Multi-station plasma processing system

Abstract

According to an embodiment of the present disclosure, a multi-station plasma processing system is provided, the system including a process chamber including at least two or more stations, a plasma generator for each of the stations, an inverter for each of the plasma generators, a sensing unit configured to measure an electrical characteristic of each of the plasma generators, and a controller configured to obtain sensing data from the sensing unit and control each of the inverters.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to multi-station plasma processing systems, and more particularly, to systems for performing plasma processes at multiple stations. [Background technology]

[0002] Plasma process technology using plasma is used in various industrial fields including not only the fields of semiconductors, displays, and medical devices, but also environmental technology fields such as air, water, and soil purification, and energy technology fields such as solar cells and hydrogen energy. Plasma process technology includes various methods for generating plasma, including direct current discharge such as corona discharge, glow discharge, and arc discharge, and alternating current discharge such as capacitively coupled discharge and inductively coupled discharge, as well as methods using shock waves and high-energy beams. Among these methods, inductively coupled discharge, which can generate high-density plasma using less power, has attracted attention.

[0003] Plasma process technologies using inductively coupled discharge include a method in which plasma is generated directly inside the process chamber, and a remote plasma method in which a process gas (e.g., radicals) required for the process is generated and the generated process gas is supplied into the chamber.

[0004] On the other hand, the remote plasma method of the related art usually performs one type of plasma process in one process chamber, making it difficult to perform multiple identical processes simultaneously or different processes in parallel, resulting in a problem that there is a limit to improving the overall process efficiency.

[0005] A plasma processing system that uses multiple stations to solve this problem is described later in this specification. Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE DISCLOSURE It is an object of the present disclosure to provide a multi-station plasma processing system.

[0007] It is an object of the present disclosure to provide a physical structure for interconnecting plasma generation systems and process chambers in a multi-station plasma processing system.

[0008] SUMMARY OF THE DISCLOSURE It is an object of the present disclosure to provide a method and apparatus for controlling a plasma generation system in a multi-station plasma processing system.

[0009] The object of the present disclosure is not limited to the above, and objects not described above will be clearly understood by those skilled in the art from the specification and the accompanying drawings. [Means for solving the problem]

[0010] According to one embodiment of the present disclosure, there is provided a multi-station plasma processing system. The system includes a process chamber including a first station and a second station, a first plasma generator fluidly coupled to the first station, a first inverter configured to provide AC power to the first plasma generator, a first sensing unit configured to sense an electrical characteristic of the first plasma generator, a second plasma generator coupled to the second station, a second inverter configured to provide AC power to the second plasma generator, a second sensing unit configured to sense an electrical characteristic of the second plasma generator, and a controller configured to control the first inverter and the second inverter. The first plasma generator includes a first discharge tube fluidly coupled to the first station and a first antenna structure disposed to surround the first discharge tube. The second plasma generator includes a second discharge tube fluidly coupled to the second station and a second antenna structure disposed to surround the second discharge tube. The first antenna structure is configured to receive AC power from the first inverter and induce plasma in the first discharge tube. The second antenna structure is configured to receive AC power from the second inverter and induce a plasma in the second discharge tube.

[0011] The object of the present disclosure is not limited to the above, and objects not described above will be clearly understood by those skilled in the art from the specification and the accompanying drawings. Effect of the Invention

[0012] According to one embodiment of the present disclosure, a multi-station remote plasma processing system is provided.

[0013] According to one embodiment of the present disclosure, a multi-station plasma process can be used to perform multiple processes in parallel.

[0014] According to one embodiment of the present disclosure, a multi-station plasma process can be used to perform different processes in parallel.

[0015] According to an embodiment of the present disclosure, it is possible to implement a plasma processing system with high process efficiency.

[0016] The effects of the present disclosure are not limited to those described above, and effects not described above will be clearly understood by those skilled in the art from the specification and the accompanying drawings. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 illustrates a system for plasma processing according to one embodiment of the present disclosure. [Diagram 2] FIG. 1 illustrates a radio frequency (RF) generator according to one embodiment of the present disclosure. [Diagram 3] FIG. 1 illustrates a plasma generator according to one embodiment of the present disclosure. [Figure 4] FIG. 1 illustrates a single station plasma process procedure according to one embodiment of the present disclosure. [Diagram 5] FIG. 1 illustrates a multi-station for plasma processing according to one embodiment of the present disclosure. [Figure 6] FIG. 1 illustrates the relationship of components in a multi-station plasma processing system according to one embodiment of the present disclosure. [Figure 7] FIG. 2 illustrates the relationship of components in a multi-station plasma processing system according to another embodiment of the present disclosure. [Figure 8] FIG. 2 illustrates the relationship of components in a multi-station plasma processing system according to another embodiment of the present disclosure. [Figure 9-10] FIG. 2 illustrates a multi-station plasma processing system according to another embodiment of the present disclosure. [Figure 11] FIG. 1 illustrates a method for controlling power in a multi-station plasma processing system according to one embodiment of the present disclosure. [Figure 12]FIG. 1 illustrates a method for frequency control in a multi-station plasma processing system according to one embodiment of the present disclosure. [Figure 13] FIG. 1 shows a block diagram of a plasma generation system according to one embodiment of the present disclosure. [Figure 14] FIG. 1 illustrates a process for obtaining sensed values ​​from a central controller according to one embodiment of the present disclosure. [Figure 15] 1 is a flow chart illustrating a plasma processing method using a plasma generation system according to one embodiment of the present disclosure. [Figure 16] 4 is a flowchart illustrating a method for power control via frequency control according to one embodiment of the present disclosure. [Figure 17] FIG. 2 illustrates a table summarizing the rules used in a power control method via frequency control according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The objects, features, and advantages of the present disclosure will become more apparent through the following detailed description taken in conjunction with the accompanying drawings, in which: Since the present disclosure may be modified in various ways and implemented by various exemplary embodiments, specific exemplary embodiments are shown in the drawings and will be described in detail below.

[0019] In the drawings, the thickness of layers and regions are exaggerated for clarity, and when a component or layer is "on" another component or layer, it includes all cases where the component or layer is on another component or layer, as well as all cases where another layer or component is disposed therebetween. Similar reference numbers indicate essentially the same components throughout the specification. In the drawings of the embodiment, components having the same function within the same scope are described with the same reference numbers, and repeated description is omitted.

[0020] Numbers used in the specification of this disclosure (eg, first, second, etc.) are merely identifiers to distinguish one component from another.

[0021] The terms "module" and "unit" used for components in the following embodiments are used only for convenience of explanation and have no distinguishing meaning or function.

[0022] In the following embodiments, the singular is intended to include the plural unless the context clearly dictates otherwise.

[0023] In the following embodiments, terms such as "comprise" or "have" mean the presence of features or components described in this specification, and do not exclude the possibility that one or more other features or components may be added.

[0024] For convenience of explanation, components may be exaggerated or reduced in size. For example, the sizes and thicknesses of components shown in the figures are provided selectively, and the present disclosure is not necessarily limited thereto.

[0025] Certain processes may be performed in an order different from that described, if the embodiment can be implemented in an alternative manner. For example, two processes described as being sequential may be performed substantially simultaneously or may be performed in the reverse order from that described.

[0026] In the following embodiments, when membranes, regions, and components are connected, this includes not only cases where the membranes, regions, and components are directly connected, but also cases where the membranes, regions, and components are indirectly connected via other membranes, regions, and components in between.

[0027] For example, in this specification, when a membrane, region, and component are electrically connected, this includes not only the case where the membrane, region, and component are directly electrically connected, but also the case where the membrane, region, and component are indirectly electrically connected via another membrane, region, and component in between.

[0028] According to one embodiment, a system for a multi-station plasma process may be provided. The system includes a process chamber including a first station and a second station, a first plasma generator coupled to the first station, a first inverter configured to provide AC power to the first plasma generator, a first sensing unit configured to sense an electrical characteristic associated with the first plasma generator, a second plasma generator coupled to the second station, a second inverter configured to provide AC power to the second plasma generator, a second sensing unit configured to sense an electrical characteristic associated with the second plasma generator, and a controller configured to control the first inverter and the second inverter. The first plasma generator includes a first discharge tube fluidly coupled to the first station and a first antenna structure disposed to surround the first discharge tube. The second plasma generator includes a second discharge tube fluidly coupled to the second station and a second antenna structure disposed to surround the second discharge tube. The first antenna structure is configured to receive AC power from the first inverter and induce a plasma in the first discharge tube. The second antenna structure is configured to receive AC power from the second inverter and induce a plasma in the second discharge tube.

[0029] The controller is configured to provide a first switch signal corresponding to a first driving frequency to the first inverter based on first sensing data obtained from the first sensing unit, and to provide a second switch signal corresponding to a second driving frequency to the second inverter based on second sensing data obtained from the second sensing unit.

[0030] The controller is configured to receive third sensory data after receiving the first sensory data, and determine whether to modify a first switch signal provided to the first inverter based on the third sensory data, and to receive fourth sensory data after receiving the second sensory data, and determine whether to modify a second switch signal provided to the second inverter based on the fourth sensory data.

[0031] The controller is configured to obtain first phase difference data and first power comparison data using the third sensed data, and to determine whether to modify a first switch signal provided to the first inverter using the first phase difference data and the first power comparison data, where the first phase difference data corresponds to a phase difference between a voltage and a current applied to the first plasma generator, and the first power comparison data corresponds to a difference between a first power applied to the first inverter and a first target power.

[0032] The controller is configured to provide a third switch signal to the first inverter corresponding to a third drive frequency less than the first drive frequency when the first phase difference data indicates a lagging condition and the first power comparison data indicates that the first power is less than the first target power.

[0033] A difference between the first drive frequency and the third drive frequency is determined based on the first target power.

[0034] The controller is configured to maintain the first switch signal applied to the first inverter when the first phase difference data indicates a lagging condition and the first power comparison data indicates that the first power is the same as the first target power.

[0035] The controller is configured to provide a third switch signal to the first inverter corresponding to a third drive frequency greater than the first drive frequency when the first phase difference data indicates a lagging condition and the first power comparison data indicates that the first power is greater than the first target power.

[0036] A difference between the first drive frequency and the third drive frequency is determined based on the first target power.

[0037] The controller is configured to provide a third switch signal to the first inverter corresponding to a third drive frequency greater than the first drive frequency when the first phase difference data indicates a lead state.

[0038] The difference between the first drive frequency and the third drive frequency is a fixed value.

[0039] The first sensing unit is configured to obtain first sensed data for a predetermined period and provide the first sensed data to the controller. The second sensing unit is configured to obtain second sensed data for a predetermined period and provide the second sensed data to the controller. The controller is configured to change a first switch signal provided to the first inverter based on the periodically obtained first sensed data such that the AC power provided to the first plasma generator changes from a first driving frequency to a third driving frequency, and to change a second switch signal provided to the second inverter based on the periodically obtained second sensed data such that the AC power provided to the second plasma generator changes from a second driving frequency to a fourth driving frequency.

[0040] The controller is configured to obtain first phase difference data representing a phase difference between a voltage and a current applied to the first plasma generator based on the first sensing data and the first switch signal, and change a first switch signal provided to the first inverter if the first phase difference data does not satisfy a first allowed phase difference condition, and to obtain second phase difference data representing a phase difference between a voltage and a current applied to the second plasma generator based on the second sensing data and the second switch signal, and change a second switch signal provided to the second inverter if the second phase difference data does not satisfy a second allowed phase difference condition.

[0041] The first sensed data corresponds to a phase of a current applied to the first plasma generator, the first switch signal corresponds to a phase of a voltage applied to the first plasma generator, the second sensed data corresponds to a phase of a current applied to the second plasma generator, and the second switch signal corresponds to a phase of a voltage applied to the second plasma generator.

[0042] There is also included a power splitter electrically coupled to the first inverter and the second inverter, the power splitter configured to provide a first DC power to the first inverter and to provide a second DC power, the second DC power having a different magnitude than the first DC power, to the second inverter.

[0043] The first sensing unit may be configured to obtain first sensed data for a predetermined period of time and provide the first sensed data to the controller. The second sensing unit may be configured to obtain second sensed data for a predetermined period of time and provide the second sensed data to the controller. The controller may be configured to change a first switch signal provided to the first inverter based on the periodically obtained first sensed data such that a frequency of the AC power provided to the first plasma generator goes from a first drive frequency to a third drive frequency, and to change a second switch signal provided to the second inverter based on the periodically obtained second sensed data such that a frequency of the AC power provided to the second plasma generator goes from a second drive frequency to a fourth drive frequency.

[0044] The controller may be configured to derive first phase difference data representing a phase difference between a voltage and a current applied to the first plasma generator based on the first sensing data and the first switch signal, and change a first switch signal provided to the first inverter if the first phase difference data does not satisfy a first allowed phase difference condition, and to derive second phase difference data representing a phase difference between a voltage and a current applied to the second plasma generator based on the second sensing data and the second switch signal, and change a second switch signal provided to the second inverter if the second phase difference data does not satisfy a second allowed phase difference condition.

[0045] The first sensed data may correspond to a phase of a current applied to the first plasma generator and the first switch signal may correspond to a phase of a voltage applied to the first plasma generator, the second sensed data may correspond to a phase of a current applied to the second plasma generator and the second switch signal may correspond to a phase of a voltage applied to the second plasma generator.

[0046] The controller may be configured to control the first inverter based on first sensing data obtained from the first sensing unit such that the first AC power is applied to the first plasma generator, and to control the second inverter based on second sensing data obtained from the second sensing unit such that the second AC power is applied to the second plasma generator.

[0047] The controller may be configured to provide the first AC power to the first plasma generator by performing a first power supply operation to provide AC power to the first plasma generator in a first pattern via a first inverter and a first freewheeling operation to not provide AC power to the first plasma generator, and to provide the second AC power to the second plasma generator by performing a second power supply operation to provide AC power to the second plasma generator in a second pattern via a second inverter and a second freewheeling operation to not provide AC power to the second plasma generator.

[0048] The ratio of the first freewheeling operation to the first power supply operation in the first pattern may be different from the ratio of the second freewheeling operation to the second power supply operation in the second pattern.

[0049] The first sensed data may correspond to an amount of power applied to the first inverter, and the second sensed data may correspond to an amount of power applied to the second inverter.

[0050] The controller may be configured to determine whether the first sensed data satisfies a first allowable power condition, and change a first AC power applied to the first plasma generator if the first sensed data does not satisfy the first allowable power condition, and to determine whether the second sensed data satisfies a second allowable power condition, and change a second AC power applied to the second plasma generator if the second sensed data does not satisfy the second allowable power condition, where the first allowable power condition and the second allowable power condition may have different ranges.

[0051] 1. Overview

[0052] (1) Technical terms

[0053] FIELD OF THE DISCLOSURE The present disclosure relates to a system for plasma processing using multiple stations, and more particularly, to a system for performing a plasma process in multiple stations using a plasma generation system.

[0054] In the specification, a plasma process is a process in which plasma is generated and the generated plasma is used, and is used in semiconductor processes, display processes, nanoprocesses, environmental improvement, etc. In the specification, semiconductor processes such as plasma ashing, plasma chemical vapor deposition (CVD), plasma etching, sputtering, and surface modification are described as main embodiments of the plasma process, but the technical ideas of the present disclosure are not limited thereto.

[0055] Plasma is a phase in which a substance is decomposed into negatively charged electrons and positively charged ions by applying high energy to the substance, and can be induced or generated in various ways. Inductively coupled plasma, which is a plasma generated by an inductive electric field or a capacitive electric field formed in a specific space by power supplied to a coil or an antenna, may generally be driven by high frequency power such as radio frequency (RF). Meanwhile, in the following, for convenience of explanation, it is assumed that the plasma generated in the plasma generation system is inductively coupled plasma, but the technical idea of ​​the present disclosure is not limited thereto.

[0056] In the specification, a station, which is an environment for performing a process on an object, may include a space or area in which the process is performed, or a component for performing the process. Furthermore, multi-station means that a station includes multiple stations.

[0057] (2) Overview of Plasma Processing System

[0058] The plasma processing system and its configuration will be described below with reference to FIG.

[0059] FIG. 1 illustrates a plasma processing system 10 according to one embodiment of the present disclosure.

[0060] 1, a plasma processing system 10 may include a plasma generation system 100 and a process chamber 200. The plasma generation system 1000 may include an RF generator and a plasma generator 2000.

[0061] The RF generator 1000 can provide power to the plasma generator 2000. For example, the RF generator 1000 can apply AC power having a specific drive frequency to the plasma generator 2000. The RF generator 1000 can change the drive frequency of the AC power provided to the plasma generator 2000 by monitoring the impedance of the plasma generator 2000 and the power applied to the plasma generator 2000. Meanwhile, AC power may be interpreted in the specification to mean an AC or AC voltage.

[0062] The plasma generator 2000 can generate plasma. Specifically, the plasma generator 2000 may include a means for generating plasma and a space in which the plasma is formed. For example, the plasma generator 2000 may include an antenna structure as a device for generating plasma, and may include a discharge tube as the space in which the plasma is formed.

[0063] The plasma generator 2000 is electrically connected to the RF generator 1000 and can provide power from the RF generator 1000, and the RF generator 1000 can obtain information regarding current or voltage from the plasma generator 2000.

[0064] The plasma generator 2000 can use the power obtained from the RF generator 1000 to generate a plasma.

[0065] The process chamber 200 can create an environment for performing a plasma process. For example, the process chamber 200 can provide a space for the plasma process, an object on which the plasma process is performed, and environmental variables (e.g., internal pressure, temperature, etc.) suitable for the plasma process.

[0066] The RF generator 1000 and the plasma generator 2000 generate plasma for a plasma process, and the process chamber 200 provides the environment in which the plasma process is carried out, thereby enabling the plasma generation system 100 to perform the plasma process.

[0067] The RF generator 1000, the plasma generator 2000, and the process chamber 200 are described in more detail below.

[0068] (3) RF generator

[0069] FIG. 2 is a diagram illustrating a radio frequency (RF) generator according to one embodiment of the present disclosure.

[0070] 2, the RF generator 1000 may include an AC power source 1100, a rectifier 1200, an inverter 1300, a sensor module 1400, and a controller 1500. The RF generator 10000 may convert a first AC power supplied from the AC power source 1100 into a second AC power and supply the second AC power to a load. For example, the RF generator 1000 may convert a first AC power used in general households and industries into a second AC power having a frequency of several hundred kHz to several tens of MHz and a magnitude of several kW or more, and provide the second AC power to a load.

[0071] The load may include the plasma generator 2000 and the plasma generated by the plasma generator 2000. The load may have a time-varying resonant frequency in response to the plasma induction.

[0072] The rectifier 1200 can convert the output of the AC power source 1100 into DC. The rectifier 1200 can convert the first AC power supplied from the AC power source 1100 into DC power and apply the DC power to both ends of the inverter 1300. Meanwhile, the DC power may be interpreted as meaning a direct current or a DC voltage in the specification.

[0073] The inverter 1300 can receive the DC power from the rectifier 1200 and provide a second AC power to a load. For example, the inverter 1300 can receive a switch signal from the controller 1500 and provide the second AC power to the load using the received switch signal.

[0074] The inverter 1300 may include at least one switch element controlled by a switch signal, and the second AC power supplied from the inverter 1300 to the load may have a drive frequency that is set based on the switch signal provided from the controller 1500 to the inverter 1300.

[0075] For example, the inverter 1300 may be implemented as a full-bridge type. Specifically, the inverter 1300 may include first to fourth switches S1, S2, S3, and S4. By receiving a switch signal from the controller 1500, the first to fourth switches S1, S2, S3, and S4 can be turned on or off. By turning on the first and third switches S1 and S3 and turning off the second and fourth switches S2 and S4, a positive voltage can be applied to the load. By turning off the first and third switches S1 and S3 and turning on the second and fourth switches S2 and S4, a negative voltage can be applied to the load. As described above, the inverter 1300 can apply AC power having a specific frequency by alternately applying a positive voltage and a negative voltage to the load.

[0076] In another example, the inverter 1300 may be implemented as a half-bridge type. Specifically, the inverter 1300 may include a first switch and a second switch. Here, the first switch and the second switch can be turned on or off by receiving a switch signal from the controller 1500. When the first switch is turned on and the second switch is turned off, a positive voltage is applied to the load, and when the first switch is turned off and the second switch is turned on, a negative voltage is applied to the load.

[0077] As described above, the inverter 1300 can apply AC power having a particular frequency by alternately applying positive and negative voltages to a load.

[0078] The implementation method of the inverter 1300 is not limited to the above-mentioned method, and may refer to a configuration including a circuit structure that performs the function of converting DC power into AC power.

[0079] The inverter 1300 may be controlled, for example, as a time delay type, a pulse width modulation (PWM) type, or a combination thereof, depending on the frequency control method.

[0080] Alternatively, a capacitive element may be disposed between the rectifier 1200 and the inverter 1300. For example, the RF generator 1000 includes a capacitor connected in parallel to the rectifier 1200 and the inverter 1300. The capacitor can discharge the AC component of the power applied to the inverter 1300 to a ground node GND.

[0081] The controller 1500 can generate the switch signal by receiving data sensed by the sensor module 1400 described below. For example, the controller 1400 may be implemented to generate the switch signal by obtaining data related to a resonant frequency, such as a current or a voltage of the load, from the sensor module 1400. Specifically, the controller 1500 can obtain phase difference data or a delay time using phase data of a current applied to the load and phase data of a voltage applied to the load obtained from the sensor module 1400, and can generate the switch signal based on the phase delay data or the delay time.

[0082] The controller 1500 may be implemented using Field Programmable Gate Array (FPGA) technology. The detailed configuration and structure of the controller 1500 are described below.

[0083] The sensor module 1400 may obtain data from the controller 1500 regarding the resonant frequency of the load or data regarding the power supplied to the load.

[0084] 2, the sensor module 1400 may include a current transformer, a filter, and a comparator. The sensor module 1400 may receive a current or voltage signal flowing to a load via a current transformer, convert the current or voltage signal to a current or voltage signal of a different magnitude, filter the converted current or voltage using a filter, and output phase data to the controller 1500 via a comparator.

[0085] A current transformer may be inductively coupled to the wires between the inverter 1300 and the load and may transform the voltage or current signal applied to the load and provide it to the filter. Specifically, the current transformer may transform the current flowing through the conductive wires connected to the load into a voltage signal.

[0086] The filter can remove the AC component from an input current or voltage signal and output the current or voltage signal to a comparator, thus allowing the filter to perform high or low band pass filtering.

[0087] The comparator can obtain the phase data. For example, the comparator can obtain the phase data by comparing the voltage signal obtained from the current transformer or the filter with a preset value. The phase data may refer to the phase data of the current applied to the load.

[0088] It should be understood that at least one of the components included in the sensor module 1400 may be omitted or implemented in a different manner.

[0089] On the other hand, although not shown in FIG. 2, RF generator 1000 may include a memory. The memory can store various data. The various data may be temporarily or semi-permanently stored in the memory. The memory may be, for example, a hard disk drive (HDD), a solid state drive (SSD), a flash memory, a read-only memory (ROM), a random access memory, or the like. The memory may be implemented as a type built into RF generator 1000 or a type removably attached to RF generator 1000.

[0090] As described above, the RF generator 1000 can control the drive frequency of the second AC power provided to the load based on the data on the resonant frequency of the load. In other words, the RF generator 1000 can output the drive frequency of the second AC power so as to correspond to the resonant frequency of the load by tracing the resonant frequency of the load that changes with plasma generation. This makes it possible to prevent unnecessary power consumption and improve the durability of the plasma system.

[0091] At least one of the components of the RF generator 1000 described above may be omitted. For example, the RF generator 1000 may obtain electrical data related to the load from an external sensor without including the sensor module 1400. As another example, the RF generator 1000 may be provided with DC power or rectified DC power from an external source without including the AC power source 1100 and the rectifier 1200.

[0092] Although the RF generator 1000 has been described above primarily for use in a single station, the functionality or structure of the arrangement may be at least partially modified when the RF generator 1000 is used in a multi-station configuration, which is described in more detail below.

[0093] (4) Plasma generator

[0094] FIG. 3 is a diagram illustrating a plasma generator 2000 according to one embodiment of the present disclosure.

[0095] Referring to FIG. 3, a plasma generator 2000 may include an antenna structure 2100 and a discharge tube 2200 .

[0096] The antenna structure 2100 is disposed around the discharge tube 2200 and can induce plasma generation by forming an electromagnetic field within the discharge tube 2200. For example, the antenna structure 2100 can be powered by the RF generator 1000 to form an electromagnetic field within the discharge tube 2200, thereby inducing plasma generation.

[0097] The antenna structure 2100 may include at least one antenna unit. For example, the antenna structure 2100 may be configured with one ring-shaped antenna unit and may be arranged to surround the discharge tube 2200. As another example, the antenna structure 2100 may include two or more antenna units with different radii of curvature, and the antenna units may be arranged in the same plane to surround the discharge tube 2200. As another example, the antenna structure 2100 may include two or more antenna units, and the two or more antenna units may be arranged to surround the discharge tube 2200 in different planes.

[0098] The antenna structure 2100 may be electrically connected to the RF generator 1000. For example, a first end of the RF generator 1000 may be electrically connected to a first end of the antenna structure 2100, and a second end of the RF generator 1000 may be electrically connected to a second end of the antenna structure 2100, so that the RF generator 1000 can supply power to the antenna structure 2100. As another example, the RF generator 1000 may be connected to the antenna structure 2100 via a specific electric element. Specifically, the first and second ends of the antenna structure 2100 may be respectively connected to a capacitor, and the capacitor may be respectively connected to the first and second ends of the RF generator 1000.

[0099] The discharge tube 2200 can provide a space in which plasma generation is induced.

[0100] The discharge tube 2200 may be fluidly connected to the process chamber 200 described below. For example, a flow path through which a fluid can move may be formed between the discharge tube 2200 and the process chamber 200. More specifically, the discharge tube 2200 and the process chamber 200 may be connected via a conduit.

[0101] The discharge tube 2200 may be made of various materials. For example, the discharge tube 2200 may be made of a non-conductive material or a thermally conductive material. Specifically, the discharge tube 2200 may be made of aluminum nitride (AlN), aluminum hydroxide (Al2O3), silicon nitride (SiN), silicon nitride (Si3N4), silicon dioxide (SiO2), yttrium oxide (Y2O3), or silicon carbide (SiC).

[0102] Additionally, discharge tube 2200 may be made of materials that do not produce particles when reacting with the gases (e.g., NF3, Ar, CO2, CH4, NF3, O2, H2, etc.) flowing into discharge tube 2200 to induce the plasma.

[0103] The plasma generator 2000 may further include a DC electrode, which may receive power and generate a direct current discharge within the discharge tube 2200.

[0104] The plasma generator 2000 may further include an ignition coil. The ignition coil may have a similar configuration to the antenna structure 2100 described above. The ignition coil may receive power and form an electromagnetic force inside the discharge tube 2200. The ignition coil may ignite a plasma with a DC electrode inside the discharge tube 2200.

[0105] 2.Types of Plasma Processes

[0106] Hereinafter, the type in which a plasma process is performed will be described with reference to FIGS.

[0107] (1) Single Station

[0108] FIG. 4 is a diagram illustrating a single station plasma process procedure according to one embodiment of the present disclosure.

[0109] The plasma process may be carried out using a plasma generation system 100 that provides a single station and process chamber 200. Referring to Figure 4, the process chamber 200 may include a head 220, a substrate 230, a substrate holder, a vacuum pump, and an interior space in which these components are disposed.

[0110] The head 220 can provide a flow path for supplying a fluid required for a process to the process chamber 200. For example, a process gas such as an ion gas or radicals generated in the plasma generation system 100, a gas provided from a specific gas supplier, etc., can flow into the process chamber 200 through the head 220 of the process chamber 200, and a process such as etching, deposition, cleaning, etc. can be performed on the substrate 230 by the inflow gas.

[0111] Substrate 230 may refer to an object on which a plasma process is performed. For example, substrate 230 may refer to a wafer used in semiconductor processing, a glass substrate used in display processing, a mask for patterning, etc.

[0112] The substrate holder can support a substrate 230 within the process chamber 200. The substrate holder can include a heating element. The substrate holder can be electrically connected to a specific power device, thereby providing power.

[0113] The vacuum pump can control the internal pressure of the process chamber 200. For example, the vacuum pump can control the internal pressure of the process chamber 200 to correspond to the plasma process being performed, for example, the inside of the process chamber 200 can be in a vacuum state or an atmospheric state.

[0114] The plasma generation system 100 may be fluidly connected to the process chamber 200 in a variety of ways.

[0115] 4A, for example, a plasma generation system 100 may be fluidly connected to a head 220 of a process chamber 200. Process gases generated in the plasma generation system 100 may flow into the process chamber 200 through the head of the process chamber 200. This configuration may be used to perform processes such as deposition, etching, cleaning, etc. on a substrate 230.

[0116] 4B, the plasma generation system 100 may be fluidly connected to the interior of the process chamber 200 without passing through the head 220 of the process chamber 200. In this case, process gas provided from a gas supplier may flow into the process chamber 200 through the head 220, and process gas generated by the plasma generation system 100 may flow into the process chamber 200 through a separate flow path rather than through the head 220. This configuration may be used to perform a process to clean the interior of the process chamber 200.

[0117] On the other hand, the connection structure between the plasma generation system 100 and the process chamber 200, or the plasma process corresponding to the connection structure, is not limited to the above.

[0118] (2) Multi-station

[0119] The configuration and structure of the plasma processing system 10 when used in a single station have been described above. Meanwhile, the plasma processing system 10 can also perform plasma processes for multiple stations. In this case, multiple plasma processes may be performed in parallel, different plasma processes may be performed in parallel, or time-series plasma processes may be performed continuously, that is, the process efficiency can be significantly improved compared to when a single station is used. In particular, as described below, when a multi-station is used and a system for a plasma process corresponding to each station is provided, the process efficiency can be maximized and the possible range of processes can be expanded.

[0120] FIG. 5 is a diagram illustrating a multi-station for plasma processing according to one embodiment of the present disclosure.

[0121] Referring to FIG. 5, the plasma processing system 10 may include two or more plasma generation systems 100, a process chamber 200 including two or more stations, a power distributor 300, a sensing unit 400, and a central controller 500.

[0122] The plasma processing system 10 may include a plurality of stations. For example, the plasma processing system 10 may include first to fourth stations 211, 212, 213, and 214. For convenience of explanation, the following description will be given assuming that the plasma processing system 10 includes four stations, but the technical idea of ​​the present disclosure is not limited thereto, and the number of stations included in the plasma processing system 10 may be changed in various ways as necessary.

[0123] The plasma processing system 10 may include a plurality of plasma generation systems 100. The plasma generation systems 100 may correspond to the stations included in the plasma processing system 10, respectively. For example, as shown in Fig. 5, the plasma processing system 10 may include first to fourth plasma generation systems 101, 102, 103, and 104, and the first to fourth plasma generation systems 101, 102, 103, and 104 may be fluidly connected to first to fourth stations 211, 212, 213, and 214, respectively. The plasma generation systems 100 can provide process gases required for the plasma process to the stations, respectively.

[0124] On the other hand, in the multi-station plasma processing system 10, the number of plasma generating systems 100 may not be the same as the number of stations. For example, the plasma processing system 10 may include first and second plasma generating systems 101, 102, and may include first and second stations 211, 212 fluidly connected to the first plasma generating system 101, and third and fourth stations 213 fluidly connected to the second plasma generating system 102. In the following, for convenience of explanation, a case will be described in which the plasma processing system 10 includes first to fourth plasma generating systems 101, 102, 103, and 104 corresponding to the first to fourth stations 211, 212, 213, and 214, respectively, but the technical idea of ​​the present disclosure is not limited thereto.

[0125] The power distributor 300 can distribute power to the plasma generation system 100. For example, the power distributor 300 can monitor the states of the first to fourth plasma generation systems 101, 102, 103, and 104 and provide the necessary power. Specifically, the power distributor 300 can receive power sensing data of each of the first to fourth plasma generation systems 101, 102, 103, and 104 from the sensing unit 400 in real time, and can provide the necessary power to each of the first to fourth plasma generation systems 101, 102, 103, and 104 based on the power sensing data. The power distributor 300 may include a power supplier, or may be supplied with power from an external source. The power applied to the power distributor 300 may be DC power obtained by rectifying AC power, and this is understood to be the same as providing DC power using the AC power source 1100 and the rectifier 1200 described with reference to FIG. 2.

[0126] The sensing unit 400 can sense electrical characteristics of components in the plasma processing system 10. The electrical characteristics may refer to data related to current, phase of current, voltage, current of voltage, phase difference between current and voltage, power, and the like. For example, the sensing unit 400 can measure the phase of the current through the plasma generator 2000 of the plasma generation system 100. As another example, the sensing unit 400 can measure (the amount of) power provided by or consumed by the plasma generation system 100. As another example, the sensing unit 400 can measure the power provided by or consumed by the plasma processing system 10. Of course, the sensing unit 400 can measure electrical characteristics at a particular element or at a particular location, and can measure electrical characteristics at multiple particular elements or at particular locations. The sensing unit 400 can measure electrical characteristics in real time while the plasma processing system 10 is operating. The sensing unit 400 can obtain sensing data by measuring electrical characteristics in the plasma generation system 100, as described above.

[0127] The sensing unit 400 may provide the acquired sensory data to the power distributor 300. The sensing unit 400 may provide the acquired sensory data to the central controller 500.

[0128] The central controller 500 can control the frequency of the power applied from the plasma generation system 100 to the plasma generator 2000. For example, the central controller 500 is electrically connected to the first RF generator of the first plasma generation system 101 and can control the first RF generator to change the drive frequency of the AC power applied to the first plasma generator of the first plasma generation system 101. The process by which the central controller 500 controls the drive frequency in each plasma generation system 100 will be described in detail below.

[0129] Besides the above components, the multi-station plasma processing system 10 may further include components for managing the plasma process, such as:

[0130] The plasma processing system 10 may include a system controller configured to control the above-mentioned power distributor 300, sensing unit 400, central control unit 500, etc., a memory unit configured to store commands executed by the system controller and data measured by the sensing unit 400, an input unit that receives input for controlling the plasma process from the outside, an output unit that outputs information related to the plasma processing system 10, and a communication unit configured to communicate with the outside.

[0131] The plasma processing system 10 may include a robotic arm configured to move a process object, such as a substrate 230, to the stations. The robotic arm may be controlled by a system controller. For example, the system controller may obtain progress data regarding the progress of the plasma process at each station and may control the robotic arm based on the obtained progress data.

[0132] The plasma processing system 10 may include a gas supplier configured to supply process gases used in the plasma process. The gas supplier may include a first gas supplier fluidly connected to at least some of the stations of the plasma processing system 10 to provide gases required for the process and / or a second gas supplier fluidly connected to the plasma generator 2000 to provide gases required for the formation of the plasma.

[0133] The first gas supplier can provide gas to each of the stations of the process chamber 200. For example, the first gas supplier can provide the same gas to the first through fourth stations 211, 212, 213, and 214. As another example, the gas supplier can include multiple gas reservoirs, each of which can be fluidly connected to different stations. The gas reservoirs can provide the same process gas or different process gases depending on the plasma process going on in each of the fluidly connected stations.

[0134] The second gas supplier can provide gas to the plasma generator 2000. For example, the second gas supplier can provide the same gas or different gas to the first to fourth plasma generators depending on the ongoing plasma process.

[0135] 3.Connections between components of the plasma process system

[0136] (1) First embodiment

[0137] The connections between the components of the multi-station plasma processing system 10 are described below.

[0138] FIG. 6 is a diagram illustrating the interconnections of components in a multi-station plasma processing system 10 according to one embodiment of the present disclosure.

[0139] For ease of explanation, the following description will be given of a plasma processing system 10 including four stations as described above with reference to FIG. 5, but the descriptions of the stations can be interpreted as being applicable to other stations unless otherwise specified.

[0140] The plasma processing system 10 may include first to fourth plasma generation systems 101, 102, 103, 104 and a process chamber 200, and the process chamber 200 may include first to fourth stations 211, 212, 213, and 214. Each station may include a head, a substrate, and a substrate holder on which the substrate is placed. For example, the first station 211 may include a first head 221 and a first substrate holder on which a first substrate 231 is placed.

[0141] Each station in the process chamber 200 may be fluidly connected to a corresponding plasma generator 2000. For example, the first head 221 of the first station 211 may be fluidly coupled to the first plasma generator 2001, and may provide process gas from the first plasma generator 2001 to the first head 221 of the first station 211. The first plasma generator 2001 may be connected to the interior space of the first station 211 through a specific flow path, rather than through the first head 221.

[0142] Each plasma generator 2000 fluidly coupled to a station may be electrically connected to a corresponding inverter 1300. For example, a first plasma generator 2001 fluidly coupled to a first station 211 may be electrically connected to a first inverter 1301.

[0143] The inverter 1300 can provide AC power to the plasma generator 2000. For example, the first plasma generator 2001 can be provided with a first AC power having a first drive frequency from the first inverter 1301 to induce plasma generation. The first inverter 1301 can receive a first switch signal from the central controller 500 and can provide the first AC power having a first drive frequency corresponding to the first switch signal to the first plasma generator 2001. Meanwhile, the drive frequency of the first AC power provided by the first inverter 1301 and the second drive frequency of the second AC power provided by the second inverter 1302 can be the same or different from each other depending on the plasma process to be performed.

[0144] The drive frequency of the AC power provided by the inverter 1300 may be altered in real time. For example, the central controller 500 may alter a first switch signal provided to the first inverter 1301 based on current and / or voltage phase data or phase data obtained from a first phase measurement unit 411 described below, and may accordingly alter a first drive frequency of the first AC power applied from the first inverter 1301 to the first plasma generator 2001.

[0145] The inverter 1300 that supplies power to the plasma generator 200 may be electrically connected to the power distributor 300. For example, the first to fourth inverters 1301, 1302, 1303, and 1304 may be electrically connected to the power distributor 300. The power distributor 300 may provide DC power to the first to fourth inverters 1301, 1302, 1303, and 1304. For example, the power distributor 300 may apply a first DC power to the first inverter 1301.

[0146] The power distributor 300 may provide different powers depending on the stations. For example, the power distributor 300 may provide a first DC power to a first inverter 1301 and a second DC power, different from the first DC power, to a second inverter 1302. In this case, the DC power provided by the power distributor 300 to each of the inverters 1300 may be set based on the plasma process performed at each of the stations and / or the power consumed by each of the power stations.

[0147] The magnitude of the DC power provided by the power distributor 300 to each of the inverters 1300 may be altered in real time. For example, the power distributor 300 may obtain data regarding the power consumed by the first inverter 1301 and the first plasma generator 2001 from the first partial power measurement unit 421 in response to the plasma process at the first station 211, and may alter the magnitude of the DC power applied to the first inverter 1301 based on the obtained partial power consumption data.

[0148] The plasma processing system 10 may include a sensing unit 400. The sensing unit 400 may include a phase measurement unit, a partial power measurement unit, and a total power measurement unit 430.

[0149] The phase measurement unit may measure the phase of a current or a voltage applied to the plasma generator 2000. For example, the first phase measurement unit 411 may measure the phase of a current or a voltage applied by the first inverter 1301 to the first plasma generator 2100. For this purpose, the first phase measurement unit 411 may be electrically connected to the first inverter 1301 and the first plasma generator 2001. Specifically, the first phase measurement unit 411 may be electrically coupled to a conductive line connecting the first inverter 1301 and the first plasma generator 2001.

[0150] As another embodiment, the phase measurement unit can measure the phase difference between the current and the voltage applied to the plasma generator 2000. Specifically, the first phase measurement unit 411 can measure the phase of the current applied to the first plasma generator 2001 from the first inverter 1301, obtain the phase of the voltage applied to the first plasma generator 2001 by obtaining a switch signal provided to the first inverter 1301, and obtain the phase difference data by comparing the phase of the current and the phase of the voltage.

[0151] The phase measurement unit can provide measurement data to the central controller 500 described below. For example, the first phase measurement unit 411 can transmit data to the central controller 500 regarding the phase of the current applied by the first inverter 1301 to the first plasma generator 2100. As another example, the first phase measurement unit 411 can transmit data to the central controller 500 regarding the phase difference between the voltage and current applied to the first plasma generator 2100. To this end, the phase measurement unit can perform wired or wireless data communication with the central controller 500.

[0152] Alternatively, the phase measurement unit may provide the above data to the power splitter 300 if necessary.

[0153] The partial power measurement unit can measure the power consumed by the inverter 1300 and the plasma generator 2000 when a plasma process is performed at the station. For example, the first partial power measurement unit 421 can measure the power consumed by the first plasma system 101 when a plasma process is performed at the first station 211 by measuring the current and voltage that the power distributor 300 applies to the first inverter 1301. To this end, the first partial power measurement unit 421 can be electrically connected to the first inverter 1301 and the power distributor 300. Specifically, the first partial power measurement unit 421 can be electrically connected to a power line through which the power distributor 300 transmits power to the first inverter 1301.

[0154] Meanwhile, the partial power measurement unit may be divided into a partial current measurement unit and a partial voltage measurement unit. The partial current measurement unit may measure the current applied to each of the inverters 1300, and the partial voltage measurement unit may measure the voltage applied to each of the inverters 1300. The partial current measurement unit requires first to fourth partial current measurement units corresponding to the first to fourth inverters 1301, 1302, 1303, and 1304, respectively, but the partial voltage measurement unit may measure the voltage of only one of the first to fourth inverters 1301, 1302, 1303, and 1304. The partial power measurement unit may calculate the power consumption corresponding to each of the stations based on the current and voltage data measured by the partial current measurement unit and the partial voltage measurement unit.

[0155] The partial power measurement units may provide the acquired power consumption data of each of the stations to the central control device 500 and / or the power distributor 300 .

[0156] The total power measurement unit 430 can measure the total power consumed by the plasma process performed in the plasma processing system 10. In other words, the total power measurement unit 430 can measure the total power consumed when the plasma process is performed in the first to fourth stations 211, 212, 213, and 214. The total power measurement unit 430 is electrically connected to the power distributor 300 and can measure the power provided from the power distributor 300 to the first to fourth inverters 1301, 1302, 1303, and 1304. The total power measurement unit 430 can provide data regarding the acquired total power consumption to the central controller 500 and / or the power distributor 300.

[0157] Alternatively, the total power measurement unit 430 may be omitted. For example, the central controller 500 can calculate the total power consumed when a plasma process is performed at the stations in the process chamber 200 based on the power data obtained from the partial power measurement units.

[0158] Although not shown in FIG. 6, the plasma processing system 10 may also include a system controller and a gas supplier.

[0159] The system controller can control the central control unit 500 and the gas suppliers. For example, the system controller can operate the central control unit 500 to control when to start and stop the plasma process and when the valves of the gas suppliers are opened. The gas suppliers have been described with reference to FIG. 5 and will not be described here.

[0160] (2) Second embodiment

[0161] 7 is a diagram showing the relationship of components in a multi-station plasma processing system 10 according to another embodiment of the present disclosure. In the following, in connection with the description of the plasma processing system 10, the description above with reference to FIG. 6 is omitted.

[0162] Referring to FIG. 7, the plasma processing system 10 may include a plurality of plasma generators 2000 and an inverter 1300 configured to apply AC power having a particular drive frequency to each of the plasma generators 2000.

[0163] The inverter 1300 can simultaneously provide AC power to the first to fourth plasma generators 2001, 2002, 2003, and 2004. The AC powers provided by the inverter 1300 to the first to fourth plasma generators 2001, 2002, 2003, and 2004 may have the same magnitude and different drive frequencies. For example, the inverter 1300 may provide a first AC power having a first drive frequency to the first plasma generator 2001 and a second DC power having a second drive frequency different from the first drive frequency to the second plasma generator 2002, where the magnitudes of the first AC power and the second AC power may be the same.

[0164] Since the plasma processing system 10 shown in FIG. 7 has a simpler structure than the plasma processing system 10 described with reference to FIG. 6, the physical volume of the plasma processing system 10 can be made smaller.

[0165] (3) Third embodiment

[0166] 8 is a diagram showing the relationship of components in a multi-station plasma processing system 10 according to another embodiment of the present disclosure. In the following, in connection with the description of the plasma processing system 10, the description above with reference to FIG. 6 is omitted.

[0167] 8, the plasma processing system 10 may include a plurality of plasma generators 2000 electrically connected in series with each other. For example, the plasma processing system 10 may include an inverter 1300 and first to fourth plasma generators 2001, 2002, 2003, and 2004 electrically connected to the inverter 1300, and the first to fourth plasma generators 2001, 2002, 2003, and 2004 may be electrically connected in series with each other. Specifically, the inverter 1300 may provide power via its first and second ends, and a first end of a first antenna structure of the first plasma generator 2001 may be electrically connected to the first end of the inverter 1300, a second end of the first antenna structure may be electrically connected to a first end of a second antenna structure of the second plasma generator 2002, a second end of the second antenna structure may be electrically connected to a first end of a third antenna structure of the third plasma generator 2003, a second end of the third antenna structure may be electrically connected to a first end of a fourth antenna structure of the fourth plasma generator 2004, and a second end of the fourth antenna structure may be electrically connected to the second end of the inverter 1300.

[0168] The first to fourth plasma generators 2001, 2002, 2003, and 2004 connected in series may be connected via electric elements such as a capacitor, an inductor, and / or a resistor.

[0169] The plasma processing system 10 may include one inverter 1300. The inverter 1300 may provide the same power to the first to fourth plasma generators 2001, 2002, 2003, and 2004. For example, the magnitude and phase of the AC power provided by the first inverter 1300 to the first to fourth plasma generators 2001, 2002, 2003, and 2004 may be the same. Accordingly, the difference in the induced electromotive force for inducing plasma in the first to fourth plasma generators 2001, 2002, 2003, and 2004 may be minimized. The power consumption of the first to fourth plasma generators 2001, 2002, 2003, and 2004 may be different.

[0170] The plasma processing system 10 may include one phase measurement unit 410. The phase measurement unit 410 may measure the phase of the voltage or current provided from the inverter 1300. The phase measurement unit 410 may provide information regarding the measured phase to the power distributor 300 or the central controller 500.

[0171] The power distributor 300 or the central control device 500 can control the inverter 1300 based on the phase information acquired from the phase measurement unit 410. For example, the power distributor 300 or the central control device 500 can acquire phase difference information between the voltage and the current applied to the first to fourth plasma generators 2001, 2002, 2003, and 2004 based on the current phase information acquired from the phase measurement unit 410 and the switch signal provided to the inverter 1300, and can provide the switch signal to the inverter 1300 so that the phase difference between the voltage and the current becomes small. For the plasma generator 2000, a plurality of phase measurement units 410 may be provided instead of one.

[0172] In a configuration in which multiple plasma generators 2000 are connected in series in the plasma processing system 10, the antenna structure 2100 of each of the plasma generators 2000 may include multiple inductive and capacitive elements.

[0173] For example, the antenna structure 2100 may include a first turn antenna arranged to surround the discharge tube 2200 and having a first radius of curvature, a second turn antenna arranged to surround the first turn antenna and having a second radius of curvature larger than the first radius of curvature, and an inter-turn capacitor electrically connecting the first turn antenna and the second turn antenna.

[0174] In the plasma processing system 10, the first turn antenna of the first plasma generator 2001 may be electrically connected to a first end of the inverter 1300, the second turn antenna of the first plasma generator 2001 may be electrically connected to a first turn antenna of the second plasma generator 2002, the second turn antenna of the second plasma generator 2002 may be electrically connected to a first turn antenna of the third plasma generator 2003, the second turn antenna of the third plasma generator 2003 may be electrically connected to a first turn antenna of the fourth plasma generator 2004, and the second turn antenna of the fourth plasma generator 2004 may be electrically connected to a second end of the inverter 1300. The first end of the inverter 1300 and the first turn antenna of the first plasma generator 2001 may be electrically connected via a capacitive element. Similarly, the second turn antenna of the first plasma generator 2001 and the first turn antenna of the second plasma generator 2002, the second turn antenna of the second plasma generator 2002 and the first turn antenna of the third plasma generator 2003, the second turn antenna of the third plasma generator 2003 and the first turn antenna of the fourth plasma generator 2004, and the second turn antenna of the fourth plasma generator 2004 and the second end of the inverter 1300 may be electrically connected via a capacitive element.

[0175] As another embodiment, the antenna structure 2100 may include a first layer antenna arranged to surround the discharge tube 2200 and having a first radius of curvature, a second layer antenna arranged to surround the discharge tube 2200 at a predetermined distance from the first layer antenna in a direction parallel to the central axis of the discharge tube 2200 and having a first radius of curvature, and an interlayer capacitor electrically connecting the first layer antenna and the second layer antenna.

[0176] In the plasma processing system 10, a first layer antenna of the first plasma generator 2001 may be electrically connected to a first end of the inverter 1300, a second layer antenna of the first plasma generator 2001 may be electrically connected to a first layer antenna of the second plasma generator 2002, a second layer antenna of the second plasma generator 2002 may be electrically connected to a first layer antenna of the third plasma generator 2003, a second layer antenna of the third plasma generator 2003 may be electrically connected to a first layer antenna of the fourth plasma generator 2004, and a second layer antenna of the fourth plasma generator 2004 may be electrically connected to a second end of the inverter 1300. The first end of the inverter 1300 and the first layer antenna of the first plasma generator 2001 may be electrically connected via a capacitive element. Similarly, the second layer antenna of the first plasma generator 2001 and the first layer antenna of the second plasma generator 2002, the second layer antenna of the second plasma generator 2002 and the first layer antenna of the third plasma generator 2003, the second layer antenna of the third plasma generator 2003 and the first layer antenna of the fourth plasma generator 2004, and the second layer antenna of the fourth plasma generator 2004 and the second end of the inverter 1300 may be electrically connected via a capacitive element.

[0177] In addition to the above examples, the antenna structure 2100 may include multiple antennas comprising multiple turns and / or multiple layers, and multiple capacitors electrically connecting the multiple antennas.

[0178] As described above, since the antenna structure 2100 includes both inductive and capacitive elements, even if the plasma generators 2000 are connected in series, the voltage applied to the inductive element in each of the plasma generators 2000 can be prevented from rising excessively, thereby improving the stability of the plasma induced in the plasma generators 2000.

[0179] (4) Fourth embodiment

[0180] 9 and 10 are diagrams illustrating a multi-station plasma processing system 10 according to another embodiment of the present disclosure.

[0181] The plasma processing system 10 may be implemented in other shapes depending on the size of the object on which the plasma process is performed. For example, when deposition, etching, or cleaning is performed on a large glass substrate as a display process using plasma, several plasma generating systems 100 may be required considering the process requirement area of ​​the large glass substrate. Of course, the plasma generating system 100 can be made large to accommodate the process requirement area of ​​the large glass substrate, but the use of several plasma generating systems 100 can make the process uniform and reduce the manufacturing cost of the system.

[0182] In the following, the plasma process is performed on a large glass substrate in a display process, but the technical idea of ​​the present disclosure is not limited thereto. In the following description, the repeated configurations as described above may be omitted unless there is a configuration that needs to be described additionally.

[0183] The substrate 230 disposed in the process chamber 200 may be divided into a plurality of process regions. For example, referring to FIG. 9, the substrate 230 may be divided into first to sixth process regions R1, R2, R3, R4, R5, and R6. The process regions are freely determined to distinguish regions in which a plasma process needs to be performed, and are not physically indicated on the substrate 230 for distinction. The number of process regions of the substrate 230 may correspond to the number of heads 220 in the process chamber 200.

[0184] For ease of explanation, the following describes a case where the substrate 230 is divided into six process regions, but the substrate 230 may be divided into other numbers of process regions having other shapes depending on the size or shape of the substrate 230.

[0185] The process chamber 200 may include heads 220 each corresponding to a process region of the substrate 230. For example, the process chamber 200 may include a first head 221 corresponding to a first process region R1. When the first head 221 corresponds to the first process region R1, a process can be sufficiently performed in the first process region R1 by a process gas flowing inside the first head 221.

[0186] 10, the plasma processing system 10 may include first to sixth inverters 1301, 1302, 1303, 1304, 1305, and 1306 corresponding to the first to sixth heads 221, 222, 223, 224, 225, and 226, respectively, in the process chamber 200, first to sixth plasma generators 2001, 2002, 2003, 2004, 2005, and 2006, a power distributor 300, and a central controller 500. The description with reference to FIG. 6, 7, or 8 may be similarly applied to the detailed connection relationship of the components.

[0187] The first to sixth inverters 1301, 1302, 1303, 1304, 1305, and 1306 and the first to sixth plasma generators 2001, 2002, 2003, 2004, 2005, and 2006 may be classified and controlled in different groups. For example, the first to third inverters 1301, 1302, and 1303 and the first to third plasma generators 2001, 2002, and 2003 may be classified in a first group, and the fourth to sixth inverters 1304, 1305, and 1306 and the fourth to sixth plasma generators 2004, 2005, and 2006 may be classified in a second group. The power distributor 300 may include a first power distributor that provides power to the first group and a second power distributor that provides power to the second group. The central controller 500 may include a first central controller that provides switch signals to the inverters in the first group and a second central controller that provides switch signals to the inverters in the second group.

[0188] 4. Multi-station method

[0189] In the following, a method for controlling the multi-station plasma processing system 10 will be described with reference to Figures 11 and 12. In the control method described below, it is assumed that the multi-station plasma processing system 10 is implemented with the structure shown in Figure 6, but the technical idea of ​​the present disclosure is not limited thereto, and the method can be similarly provided even if the structure of the plasma processing system 10 is implemented with a structure slightly modified from the structures shown in Figures 7, 8, and 9 or Figures 6-9.

[0190] (1) Power control method

[0191] FIG. 11 is a diagram illustrating a method for controlling power in a multi-station plasma processing system 10 according to one embodiment of the present disclosure.

[0192] Referring to FIG. 11, the power control method may include a substrate positioning step S1100, a gas supplying step S1200, a power distribution step S1300, an AC power providing step S1400, a power measuring step S1500, a power condition determining step S1600, an AC power parameter changing step S1700, and an AC power parameter maintaining step S1800.

[0193] These steps are explained in more detail below.

[0194] In the substrate placement step S1100, the substrate 230 may be placed in each of the stations. For example, the system controller may receive a user input and control a robot arm based on the received user input to place the substrate 230 prepared for the process on the substrate holder of each of the stations. The system controller may place the substrate 230 in a station where a plasma process is performed among the first to fourth stations 211, 212, 213, and 214.

[0195] In the gas supply step S1200, gas can be supplied to the stations and / or the plasma generator 2000. For example, the system controller can control the gas generators so that gases required for the process are supplied to the first to fourth stations 211, 212, 213, and 214. The system controller can control the gas supplier so that gases required for forming plasma and gases for the process are supplied to the first to fourth plasma generators 2001, 2002, 2003, and 2004.

[0196] In the power distribution step S1300, the power distributor 300 can distribute power to the inverters 1300. For example, the power distributor 300 can receive power from a power supply of the plasma processing system 10 or an external power supply, and distribute the power to the first to fourth inverters 1301, 1302, 1303, and 1304.

[0197] The power distributor 300 can provide the inverters 1300 with power having a magnitude required for the plasma process performed at each station. For example, the power distributor 300 provides the first inverter 1301 with a first power required for the first plasma process performed at the first station 211, and provides the second inverter 1302 with a second power required for the second plasma process performed at the second station 212. Here, if the first plasma process and the second plasma process are different, the first power and the second power may be different. Otherwise, the power provided by the power distributor 300 may be the same for each inverter.

[0198] The power distributor 300 may selectively provide power to the inverters 1300 as needed. For example, the power distributor 300 may provide power only to the inverters 1300 for those of the stations where a plasma process is performed. As another example, the power distributor 300 may receive data regarding the power consumed by each of the inverters 1300 from a partial power measurement unit and may shut off power to the inverters 1300 if there is a problem.

[0199] In the AC power providing step S1400, the inverter 1300 can provide AC power to the plasma generator 2000. For example, the first inverter 1301 can obtain a first DC power from the power distributor 300 and apply a first AC power having a first driving frequency to the first plasma generator 2001.

[0200] The AC powers provided by the inverters 1300 may have different drive frequencies. For example, the first inverter 1301 may apply a first AC power having a first drive frequency to the first plasma generator 2001, and the second inverter 1302 may apply a second AC power having a second drive frequency to the second plasma generator 2002. In other words, AC powers having different drive frequencies may be applied to the plasma generators 2000, respectively, and the frequencies may be individually controlled at the stations accordingly, as described below.

[0201] In the power measurement step S1500, the partial power measurement units may measure the power consumed when a plasma process is performed in each of the stations. For example, the first partial power measurement unit 421 may measure the power consumed when a first plasma process is performed in the first station 211. The first partial power measurement unit 421 may provide partial power measurement data relating to the measured power to the power distributor 300 and / or the central controller 500.

[0202] In the power measurement step S1500, the total power measurement unit 430 can measure the power consumed by all the stations. For example, the total power measurement unit 430 can transmit total power data obtained by measuring the power consumed by the first to fourth inverters 1301, 1302, 1303, and 1304 and the first to fourth plasma generators 2001, 2002, 2003, and 2004 to the power distributor 300 and / or the central controller 500.

[0203] In the power condition determination step S1600, the central control device 500 can determine whether the measured power is within an allowable power range. The allowable power range may refer to a reference power range set for a station. The allowable power range may be set based on a target power or amount of power in the plasma generation system 100. The allowable power range may be set differently for each station or for each plasma process to be performed.

[0204] For example, the central control device 500 may compare the first partial power consumption data of the first inverter 1301 and the first plasma generator 2001 measured in the power measurement step S1500 with a first allowable power range. The central control device 500 may maintain the magnitude or amount of the AC power when the first partial power data is within the first allowable power range, and may control the first inverter 1301 and / or the power distributor 300 to change the magnitude or amount of the first power applied to the first plasma generator 2001 when the first partial power data falls outside the first allowable power range.

[0205] The power condition determination step S1600 may be performed by the power distributor 300 or the system controller. Otherwise, the power condition determination step S1600 may be performed by a sub-controller corresponding to each station.

[0206] In the AC power parameter changing step S1700, the central controller 500 can change the parameters of the AC power applied to the plasma generator 2000. The AC power parameters may refer to the power, amount of power, voltage, current, etc. applied to the plasma generator 2000.

[0207] The central controller 500 can change the pattern of application of AC power to the plasma generator 2000 to change the parameters of the AC power applied to the plasma generator 2000 .

[0208] For example, the central controller 500 can change the parameters of the AC power applied to the plasma generator 2000 using a power supply operation and a freewheeling operation. The power supply operation may mean an operation of applying AC power to the plasma generator 2000 for a preset time, and the freewheeling period may mean an operation of not applying AC power to the plasma generator 2000 for a preset time. The central controller 500 can control the intensity or amount of AC power per unit time applied to the plasma generator 2000 by repeating the power supply operation and the freewheeling operation in a specific pattern. Specifically, in order to reduce the amount of power or power per unit time applied to the plasma generator 2000, the central controller 500 can perform the freewheeling operation continuously, or can make the proportion of the freewheeling operation greater than the power supply operation for a predetermined time. The central controller 500 can perform the power supply operation or the freewheeling operation using a switch signal provided to the inverter 1300.

[0209] Meanwhile, the AC power parameter changing step S1700 may be performed by the power distributor 300. For example, the power distributor 300 may change the magnitude of the power provided to the inverter 1300.

[0210] The AC power parameter changing step S1700 may be performed by a system controller, for example, the operation of controlling the power parameters by the central control unit 500 described above may be performed by the system controller.

[0211] In a maintaining AC power parameters step S1800, parameters of the AC power applied to the plasma generator 2000 may be maintained. For example, the central controller 500 may maintain the switch signal applied to the inverter 1300. However, as described below, if the drive frequency needs to be changed, the central controller 500 may change the switch signal applied to the inverter 1300.

[0212] In the AC power parameter maintaining step S1800, if certain conditions are met, for example, a predetermined time has elapsed, the method can enter the power measurement step S1500, which allows the AC power applied to the plasma generator 2000 to be controlled based on the power consumed by the inverter 1300 and the plasma generator 2000 in real time or periodically.

[0213] When using the above power control method, it is possible to control power individually at the stations of the plasma processing system 10, and to perform station-fit management for each station, even when different plasma processes are performed at the stations.

[0214] (2) Frequency control method

[0215] FIG. 12 is a diagram illustrating a method for controlling frequency in a multi-station plasma processing system 10 according to one embodiment of the present disclosure.

[0216] Referring to FIG. 12, the frequency control method may include a substrate placement step S2100, a gas supply step S2200, an AC power supply step S2300, a phase difference measurement step S2400, a phase difference condition determination step S2500, a frequency change step S2600, and a frequency maintenance step S2700.

[0217] These steps are explained in more detail below.

[0218] The substrate placement step S2100 and the gas supply step S2200 are applied in the same manner as in FIG.

[0219] In the AC power providing step S2300, the central controller 500 can use the inverter 1300 to provide AC power having a specific driving frequency to the plasma generator 2000. Specifically, the driving frequency of the AC power provided from the inverter 1300 can correspond to a switch signal provided from the central controller 500 to the inverter 1300. In other words, the frequency of the AC power provided by the inverter 1300 to the plasma generator 2000 can be controlled according to the switch signal provided from the central controller 500 to the inverter 1300.

[0220] For example, the central control device 500 can provide a first switch signal to the first inverter 1301, and the first inverter 1301 can provide AC power having a first drive frequency to the first plasma generator 2001 based on the first switch signal.

[0221] The central controller 500 can increase or decrease the driving frequency of the AC power provided by the inverter 1300 based on the phase difference measured in a phase difference measuring step S2400 described below.

[0222] In the phase difference measurement step S2400, the central controller 500 can obtain data regarding the phase difference between the voltage and current applied to each plasma generator 2000.

[0223] For example, the central controller 500 can obtain the first phase difference data by comparing first current phase data related to the phase of the current applied to the first plasma generator 2001 with first voltage phase data related to the phase of the voltage applied to the first plasma generator 2001. To this end, the first phase measurement unit 411 can measure the phase of the current applied from the first plasma generator 2001 and provide the first current phase data to the central controller 500, which can obtain the first voltage phase data related to the phase of the voltage applied to the first plasma generator 2001 based on the first switch signal provided to the first inverter 1301.

[0224] In the phase difference condition determining step S2500, the central controller 500 can determine whether the phase difference data obtained in the phase difference measuring step S2400 is within an allowable phase difference range.

[0225] The allowable phase difference range may be understood as a criterion for maintaining the induced plasma in the plasma generation system 100. Specifically, the resonant frequency (or impedance) of the plasma generator 2000 may be changed by the plasma formed when the plasma is induced in the plasma generation system 100, and the greater the difference between the resonant frequency of the plasma generator 2000 and the driving frequency of the AC power provided from the inverter 1300, the lower the power transmitted to the plasma generator 2000, and the less likely the plasma will be maintained. Accordingly, in order to form and maintain the plasma, it is necessary to continuously monitor the difference between the resonant frequency of the plasma generator 2000 and the driving frequency of the AC power provided from the inverter 1300, and control the driving frequency of the inverter 1300 to prevent the difference from increasing, and the allowable phase difference range may be set under this condition.

[0226] The allowable phase difference range may be set to be different for each station. For example, when the plasma processes or process environments performed in the first station 211 and the second station 212 are different, the first allowable phase difference range in the first station 211 may be different from the second allowable phase difference range in the second station 212.

[0227] The central controller 500 can compare the phase difference data with the allowable phase difference range. For example, the central controller 500 can obtain first phase difference data regarding the first inverter 1301 and the first plasma generator 2001, and can maintain a first drive frequency of the first AC power applied to the first plasma generator 2001 when the first phase difference data is within a first allowable phase difference range, and can change the first drive frequency of the first AC power applied to the first plasma generator 2001 to a second drive frequency when the first phase difference data is outside the first allowable phase difference range.

[0228] In the frequency changing step S2600, the central controller 500 can change the drive frequency of the AC power applied to the plasma generator 2000 by controlling the inverter 1300. For example, when it is necessary to change the drive frequency while applying a first switch signal corresponding to a first drive frequency to the first inverter 1301, the central controller 500 can apply a second switch signal corresponding to a second drive frequency different from the first drive frequency to the first inverter 1301.

[0229] Based on the phase difference data acquired in the above phase difference measurement step S2400, the central controller 500 can increase or decrease the drive frequency of the AC power provided by the inverter 1300. If the phase difference data indicates that the phase of the voltage applied to the plasma generator 2000 leads the phase of the current, the central controller 500 can decrease the drive frequency of the AC power provided by the inverter 1300. However, if the phase difference data indicates that the phase of the voltage applied to the plasma generator 2000 lags the phase of the current, the central controller 500 can increase the drive frequency of the AC power provided by the inverter 1300.

[0230] In the frequency maintaining step S2700, the frequency of the AC power applied to the plasma generator 2000 may be maintained. For example, the central controller 500 may maintain rather than change the switch signal applied to the inverter 1300. However, as described above, if the AC power parameters need to be changed, the central controller 500 may change the switch signal applied to the inverter 1300.

[0231] In the frequency maintaining step S2700, if a certain condition is met, e.g., a predetermined time has elapsed, the method can enter the phase difference measuring step S2400 and accordingly control within an acceptable range the phase difference between the current and voltage applied to the plasma generator 2000 in real time or periodically.

[0232] When using the above frequency control method, it is possible to individually control the frequency at the stations of the plasma processing system 10, thereby improving the efficiency of the plasma process performed at each station. In particular, when plasma is induced in several plasma generators 2000, the fluctuation periods of the resonant frequencies (or impedances) of the plasma generators 2000 are inevitably different, so that it is necessary to individually monitor and manage the plasma generators 2000 using the above frequency control method.

[0233] Meanwhile, the power control method and the frequency control method described above may be performed sequentially or in parallel. For example, after a substrate is placed and gas is supplied in the plasma processing system 10, the central controller 500 may perform the power control method and the frequency control method sequentially or in parallel. As another example, the central controller 500 may first perform the power control method and then perform the frequency control method. As another example, the central controller 500 may first perform the frequency control method and then perform the power control method.

[0234] 5. Implementation of Plasma Generation System

[0235] (1) Overall circuit design

[0236] 13 and 14, a method for implementing the plasma generation system 100 according to an embodiment will be described below. Here, the plasma generation system 100 will be described as performing a plasma process in four stations, but the technical idea of ​​the present disclosure is not limited thereto.

[0237] FIG. 13 is a block diagram of a plasma generation system 100 according to one embodiment of the present disclosure.

[0238] Referring to FIG. 13, the plasma generation system may include an AC power supply 1100, a line filter, a rectifier 1200, a SMPS (switched mode power supply), a power distributor 300, and a central controller 500.

[0239] The description of the AC power source 1100 and the rectifier 1200 is skipped since they are the same as above. The power distributor 300 is electrically connected to the rectifier 1200, so that it may receive DC power from the AC power source 1100.

[0240] The line filter is electrically interposed between the AC power source 1100 and the rectifier 1200 and serves to remove noise, and the SMPS may serve to provide power to the central control unit 500, which is operated using the power rectified by the rectifier 1200.

[0241] 13, the plasma generation system 100 may include first to fourth partial sensing units 401, 402, 403, 404, first to fourth inverters 1301, 1302, 1303, 1304, and first to fourth plasma generators 2001, 2002, 2003, 2004. Each inverter may be electrically connected to a respective plasma generator, and each partial sensing unit may measure an electrical characteristic related to each inverter. For example, the first inverter 1301 may provide power to the first plasma generator 2001, and the first partial sensing unit 401 may measure the power applied to the first inverter 1301 and the phase of the current flowing through the first plasma generator 2001.

[0242] Referring to FIG. 13, the central control unit 500 may include a frequency adjuster, a phase detector, a power calculator, a power comparator, and a DDS (Direct Digital Synthesizer).

[0243] The phase detector may obtain phase difference data. The phase detector may obtain phase difference data between the current and the voltage by using the current signal obtained from the sensing unit 400 and the voltage signal output from the DDS. Here, the phase difference data may mean data corresponding to the phase difference between the voltage and the current applied to the load as described above.

[0244] The phase detector may obtain phase difference data for each of the plasma generators in the stations. For example, the phase detector may obtain first phase difference data for the first plasma generator 2001 in the first station.

[0245] The phase detector may provide the phase difference data to a frequency adjuster.

[0246] The power calculator may obtain power consumption data, which may refer to data of the power consumed in the inverter 1300 and the plasma generator 2000.

[0247] The power calculator may use the voltage and current data obtained from the sensing unit 400 to obtain power consumption data.

[0248] The power calculator may calculate the power consumed at each station. For example, the power calculator may calculate a first power consumption consumed at the first inverter 1301 and / or the first plasma generator 2001 using the first current data and the first voltage data applied to the first inverter 1301 obtained via the first sensing unit 401. Here, the calculated power consumption data for each station may have different values.

[0249] The power calculator may provide power consumption data to the power comparator.

[0250] The power comparator may compare the power consumption data and the target power data.The power comparator may obtain power comparison data by comparing the power consumption data and the target power data.

[0251] Here, the power consumption data may represent the power consumed by the inverter 1300 and / or the plasma generator, or the power consumption data may represent the power applied to the inverter 1300 and / or the plasma generator.

[0252] Here, the target power data may represent the power that needs to be consumed by the inverter 1300 and / or the plasma generator, or the target power data may represent the power that needs to be applied to the inverter 1300 and / or the plasma generator.

[0253] The power comparator may compare the power consumption and the target power for each station. For example, the power comparator may obtain first power comparison data by comparing first power consumption data of a first station with a first target power.

[0254] Here, the power comparison data calculated for each station may have different values.

[0255] Here, the target power set for each station may be determined according to the type of process performed at each station, or the equipment or goals used at each station. The target power set for each station may have different values ​​or the same value.

[0256] The power comparator may provide the power comparison data to a frequency regulator.

[0257] The frequency regulator may calculate the drive frequency. The frequency regulator may calculate the drive frequency based on the phase difference data and the power comparison data. The method by which the frequency regulator calculates the drive frequency is described in detail in FIG. 16 and FIG. 17.

[0258] The frequency regulator may calculate a drive frequency for each station. For example, the frequency regulator receives first phase difference data from the phase detector and first power comparison data from the power comparator, and calculates a first drive frequency by using the first phase difference data and the first power comparison data. Here, the calculated drive frequency for each station may have a different value.

[0259] The frequency adjuster may provide a drive frequency to the DDS.

[0260] The DDS may provide a signal corresponding to a drive frequency to each inverter. For example, the DDS may provide a first signal corresponding to a first drive frequency to the first inverter 1301, and the DDS may provide a second signal corresponding to a second drive frequency to the second inverter 1302. Here, the first drive frequency and the second drive frequency may be different from each other.

[0261] The DDS may determine the signal to output by receiving data regarding the drive frequency from a frequency regulator. For example, the DDS may obtain the drive frequency from a frequency regulator and output a signal corresponding to the obtained drive frequency.

[0262] (2) Design of the sensing circuit

[0263] FIG. 14 is a diagram illustrating a process of acquiring sensed values ​​from the central control device 500 according to one embodiment of the present disclosure. In FIG. 14, for convenience of explanation, only a circuit for acquiring sensed values ​​for one station or one plasma generator is shown. In other words, the process of acquiring sensed values ​​shown in FIG. 14 is a process of acquiring sensed values ​​for the first inverter 1301 and the first plasma generator 2001, and the same circuit may be configured for other inverters and plasma generators.

[0264] Referring to FIG. 14, the first sensing unit 401 may include a first partial current measuring unit 421a, a first partial voltage measuring unit 421b, and a first phase measuring unit 411.

[0265] The first partial current measuring unit 421a may be electrically interposed between the first inverter 1301 and the power calculator. The first partial current measuring unit 421a may measure a current applied to the first inverter 1301 and provide the current to the power calculator. An ADC (Analog-to-Digital Converter) may be disposed between the first partial current measuring unit 421a and the power calculator to convert an analog signal measured by the first partial current measuring unit 421a into a digital signal.

[0266] The first partial voltage measurement unit 421b may be electrically interposed between the first inverter 1301 and the power calculator. The first partial measurement unit 421b may measure a potential difference between both ends of the first inverter 1301 and provide it to the power calculator. An ADC may be disposed between the first partial voltage measurement unit 421b and the power calculator to convert an analog signal measured by the first partial voltage measurement unit 421b into a digital signal.

[0267] The first phase measurement unit 411 may be coupled to the first conductor between the first inverter 1301 and the first plasma generator 2001. One end of the first phase measurement unit 411 may be coupled to the first conductor, and the other end of the first phase measurement unit 411 may be electrically connected to a phase detector.

[0268] Meanwhile, the phase detector may receive the first signal output from the DDS to the first inverter 1301. The phase detector may detect the phase of the voltage by using the first signal output from the DDS to the first inverter 1301, and generate phase difference data by using the current phase data obtained from the first phase measurement unit 411.

[0269] (3) Power control method

[0270] A method for controlling power applied to each station in a multi-station system according to an embodiment will be described below with reference to Figs.

[0271] FIG. 15 is a flow chart illustrating a method of plasma processing using the plasma generation system 100 according to one embodiment of the present disclosure.

[0272] Referring to FIG. 15, a method for plasma processing may include a step S3100 of placing a substrate, a step S3200 of supplying a sub-gas, a step S3300 of igniting a plasma, a step S3400 of changing an input gas, and a step S3500 of controlling power.

[0273] Each of the steps is described below. The plasma processing method may be performed independently at different stations of the multi-station system. The plasma processing method may also be performed simultaneously or at different times at different stations.

[0274] Step S3100 of placing the substrate is the same as step S1100 of arranging the substrate described in FIG. 11, so the description will be skipped.

[0275] After placing the target for the plasma process, a sub-gas may be supplied to the plasma generator 2000 (S3200), where the sub-gas may be interpreted as a gas for igniting the plasma. For example, the sub-gas may be argon gas.

[0276] A plasma may be ignited (S3300) by the plasma generator 2000. To ignite the plasma, the plasma generator 2000 may further include the DC electrode and / or an ignition coil as described above.

[0277] Next, the gas input to the plasma generator 2000 may be changed (S3400). Here, the changed gas may be interpreted as a gas for the plasma process. For example, the gas may be NF3 if the plasma process is used for cleaning. Also, the changed gas may be O2, N2, NH3, and / or H2 depending on the purpose of the plasma process.

[0278] The time when the input gas is changed may be later than the time when the plasma is ignited, or the time when the input gas is changed may be a predetermined time (e.g., 3 to 5 seconds) after power is applied to the plasma generator 2000 for plasma ignition, or the input gas may be changed when plasma ignition is detected, and the plasma ignition may be detected based on the power consumption in the plasma generator 2000.

[0279] At this time, the driving frequency of the AC power applied by the inverter 1300 to the plasma generator 2000 for igniting the plasma may be maintained at a constant value. In other words, in the process of igniting the plasma, the power control method by adjusting the frequency described below does not need to be used.

[0280] A plasma process may be performed while maintaining the plasma after changing the input gas.

[0281] While the plasma is maintained, the power consumed by the plasma generator 2000 may be controlled (S3500). The central controller 500 may change the power consumption in the plasma generator 2000 by changing the parameters of the AC power applied to the plasma generator 2000.

[0282] For example, the central controller 500 may control the power applied to the plasma generator 2000 via the inverter 1300 by using power feed or freewheeling operation as described above.

[0283] On the other hand, power control by power supply operation and freewheeling operation has an advantage that precise power control is possible, but the complexity of the circuit for implementing the inverter 1300 is relatively increased, and the resource of the central control device 500 for handling the control signal is also increased. This may be a large burden on the system design when there are multiple stations instead of one, i.e., when the plasma process is performed in a multi-station, as the number of stations increases.

[0284] As a way to compensate for this drawback, the central control device 500 may change the driving frequency of the AC power applied to each plasma generator 2000, and the AC power applied to each plasma generator 2000 or the power consumption in each plasma generator 2000.

[0285] The basic algorithm for power control by frequency adjustment is as follows:

[0286] The power consumption in the plasma generator 2000 may vary depending on the difference between the resonant frequency and the drive frequency of the plasma generator 2000 and the phase difference between the voltage and current applied to the plasma generator 2000. For example, when the phase of the voltage applied to the plasma generator 2000 and the phase of the current applied to the plasma generator 2000 become the same, the power consumption in the plasma generator 2000 may increase.

[0287] Furthermore, if the phase of the voltage applied to plasma generator 2000 leads the phase of the current applied to plasma generator 2000, then when the drive frequency increases, the imaginary part of the impedance of plasma generator 2000 increases, causing the output current to decrease, resulting in a decrease in the power consumed by plasma generator 2000. Conversely, when the drive frequency decreases, the imaginary part of the impedance of plasma generator 2000 decreases, causing the output current to increase, resulting in an increase in the power consumed by plasma generator 2000.

[0288] A method for controlling the power applied to or consumed by the plasma generator 2000 by adjusting the frequency will be described below with reference to FIGS. 16 and 17. FIG.

[0289] FIG. 16 is a flow chart illustrating a method for power control via frequency control according to one embodiment of the present disclosure.

[0290] Referring to FIG. 16, a method for controlling power by adjusting frequency may include a step S3510 of obtaining phase difference data, a step S3520 of obtaining power comparison data, and a step S3530 of maintaining or changing the frequency.

[0291] The central controller 500 may obtain phase difference data of the voltage and current applied to the plasma generator 2000. For example, a phase detector of the central controller 500 may obtain the phase difference data based on the voltage signal and the current signal obtained from the sensing unit 400.

[0292] The central controller 500 may obtain the power comparison data S3520.

[0293] First, the power calculator of the central controller 500 may directly or indirectly calculate the power consumed by the plasma generator 2000. For example, the power calculator may obtain signals of the voltage and current applied to the plasma generator 2000, and may measure the power consumption in the plasma generator 2000. As another example, the power calculator may obtain a signal of the voltage applied to the inverter 1300 and a signal of the current flowing through the plasma generator 2000, and may calculate the power consumed by the plasma generator 2000. To calculate the power, the power calculator may receive data of the electrical characteristics from the sensing unit 400 as described above.

[0294] A power comparator in the central controller 500 may compare the measured power and the target power calculated from the power calculator.

[0295] The step S3510 of obtaining phase difference data and the step of obtaining power comparison data described above may be performed in parallel, or one step may be performed before the other.

[0296] The central controller 500 may maintain or change the frequency of the AC power applied to the inverter 1300 (S3530).

[0297] The central controller 500 may adjust the frequency based on a specific rule, which may be based on, for example, the phase difference data and power comparison data discussed above.

[0298] Specific rules according to one embodiment are described below with reference to FIG.

[0299] FIG. 17 is a table summarizing the rules used in a method for power control via frequency control according to one embodiment of the present disclosure.

[0300] Here, the phase difference data is the phase of the voltage relative to the phase of the current, and can be interpreted as follows: When the phase difference data is positive (+), it is a case of "lagging", meaning that the phase of the current lags behind the phase of the voltage. When the phase difference data is negative (-), it is a case of "leading", meaning that the phase of the current leads the phase of the voltage.

[0301] In addition, the power comparison data is a value obtained by subtracting the measured power from the target power so that the target power is greater than the measured power when the power comparison data is positive (+) and the target power is less than the measured power when the power comparison data is negative (-).

[0302] On the other hand, the phase difference data and the power comparison data are not limited to being interpreted as described above.

[0303] Referring to FIG. 17, the central controller 500 may determine the drive frequency as follows.

[0304] When the phase difference data is 0 and the power comparison data is positive (+) or 0, the drive frequency can be maintained.

[0305] When the phase difference data is 0 and the power comparison data is negative (-), the driving frequency can be increased by a specific value. Here, the specific value can be determined based on the target power and the measured power. For example, the specific value may be determined by equation (1).

[0306] Equation (1) JPEG2025503351000002.jpg13170

[0307] Here, Pset means the target power, Pmea means the measured power, and f0 means the reference frequency. The reference frequency can be determined from 1 Hz to 1 kHz. When the reference frequency is increased, the time for the measured power to reach the target power may be shortened.

[0308] When the phase difference data is positive (+) and the power comparison data is positive (+), the driving frequency can be decreased by a specific value.

[0309] When the phase difference data is positive (+) and the power comparison data is 0, the drive frequency can be maintained.

[0310] When the phase difference data is positive (+) and the power comparison data is negative (-), the driving frequency can be increased by a specific value.

[0311] When the phase difference data is negative (-), the driving frequency can be increased by a fixed value regardless of the power comparison data. The central controller 500 may increase the driving frequency so that the phase difference data is positive (+) instead of negative (-). This is because when the phase difference data is negative (-), hard switching occurs in the switch of the inverter 130, which may cause damage to the switch. In other words, in the plasma process, maintaining the phase difference data positive (+) enables ZVS (zero voltage switching), thereby preventing damage to the switch.

[0312] Here, in order to quickly make the phase difference data positive (+), the fixed value can be relatively larger than the specific value mentioned above. For example, the fixed value can be determined between 100 Hz and 100 kHz. However, if the fixed value is too large, the driving frequency changes significantly, and the change degree of the impedance of the load also increases, which may result in the stability of the plasma being impaired.

[0313] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present disclosure, but are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified in other embodiments by a person skilled in the art to which the embodiment relates. Therefore, configurations related to the combination and modification should be interpreted as being included in the scope of the present disclosure.

[0314] Although the present disclosure has been described above with reference to the embodiments, the embodiments are merely examples and do not limit the present disclosure, and those skilled in the art will know that the present disclosure can be changed and modified in various ways not exemplified above without departing from the scope of the present disclosure. That is, the components described in detail in the embodiments of the present invention may be modified. Furthermore, differences regarding changes and modifications should be interpreted as being included in the scope of the present invention, which is determined by the scope of the claims.

Claims

1. 1. A multi-station plasma processing system, comprising: a process chamber including a first station and a second station; a first plasma generator coupled to the first station, the first station being separate from the first plasma generator; a first inverter configured to provide AC power to the first plasma generator; a first sensing unit configured to sense an electrical characteristic associated with the first plasma generator; a second plasma generator coupled to the second station, the second plasma generator being separate from the first plasma generator and the second station being separate from the second plasma generator; a second inverter configured to provide AC power to the second plasma generator; a second sensing unit configured to sense an electrical characteristic associated with the second plasma generator; a controller configured to control the first inverter and the second inverter; the first plasma generator includes a first discharge tube fluidly coupled to the first station and a first antenna structure disposed to surround the first discharge tube; the second plasma generator includes a second discharge tube fluidly coupled to the second station and a second antenna structure disposed to surround the second discharge tube; the first antenna structure is configured to receive AC power from the first inverter, induce plasma in the first discharge tube, generate first active species in the first discharge tube, and transfer the first active species from the first discharge tube to the first station; the second antenna structure is configured to receive AC power from the second inverter, induce plasma in the second discharge tube, generate second active species in the second discharge tube, and transfer the second active species from the second discharge tube to the second station.

2. The controller providing a first switch signal corresponding to a first driving frequency to the first inverter based on first sensing data obtained from the first sensing unit; 2. The system of claim 1, further configured to provide a second switch signal corresponding to a second drive frequency to the second inverter based on second sensing data obtained from the second sensing unit.

3. The controller receiving third sensing data after receiving the first sensing data; determining whether to change the first switch signal provided to the first inverter based on the third sensing data; receiving fourth sensing data after receiving the second sensing data; 3. The system of claim 2, further configured to determine whether to modify the second switch signal provided to the second inverter based on the fourth sensed data.

4. The controller obtaining first phase difference data and first power comparison data using the third sensed data; configured to use the first phase difference data and the first power comparison data to determine whether to modify the first switch signal provided to the first inverter; the first phase difference data corresponds to a phase difference between a voltage and a current applied to the first plasma generator; 4. The system of claim 3, wherein the first power comparison data corresponds to a difference between a first power applied to the first inverter and a first target power.

5. The controller 5. The system of claim 4, further configured to provide a third switch signal to the first inverter corresponding to a third drive frequency less than the first drive frequency when the first phase difference data indicates a lagging condition and the first power comparison data indicates the first power is less than the first target power.

6. The system of claim 5 , wherein a difference between the first drive frequency and the third drive frequency is determined based on the first target power.

7. The controller 5. The system of claim 4, further configured to maintain the first switch signal applied to the first inverter when the first phase difference data indicates a lagging condition and the first power comparison data indicates the first power is the same as the first target power.

8. The controller 5. The system of claim 4, further configured to provide a third switch signal to the first inverter corresponding to a third drive frequency greater than the first drive frequency when the first phase difference data indicates a lagging condition and the first power comparison data indicates the first power is greater than the first target power.

9. The system of claim 8 , wherein a difference between the first drive frequency and the third drive frequency is determined based on the first target power.

10. The controller 5. The system of claim 4, further configured to provide a third switch signal to the first inverter corresponding to a third drive frequency greater than the first drive frequency when the first phase difference data indicates a lead state.

11. 11. The system of claim 10, wherein the difference between the first drive frequency and the third drive frequency is a fixed value.

12. the first sensing unit is configured to acquire the first sensing data for a predetermined period of time and provide the first sensing data to the controller; the second sensing unit is configured to acquire the second sensory data for a predetermined period of time and provide the second sensory data to the controller; The controller changing the first switch signal provided to the first inverter based on the first sensing data periodically obtained so that the frequency of the AC power provided to the first plasma generator changes from the first driving frequency to a third driving frequency; 3. The system of claim 2, further comprising: a second switch signal provided to the second inverter, the second switch signal being changed based on the second sensed data obtained periodically, so that the frequency of the AC power provided to the second plasma generator changes from the second drive frequency to a fourth drive frequency.

13. The controller obtaining first phase difference data representing a phase difference between a voltage and a current applied to the first plasma generator based on the first sensing data and the first switch signal; If the first phase difference data does not satisfy a first allowable phase difference condition, the first switch signal provided to the first inverter is changed; obtaining second phase difference data representing a phase difference between a voltage and a current applied to the second plasma generator based on the second sensing data and the second switch signal; 13. The system of claim 12, further configured to modify the second switch signal provided to the second inverter if the second phase difference data does not satisfy a second acceptable phase difference condition.

14. the first sensing data corresponds to a phase of the current applied to the first plasma generator, and the first switch signal corresponds to a phase of the voltage applied to the first plasma generator; 14. The system of claim 13, wherein the second sensed data corresponds to a phase of the current applied to the second plasma generator and the second switch signal corresponds to a phase of the voltage applied to the second plasma generator.

15. a power divider electrically coupled to the first inverter and the second inverter; 2. The system of claim 1, wherein the power splitter is configured to provide a first DC power to the first inverter and a second DC power, the second DC power having a different magnitude than the first DC power, to the second inverter.

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