Plasma condition monitor for connection to an impedance matching circuit for a plasma generation system, plasma generation system, and method for monitoring a plasma generation system

Abstract

A plasma condition monitor (1) for a plasma generation system (100) having an impedance matching circuit (50) includes: a) detecting a first set of time-varying measurements (30), the first set of time-varying measurements (30) being related to time-sequentially picked-up impedances detectable at one of a plurality of terminals (50a, 50b) of the impedance matching circuit (50); and b) detecting a second set of time-varying measurements (31) of at least one measurand, the at least one measurand being a voltage (32), a current (33), and a phase relationship between the voltage (32) and the current (33). (34), wherein the time-varying measurements (31) are taken consecutively in time, and c) detecting a second group of time-varying measurements (31) of at least one measurand, wherein the time-varying measurements (31) are taken consecutively in time; and c) displaying the first group on a first chart (35) and the second group on a second chart (36), wherein the first chart (35) is a chart without a time axis and the second chart (36) has two axes (36a, 36b), one of which (36b) is a time axis, configured to display the first group on the first chart (35) and the second group on the second chart (36). Both groups of time-varying measurements (30, 31) are taken within the same time period.

Description

[Technical Field]

[0001] The present invention relates to a plasma condition monitor for connection to an impedance matching circuit for a plasma generation system, a plasma generation system, and a method for monitoring a plasma generation system.

[0002] Surface treatment of workpieces with plasma and, for example, in semiconductor manufacturing and in the machining of workpieces with gas lasers are industrial processes in which plasma is generated in a plasma chamber by direct current or by high-frequency alternating current signals with operating frequencies in the range of several tens of kilohertz to gigahertz. In such plasma processes, small errors can lead to significant damage.

[0003] The plasma chamber is connected to a high-frequency generator (HF generator) via further electronic components, such as coils, capacitors, lines or transformers. These may comprise an oscillator circuit, a filter or an impedance matching circuit. The HF generator is typically configured as a power converter, which converts a conventional mains voltage with a frequency of 50-60 Hz into the desired HF voltage and thus into the corresponding power during operation.

[0004] A problem with plasma processes is that the electrical load impedance of the plasma chamber (=consumer) generated during the process varies dramatically depending on the conditions inside the plasma chamber, especially the workpiece characteristics, electrode and gas ratios.

[0005] High frequency generators have a limited working range with respect to the impedance of the connected electrical load (=consumer). If the load impedance deviates from the permissible range, damage or even destruction of the HF generator will occur.

[0006] For this reason, an impedance matching circuit (matchbox) is generally required to convert the load impedance to the rated impedance at the generator output.

[0007] Various impedance matching circuits are known. For example, impedance matching circuits are permanently adjusted and consist of electrical components, particularly coils and capacitors, that have a preset transforming effect, i.e., that cannot be changed during operation. This is particularly advantageous when operation is always constant, as in the case of gas lasers. Furthermore, impedance matching circuits are known in which at least some of the components are mechanically variable. For example, motor-operated rotary capacitors are known, in which the capacitance value can be changed by changing the arrangement of the capacitor plates relative to one another. Also known are switchable reactances, such as capacitors, each of which may have different values.

[0008] Roughly speaking, three impedance ranges can be assigned to a plasma. Before ignition, an extremely high impedance occurs, typically greater than 1 kΩ. During normal operation, i.e., during regular operation with the plasma, a relatively low impedance occurs, typically less than 100 Ω. During undesirable localized discharges (arcs) or plasma fluctuations, an extremely low impedance occurs, typically less than 0.5 Ω. In addition to these three identified impedance ranges, other special conditions can occur with other assigned impedance values. If the load impedance changes suddenly, and the load impedance or the transformed load impedance falls outside the acceptable impedance range, this can damage the HF generator or the transmission device between the HF generator and the plasma chamber. Furthermore, undesired, but stable, plasma conditions can occur.

[0009] Such an impedance matching circuit is described, for example, in DE 10 2009 001 355 A1.

[0010] Due to different plasma conditions, impedance does not always provide information about whether the existing plasma condition is the desired plasma condition.

[0011] The object of the invention herein is therefore to provide the operator of a plasma generation system with the possibility to very quickly and reliably recognize undesirable plasma states and to take measures based on this information.

[0012] This problem is solved by a plasma state monitoring device according to independent claim 1, as well as by a plasma generation system according to claim 31 and a method for monitoring a plasma generation system according to claim 32. Claims 2 to 30 describe improvements according to the invention to the plasma state monitoring device.

[0013] The plasma condition monitor according to the present invention is adapted to be connected to an impedance matching circuit for a plasma generation system. The impedance matching circuit is sometimes referred to as a matchbox. The plasma condition monitor is configured to detect a first set of time-varying measurements. The first set of time-varying measurements is related to a time-sequentially picked-up impedance detectable at one terminal (e.g., an input terminal or an output terminal) of the impedance matching circuit. Preferably, the first set of time-varying measurements is an impedance. The first set of time-varying measurements may be a reflection coefficient related to the impedance. The term "picked up" refers to both measurement and calculation. The plasma condition monitor is further configured to detect a second set of time-varying measurements of at least one measurand. The at least one measurand is selected from voltage, current, or a phase relationship between current and voltage. The time-varying measurements of each measurand are also picked up time-sequentially. Preferably, at least two, more preferably all three, measurands are selected. More preferably, the second set includes the same number of time-varying measurements for each measurand. Thus, there may be 100 time-varying measurements of voltage. There may be 100 time-varying measurements of current. There may be 100 time-varying measurements of the phase relationship between current and voltage. In this case, preferably, only the time-varying measurements of each measurand are taken consecutively in time. Thus, for example, a first time-varying measurement of voltage, a first time-varying measurement of current, and a first time-varying measurement of the phase relationship may be taken at the same time or immediately consecutively, i.e., in a very narrow time relationship. Then, a second time-varying measurement of each measurand is taken consecutively in time after the first time-varying measurement of each of the same measurands. Furthermore, the plasma state monitor is configured to display the first group of time-varying measurements on a first chart.The first chart is a chart without a time axis, particularly a chart for displaying complex impedance or its inverse, complex reflection coefficient, and / or reflected output in complex form, preferably a Smith chart. "Complex" herein refers to a mathematical term for a numerical value having a real part and an imaginary part. The plasma condition monitoring device is further configured to display time-variable measurements of at least one measurand of a second group on a second chart. The second chart may preferably be a chart with two axes, one of which is a time axis. The time-variable measurements of the first group and the time-variable measurements of each measurand of the second group are detected at least partially or completely within the same time period, thereby enabling condition monitoring of the plasma generation system. The expression "partially the same time period" preferably means that the first time-variable measurements of the first group and the first time-variable measurements of at least one measurand of the second group are detected with a time offset of less than 500 ms, 100 ms, or 50 ms from each other. This allows the operator of the plasma generation system to very clearly determine the relationship between a detected quantity, such as impedance, and a detected measured quantity, such as voltage, current, and / or the phase relationship between current and voltage. The parallel visualization of various system parameters makes it immediately clear to the operator whether a permissible plasma state exists. This allows the operator to intervene very quickly in adjusting the plasma generation system. If only impedance were displayed, an undesirable plasma state would not be recognized or would not be recognized immediately. By additionally displaying at least one other measured quantity, the operator can directly obtain information regarding whether the other measured quantity and the detected impedance are compatible with the desired plasma state. This can reduce or avoid significant damage to, for example, semiconductor products manufactured by plasma processes.

[0014] In one advantageous refinement, an output device is provided. The plasma condition monitor is configured to simultaneously display the first and second charts on the same output device so that the first and second charts can be viewed by an observer at the same time. The output device may be a screen. The output device may also be a single web server that is accessed by the computer and displayed on the screen.

[0015] In one advantageous refinement, the plasma state monitor is configured to detect the first group of time-variable measured values ​​and the second group of time-variable measured values ​​of at least one measurand at a measuring point within the plasma generation system. It is particularly advantageous for both groups of time-variable measured values ​​to be detected at the same measuring point, which allows particularly good comparability.

[0016] In an advantageous refinement, the measurement point can be arranged in the region of the input terminal of the impedance matching circuit. Alternatively, the measurement point can be arranged in the region of the output terminal of the impedance matching circuit. The input or output terminal can be, for example, a plug connection provided on the housing of the impedance matching circuit. The term "in the region" particularly means that the measurement point can be arranged less than 50 cm, less than 30 cm, or less than 10 cm from the input or output terminal. The measurement point can preferably be arranged outside the housing of the impedance matching circuit. The measurement point can also be arranged inside the housing of the impedance matching circuit.

[0017] In an advantageous refinement, a measurement unit is provided, which is configured to measure a second group of time-varying measured values ​​in the form of at least one measurand, in particular a plurality of measurands. The plasma state monitor may further be configured to calculate the first group of time-varying measured values ​​from the measured time-varying measured values ​​of at least one measurand of the second group (current, voltage and / or phase relationship between current and voltage). Preferably, complex currents and complex voltages are measured, on the basis of which impedance, i.e. the first group of time-varying measured values, can be calculated.

[0018] In an advantageous refinement, the measuring unit is configured to measure a second group of time-variable measured values ​​in the form of the measurands current and voltage. In this case, in particular, complex values ​​related to the measured values ​​of current and voltage are determined. The plasma state monitor may be configured, in particular, to calculate a phase relationship from the measured current and the measured voltage. In this case, time-variable measured values ​​for the current and voltage, respectively, measured simultaneously or as close as possible in time to one another, may be processed. Preferably, a phase value is calculated for each measured value for the current and each measured value for the voltage. The three time-variable measured values ​​of the three measurands may then be plotted on a second chart. This refinement is particularly advantageous in that only the current and voltage need to be actually measured.

[0019] In an advantageous refinement, the measuring unit comprises a directional coupler, via which, for example, the power of the incident wave and the power of the outgoing wave can be measured. In this case, the power measurement of the forward output can be related to the incident wave. In this case, the power measurement of the reflected output can be related to the outgoing wave. As an alternative to a directional coupler, the measuring unit can comprise a current sensor and a voltage sensor.

[0020] In an advantageous refinement, the measurement unit comprises a digitizing device, in particular in the form of an A / D converter (analog / digital converter). The digitizing device is configured to digitize the second group of time-variable measured values ​​of at least one measurand. The digitizing device preferably has a sample rate (sampling rate) of more than 50 kHz. The sample rate may preferably be more than 0.5 MS / s (megasamples per second), including 1 MS / s, 10 MS / s, or 100 MS / s. This ensures that rapid changes in the first group of time-variable measured values ​​can also be detected. The digitizing device is in particular configured to digitize the time-variable measured values ​​of the current and the time-variable measured values ​​of the voltage simultaneously or in direct succession. In this case, the digitizing device may comprise an A / D converter with at least two channels or two A / D converters. The digitizing device may also comprise an FPGA and / or a DSP for subsequent mathematical processing of the digitized measured values.

[0021] In one advantageous refinement, a storage device is provided. The digitizing device is configured to store the second group of digitized time-varying measurement values ​​in the storage device. The storage device may be configured, for example, as a ring buffer. The plasma condition monitor in general, or the digitizing device in particular, may also be configured to store the calculated phase relationship between current and voltage in the storage device. The same may also apply to the first group of time-varying measurement values, i.e., in particular, the impedance.

[0022] In one advantageous refinement, the plasma condition monitor is configured to receive a trigger signal, particularly in the form of a pulse signal of the HF generator. The plasma condition monitor may further be configured to detect a first group of time-variable measured values ​​and a second group of time-variable measured values, including at least one measurand, when such a trigger signal is present. Preferably, the time-variable measured values ​​are detected over a defined period or continuously and are designed to be displayed on the first and second charts. The detection over a defined period or the continuous detection may also include storage in a memory device. In the case of continuous detection, the memory device may be written forward again as soon as it is completely filled. Therefore, a memory device in the form of a ring buffer is particularly advantageous. The plasma condition monitor is preferably configured to trigger on the rising edge of the pulse signal of the HF generator. Alternatively, the plasma condition monitor may trigger on the falling edge.

[0023] In one advantageous refinement, the plasma condition monitor is configured to continuously detect and display new measurements of the first and second groups on the first and second charts, thereby continuously updating the first and second charts.

[0024] In one advantageous refinement, the plasma condition monitor is configured to detect a predetermined number of measured values ​​from the first and second groups each time a trigger signal is received and to plot the measured values ​​on the first and second charts, respectively. Thus, the first and second charts can be continuously updated with the instantaneous measured values ​​from the first and second groups when the trigger signal is periodically generated. "Plotting the charts" means that the plasma condition monitor is configured to transmit the corresponding values ​​to an output device, which can then display the values ​​accordingly.

[0025] In an advantageous refinement, the number of time-variable measured values ​​in the first group corresponds to the number of time-variable measured values ​​of each measurand in the second group or deviates from the number of time-variable measured values ​​of each measurand in the second group by a maximum of 10%. Thus, for example, there may be 100 time-variable measured values ​​for impedance, and preferably 100 time-variable measured values ​​for current, 100 time-variable measured values ​​for voltage, and, for example, 100 time-variable measured values ​​for the phase relationship between current and voltage. This makes it particularly easy to compare and contrast the individual measured values.

[0026] In one advantageous refinement, the plasma state monitor is configured to plot at least some or all of the first group of time-variable measured values ​​on the first chart with different characteristics, in particular colors. In this case, the characteristics mark the time points at which the first group of time-variable measured values ​​were detected. Thus, for example, 100 time-variable measured values ​​for impedance can be plotted on the first chart in yellow or blue, depending on the time points at which the measured values ​​were detected. Color also means different gray values. Another possibility for a characteristic is, for example, plotting some or all of the time-variable measured values ​​on the first chart with different hatching. This allows the operator to directly see the order in which the first measured values ​​were picked up. This is even more applicable when the first chart on which the first group of measured values ​​is plotted is preferably a chart without a time axis, such as a Smith chart.

[0027] In one advantageous refinement, the plasma state monitor is configured to plot the first group of time-varying measurement values ​​on the first chart by a characteristic transition, in particular a color transition (which also includes grayscale), the characteristic transition being selected such that the first group of time-varying measurement values ​​detected relatively earlier are displayed darker than the first group of time-varying measurement values ​​detected relatively later, and the first group of time-varying measurement values ​​detected relatively later are displayed brighter. This can also be done in the reverse manner.

[0028] In one advantageous refinement, the first axis of the second chart is a measurement value axis and the second axis of the second chart is a time axis. Preferably, the time axis is the abscissa and the measurement value axis is the ordinate.

[0029] In an advantageous refinement, an input unit is provided and is configured to detect user input. The input unit may comprise a mouse, a keyboard and / or a touch-sensitive screen. Basically, the input unit may be any device suitable for precisely moving or positioning a pointer, in particular a mouse pointer, a cursor or a marker, on the screen.

[0030] In one advantageous refinement, the plasma condition monitor is configured to check, via the input unit, which time-varying measurement value in the first or second chart has been selected by the user. The plasma condition monitor is then configured to visually highlight, in another chart, time-varying measurement values ​​detected within the same time period as the selected time-varying measurement value. In the case where the user selects the 100th time-varying measurement value in the form of impedance in the first group, the plasma condition monitor is configured to highlight the 100th time-varying measurement value of each measurand in the second group. Thus, the plasma condition monitor can highlight the 100th time-varying measurement value for voltage, current, and / or the phase relationship between current and voltage. Conversely, in the case where the 50th time-varying measurement value for voltage in the second group has been selected, the plasma condition monitor can highlight the 50th time-varying measurement value for impedance in the first group. The visual highlighting can be achieved, for example, by enlarging each measurement value. A border can also be added.

[0031] In one advantageous refinement, the plasma condition monitor is configured to ascertain which measurement value of the first group of entered time-variable measurement values ​​has been selected by the user in the first chart via the input unit.

[0032] In one advantageous refinement, the plasma condition monitor is configured to display the first group of selected time-variable measured values ​​in the first chart in a visually emphasized manner, in particular by enlarging and / or bordering them.

[0033] In one advantageous refinement, the plasma condition monitor is configured to visually highlight time-varying measurements of each measurand of a second group that are plotted on a second chart and detected within the same time period as the selected time-varying measurements of the first group.

[0034] In one advantageous refinement, the plasma condition monitor is configured to visually highlight the time-variable measured value of each measured quantity of the second group by enlarging and / or framing it. Additionally or alternatively, the plasma condition monitor is configured to slide or fill in a corresponding marking line at the location of each measured value having a corresponding measured quantity of the second group (current, voltage and / or phase relationship), thereby visually highlighting this marking line.

[0035] In one advantageous refinement, the plasma state monitor is configured to ascertain which of the time-variable measured values ​​of each of the second group of measured quantities (current, voltage and / or phase relationship) has been selected by the user in the second chart via the input unit.

[0036] In one advantageous refinement, the plasma condition monitor is configured to confirm that the user has slid a marking line and / or a cursor on the second chart along the time axis via the input unit. Additionally or alternatively, the plasma condition monitor is configured to confirm that the user has marked a point and / or an area on the second chart via the input unit. This allows the plasma condition monitor to confirm which measurement value has been selected from the time-variable measurement values ​​of each of the second group of measured quantities on the second chart.

[0037] In one advantageous refinement, the plasma state monitoring device is configured to visually highlight (in particular by a feature) the first group of time-varying measurement values ​​that are entered in the first chart and that are detected within the same period as the second group of selected time-varying measurement values ​​of at least one measured quantity (voltage, current and / or phase relationship).

[0038] In an advantageous refinement, the plasma state monitor is configured to mark a predetermined region on a first chart. The plasma state monitor is further configured to highlight a first group of time-variable measurement values ​​that lie outside the region on the first chart. Additionally or alternatively, the plasma state monitor is configured to visually highlight a second group of time-variable measurement values ​​of at least one measurand that are detected within the same time period as the first group of time-variable measurement values ​​that lie outside the region on the second chart. This is particularly advantageous in that it allows defining an acceptable impedance range. If the first group of time-variable measurement values ​​(impedance target values) lie outside the region, the second group of time-variable measurement values ​​corresponding to the first group of time-variable measurement values ​​may also be highlighted. This allows the user to directly understand whether the desired plasma state has been achieved.

[0039] In one advantageous refinement, the plasma state monitor is configured to visually highlight the time-variable measurement values ​​of at least one measurable quantity of the second group by enlarging and / or displaying them with a border and / or by displaying them with another feature, in particular color, and / or by adding a marking immediately adjacent to each time-variable measurement value of at least one measurable quantity of the second group.

[0040] In an advantageous refinement, the plasma condition monitor is configured to output a warning if a first group of time-variable measured values ​​in the first chart is located outside the range. The warning may be acoustic and / or optical. Additionally or alternatively, the first group of time-variable measured values ​​and the corresponding time-variable measured values ​​of at least one measured quantity in the second group can be permanently stored in a storage device. In this case, a more accurate subsequent evaluation is further possible. Additionally or alternatively, the plasma condition monitor can be configured to switch off the HF generator or reduce its output power.

[0041] In an advantageous refinement, the plasma condition monitor is configured to fill in a further region on the first chart, and may further be configured to switch off or influence, for example reduce, the output power of the HF generator if one time-variable measurement value of the first group or a predetermined number of time-variable measurement values ​​of the first group are located outside the further region.

[0042] In an advantageous refinement, the plasma condition monitor is configured to define the region based on user input via the input unit, such that a user can indicate or input a region within which the first group of time-varying measurements (particularly impedance) are considered acceptable.

[0043] The plasma condition monitor may optionally have different regions for different plasma processes pre-stored in a memory device.

[0044] In one advantageous refinement, the plasma condition monitor is configured to continuously detect a first group of time-varying measurements and a second group of time-varying measurements and to enter the measurements into respective first and second charts.

[0045] In one advantageous refinement, the plasma condition monitor is configured to form the first group of time-varying measurement values ​​and the second group of time-varying measurement values ​​for at least one measurand from averaged individual measurement values, so that the time-varying measurement values ​​plotted on the first and second charts can consist of or include average values.

[0046] In an advantageous refinement, the plasma condition monitor is configured to detect a third group of time-varying measurements and preferably a fourth group of time-varying measurements. The plasma condition monitor may then be further configured to display the third group on a third chart and preferably the fourth group on a fourth chart. Preferably, the third and / or fourth groups of time-varying measurements are picked up at different measurement locations than the first and second groups of time-varying measurements. The third group of time-varying measurements may preferably be impedance values. The fourth group of time-varying measurements may preferably be at least one measurand selected from voltage, current, and / or the phase relationship between voltage and current. The third chart may be a chart without a time axis, in particular a Smith chart. The fourth chart may have two axes, one of which is a time axis. Preferably, all of the configurations described above for the first and second groups also apply to the third group, in particular to the fourth group.

[0047] The plasma generation system according to the present invention comprises the plasma state monitoring device described above. It also comprises an impedance matching circuit, an HF generator, and at least one consumer, preferably in the form of a plasma chamber. The HF generator is connected to the HF input of the impedance matching circuit. The HF output of the impedance matching circuit is connectable, in particular connected, to the at least one consumer. A first set of time-varying measured values ​​can be detected at the HF input of the impedance matching circuit. A second set of time-varying measured values ​​of at least one measured quantity can also be detected at the HF input of the impedance matching circuit.

[0048] The method according to the present invention is used to monitor a plasma generation system by means of a plasma condition monitor for connection to an impedance matching circuit, wherein the plasma condition monitor comprises: a) detecting a first set of time-varying measurements, the first set of time-varying measurements being related to time-successively picked-up impedances detectable at one of a plurality of terminals of the impedance matching circuit; b) detecting a second group of time-varying measurements of at least one measurand, wherein the at least one measurand is i) voltage, ii) current; iii) Phase relationship between current and voltage It is selected from The time-varying measurements of each measurand are taken sequentially in time. detecting a second set of time-varying measurements of at least one measurand; c) a method step of displaying the first group on a first chart and the second group on a second chart, where the first chart is a chart without a time axis, in particular a Smith chart, and the second chart has two axes, one of which is a time axis, and the time-varying measured values ​​of the first group and the time-varying measured values ​​of each measurand of the second group are detected at least partially within the same time period, thereby enabling status monitoring of the plasma generation system; The method may be configured to perform the following steps:

[0049] Various embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which like objects are provided with the same reference numerals. [Brief explanation of the drawings]

[0050] [Figure 1] 1 illustrates an embodiment of a plasma generation system including an HF generator, an impedance matching circuit, a plasma state monitor, and a plasma chamber. [Figure 2A] 1A and 1B show two different implementations for an impedance matching circuit. [Figure 2B] 1A and 1B show two different implementations for an impedance matching circuit. [Figure 3] FIG. 1 shows an embodiment for a measurement unit. [Figure 4] FIG. 1 shows first and second charts with time-varying measurements. [Figure 5] 5 shows a second chart based on FIG. 4, in which another time-varying measurement value having at least one measurand is selected. [Figure 6] FIG. 10 is a diagram showing first and second charts in which a predetermined area is filled in on the first chart. [Figure 7] 7 is a diagram based on FIG. 6 showing that a first group of multiple time-varying measurements in a first chart are located outside the region. [Figure 8] 1 is a flowchart illustrating a method for monitoring a plasma generation system. [Figure 9] 1 illustrates an embodiment of a control unit, for example, a plasma state monitor.

[0051] 1 shows a plasma generation system 100 that is used, inter alia, for surface treatment of workpieces. In addition to processing surfaces by plasma processes, the plasma generation system 100 may also be used in semiconductor manufacturing processes and for laser pumping of gas lasers, such as CO gas lasers.

[0052] The plasma generation system 100 comprises a plasma state monitor 1, an impedance matching circuit 50, an HF generator 60, and a plasma chamber 70 (consumer). The HF generator 60 is electrically connected to the impedance matching circuit 50 via a connecting cable 2a, which is preferably a first connecting cable 2a, in particular at least one first coaxial cable 2a. The first connecting cable 2a is connected to an output terminal 60a of the HF generator 60 and to an input terminal 50a of the impedance matching circuit 50. The impedance matching circuit 50 is further electrically connected to the plasma chamber 70 via a further, in particular a second, connecting cable 2b, which is preferably a second coaxial cable 2b. In most cases, the impedance matching circuit 50 is located near the plasma chamber 70, particularly at a distance of 10 cm or less, and preferably directly on the plasma chamber 70, so that the second connecting cable 2b is also configured to be correspondingly short and has only a few mechanical parts, such as plugs and / or line connectors. The second connecting cable 2b is connected to the output terminal 50b of the impedance matching circuit 50 and the input side of the plasma chamber 70. Preferably, the second connecting cable 2b is connected to an electrode inside the plasma chamber 70.

[0053] The first connecting cable 2a is longer than the second connecting cable 2b. Preferably, the first connecting cable 2a is 2, 3, 4, 5, 6, 7 or at least 8 times longer than the second connecting cable 2b.

[0054] The plasma generation system 100 suitably comprises an output device 80, which is preferably a screen. An input unit 9 is also provided. The input unit 9 is suitable for precisely moving a cursor or a marker on the output device 80. The input unit 9 may be, for example, a keyboard and / or a mouse. A touch-sensitive screen may also be considered as the input unit 9.

[0055] The plasma chamber 70 may be considered a consumer (load). Depending on the use case, for example, one or more electrodes 3 may be provided in the plasma chamber 70, at least one of which is connected to the second connecting cable 2b. In Figure 1, a plasma 4 is shown as a dot inside the plasma chamber 70.

[0056] Preferably, the plasma generation system 100 further comprises an optical device 90. The optical device 90 is preferably disposed within the plasma chamber 70 and configured to visually detect the plasma 4 and thus the plasma state. The optical device 90 may be, for example, an optical conductor, such as glass fiber. While cameras may be used, they are often omitted for cost reasons. Furthermore, lenses and other protective glasses may quickly become fogged by the plasma 4.

[0057] The following provides a detailed description of the plasma state monitoring device 1. The plasma state monitoring device 1 is preferably at least one processor (for example, a microcontroller) and / or a programmable logic device, for example, an FPGA (Field Programmable Gate Array).

[0058] In one embodiment, the plasma state monitor 1 may be used to control, for example, the impedance matching circuit 50. Thus, the plasma state monitor 1 may be configured to control the impedance matching circuit 50 so that the impedance matching circuit 50 produces a specified impedance target value.

[0059] 1, the input terminal 50a of the impedance matching circuit 50 is directly attached to the housing of the impedance matching circuit 50. Essentially, the input terminal 50a is also in contact with the end of the first connecting cable 2a where the first connecting cable 2a is connected to the HF generator 60. This allows the cable impedance of the first connecting cable 2a to be taken into account as well.

[0060] In accordance with the present invention, plasma state monitor 1 is used to detect a first group of time-varying measurements 30, where first group of time-varying measurements 30 is related to an impedance detectable at input terminal 50a or output terminal 50b of impedance match circuit 50. Additionally, plasma state monitor 1 may be used to detect a second group of time-varying measurements 31 of at least one measurand, where the at least one measurand is selected from voltage 32, current 33, and phase relationship 34 between voltage 32 and current 33. As will be described in more detail below starting with FIG. 4, plasma state monitor 1 may be further configured to display the first group on a first chart 35, where first chart 35 may preferably be a Smith chart. The plasma state monitoring device 1 may further be configured to display the second group on a second chart 36, in which case the second chart 36 may particularly have two axes 36a, 36b, in which case one axis 36a may preferably be a time axis.

[0061] The plasma state monitor 1 comprises at least one measuring unit 5. A time-varying measured value 31 having at least one measurand 32, 33, 34 of a second group may be measured by the at least one measuring unit 5.

[0062] At least one measuring unit 5 is preferably arranged between the first connecting cable 2a and the impedance matching circuit 50. In this case, a further measuring unit 6 is arranged between the impedance matching circuit 50 and the load 70.

[0063] 2A and 2B show different embodiments of the impedance matching circuit 50. In Fig. 2A, the impedance matching circuit 50 is L-shaped. In Fig. 2B, the impedance matching circuit 50 is T-shaped.

[0064] In FIG. 2A, the input terminal 50a of the impedance matching circuit 50 is connected to the first coil 10 (first inductance) and the second coil 11 (second inductance). The first and second coils 10, 11 are connected with their first terminals to a common node, which is the input terminal 50a of the impedance matching circuit 50. The first coil 10 is connected to ground via a first capacitor 12 (first capacitor). The second coil 11 is connected to the output terminal 50b via a second capacitor 13 (second capacitor). The first and second capacitors 12, 13 are adjustable components, particularly in the form of rotary capacitors whose capacitance can be changed via stepper motors. Alternatively, solid-state switches can be used to switch the capacitors on and off as quickly as possible. In particular, the plate spacing of the first and second capacitors 12, 13 can be changed. In one embodiment, the plasma state monitoring device 1 can be configured to control the respective stepper motors accordingly. Basically, the control may be performed by a control device. The capacitances of the first and second capacitors 12, 13 may be adjusted independently of each other. Preferably, the impedance matching circuit 50 does not have any additional components. Naturally, the positions of the first coil 10 and the first capacitor 12 may be interchanged. In this case, the first capacitor 12 is arranged at the input terminal 50a of the impedance matching circuit 50, and the first coil 10 is arranged at ground potential. Additionally or alternatively, the positions of the second coil 11 and the second capacitor 13 may be interchanged. In this case, the second capacitor 13 is arranged at the input terminal 50a of the impedance matching circuit 50, and the second coil 11 is arranged at ground potential.

[0065] In FIG. 2B, the input terminal 50a of the impedance matching circuit 50 is connected to the first capacitor 12 (first capacitor). The first capacitor 12 is connected to both the first coil 10 (first inductance) and the second coil 11 (second inductance). This is done via a common node to which the first capacitor 12 and the first and second coils 10, 11 are connected. The first coil 10 is also connected to ground potential. The second coil 11 is connected (series circuit) to the second capacitor 13 (second capacitor). The second capacitor 13 is connected to the output terminal 50b of the impedance matching circuit 50. The positions of the second coil 11 and the second capacitor 13 may be interchanged. In this case, the second capacitor 13 is connected to the common node, and the second coil 11 is connected to the output terminal 50b of the impedance matching circuit 50. Preferably, the impedance matching circuit 50 does not have any additional components.

[0066] 3 shows an example of a possible construction of the measuring unit 5 or a further measuring unit 6. In this example, the measuring units 5, 6 are configured to contactlessly measure voltage and contactlessly measure current.

[0067] For this purpose, each measuring unit 5 , 6 comprises a current sensor 15 and a voltage sensor 16 .

[0068] However, preferably, the phase relationship between current and voltage is also measured so that the impedance and hence the first group of time-varying measurements 30 can be calculated.

[0069] The current sensor 15 of the measuring unit 5 and / or of the further measuring unit 6 is formed as a coil, in particular in the form of a Rogowski coil.

[0070] Both ends of the coil are preferably connected to each other via a shunt resistor 17. The voltage dropped across the shunt resistor 17 may be digitized by a first A / D converter 18. The first A / D converter 18 may be part of the digitizing device.

[0071] The voltage sensor 16 of the measuring unit 5 and / or the further measuring unit 6 is preferably configured as a capacitive voltage divider. The first capacitor 19 is formed by a conductive ring 19. Alternatively, a conductive cylinder may be used. The corresponding first or second connecting cable 2a, 2b is guided through the conductive ring 19. The second capacitor 20 of the voltage sensor 16 configured as a voltage divider is connected to ground potential. A second A / D converter 21 is connected in parallel to the second capacitor 20 and is configured to detect and digitize the voltage drop across the second capacitor 20. The second A / D converter 21 may be part of the digitizing device.

[0072] In principle, the measuring unit 5 and the further measuring unit 6 may be arranged or configured on one (common) printed circuit board. The first capacitor 19 may be formed by a coating on the first and the opposite second side of the printed circuit board. In this case, the coatings on the first and second sides are electrically connected to each other by an interlayer connection. The first or second connecting cable 2a, 2b is guided through an opening in the printed circuit board. The second capacitor 20 may be formed by a separate component.

[0073] The current sensor 15 in the form of a coil, in particular a Rogowski coil, is located further away from the first or second connecting cable 2a, 2b than the first capacitor 19. The coil can likewise be formed on the same printed circuit board with a corresponding coating and interconnections. The coil for measuring the current and the first capacitor for measuring the voltage preferably run in a common plane.

[0074] The shunt resistor 17 may also be arranged on the printed circuit board. The same applies to the first and / or second A / D converters (analog / digital converters) 18, 21.

[0075] The measurement unit 5 and / or the further measurement unit 6 may be formed as a directional coupler.

[0076] 4 shows a first chart 35 and a second chart 36 for the measurement unit 5. The measurement unit 5 is preferably arranged at the input terminal 50a of the impedance matching circuit 50. In the case where a further measurement unit 6 is used, which is preferably arranged at the output terminal 50b of the impedance matching circuit 50, the first chart 35 and the second chart 26 for the further measurement unit 6 may be selected via the corresponding tabs.

[0077] As explained, the measurement unit 5 allows the measurement of the voltage 32 and the current 33. The plasma state monitor 1 is configured to determine the phase relationship 34 between the voltage 32 and the current 33 from the voltage 32 and at the current 33. Preferably, a complex value associated with the complex impedance can be determined in this way. This complex value is a measurand for each of the second group of time-varying measurements 31. The measurement unit 5 is configured to successively measure a number of time-varying measurements 31 for the voltage 32. The number of time-varying measurements 31 for the voltage 32 is plotted on a second chart 36. The second axis 36b is a time axis for representing the 1000 successively taken time-varying measurements 31 for each of the second group of measurands. The first axis 36a shows the corresponding values ​​for each measurand. Basically, the different measurands, i.e., the voltage 32, the current 33, and the phase relationship 34, can be normalized. In the illustrated FIG. 4, a voltage 32 of 200V and a current 33 of 7A are located at the same point on the first axis 36a.

[0078] The plasma state monitor 1 is particularly configured to continuously detect a second group of time-varying measurements 31 via the measurement unit 5. The displayed measurements 31 for the voltage 32 may, for example, comprise a number of averaged voltage values. The same may apply to the current 33 and the phase relationship 34.

[0079] The plasma state monitoring device 1 is further preferably configured to enter each newly detected or newly averaged measurement value 31 for each measurand of the second group in a second chart 36. If there are a predetermined number of measurement values ​​31 for each measurand, for example, 1000, it is also possible to enter new time-variable measurement values ​​31 having each measurand of the second group in the second chart 36.

[0080] The plasma state monitor 1 is also configured to calculate a first group of time-varying measured values ​​30 from a second group of time-varying measured values ​​31. In this way, the impedance can be calculated from the (complex) voltage 32 and the (complex) current 33. It is obvious that only values ​​for voltage 32 and current 33 determined by the measuring unit 5 within the same time period are processed together. In this case, the plasma state monitor 1 is configured to enter the first group of time-varying measured values ​​30 into a first chart 35.

[0081] The number of time-varying measurements 30 in the first group plotted in the first chart 35 and the number of time-varying measurements 31 for each measurand in the second group plotted in the second chart 36 are preferably the same. Thus, in the illustrated embodiment, there are preferably 1000 time-varying measurements 30 in the first group and 1000 time-varying measurements 31 each for voltage 32, current 33, and phase relationship 34. After first chart 35 and second chart 36 are displayed together on output device 80, it is very easy for the user to form a relationship between the displayed impedance and the displayed progression for voltage 32, current 33, and phase relationship 34.

[0082] The plasma state monitoring device 1 preferably further comprises a memory device 8 in which a first group of time-varying measurement values ​​30 and / or a second group of time-varying measurement values ​​31 for individual measured quantities may be stored.

[0083] Preferably, the plasma state monitor 1 is configured to receive a trigger signal, which may be an edge of a pulse signal from the HF generator 60. After detecting the trigger signal, a first group of a predetermined number of time-variable measurement values ​​30 and a second group of time-variable measurement values ​​31 having each of the measured quantities are detected and displayed on the output device 80 as a first or second chart 35, 36.

[0084] 4 also shows that the plasma condition monitor 1 is configured to plot at least some or all of the first group of time-varying measurements 30 on a first chart 35 with different characteristics. Preferably, the different characteristics are different colors. However, different hatching may also be used. The characteristics represent the time points at which the first group of time-varying measurements 31 were detected. In FIG. 4, the older time-varying measurements 31 in the first group are shown brighter than the newer time-varying measurements 31 in the first group.

[0085] 4 also shows a first legend 37, which is preferably written on the second chart 36. The first legend 37 is shown along the second axis 36b and includes a summary of the characteristics. The first legend 37 therefore varies from light to dark along the second axis 36b (time axis). This allows a particularly easy assignment of each time-varying measured value 30 of the first group to each time-varying measured value 31 of each measurand of the second group from the first chart 35 to the second chart 36. The user immediately knows which time-varying measured value 30 of the first group corresponds to which time-varying measured value 31 of the second group.

[0086] 4 also preferably shows a second legend 38 indicating the different features and, for each feature, information which of the first group of time-varying measurements 31 they correspond to. In this example, the brightest features are used for the oldest 100 time-varying measurements 31. In this example, the darkest features are used for the latest 100 time-varying measurements 31.

[0087] The plasma state monitor 1 is configured to check, via the input unit 9, which of the first or second group of time-variable measured values ​​30, 31 in the first or second chart 35, 26 the user has selected. In FIG. 4, a pointer 39 is shown, particularly a mouse pointer 39. This pointer 39 can be moved by the user. This can be done via the input unit 9. In FIG. 4, the user has clicked, for example, on the second chart 36. In the illustrated configuration, the plasma state monitor 1 is configured to draw a cursor 40 and / or a marking line 41, which is positioned across each measured value. In this example, the cursor 40 and marking line 41 mark the time at which approximately the 300th time-variable measured value 31 of the second group is displayed. The marking line 41 visually highlights the corresponding measured value of the second group of time-variable measured values ​​31. The marking line 41 preferably extends parallel to the first axis 36a. It is also possible to display the measured quantity (voltage 32, current 33 and / or phase relationship 34) at the cursor 40 in a second chart 36, enlarged and / or in a different color.

[0088] At the same time, the plasma condition monitor 1 is configured to visually highlight the first group of time-varying measurements 30 that are entered in the first chart 35 and that are detected within the same time period as the second group of selected time-varying measurements 31. In FIG. 4, the corresponding time-varying measurements 30 are highlighted by borders.

[0089] Basically, the user can click on the first chart 35 and select one of the time-variable measurement values ​​30 entered in this first chart 35. In this case, the plasma state monitoring device 1 is configured to visually highlight the measurement quantity of the corresponding time-variable measurement value 31 in the second chart 36. This can be done, for example, by sliding or fading in the marking line 41. Additionally or alternatively, the cursor 40 can also be slid or faded in to a corresponding point on the time axis (second axis 36b). Additionally or alternatively, each measurement quantity can be enlarged and / or displayed in a different color in the second chart 36.

[0090] FIG. 5 shows a user marking other time-varying measurement values ​​31 of the measurands, voltage 32, current 33, and phase relationship 34. This may be done by sliding the cursor 40 and / or marking line 41 based on FIG. 4. Thus, the user may, for example, click on the cursor 40 and / or marking line 41 and slide it along the time axis (second axis 36b). Such movement is indicated by the arrow direction in FIG. 4. For this purpose, the user may use a mouse and / or keyboard. Alternatively, the user may jump to another time point on the time axis (second axis 36b) by simple keyboard input. Alternatively, other time-varying measurement values ​​31, 30 may be selected in the second and first charts 36, 35 by clicking on another time point in the second chart 36. The plasma state monitoring device 1 is configured to visually highlight the first group of other time-varying measurement values ​​30 in the first chart 30. The other time-varying measurement 30 is taken within the same time period as the correspondingly selected time-varying measurement 31 in the second chart 36 .

[0091] 6 shows that the plasma condition monitor 1 is configured to fill in a region 42 on the first chart 35. The region 42 can be filled in by moving the mouse. The corresponding corner points can be set, for example, by clicking. The region 42 can also be loaded from the memory device 8. Depending on the plasma process, different regions 42 can be defined. In this case, the impedance located inside the region 42 is considered to be an allowed impedance.

[0092] The plasma state monitor 1 is configured to visually highlight the first group of time-variable measurement values ​​30 located outside the region 42 in the first chart 35. This is shown in FIG. 7. The visual highlighting may be achieved by selecting a different color, size, and / or border for the first group of time-variable measurement values ​​30 located outside the region 42. It is also possible to fill in an additional region 43 in which the first group of time-variable measurement values ​​30 located outside the region 42 are located. In this case, one or more such additional regions 43 may be present.

[0093] In this regard, the plasma state monitor 1 may be configured to visually highlight in the second chart 36 the time-variable measurements 31 of each measurand that were taken within the same time period as the first group of time-variable measurements 30 in the first chart 35 that are located outside the region 42. In FIG. 7, this visual highlighting is achieved by a corresponding bar 44. The bar 44 extends parallel to the second axis 36b (time axis) and extends across the region in which the second group of time-variable measurements 31 are located, with the corresponding first group of time-variable measurements 30 located outside the region 42. In this case, there may be one or more such bars 44.

[0094] In the case where a first group of time-variable measurements 30 is located outside the region 42, the plasma state monitor 1 may be configured to store the time-variable measurements 30 or all of the first group of time-variable measurements 30 picked up within a defined time window in the memory device 8. In this regard, it is preferred that a second group of time-variable measurements 31 of at least one measurand is also stored in the memory device 8.

[0095] The plasma condition monitor 1 is also preferably configured to output a warning message 45, in this case an optical warning message on the output device 80. Additionally or alternatively, an acoustic warning message may also be present. The plasma condition monitor 1 may also be configured to switch off the HF generator 60 or to affect the output power of the HF generator 60, in particular to reduce the output power.

[0096] 8 shows a flowchart illustrating a method for monitoring a plasma generation system 100 using the plasma state monitor 1. In a first method step S1, a first group of time-varying measured values ​​30 is detected, where the first group of time-varying measured values ​​30 is related to time-sequentially picked-up impedances detectable at the input terminal 50a or the output terminal 50b of the impedance matching circuit 50. In a second method step S2, a second group of time-varying measured values ​​31 of at least one measurand (voltage 32, current 33, and phase relationship 34) is detected, where the time-varying measured values ​​31 of each measurand are time-sequentially picked-up. In a third method step S3, the first group is displayed on a first chart 35, where the first chart 35 is a chart without a time axis, in particular a Smith chart. The second group is displayed on a second chart 36, which in this case has two axes 36a, 36b, one of which, 36b, is a time axis. The time-varying measured values ​​30 of the first group and the time-varying measured values ​​31 of each measurand of the second group are at least partially detected within the same time period. This allows the user to particularly easily monitor the status of the plasma generation system 100.

[0097] FIG. 9 illustrates a schematic diagram of an embodiment of a control unit 600, hereinafter referred to as a "control system" 600, suitable for executing instructions for implementing one or more aspects of the methods in the apparatus of the present invention. For example, control system 600 may be used to implement the aforementioned methods and / or plasma condition monitor 1 according to the present invention and / or described herein. The components illustrated in FIG. 9 are intended to be exemplary and do not limit the scope of use or functionality of hardware, software, firmware, embedded logic components, or combinations of such components, for implementing specific embodiments of the present invention. Some or all of the illustrated components may be part of control system 600.

[0098] The control system 600, in this embodiment, comprises at least one processor 601, such as a central processing unit (CPU, DSP) or a programmable logic device (PLD, FPGA). The control system 600 may also comprise a main memory 603 and a data memory 608, both of which communicate with each other and with other components via a bus 640. The bus 640 may connect a display 632, one or more input devices 633, one or more output devices 634, one or more storage devices 635, and various storage media 636 to each other and to one or more devices of the processor 601, the main memory 603, and the data memory 608. All of these elements may be coupled to the bus 640 directly or via one or more interfaces 622, 623, 624, 625, 626 or adapters.

[0099] The control system 600 may have any suitable physical form, including, but not limited to, one or more integrated circuits (ICs), a printed circuit board (PCB), a mobile handheld device, a laptop or notebook computer, a distributed computer system, a computational grid, or a server. The processor 601 or central processing unit (CPU) optionally has a cache memory unit 602 for temporary local storage of instructions, data, or processor addresses. The processor 601 is configured to facilitate the execution of instructions stored on at least one storage medium.

[0100] The memories 603, 608 may include a variety of different components, including, but not limited to, direct access memory components such as RAM 604, particularly static RAM "SRAM," dynamic RAM "DRAM," etc., read-only components such as ROM 605, and any combination thereof. The ROM 605 may function to communicate data and instructions unidirectionally to one or more processors 601, and the RAM 604 may function to communicate data and instructions bidirectionally to one or more processors 601.

[0101] The storage device 8 may be formed as a part of such memories 603 and 608, or may be formed as such memories 603 and 608.

[0102] Read-only memory 608 is optionally bidirectionally connected to one or more processors 601 by memory control unit 607. Read-only memory 608 provides additional storage capacity. Memory 608 may be used to store operating system 609, programs 610, data 611, applications 612, application programs, and the like. Often, but not always, memory 608 is a secondary storage medium (e.g., a hard disk) that is slower than primary memory (e.g., memory 603). Memory 608 may include, for example, magnetic, optical, or transistorized storage devices, solid-state storage devices (e.g., flash-based systems), or a combination of any of the above elements. Information memory 608 may, in appropriate cases, be integrated within memory 603 as virtual memory.

[0103] The bus 640 connects the various subsystems together. The bus 640 may be any of several types of bus structures, such as a memory bus, a memory controller, a peripheral bus, a local bus, and any combination thereof, using various bus architectures. Information and data may be displayed via the display 632. Examples of the display 632 include, but are not limited to, a liquid crystal display (LCD), an organic liquid crystal display (OLED), a cathode ray tube (CRT), a plasma display, and any combination thereof. The display 632 may be connected to the processor 601, the memory 603, 608, the input device 633, and other components via the bus 640.

[0104] The output device 80 may be formed as part of such a display 632 or may be formed as such a display 632 .

[0105] The bus 640 may connect all the aforementioned components to an external network, e.g., the cloud 630, by means of a network interface 620. This network may be, for example, a LAN, a WLAN, etc. The network may comprise connections to other storage media, servers, printers, display devices, etc. The network may have access to telecommunications devices and the Internet. The bus 640 may connect all the aforementioned components to a graphics controller 621 and a graphics interface 622, which may be connected to at least one display 632.

[0106] The bus 640 may connect all of the aforementioned components to an input interface 623 that may be connected to at least one input device 633. The input device may include, for example, a keypad, keyboard, mouse, pen, touch screen, etc.

[0107] The input unit 9 may be formed as a part of such an input device 633 or may be formed as such an input device 633 .

[0108] The bus 640 may connect all of the aforementioned components to an output interface 624 which may be connected to at least one output device 634. The output device 634 may include a light emitting display, an LED display, a display such as an LCD, an OLED, etc., or an interface to such a device.

[0109] A bus 640 may connect all the aforementioned components to a memory access interface 625 which is connectable to at least one storage device 635. The bus 640 may connect all the aforementioned components to another memory access interface 626 which is connectable to at least one storage medium 636. The storage device 635 or storage medium 636 may be, for example, a solid-state, magnetic or optical memory, and may in particular comprise a non-volatile memory. The storage medium may be separated from the control system during operation of the control system without loss of data.

[0110] Display 632, input device 633, output device 634, storage device 635, and storage medium 636 may each be located external to control system 600 or may be integrated within control system 600. These elements may be connected to control system 600 via a connection to the internet or another network interface.

[0111] The invention is not limited to the described embodiments: within the scope of the invention, all features described and / or shown can be combined with one another in any combination.

Claims

1. A plasma condition monitor (1) for connection to an impedance matching circuit (50) for a plasma generation system (100), comprising: a) detecting a first set of time-varying measurements (30), the first set of time-varying measurements (30) being related to time-sequentially picked-up impedances detectable at one of a plurality of terminals (50a, 50b) of the impedance matching circuit (50); b) detecting a second group of time-varying measurements (31) of at least one measurand, said at least one measurand being: i) voltage (32); ii) current (33); iii) The phase relationship (34) between the voltage (32) and the current (33) It is selected from the time-variable measurements (31) of each of the measurands are taken successively in time; Detecting a second group of time-varying measurements (31) of at least one measurand; c) displaying the first group on a first chart (35) and the second group on a second chart (36), wherein the first chart (35) is a chart without a time axis, in particular a Smith chart, and the second chart (36) has two axes (36a, 36b), one of which (36b) is a time axis, and the time-variable measured values ​​(30) of the first group and the time-variable measured values ​​(32) of each measured quantity of the second group are detected at least partially within the same period, thereby enabling status monitoring of the plasma generation system (100). The plasma state monitoring device (1) is configured as follows.

2. an output device (80) is provided, The plasma state monitoring device (1) is configured to simultaneously display the first chart (35) and the second chart (36), in particular on the same output device (80).

2. A plasma state monitoring device (1) according to claim 1.

3. The plasma state monitoring device (1) according to claim 1 or 2, characterized in that the plasma state monitoring device (1) is configured to detect the first group of time-variable measured values ​​(30) and the second group of time-variable measured values ​​(31) of the at least one measured quantity at a measurement point inside the plasma generation system (100).

4. the measurement point can be located in the region of the input terminal (50a) of the impedance matching circuit (50), or The measurement point can be located in the region of the output terminal (50b) of the impedance matching circuit (50).

4. The plasma state monitoring device (1) according to claim 3.

5. - a measuring unit (5) is provided, the measuring unit (5) is adapted to measure at least one of the measurands, in particular the second group of time-variable measured values ​​(31) in the form of a plurality of measurands, The plasma state monitor (1) is particularly adapted to calculate the first group of time-variable measured values ​​(30) from the measured time-variable measured values ​​(31) of the at least one measurand of the second group.

5. A plasma state monitoring device (1) according to any one of claims 1 to 4.

6. - said measuring unit (5) is adapted to measure said second group of said time-variable measured values ​​(31) in the form of said measurands voltage (32) and current (33); The plasma state monitor (1) is particularly adapted to calculate the phase relationship (34) from the voltage (32) and the current (33).

6. A plasma state monitoring device (1) according to claim 5.

7. - said measuring unit (5) comprises a directional coupler, or - said measuring unit (5) comprises a current sensor (15) and a voltage sensor (16); 7. A plasma state monitoring device (1) according to claim 5 or 6, characterized in that:

8. The plasma state monitoring device (1) according to any one of claims 5 to 7, characterized in that the measurement unit comprises a digitizing device configured to digitize the second group of time-variable measurement values ​​(31), the digitizing device having a sampling rate of more than 50 kHz, 500 kHz, 2 MHz, 5 MHz, 50 MHz or more than 100 MHz.

9. A plasma state monitoring device (1) according to any one of claims 1 to 8, characterized in that a memory device (8) is provided and the digitizing device is configured to store the second group of digitized time-variable measurement values ​​(31) in the memory device (8).

10. The plasma state monitor (1) according to any one of claims 1 to 9, characterized in that the plasma state monitor (1) is configured to receive a trigger signal, in particular in the form of a pulse signal of an HF generator (60), and to detect the first group of time-variable measured values ​​(30) and the second group of time-variable measured values ​​(31) of at least one measured quantity when the trigger signal is present.

11. The plasma state monitoring device (1) according to claim 10, characterized in that the plasma state monitoring device (1) is configured to detect a predetermined number of measurement values ​​(30) of the first group and a predetermined number of measurement values ​​(31) of the second group each time a trigger signal is received and to enter these values ​​into the first and second charts (35, 36), respectively.

12. - A plasma state monitoring device (1) according to any one of claims 1 to 11, characterized in that the number of the time-variable measured values ​​(30) of the first group corresponds to the number of the time-variable measured values ​​(31) of each measured quantity of the second group or deviates from the number of the time-variable measured values ​​(31) of each measured quantity of the second group by a maximum of 10%.

13. The plasma state monitoring device (1) according to any one of claims 1 to 12, characterized in that the plasma state monitoring device (1) is configured to plot at least some or all of the first group of time-variable measurement values ​​(30) on the first chart (35) with different characteristics, in particular colors, which indicate the time at which the first group of time-variable measurement values ​​(30) were detected.

14. the plasma state monitor (1) is configured to plot the first group of time-variable measured values ​​(30) on the first chart (35) by a characteristic transition, in particular a color transition, which characteristic transition comprises: a) the first group of time-varying measurements (30) detected relatively early are displayed darkly and the first group of time-varying measurements (30) detected relatively later are displayed brightly; or b) The first group of time-varying measurement values ​​(30) detected relatively early are displayed brightly, and the first group of time-varying measurement values ​​(30) detected relatively late are displayed darkly.

14. The plasma state monitor (1) according to claim 13, characterized in that the plasma state monitor (1) is selected as follows:

15. A plasma state monitoring device (1) according to any one of claims 1 to 14, characterized in that the first axis (36a) of the second chart (36) is a measurement value axis and the second axis (36b) of the second chart is a time axis.

16. The plasma state monitor (1) according to any one of claims 1 to 15, characterized in that an input unit (9) is provided, which is configured to detect a user input.

17. the plasma state monitor (1) is configured to ascertain, via the input unit (9), which time-variable measurement value (30, 31) in the first or second chart (35, 36) has been selected by a user; The plasma state monitor (1) is configured to visually highlight in another chart (36, 35) time-variable measurements (31, 30) detected within the same time period as the selected time-variable measurements (30, 31).

17. The plasma state monitor (1) according to claim 16, characterized in that

18. The plasma state monitoring device (1) according to claim 16 or 17, characterized in that the plasma state monitoring device (1) is configured to check which measurement value of the first group of entered time-variable measurement values ​​(30) has been selected by the user in the first chart (35) via the input unit (9).

19. The plasma state monitoring device (1) according to claim 17 or 18, characterized in that the plasma state monitoring device (1) is configured to visually highlight the first group of selected time-variable measurement values ​​(30) in the first chart (35), in particular by enlarging and / or framing them.

20. The plasma state monitoring device (1) according to any one of claims 17 to 19, characterized in that the plasma state monitoring device (1) is configured to visually highlight the time-variable measurement values ​​(31) of each of the second group of measured quantities that are entered in the second chart (36) and detected within the same period as the selected time-variable measurement values ​​(30) of the first group.

21. the plasma state monitor (1) measures the time-variable measured values ​​(31) of each of the second group of measurands, a) Displaying by enlarging and / or bordering, and / or b) marking lines (41) located across each measurement volume; The plasma state monitor (1) according to claim 20, characterized in that it is configured to be visually emphasized by

22. The plasma state monitoring device (1) according to any one of claims 16 to 21, characterized in that the plasma state monitoring device (1) is configured to confirm which of the time-variable measured values ​​(31) containing each measured value of the second group has been selected in the second chart (36) via the input unit (9).

23. The plasma state monitoring device (1) a) confirming that the user has slid the marking line (41) and / or the cursor (40) in the second chart (36) along the time axis (36b) via the input unit (9); and / or b) confirming that the user has marked points and / or areas on the second chart (36) via the input unit (9); It is structured as follows: This allows the plasma state monitoring device (1) to confirm which of the time-variable measurement values ​​(31) in which each measurement quantity of the second group is entered has been selected.

23. The plasma state monitor (1) according to claim 22, characterized in that

24. The plasma state monitoring device (1) according to claim 22 or 23, characterized in that the plasma state monitoring device (1) is configured to visually highlight the first group of time-variable measurement values ​​(30) that are entered in the first chart (35) and detected within the same period as the selected time-variable measurement values ​​(31) of the at least one measured quantity of the second group.

25. - the plasma state monitor (1) is configured to fill in a predetermined area (42) on the first chart (35); the plasma state monitor (1) is configured to highlight in the first chart (35) the first group of time-variable measurements (30) that are located outside the region (42); and / or The plasma state monitoring device (1) according to any one of claims 1 to 24, characterized in that the plasma state monitoring device (1) is configured to visually highlight in the second chart (36) the time-variable measurement values ​​(31) of the second group of the at least one measured quantity detected within the same period as the time-variable measurement values ​​(30) of the first group located outside the region (42).

26. the plasma state monitor (1) measures the time-varying measurements (31) of the at least one measurand of the second group, a) displayed by enlarging and / or bordering; b) by other characteristics, in particular by color; c) adding a marking immediately adjacent to each of said time-variable measurements (31) of each measurand of said second group; The plasma state monitor (1) according to claim 25, characterized in that it is configured to visually emphasize by

27. The plasma state monitor (1) according to claim 25 or 26, characterized in that the plasma state monitor (1) is configured to output a warning if the first group of time-variable measured values ​​(30) in the first chart (35) are located outside the region (42).

28. The plasma state monitor (1) according to any one of claims 16, 25 to 27, characterized in that the plasma state monitor (1) is configured to define the region (42) by user input via an input unit (9).

29. The plasma state monitor (1) according to any one of claims 1 to 28, characterized in that the plasma state monitor (1) is configured to continuously detect the first group of time-variable measured values ​​(30) and the second group of time-variable measured values ​​(31) and to enter them into the first and second charts (35, 36), respectively.

30. The plasma state monitor (1) according to any one of claims 1 to 29, characterized in that the plasma state monitor (1) is configured to detect a third group of time-variable measured values ​​and a fourth group of time-variable measured values, and the plasma state monitor (1) is further configured to display the third group on a third chart and the fourth group on a fourth chart.

31. A plasma generation system (100) having a plasma state monitor (1) according to any one of claims 1 to 30, an impedance matching circuit (50) is provided, - an HF generator (60) and at least one consumer, preferably in the form of a plasma chamber (70), are provided; said HF generator (60) is connected to the HF input (50a) of said impedance matching circuit (50); the HF output (50b) of said impedance matching circuit (50) is connectable, in particular connected, to said at least one consumer; the first group of time-varying measurements (30) is detected at the HF input (50a) of the impedance matching circuit (50), the second group of time-varying measured values ​​(31) of the at least one measurand are detected at the HF input (50a) of the impedance matching circuit (50); A plasma generation system (100).

32. 1. A method for monitoring a plasma generation system (100) by a plasma condition monitor (1) for connection to an impedance matching circuit (50), the plasma condition monitor (1) comprising: a) a method step (S) of detecting a first group of time-varying measurements (30) １ ) comprising a method step (S) of detecting a first group of time-varying measurements (30) related to time-sequentially picked-up impedances detectable at one of the terminals (50a, 50b) of the impedance matching circuit (50). １ )and, b) a method step (S) of detecting a second group of time-varying measured values ​​(31) of at least one measurand ２ ) wherein the at least one measurand is i) voltage (32); ii) current (33); iii) The phase relationship (34) between the voltage (32) and the current (33) It is selected from the time-variable measurements (31) of each of the measurands are taken successively in time; A method step (S) of detecting a second group of time-varying measured values ​​(31) of at least one measurand. ２ )and, c) a method step (S) of displaying said first group on a first chart (35) and said second group on a second chart (36). ３ ) wherein the first chart (35) is a chart without a time axis, in particular a Smith chart, and the second chart (36) has two axes (36a, 36b), one of which (36b) is a time axis, and the time-variable measured values ​​(30) of the first group and the time-variable measured values ​​(31) of each measured quantity of the second group are detected at least partially within the same period, thereby enabling a state monitoring of the plasma generation system (100), a method step (S) of displaying the first group on the first chart (35) and the second group on the second chart (36). ３ )and The method is configured to perform the following.

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