Energy supply assembly, plasma generation device and method for controlling a plurality of plasma processes

Abstract

The invention relates to an energy supply assembly (10) for a plurality of plasma generators (17a, 17b, 17n), which are each designed in particular to excite a gas, at a remote location from a plasma processing process, to form a gas plasma, having: f) a power input terminal (2) for connecting a supply power (7), g) a data terminal (13) for connection to a controller (4), h) wherein the energy supply assembly is designed to convert power from the power input terminal (2) into an AC voltage output using an AC voltage generator stage (6), i) wherein the energy supply assembly is designed, by means of a data terminal (13), - to determine that the AC voltage power can be provided to a first load (9a) as a first AC voltage power and to a second load (9b), located remotely from the first, as a second AC voltage power, wherein in particular the two loads cannot be energised at the same time, and - to be controllable in such a way that the first and the second AC voltage power sets different characteristics at least for one or more of the follow control values: - output current, - output voltage, - output frequency, - output power, - output curve of current and / or voltage, and wherein the energy supply assembly (10) is designed to emit a control signal for an impedance adaptation device (15a, 15b, 15n) associated with one of the AC voltage powers.

Description

[0001] Power supply arrangement, plasma generation device and method for controlling multiple plasma processes

[0002] The invention relates to a power supply arrangement for a plurality of plasma generators, a plasma generation device with such a power supply arrangement and a method for controlling a plurality of plasma processes with such a power supply arrangement.

[0003] The plasma generation devices can, in particular, be designed to excite a gas into a gas plasma at a location remote from the plasma processing site. Such plasma generators are also known as "remote plasma sources." Such a plasma generator is described, for example, in WO2014 / 016335 A1 or US2007 / 0103092 A1.

[0004] The power supply assembly is often offered as a unit with the plasma generator, i.e., the plasma chamber in which the gas plasma is generated. When processing and / or manufacturing materials in a processing chamber, several such spatially separated gas plasma generators are often required. These can be used, for example, to excite gas, with the excited gas being used in the processing. They can also be used, for example, to excite gas, with the gas exiting the processing chamber being excited.

[0005] Multiple units consisting of a power supply arrangement and a plasma generator are costly, and the risk of one of the units failing increases with the number of such units. The object of the present invention is to provide a power supply arrangement, a plasma generation device, and / or a method for controlling multiple plasma processes that overcomes these disadvantages.

[0006] This object is achieved by a power supply arrangement according to claim 1, a plasma generating device according to claim 11 and / or a method according to claim 15. Advantageous embodiments are disclosed in the subclaims and / or in the description.

[0007] Accordingly, in one aspect of solving the problem, a power supply arrangement for a plurality of plasma generators is disclosed, each of which is in particular designed to excite a gas spatially remote from a plasma processing station to form a gas plasma, comprising: a) a power input connection for connecting a supply power, b) a data connection for connecting to a controller, c) wherein the power supply arrangement is designed to convert power from the power input connection into an AC voltage power with an AC voltage generator stage, d) wherein the power supply arrangement is configured to:

[0008] • ensure that the AC power can be supplied to a first load as a first AC power and to a second load remote from the first as a second AC power, in particular the two loads are not supplied simultaneously, and

[0009] • to be controllable in such a way that the first and the second AC voltage output can have different characteristics at least for one or more of the following control values:

[0010] • Output current,

[0011] • Output voltage,

[0012] • Output frequency,

[0013] • Output power,

[0014] • Output curve of current and / or voltage, and e) wherein the power supply arrangement is configured to output a control signal for an impedance matching device associated with one of the AC voltage supplies.

[0015] 'Characteristics for tax values' means concrete predefined values ​​for one or more of the tax values.

[0016] For example, for the first AC power, the output power can be 3 kW, the output frequency 30 kHz, and the output current waveform can be rectangular pulses with a pulse-to-pause ratio of 70% and a repetition rate of 100 Hz. For example, for the second AC power, the output power can be 4 kW, the output frequency 35 kHz, and the output current waveform can be rectangular pulses with a pulse-to-pause ratio of 70% and a repetition rate of 100 Hz, just like the first AC power.

[0017] As a control value characteristic, an extreme value, i.e. a value that should not be exceeded, can also be specified additionally or alternatively for one or more of the control values, e.g. a maximum current of 10 A or a minimum power of 100 W.

[0018] The first and second AC voltage outputs differ in at least one of these control value characteristics.

[0019] In one aspect, the tax value characteristics differ in at least two of these tax value characteristics, more preferably in at least three.

[0020] An impedance matching device is a device that can convert an output impedance, which is connected at its output, for example, towards the load, in such a way that a predeterminable impedance can be set at its input. There are many types of impedance matching devices. Descriptions of such devices can be found, for example, in WO 2016 / 177766 A1, WO 2017 / 072087 A1, WO 2019 / 185423 A1, WO 2021 / 255250 A1. They often have both variable and non-variable reactances, i.e. inductances and capacitances. Impedance-changing elements such as transmission lines, resistors, transformers, baluns, and couplers are also known. The variable elements can be electronically controlled and variable. For example, vacuum capacitors can be changed using motors, or reactances can be switched on and off.

[0021] An AC voltage generator stage is an electronic circuit designed to convert a first electrical output, e.g., direct current, into alternating current. AC power is characterized by the fact that the voltage and current periodically change their sign. The voltage and current can exhibit different waveforms. The voltage and / or current can, for example, be approximately sinusoidal or approximately rectangular. In the latter case, one often speaks of a bipolar voltage generator stage. Such an AC voltage generator stage frequently comprises a bridge circuit composed of switching elements, in particular transistors, preferably MOSFETs or IGBTs.

[0022] In one aspect, the power supply arrangement further comprises: a) a first power output terminal for supplying the first AC power to the first load, b) a second power output terminal for supplying the second AC power to the second load remote from the first load.

[0023] In one aspect, the power supply arrangement further comprises a switching unit, which is in particular part of the power supply arrangement, wherein the power supply arrangement is configured to be controllable via the data connection such that the switching unit can connect the AC voltage power generated by the AC voltage generator stage to one of the power output connections and / or loads, and in doing so can adjust the different characteristics of the respective AC voltage power. The switching unit here refers to an electronic component that is configured to pass an electrical signal in a first setting from a first of its contacts to a second of its contacts and to hinder, in particular prevent, this passing through in a second setting.Advantageously, the switching unit can transmit the electrical signal from the first contact to a third contact in the second setting, and can impede, in particular prevent, this transmission in the first setting. A switching unit can be a transistor, in particular a power transistor, advantageously an IGBT or MOSFET. Other embodiments such as PIN diodes or electromechanical switches are also conceivable.

[0024] In one aspect, a power supply arrangement is disclosed for a plurality of plasma generators, each of which is in particular designed to excite a gas into a gas plasma at a location remote from plasma processing, comprising: a) a power input connection for connecting a supply power, b) a data connection for connecting to a controller, which can in particular be arranged inside or outside the power supply arrangement, c) wherein the power supply arrangement is designed to convert power from the power input connection with an AC voltage generator stage into a first and a second AC voltage power, d) a first power output connection for supplying the first AC voltage power to a first load, e) a second power output connection for supplying the second AC voltage power to a second load remote from the first load, f) wherein the power supply arrangement is configured,to be controllable via the data connection in such a way that the first and second AC voltage outputs can have different characteristics at least for one or more of the following control values:

[0025] • Output current,

[0026] • Output voltage,

[0027] • Output frequency,

[0028] • Output power,

[0029] • Output curve of current and / or voltage, and g) wherein the power supply arrangement is configured to output a control signal, in particular a plurality of control signals, for one, in particular for one impedance matching device each, which is assigned to one of the AC voltage powers.

[0030] This allows multiple plasma processes or multiple plasma generators to be operated with a single power supply arrangement. This increases reliability and significantly reduces costs. By providing one or more control signals for the impedance matching device(s) assigned to the plasma generator(s), these can also be individually adapted to the respective AC voltage output of the respective plasma generator.

[0031] In one aspect, the power supply arrangement can comprise one, in particular a plurality of, switching units. The power supply arrangement is configured to ensure, via the data connection, that the switching unit(s) connect the AC voltage power generated by the AC voltage generator stage to one of the power output terminals. The power supply arrangement can further be configured to adjust the different characteristics of the respective AC voltage power. Thus, one power supply arrangement can supply the individual plasma generators with one AC voltage generator stage. This saves considerable costs.

[0032] In one aspect, one, in particular several, switching units can be arranged outside the power supply arrangement, wherein the power supply arrangement is configured to be able to control them via the data connection in such a way that the switching unit(s) connect the AC voltage power generated by the AC voltage generator stage to one of the power output connections and can thereby adjust the different characteristics of the respective AC voltage power. Thus, one power supply arrangement can supply the individual plasma generators with one AC voltage generator stage. This saves considerable costs and is also very flexibly adaptable to the respective application.

[0033] A connecting line for transmitting the AC power, 1 m or more in length, in particular 3 m or more in length, can be arranged between the impedance matching device(s) and a power supply arrangement. This makes the use of the power supply arrangement particularly flexible and therefore cost-effective.

[0034] In one aspect, the power supply arrangement can be designed such that the total power ratings of all AC voltages that can be delivered, in particular output, to the loads are greater than the power rating of the AC voltage generator stage. Thus, an AC voltage generator stage with a relatively low power rating can be used to supply multiple plasma generators, each of which individually requires no more power rating than the AC voltage generator stage can provide, but which, taken together, would require a significantly higher power rating. This works because the plasma generators can be supplied sequentially, i.e., never all at the same time.

[0035] In one aspect, the power supply arrangement may be configured to output different drive signals for a plurality of impedance matching devices, each associated with one of the AC voltage supplies.

[0036] In one aspect, the power supply arrangement can be configured to receive one and / or more plasma signals, in particular one and / or more plasma voltages, from one of the plasma generators.

[0037] A plasma signal is a signal that is detected, e.g., measured, in or in the immediate vicinity of the generated plasma. This can, for example, be a signal measured on the winding side of the excitation transformer used to excite the plasma. It can also be a measured light signal, an electromagnetic wave in the non-visible range, e.g., UV or X-ray range, an electric or magnetic field, a noise, vibration, or ultrasonic signal. Particularly preferred is a plasma voltage, which is measurable in particular on or at the winding side of the excitation transformer.

[0038] In one aspect, the power supply arrangement can be configured to assign one or more of the transmitted plasma signals to the characteristics of the AC voltage powers, in particular to adjust the characteristics of the AC voltage powers depending on the respective plasma signals. This allows all plasma generators to be individually controlled very precisely and reliably by a power supply arrangement.

[0039] In one aspect, the power supply arrangement can be configured to receive one and / or more voltages and / or currents from a current and / or voltage sensor arranged and configured to measure the current and / or voltage of the AC power. In particular, the power supply arrangement can further be configured to assign one or more of the transmitted voltages and / or currents to the characteristics of the AC power, in particular to adjust the characteristics of the AC power depending on the respective voltages and / or currents.

[0040] This allows all plasma generators to be controlled individually and very precisely by a power supply arrangement.

[0041] In one aspect, the power supply arrangement can be configured to receive one and / or more voltages and / or currents from a current and / or voltage sensor arranged and configured to measure current and / or voltage in or at an impedance matching device. In particular, the power supply arrangement can further be configured to assign one or more of the transmitted voltages and / or currents to the characteristics of the AC voltage outputs, in particular to adjust the characteristics of the AC voltage outputs depending on the respective voltages and / or currents. This allows all plasma generators to be individually controlled very precisely and reliably by one power supply arrangement.

[0042] In one aspect, the control system can be integrated into the power supply assembly. This enables further cost savings and allows all plasma generators to be individually controlled very precisely and reliably from a single power supply assembly.

[0043] In one aspect, a plasma generating device may comprise: a) a power supply arrangement as described above and b) a plurality of plasma generators which are connected to the power supply arrangement, in particular to the power output terminals thereof, and which can each be operated according to the control value characteristics.

[0044] In one aspect, the plasma generation device can have a first transformer arrangement, in particular a transformer arrangement for each plasma generator, for coupling the AC power to the load, wherein the transformer arrangement is preferably arranged in the immediate vicinity of the load. This enables further cost savings and thus all plasma generators can be controlled very precisely and reliably individually by a power supply arrangement. The term "transformer arrangement" refers to an electrical inductive component that has a first winding and a second winding and can transfer an AC power applied to the first winding (primary winding) to the second winding (secondary winding). There are many different construction options for such a transformer arrangement; the windings can, for example,They can be wound on a magnetic core, arranged planarly on a circuit board, or represent a combination of both designs, with further variations also possible. A possible second winding can, for example, also be the generated plasma itself. An example of such a transformer arrangement is disclosed in US Pat. No. 9,368,328 B2 as "transformer 35."

[0045] In one aspect, the plasma generation device can comprise an impedance matching device, in particular a plurality of impedance matching devices, wherein preferably one impedance matching device is arranged between each power supply arrangement and the plasma generator. This enables further cost savings and thus allows all plasma generators to be individually controlled very precisely and reliably by one power supply arrangement.

[0046] In one aspect, the plasma generation device can have a connecting line of 1 m or more, in particular 3 m or more, between the impedance matching device and the power supply arrangement. This makes the plasma generation device particularly flexible in use.

[0047] In one aspect, the plasma generation device can be used to post-treat a gas exiting a plasma processing device. In one aspect, the plasma generation device can be used to pre-treat a gas introduced into a plasma processing device. In particular, the plasma generation device can comprise both plasma generators.

[0048] In one aspect, the impedance matching device(s) may comprise one or more of the following components: a) inductors, b) capacitors, wherein the inductors and / or capacitors may be adjustable, controlled by a signal connected to the data port. This enables further cost savings and allows all plasma generators to be individually controlled very precisely and reliably by a power supply arrangement.

[0049] In one aspect, one, or in particular several, of the plasma generators can be designed to excite a gas into a gas plasma at a location remote from a plasma processing site. Thus, they can be advantageously used as so-called remote plasma sources.

[0050] In one aspect, a method for controlling a plurality of plasma processes, each of which is in particular designed to excite a gas into a gas plasma at a location remote from a plasma processing operation, may be provided with the following steps: a) supplying a power supply arrangement with electrical supply power, b) converting the electrical supply power into a first AC voltage and supplying the first AC voltage to a first load of a first plasma generator, c) converting the electrical supply power into a second AC voltage and supplying the second AC voltage to a second load of a second plasma generator, wherein in particular steps b) and c) do not occur at the same time, d) controlling the AC voltages according to different characteristics at one or more of the following control values:

[0051] • Output current,

[0052] • Output voltage,

[0053] • Output frequency,

[0054] • Output power,

[0055] • Output waveform of current and / or voltage, and e) generation and output of a control signal for an impedance matching device associated with one of the AC voltage outputs.

[0056] In this way, multiple plasma processes or multiple plasma generators can be operated with one power supply arrangement. This increases reliability and significantly reduces costs. By providing one or more control signals for the impedance matching device(s) assigned to the plasma generator(s), these can also be individually adapted to the respective AC voltage output at the respective plasma generator. All of the previously described features of the device(s) can also be used to further develop the method.

[0057] In one aspect, the method may supply a plurality of AC power supplies to a respective load of an associated plasma generator, wherein the AC power supplies are not supplied to the loads simultaneously and each load is operated with its associated control characteristic and, in particular, generate and output a plurality of control signals for impedance matching devices associated with one of the AC power supplies.

[0058] In one aspect, the first and / or second AC power can each be transmitted via a connecting line 1 m or more long, in particular 3 m or more long. This makes the method very flexible and therefore cost-effective.

[0059] In one aspect, a computer program product can be provided for controlling a previously described power supply arrangement, in particular for features g) and f), and / or for method steps d) and e).

[0060] In one aspect, a non-volatile storage medium may be provided with instructions stored thereon for execution by a processor or for configuring a programmable logic device for carrying out the control of a previously described power supply arrangement, in particular for features g) and f), and / or for method steps d) and e).

[0061] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, based on the figures of the drawing, which illustrate details essential to the invention, and from the claims. The features shown therein are not necessarily to scale and are presented in such a way that the special features of the invention can be clearly seen. The various features can be implemented individually or in combinations in variants of the invention.

[0062] Embodiments of the invention are shown in the schematic drawing and explained in the following description.

[0063] They show:

[0064] Fig. 1 shows a first plasma generating device with a first power supply arrangement;

[0065] Fig. 2 shows a second plasma generating device with a second power supply arrangement;

[0066] Fig. 3 Time diagrams of the output power at a first power output terminal;

[0067] Fig. 4 Time diagrams of the output power at a second power output terminal;

[0068] Fig. 5 shows a rectifier bridge circuit;

[0069] Fig. 6 a bipolar power converter bridge;

[0070] Fig. 7 shows a first embodiment of a switching unit;

[0071] Fig. 8 shows a second embodiment of a switching unit;

[0072] Fig. 9 is a flow chart for a process flow.

[0073] Fig. 1 shows a first plasma generation device 1 with a first power supply arrangement 10 and, by way of example, three plasma generators 17a, 17b, ... 17n. The plasma generation units 17a, 17b, 17n each comprise a load 9a, 9b, ... 9n, which is each connected to a power output terminal 3a, 3b, ... 3n via an impedance matching device 15a, 15b, ... 15n. For the sake of clarity, only three plasma generation units 17a, 17b, 17n, each with an impedance matching device 15a, 15b, ... 15n, were shown. Of course, there can also be more than three such devices. This is indicated, for example, by the three dots between the power output terminals 3b and 3n. At the power output terminals 3a, 3b, ... 3n there are measuring sensors CTla, CTlb, ... CTln, e.g. for current and / or voltage measurements.The signals detected there are fed via a data bus 16 to a data connection 13, which is connected to the controller 4. Sensors for frequency, phase, power, especially forward and / or reflected power, are also possible here.

[0074] The loads 9a, 9b, ... 9n here are, in particular, so-called "remote plasma sources" (RPS). These are special plasma generators 17a, 1b, ... 17n that are designed to excite a gas into a gas plasma at a location remote from a plasma processing site. Transformer arrangements T1a, T1b, ... T1n are advantageously used for plasma excitation of this type. On the secondary side of these transformer arrangements facing the plasma, several plasma signals CT4a, CT4b, CT4n can be detected, in particular one and / or more plasma voltages. These can also be transmitted to the data connection 13 via the data bus 16.

[0075] At least one plasma generator 17a is connected to a power output terminal 3a of the power supply arrangement 10 via an impedance matching device 15a. In the present exemplary embodiment, all plasma generators 17a, 17b, ... 17n are each connected to a power output terminal 3a, 3b, ... 3n of the power supply arrangement 10 via an impedance matching device 15a, 15b, ... 15n.

[0076] The impedance matching devices 15a, 15b, ... 15n comprise, for example, several switchable inductors Lia, L2a, L3a, Llb, L2b, L3b, Lin, L2n, L3n. These are provided, in particular, in parallel with the connecting lines between the plasma generator 17a, 17b, ... 17n and the power output terminal 3a, 3b, ... 3n of the power supply arrangement 10. This allows the impedance matching to be carried out very quickly in stages. The current through these inductors Lia, L2a, L3a, Llb, L2b, L3b, Lin, L2n, L3n can be measured using measuring sensors CT2a, CT2b, ... CT2n. These measured signals can also be fed to the data bus 16.

[0077] The impedance matching devices 15a, 15b, ... 15n each have, for example, a capacitance Cla, Clb, ... Cln. This can, in particular, be an adjustable capacitance, e.g., by means of an adjustable vacuum capacitor. The capacitances can, as shown here, be provided in series between the plasma generator 17a, 17b, ... 17n and the power output terminal 3a, 3b, ... 3n of the power supply arrangement 10. This allows for very reliable impedance matching.

[0078] A further inductance L4a, L4b, L4n can also be provided, as shown here, in series between the plasma generator 17a, 17b, ... 17n and the power output terminal 3a, 3b, ... 3n of the power supply arrangement 10. This can be realized at least partially by the leakage inductance of the transformer arrangements T1a, T1b, Tin.

[0079] At the output or within the impedance matching devices 15a, 15b, ... 15n, additional sensors CT4a, CT4b, CT4n can be provided, which are suitable for measuring current, voltage, phase, impedance, and / or power. These measured signals can also be fed to the data bus 16.

[0080] The power supply arrangement 10 comprises a power input terminal 2 for connection to an electrical supply power 7.

[0081] The power supply arrangement 10 further comprises a first power converter stage 5 configured to convert the input power at the power input terminal 2 into an intermediate power, preferably into a DC link power 12. Several first power converter stages 5 for converting the input power at the power input terminal 2 into an intermediate power, preferably into an intermediate power 12, may also be part of the power supply arrangement 10 and preferably connected in parallel.

[0082] The power supply arrangement 10 further comprises, in particular, an AC voltage generator stage 6, which is connected downstream of the first power converter stage 5 and is configured to convert the intermediate power from the first power converter stage into a bipolar output power. Between the power converter stage 5 and the further AC voltage generator stage 6, an energy storage element, such as an inductor or a capacitor, can be implemented, in particular, for smoothing the current or voltage.

[0083] The power supply arrangement 10 further comprises a plurality of switching units 8a, 8b, . . . 8n arranged here, for example, between the AC voltage generator stage 6 and the power output terminals 3a, 3b, . . 3n.

[0084] One or more switching units can also be arranged outside the power supply arrangement 10, in particular in the vicinity, immediately before or after, or internally in one of the impedance matching devices 15a, 15b, ... 15n (not shown). Since the data bus 16 already has a connection outside the power supply arrangement 10, the switching units can also be controlled outside the power supply arrangement 10.

[0085] The power supply arrangement 10 further comprises a controller 4 which is designed to adjust the power supply arrangement 10 to deliver the bipolar output power to the power output terminals 3a, 3b, 3n using at least one of the following control parameters: power, voltage, current, excitation frequency or threshold value for protective measures, so that at least one of the control parameters at a first power output terminal 3a differs from the corresponding control parameter at another power output terminal 3b, . . . 3n.

[0086] In this example, the controller 4 has connections to the power converter stages 5 and the switching units 8a, 8b, . . . 8n. Some of these connections can be optional, such as the connection to the power converter stage 5. The controller 4 can be configured to switch a switching unit 8a, 8b, . . . 8n from a closed state to an open state only when the absolute value of the current through the switch is less than one ampere, preferably zero. This has the advantage that switching units 8a, 8b, . . . 8n can be used that do not have to be designed for switching higher currents. This makes the device even more cost-effective. The plasma generation device 1 can comprise a controller external to the power supply arrangement 10. This external controller can also control the plasma process in the loads 9a, 9b, . . . 9n.

[0087] The controller 4 can also be configured to switch a switching unit 8a, 8b, . . . 8n from an open state to a closed state only when the absolute value of the voltage across the open switch is less than 20 volts, preferably zero. This has the advantage of allowing the use of a switching unit that does not need to be designed to switch higher voltages. This makes the device even more cost-effective.

[0088] The power supply arrangement 10 is capable of converting an electrical input power into a bipolar output power and supplying this output power to at least two independent loads 9a, 9b, ... 9n, the power supply arrangement comprising:

[0089] - a power input terminal 2 for connection to an electrical supply 7,

[0090] - at least two, preferably more than two, power output terminals 31, 3b, ... 3n, each for connection to one of the loads 9a, 9b, ... 9n,

[0091] - a controller 4 configured to control the power supply arrangement to deliver the bipolar output power to the power output terminals using at least one of the following control parameters:

[0092] Power, voltage, current, excitation frequency, or threshold for protective measures by obtaining a complete set of setpoints for the parameters of the power output terminals, wherein the controller 4 is in particular further adapted to calculate whether the power supply arrangement is capable of delivering each setpoint to each power output terminal and, if so, to calculate a sequence of pulses for power delivery to the power output terminals to provide the power for the plasma process.

[0093] In a further aspect, the controller 4 can be configured to control the power supply arrangement 10 such that at least one of the control parameters at a first power output terminal 3a, 3b, ... 3n is different from the corresponding control parameter of another power output terminal. This allows a single power supply arrangement with a given maximum power to be used instead of several.

[0094] In this disclosure, bipolar output power refers to an output power with an alternating current where the current changes direction at a frequency that can excite the plasma process (excitation frequency). Control parameters can be measured values ​​or setpoints of the aforementioned parameters.

[0095] The measured and setpoint values ​​can be absolute values, instantaneous values, effective values, such as an RMS (root mean square) value, or extreme values ​​(e.g. maximum or minimum values).

[0096] The input power can be electrical power supplied from an AC grid. It can also be a DC power line (AC: alternating current; DC: direct current).

[0097] The controller 4 may consist of a microcontroller on which a software program runs when the power supply arrangement is in operation.

[0098] The controller 4 can have multiple interfaces, such as data connections to external components, monitors, keyboards, which can be connected wired or wirelessly.

[0099] The controller can have a computing section and a memory section. The memory section can be divided for different purposes, e.g., monitor memory, RAM, data memory, or program memory.

[0100] A threshold can be a value used to detect plasma ignition or collapse. It can be set differently for each output port and change over time.

[0101] The bipolar output power may be a power value of more than 1 kW, preferably more than 10 kW. The bipolar output power may have a frequency of more than 1 kHz, preferably more than 10 kHz, preferably more than 50 kHz.

[0102] In a further aspect, the power supply arrangement 10 may comprise a power converter stage 5 which is designed to convert the input power into an intermediate power, preferably into a DC link power.

[0103] In a further aspect, the power supply arrangement may comprise at least one AC voltage generator stage 6, which is designed to convert the intermediate power from the first power converter stage 5 into the bipolar output power.

[0104] In a further aspect, the power supply arrangement 10 may comprise at least two further AC voltage generator stages 6a, 6b,... 6n, which are designed to convert the intermediate power from the first power converter stage 5 into a plurality of bipolar output power signals and to supply these powers to the power output terminals.

[0105] In a further aspect, the controller 4 can be designed to control the power converter stage 5 and / or AC voltage generator stages 6, 6a, 6b, ... 6n such that, during use, the power supply arrangement 10 delivers a first power output signal, in particular at a first power output terminal for a first time frame, at a first time and a second power output signal, in particular at a second power output terminal for a second time frame, at a second time, wherein the first time is different from the second time and / or the first time frame is different from the second time frame.

[0106] In a further aspect, the power supply arrangement may comprise one or more switching units 8a, 8b, ... 8n between the power converter stage(s) and the power output terminals 3a, 3b, ... 3n. In a further aspect, the switching units 8a, 8b, ... 8n are controlled by the controller 4.

[0107] In a further aspect, the controller 4 can be designed to control the power converter stage 5, and / or AC voltage generator stages 6, 6a, 6b, ... 6n and / or the switching units 8a, 8b, ... 8n such that the power supply arrangement, during operation, supplies a first output power signal at the first power output terminal for a first time frame at a first time and a second power signal at the second power output terminal for a second time frame at a second time, wherein the first time is different from the second time and / or the first time frame is different from the second time frame.

[0108] In a further aspect, the switching units 8a, 8b, ... 8n are designed such that they can conduct current in two opposite directions.

[0109] In a further aspect, the controller 4 may be configured to switch a switching unit 8a, 8b, ... 8n from a closed state to an open state only when the magnitude of the current through the switch is less than one ampere, preferably zero.

[0110] In a further aspect, the controller 4 may be configured to activate a switching unit from an open state to a closed state only when the magnitude of the voltage across the open switch is less than 20 volts, preferably zero.

[0111] In a further aspect, at least one of the power converter stage 5 and / or AC voltage generator stages 6, 6a, 6b, ... 6n comprises a bridge circuit, preferably a full bridge circuit.

[0112] A bridge circuit can be a rectifier bridge circuit capable of rectifying AC power. A bridge circuit can be a switching bridge circuit capable of generating bipolar output power.

[0113] In another aspect, the power supply assembly 10 may include a housing that encloses all other parts of the unit.

[0114] In another aspect, the input terminals can be connected directly to the control cabinet.

[0115] In a further aspect, the power output terminals 3a, 3b, ... 3n may be directly connected to the housing.

[0116] In a further aspect, a plasma processing device 1 may comprise:

[0117] - two, preferably more than two, loads 9a, 9b, ... 9n,

[0118] - an electrical power supply arrangement 10 as described above.

[0119] Each load 9a, 9b, ... 9n can be connected to one of the power output terminals 3a, 3b, ... 3n of the power supply arrangement.

[0120] The object of the invention is also achieved by a controller 4 for controlling a plurality of plasma processes in a plurality of loads by converting an electrical input power into a bipolar output power and delivering this output power to the loads, wherein the controller is designed to control a power supply arrangement for delivering the bipolar output power to the power outputs, using at least one of the following control parameters:

[0121] Power, voltage, current, excitation frequency or threshold for protective measures by obtaining a complete set of setpoints for the parameters of the power output terminals, wherein the controller is further configured to calculate whether the power supply arrangement is capable of delivering each setpoint to each power output terminal and, if so, to calculate a sequence of pulses for power delivery to the power output terminals to provide power for the plasma process.

[0122] In a further embodiment of the controller 4, the complete set of setpoints can be provided by an interface connection, preferably from a controller external to the power supply arrangement, wherein the external controller also controls the plasma process in the plasma chambers.

[0123] In a further embodiment of the controller 4, the calculation may include determining the maximum target power at all times and comparing it with the maximum power of the power supply arrangement.

[0124] In a further embodiment of the controller 4, an error message may be given if the result of the calculation shows that there is no possibility of supplying the power of the setpoint to each power output terminal.

[0125] In a further embodiment of the controller 4, one or more possibilities to change the process with a new set of setpoints may be given in case the result of the calculation is that there is no possibility of power delivery of the setpoint to each power output terminal.

[0126] In a further embodiment of the controller 4, the controller can control the power supply arrangement such that at least one control parameter of a first plasma chamber is different from a corresponding control parameter of another plasma chamber.

[0127] The plasma processes in the various loads 9a, 9b, ... 9n can be different or identical. They can be identical but in a different state, i.e., the plasma process in a first load is, for example, in an initial gas excitation state, while the plasma process in another load is initially in the gas conversion state. Bipolar transistors 81, 82, 91, 92 can be used for the switching units 8a, 8b, ... 8n, as shown in Figs. 7 and 8. These bipolar transistors are significantly less expensive than MOSFETs. The bipolar transistors 81, 82, 91, 92 can be IGBTs, which are low-cost transistors that conduct high currents with low energy loss. This makes the power supply arrangement 1 even more economical, since no expensive cooling devices are required.

[0128] In Fig. 7 and 8, additional diodes 83, 84, 93, 94 are connected to conduct current in the desired direction and to block current in the undesired direction.

[0129] The power converter stage 5 may include a rectifier circuit, preferably a rectifier bridge circuit 50, as shown in Fig. 5. Four rectifier diodes 52, 53, 54, 55 are connected in a bridge circuit to rectify the alternating current from the first terminal 51 to the second terminal 56. At least one of the following elements may additionally be connected to the first terminal 51: a filter, an overvoltage protection circuit, or an overcurrent protection circuit. A filter may consist of one or more energy-storing elements such as capacitors or inductors.

[0130] The AC voltage generator stage 6 may comprise a switching bridge, preferably a full-bridge circuit 60, as shown in Fig. 6. This full-bridge circuit 60 comprises four switching units 62, 63, 64, 65. These switching units may be transistors, bipolar transistors, IGBTs, and particularly preferably MOSFETs. A filter circuit with one or more energy storage elements such as a capacitor 61 and / or inductors 66, 67 may be connected to the input of the second AC voltage generator stage 6. The full-bridge circuit 60 may further comprise several diodes as shown.

[0131] The power supply arrangement 10 may comprise a housing that encloses all other parts of the power supply arrangement 10. It may be made of metal and thus offer good protection against electromagnetic interference. The power input terminal 2 may be directly connected to the housing. The power output terminals 3a, 3b, . . . 3n may also be directly connected to the housing 10. In a power supply arrangement 10, the combined current-carrying capacity of all switching units 8a, 8b, . . . 8n may be higher than the maximum current-delivery capacity of the power converter stage 5.

[0132] Fig. 2 shows a second plasma generation device 1' with a second power supply arrangement 10'. The second power supply arrangement 10' is an alternative to the first power supply arrangement 10, as shown in Fig. 1. All elements that correspond to those in Fig. 1 have the same reference numerals. The power supply arrangement 10' shown in Fig. 2 contains, instead of the switching unit(s) 8a, 8b, . . . 8n, a plurality of power converter stages 6a, 6b, . . . 6n, which are designed to convert the DC intermediate power 12 from the first power converter stage 5 into a plurality of bipolar output power signals and to supply these power signals to the power output terminals 3a, 3b, . . . 3n. All power converter stages 6a, 6b, . . . 6n are controllable by the controller 4. All power converter stages 6a, 6b, . . 6n can consist of full bridges 60 and filter elements 61, 66, 67, as shown in Fig. 6.

[0133] Measuring sensors CT1a, CT1b, CTln for measuring voltage, current, frequency, or power can be connected to the power output terminals 3a, 3b, ... 3n. The power supply arrangement 1 can also include several power converter stages 5, which are designed to convert the input power at the power input terminal 2 into an intermediate power, preferably into DC link power 12, and are preferably connected in parallel.

[0134] The connecting lines for transmitting the AC power between the power supply arrangement 10 and one or more impedance matching devices 15a, 15b, ... 15n can be 1 m or more in length, in particular 3 m or more in length. These cables can in particular have a predetermined impedance, which can preferably be a real impedance without an imaginary part and can particularly preferably be in the range of 45 to 80 Ω. In such cases, one or more impedance matching devices 15a, 15b, ... 15n and the control signal(s) for them are particularly helpful. Fig. 3 shows a time diagram of the output power at a first power output terminal 3a. The t axis is the time axis, and the S30 axis can be, for example, the voltage, current, or power axis. While the S30 axis represents the actual values ​​of these parameters, the S31 axis represents an effective value of these parameters. In the first diagram of Fig.3 with the axis S30, the bipolar signal is shown in two signal sequences 31, 32. The signal sequence 31 has an excitation frequency with a period of 2 / 11 of the time window, which begins at time T31 and ends at time T32. The signal sequence 32 has an excitation frequency with a period of 2 / 11 of the time window, which begins at time T33 and ends at time T34. In this example, these frequencies are the same, but it is possible that these frequencies could be different. In the second diagram of Fig. 3 with the axis S31, the RMS values ​​of the two signal sequences 31, 32 are shown in two signal sequences 33, 34. Two threshold lines 35, 36 are also drawn in this diagram. They can be used to detect a plasma breakdown, for example in the case of a plasma breakdown. B. of an arc or ignition of the plasma, when the effective value of one of the parameters power, voltage or current exceeds such a threshold.

[0135] In a power supply arrangement 1', the current carrying capacity of all power converter stages 6a, 6b,... 6n together can be higher than the maximum current delivery capacities of all power converter stages 5 together.

[0136] Fig. 4 shows a timing diagram of the output power at another power output terminal 3b, 3n. The t axis is the time axis, and the S40 axis can be, for example, the voltage, current, or power axis. While the S40 axis represents the actual values ​​of these parameters, the S41 axis represents an effective value of these parameters. In the first diagram of Fig. 4 with the S40 axis, the bipolar signal is represented by two signal sequences 41, 42. The signal sequence 41 has an excitation frequency with a period of 1 / 7 of the time window, which begins at time T41 and ends at time T42. At time T43, a second pulse 44 begins, the end of which is not visible in this diagram. At time T43, the second signal sequence 42 begins. From this example, it can be seen that the frequencies of signal sequences 31, 32 and signal sequences 41, 42 are different, with the frequency of signal sequences 41, 42 being higher than the frequency of signal sequences 31, 32.

[0137] In addition to or alternatively to excitation with different frequencies, the power, voltage, current or threshold value for protective measures may also be different between two different power output terminals 3a, 3b, . 3n or at two different loads 9a, 9b, . . 9n.

[0138] This diagram also shows two threshold lines 45 and 46. They can be used to detect a plasma breakdown, such as an arc or plasma ignition, when the effective value of one of the parameters power, voltage, or current exceeds such a threshold.

[0139] The invention operates by controlling multiple plasma processes in the multiple loads 9a, 9b, ... 9n with the controller 4 by converting an electrical input power into a bipolar output power, as shown in the signal sequences 31, 32, 41, 42, and delivering this output power to the loads 9a, 9b, ... 9n. The controller 4 controls the power supply arrangement 1 to deliver the bipolar output power to the power output terminals 3a, 3b, ... 3n using at least one of the following control parameters: power, voltage, current, excitation frequency, or threshold for protective measures, by obtaining a complete set of setpoint values ​​for the parameters of the power output terminals 3a, 3b, ... 3n. The controller 4 is further configured to calculate whether the power supply arrangement 1, 1' is capable of delivering each setpoint value to each power output terminal 3a, 3b, ...3n, and, if applicable, to calculate a sequence of pulses for power delivery to the power output terminals 3a, 3b, ... 3n to provide the power for the plasma process.

[0140] For this purpose, the controller 4 can control the power converter stages 6, 6a, 6b, . . . 6n or the switching units 8a, 8b, . . . 8n such that the unit 1, during operation, at a first time T31, supplies a first output power signal to the first power output terminal 3a for a first time frame T31-T32 and at a second time T41, supplies a second power signal to a second power output terminal 3b, . . 3n for a second time frame T41-T42, wherein the first time T31, T41 differs from the second time T32, T42 and / or the first time frame T31-T32 differs from the second time frame T41-T42.

[0141] A plasma generation device 1, as in Fig. 1, and a plasma generation device 1' as in Fig. 2 impose restrictions on the simultaneous operation of more than one power output terminal 3a, 3b, ... 3n. For plasma generation devices 1' as in Fig. 2, these restrictions arise when, for example, the total power or processing capacity of the output stage connected to an input stage exceeds the power or instantaneous capacity of this input stage, so that the maximum output power cannot be provided simultaneously at all power output terminals 3a, 3b, ... 3n. For plasma generation devices as in Fig. 1, the maximum output power can only be provided at one power output terminal 3a, 3b, ... 3n, or part of the power can be provided at more than one power output terminal 3a, 3b, ... 3n.In case independent operation of different plasma processes is necessary, this can be achieved as long as the total duty cycle of all processes plus the time for switching between outputs is less than the total cycle time.

[0142] These constraints define ranges in which operation is possible and ranges in which operation is not possible within the space of the aforementioned parameters. For each demand to provide power to an output or set of power output terminals 3a, 3b, ... 3n, the position within or outside the range in which operation is possible must be determined. This results in the need for scheduling control.

[0143] A sequence controller 14 may be part of the controller 4. Its algorithm determines the output power to be delivered for each of the power output terminals for each demand on the power supply arrangement 1 or for a demand to change one or more parameters, whether the demand is within the possible operating range. For a process as shown in Figs. 3 and 4, in which power is delivered to the power output terminals 3a, 3b, ... 3n, with the various power output terminals 3a, 3b, ... 3n being operated at different power levels, with different pulse duty cycles, or different pulse frequencies, the sequence controller ensures that:

[0144] - the pulse frequencies are integer multiples of each other to avoid pulse overlaps (for plasma devices 1' as in Fig. 2)

[0145] - for overlapping pulses, the total power and current required does not exceed the maximum possible (for plasma devices l' as in Fig. 2)

[0146] - if possible maxima are exceeded for a limited period in the cycle, a pattern without this exceedance is found (for plasma devices l' as in Fig. 2)

[0147] - the sum of the pulses in time points plus the time for switching between outputs is less than the smallest pulse cycle frequency (for plasma devices 1 as in Fig. 1)

[0148] - a newly requested output pulse pattern in a specific output is activated at a correct time to fit into existing pulse patterns of other outputs (for plasma devices 1 as in Fig. 1)

[0149] - Total average power limits and currents are not exceeded

[0150] - A warning is issued to the user if the requested sequence is outside the possible range

[0151] - A possible modified sequence is recommended to the user.

[0152] Fig. 9 shows a flowchart for a process sequence. The process can be particularly distinguished by its suitability for controlling multiple plasma processes, each of which is designed to excite a gas into a gas plasma at a location remote from a plasma processing site, i.e., for controlling multiple so-called "Remote Plasma Sources" (RPS), with the following steps:

[0153] Step 71: Supplying a power supply arrangement 10 with electrical supply power,

[0154] Step 72: Converting the electrical supply power into a first AC voltage and supplying the first AC voltage to a first load 9a of a first plasma generator 17a, Step 73: Converting the electrical supply power into a second AC voltage and supplying the second AC voltage to a second load 9b of a second plasma generator 17b, wherein steps 73 and 72 do not occur at the same time, Step 74: Controlling the AC voltages according to different characteristics at one or more of the following control values:

[0155] • Output current,

[0156] • Output voltage,

[0157] • Output frequency, • Output power,

[0158] • Output waveform of current and / or voltage, and

[0159] Step 75: Generation and output of a control signal for an impedance matching device 15a, 15b, 15n associated with one of the AC voltage supplies.

Claims

Patent claims 1. Power supply arrangement (10) for several plasma generators (17a, 17b, 17n), each of which is specifically designed to excite a gas to a gas plasma at a location remote from a plasma processing step, comprising: a) a power input port (2) for connecting a power supply (7), b) a data port (13) for connecting to a controller (4), c) wherein the power supply arrangement (10) is designed to convert power from the power input port (2) into AC power via an AC voltage generator stage (6), d) wherein the power supply arrangement (10) is configured to transmit data via the data port (13) • to ensure that the AC power can be supplied to a first load (9a) as a first AC power and to a second load (9b) located some distance from the first as a second AC power, in particular that the two loads are not supplied simultaneously, and • to be controllable in such a way that the first and second AC voltage outputs can exhibit different characteristics at least for one or more of the following control values: • Output current, • Output voltage, • Output frequency, • Output power, • Output waveform of current and / or voltage, and e) wherein the power supply arrangement (10) is configured to output a drive signal for an impedance matching device (15a, 15b, 15n) associated with one of the AC power supplies. Power supply arrangement (10) according to claim 1, comprising: a) a first power output terminal (3a) for supplying the first AC power to the first load (9a), b) a second power output terminal (3b) for supplying the second AC power to the second load (9b) located at a distance from the first. Power supply arrangement (10) according to any of the preceding claims, further comprising a switching unit (8a, 8b), which is in particular part of the power supply arrangement (10), wherein the power supply arrangement (10) is configured to ensure, via the data terminal (13), that the switching unit (8a, 8b) can switch the AC power generated by the AC power generator stage (6) to each of the power output terminals (3a, 3b) and / or loads (9a / 9b), and is configured to be able to adjust the different characteristics of the respective AC power.Power supply arrangement (10) according to any one of the preceding claims, wherein it is configured such that the sum of all rated powers of all AC voltage powers available to the loads (9a, 9b, ... 9n) is greater than the rated power of the AC voltage generator stage (6). Power supply arrangement (10) according to any one of the preceding claims, wherein it is configured to output different control signals for several impedance matching devices (15a, 15b), each of which is assigned to one of the AC voltage powers. Power supply arrangement (10) according to any one of the preceding claims, wherein it is configured to receive one and / or more plasma signals (CT4a, CT4b, CT4n), in particular one and / or more plasma voltages, from one of the plasma generators (17a, 17b, 17n). Power supply arrangement (10) according to one of the preceding claims, wherein it is configured to assign one or more of the transmitted plasma signals (CT4a, CT4b, CT4n) to the characteristics of the AC voltage powers, in particular to adjust the characteristics of the AC voltage powers depending on the respective plasma signals (CT4a, CT4b, CT4n).Power supply arrangement (10) according to one of the preceding claims, wherein it is configured to receive one and / or more voltages and / or currents from a current and / or voltage sensor (CT1a, CT1b, CT1l) which is arranged and configured to measure current and / or voltage of the AC power supply, and wherein the power supply arrangement (10) is in particular further configured to assign one or more of the transmitted voltages and / or currents to the characteristics of the AC power supplies, in particular to adjust the characteristics of the AC power supplies depending on the respective voltages and / or currents.Power supply arrangement (10) according to any one of the preceding claims, wherein it is configured to receive one and / or more voltages and / or currents from a current and / or voltage sensor (CT2a, CT2b, CT2n, CT3a, CT3b, CT3n) which is arranged and configured to measure current and / or voltage in or at an impedance matching device (15a, 15b, 15n), and wherein the power supply arrangement (10) is further configured, in particular, to assign one or more of the transmitted voltages and / or currents to the characteristics of the AC power, in particular to adjust the characteristics of the AC power depending on the respective voltages and / or currents. Power supply arrangement (10) according to any one of the preceding claims, wherein the control unit (4) is integrated into the power supply arrangement (10).

11. Plasma generating device (1), comprising: a) a power supply arrangement (10) according to any of the preceding Claims and b) several plasma generators (17a, 17b, 17n) which are connected to the power supply arrangement (10), in particular to the power output terminals (3a, 3b, 3n) thereof, and which can each be operated according to the control value characteristics.

12. Plasma generation device (1) according to claim 11, further comprising a first transformer arrangement (Tla), in particular a transformer arrangement (Tla, Tlb, Tin) for each plasma generator (17a, 17b, 17n) for coupling the AC voltage power to the load (9a, 9b, 9n), wherein preferably the transformer arrangement (Tla, Tlb, Tin) is arranged in the immediate vicinity of the load (9a, 9b, 9n).

13. Plasma generation device (1) according to one of the preceding claims 11 or 12, further comprising an impedance matching device (15a), in particular several impedance matching devices (15a, 15b, 15n), wherein preferably one impedance matching device (15a, 15b, 15n) is arranged between power supply arrangement (10) and plasma generator (17a, 17b, 17n).

14. Plasma generation device (1) according to any one of the preceding claims 11 to 13, wherein one, in particular several of the plasma generators (17a, 17b, 17n), (as so-called remote plasma sources) are designed to excite a gas to a gas plasma at a location remote from a plasma processing operation.

15. Method for controlling several plasma processes, each designed in particular to excite a gas to a gas plasma at a location remote from a plasma processing operation, comprising the following steps: a) supplying a power supply arrangement (10) with electrical power, b) Converting the electrical supply power into a first AC voltage power and supplying the first AC voltage power to a first load (9a) of a first plasma generator (17a), c) Converting the electrical supply power into a second AC voltage power and supplying the second AC voltage power to a second load (9b) of a second plasma generator (17b), wherein, in particular, steps b) and c) do not occur simultaneously, d) Controlling the AC voltage powers according to different characteristics at one or more of the following control values: • Output current, • Output voltage, • Output frequency, • Output power, • Output waveform of current and / or voltage, and e) generation and output of a drive signal for an impedance matching device (15a, 15b, 15n) associated with one of the AC powers.

Images