasma process control system (2); or b) designed as a module in the RF generator (3) and in the impedance matching circuit A (9); or c) designed as a module in the plasma process control system (2).
  16. 16. Method for generating a transformation table and/or a transformation function to transform control data B for the impedance matching circuit B (4) into control data A for the impedance matching circuit A (9), the method comprising the following method steps: - connecting a vector network analyzer (13) to the input terminal (4a) and the output terminal (4b) of the impedance matching circuit B (4); - determining an impedance at the output terminal (4b) for a position for at least one mechanically, in particular motor-adjustable, reactance of the impedance matching circuit B (4); - changing the position of the at least one mechanically, in particular motor-adjustable, reactance of the impedance matching circuit B (4) and repeating the method step of determining; - connecting one or the vector network analyzer (13) to the input terminal (9a) and the output terminal (9b) of the impedance matching circuit A (9); - determining an impedance at the output terminal (9b) for a position for at least one mechanically, in particular motor-driven, adjustable reactance (52, 53) of the impedance matching circuit A (9); - changing the position of the at least one mechanically, in particular motor-adjustable, reactance (52, 53) of the impedance matching circuit A (9) and repeating the method step of determining; - Creating a transformation table and/or a transformation function by means of which a position of the at least one mechanically, in particular motor-driven, adjustable reactance of the impedance matching circuit B (4) can be converted into a position for the at least one mechanically, in particular motor-driven, adjustable reactance (52, 53) of the impedance matching circuit A (9), wherein the impedance at the output terminal of the impedance matching circuit A (9): a) is equal to the impedance at the output terminal of the impedance matching circuit B (4); or b) deviates by less than a threshold value.

Description

Transformation system for connecting a plasma process control system to an impedance matching circuit, plasma generation system with such a transformation system and a method for generating a transformation table and/or a transformation function The invention relates to a transformation system for connecting a plasma process control system to an impedance matching circuit, a plasma generation system with such a transformation system and a method for generating a transformation table and/or a transformation function. The surface treatment of workpieces using plasma and gas lasers are industrial processes in which a plasma is generated, particularly in a plasma chamber, using direct current or a high-frequency alternating signal with an operating frequency in the range of a few 10 kHz up to the GHz range. The plasma chamber is connected to a high frequency generator (HF generator) via other electronic components such as coils, capacitors, cables or transformers. These additional components can represent resonant circuits, filters or impedance matching circuits. Plasma processes represent a highly variable load for a high-frequency generator, which depends on the conditions in the plasma chamber. In particular, the properties of the workpiece, electrodes and gas conditions are important. High frequency generators have a limited operating range with respect to the impedance of the connected electrical load. If the If the load impedance is outside of an acceptable range, the required energy/power cannot be delivered to the consumer. The HF generator may also be damaged. For this reason, an impedance matching circuit, also called a “match box”, is often used, which transforms the impedance of the load to a nominal impedance of the generator output. Different impedance matching circuits are known. For example, the impedance matching circuits can be fixed and have a predetermined transformation effect, i.e. they consist of electrical components, in particular coils and capacitors, which are not changed during operation. This is particularly useful when operation always remains the same, such as with a gas laser. Impedance matching circuits are also known in which at least some of the components of the impedance matching circuit can be changed mechanically. For example, motor-driven variable capacitors are known whose capacitance value can be changed by changing the arrangement of the capacitor plates relative to one another. Impedance matching circuits are also known in which at least some of the components of the impedance matching circuit can be changed electrically or magnetically. For example, reactances can be switched on using semiconductor components or reactances can be changed in their properties by applying electrical and/or magnetic fields. A plasma can be roughly assigned to three impedance ranges. Before ignition, very high impedances exist. In normal operation, ie when plasma is used as intended, lower impedances exist. Very small impedances can occur in the case of unwanted local discharges, also called 'arcs', or in the case of plasma fluctuations. In addition to these three In addition to the identified impedance ranges, other special states with other associated impedance values can occur. If the load impedance changes suddenly and the load impedance or the transformed load impedance moves out of a permissible impedance range, the RF generator or transmission equipment between the RF generator and the plasma chamber can be damaged. There are also stable states of the plasma that are not desired. An impedance matching circuit is described, for example, in DE 10 2009 001 355 A1. Plasma processes that are carried out using such a plasma generation system, which includes at least the RF generator and the impedance matching circuit, must always proceed in exactly the same way in order to achieve the same result. This is all the more true since the plasma process is integrated into a semiconductor process. Semiconductor processes include many other steps, whereby each step must proceed within a precisely predefined framework. Each process parameter must always be exactly the same, otherwise a wafer, for example, cannot be produced reproducibly. One problem is replacing one component of the plasma generation system with another component. Reasons for such a replacement can be seen in better properties, such as lower energy consumption, of the new component. For example, the impedance matching circuit B can be replaced by a new impedance matching circuit A, which is, for example, more efficient or can be operated over a larger frequency range or can be adjusted more precisely or quickly. It is therefore the object of the present invention to provide a way to continue to achieve a stable and reproducible plasma process, even if one component of the plasma generation system is replaced by another component. The object is achieved by a transformation system for connecting a plasma process control system t