Substrate processing system, maintenance device, and maintenance method

Abstract

Disclosed is a substrate processing system comprising a plasma processing chamber, a transport chamber, a transport device, at least one light source, and a light receiving device. The plasma processing chamber comprises an optical window. The transport device is disposed in the transport chamber. The transport device comprises an end effector. The transport device is configured to move the end effector between a processing space in the plasma processing chamber and a space in the transport chamber. The at least one light source is attached to the end effector. The light receiving device is disposed outside the plasma processing chamber. The light receiving device is configured to receive, via the optical window, a reference light from the at least one light source transported into the plasma processing chamber.

Description

Substrate Processing System, Maintenance Device, and Maintenance Method 【0001】 Exemplary embodiments of the present disclosure relate to a substrate processing system, a maintenance device, and a maintenance method. 【0002】 The substrate processing system is used in plasma processing of a substrate. The substrate processing system includes a process module, a transfer module, and a control unit. The process module includes a plasma processing chamber that provides a processing space therein. Patent Document 1 discloses an optical correction device disposed in an atmospheric-open plasma processing chamber. 【0003】 Japanese Unexamined Patent Application Publication No. 2018-91836 【0004】 The present disclosure provides a technique for easily performing maintenance of a plasma processing chamber. 【0005】 In one exemplary embodiment, a substrate processing system is provided. The substrate processing system includes a plasma processing chamber, a transfer chamber, a transfer device, at least one light source, and a light receiving device. The plasma processing chamber has an optical window. The transfer chamber is connected to the plasma processing chamber. The transfer device is disposed in the transfer chamber. The transfer device has an end effector. The transfer device is configured to move the end effector between the processing space in the plasma processing chamber and the space in the transfer chamber. At least one light source is attached to the end effector. The light receiving device is configured to receive reference light from at least one light source transported into the plasma processing chamber through the optical window. 【0006】 According to one exemplary embodiment, maintenance of the plasma processing chamber is easily performed. 【0007】Figure 1 shows a substrate processing system according to one exemplary embodiment. Figure 2 is a diagram illustrating an example configuration of a plasma processing system. Figure 3 is a diagram illustrating an example configuration of a capacitively coupled plasma processing apparatus. Figure 4 shows an end effector according to one exemplary embodiment. Figure 5 is a partially enlarged cross-sectional view of a plasma processing chamber according to one exemplary embodiment. Figure 6 is a schematic diagram showing the field of view of a light receiving device according to one exemplary embodiment. Figure 7 shows a maintenance device according to one exemplary embodiment. Figure 8 is a flowchart showing a maintenance method according to one exemplary embodiment. Figure 9 is a partially enlarged cross-sectional view of a plasma processing chamber according to another exemplary embodiment. Figure 10 is a flowchart showing details of an example of a process for measuring the light intensity of a reference light. 【0008】 Various exemplary embodiments will be described in detail below with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals. 【0009】 Figure 1 shows a substrate processing system according to one exemplary embodiment. As shown in Figure 1, the substrate processing system PS comprises at least one process module, a transport module VTM, at least one light source 60, a light receiving device 80, and a control circuit MC. The substrate processing system PS may also comprise a plurality of process modules PM1 to PM6 as at least one process module. In one embodiment, the substrate processing system PS may further comprise load ports LP1 to LP4, an aligner AN, load lock modules LL1 and LL2, and a ring stocker SR. 【0010】The substrate processing system PS may further include a loader module LM. The loader module LM is an example of an atmospheric transport module. The loader module LM includes an atmospheric chamber ACH. The pressure in the atmospheric chamber ACH of the loader module LM is set to atmospheric pressure. The loader module LM may have an FFU (Fan Filter Unit). The loader module LM is, for example, an EFEM (Equipment Front End Module). The loader module LM is positioned between each of the load ports LP1 to LP4 and each of the load lock modules LL1 and LL2. The load ports LP1 to LP4 are arranged along one of a pair of edges along the longitudinal direction of the loader module LM. The load lock modules LL1 and LL2 are arranged along the other of a pair of edges along the longitudinal direction of the loader module LM. Each of the load ports LP1 to LP4 is configured to support a cassette CST placed on top of it. The cassette CST is a container that houses multiple circuit boards W inside. The cassette CST is, for example, a FOUP (Front-Opening Unified Pod). 【0011】 The loader module LM includes a transport device TR3. The transport device TR3 may be a transport robot. The transport device TR3 is located inside the atmospheric chamber ACH of the loader module LM. The transport device TR3 may include a movable part AR31 and an end effector FK31. In one example, the movable part AR31 is the arm of a transport robot. The end effector FK31 is attached to the tip of the movable part AR31 and is configured to support the substrate W placed on it. The transport device TR3 transports the substrate W based on operation instructions output by the control circuit MC, which will be described later. The transport device TR3 transports the substrate W between any two of the cassette CST, load lock modules LL1 and LL2, aligner AN, and ring stocker SR. 【0012】In one example, the ring stocker SR is positioned along the edge of the loader module LM in the short direction. The ring stocker SR may also be positioned along the edge of the loader module LM in the longitudinal direction. The ring stocker SR may also be positioned inside the loader module LM. The ring stocker SR is configured to accommodate ring members within it. 【0013】 In one embodiment, the aligner AN is located within the ring stocker SR. The aligner AN may be located along one of a pair of edges along the short direction of the loader module LM. The aligner AN may be located along the edge along the longitudinal direction of the loader module LM. The aligner AN may be located within the atmospheric chamber ACH of the loader module LM. 【0014】 Each of the load lock modules LL1 and LL2 is positioned between the transport module VTM and the loader module LM. Each of the load lock modules LL1 and LL2 provides a pressure reducing chamber DCH1 and DCH2. Each of the load lock modules LL1 and LL2 is connected to the loader module LM via a gate valve G3. Each of the load lock modules LL1 and LL2 is connected to the transport module VTM via a gate valve G2. 【0015】 The transport module VTM includes a vacuum chamber VCH. The vacuum chamber VCH is an example of a transport chamber. In the example shown in Figure 1, the transport module VTM is configured to transport the substrate W through a reduced-pressure space within the vacuum chamber VCH. The vacuum chamber VCH is connected to load lock modules LL1 and LL2, respectively, via gate valve G2. Process modules PM1 to PM6 are connected to the vacuum chamber VCH via gate valve G1. 【0016】The transport module VTM includes a transport device TR located inside the vacuum chamber VCH. The transport device TR may be a transport robot. The transport device TR has an end effector. In one example, the end effector is configured to support a substrate W. For example, the transport module VTM is configured to transport a substrate W. In the example shown in Figure 1, the transport device TR has movable parts AR11, AR12 and end effectors FK11, FK12. In one example, the movable parts AR11, AR12 are arms of a transport robot. The end effector FK11 is attached to the tip of the movable part AR11 and is configured to support a substrate W placed on it. The end effector FK12 is attached to the tip of the movable part AR12 and is configured to support a substrate W placed on it. The transport device TR transports the substrate W based on operation instructions output by a control circuit MC, which will be described later. 【0017】 The transport device TR holds the substrate W with end effectors FK11 and FK12. The transport device TR transports the substrate W through any two of the paths between the load lock modules LL1 and LL2, the process modules PM1 to PM6, and the vacuum chamber VCH of the transport module VTM. 【0018】 In one embodiment, each of the process modules PM1 to PM6 is configured to perform a dedicated process on the substrate W. At least one of the process modules PM1 to PM6 is a substrate processing system, such as the plasma processing apparatus 1 described later. 【0019】 The control circuit MC is, for example, a computer. The control circuit MC may consist of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and auxiliary storage devices, etc. The CPU operates based on a program stored in the ROM or auxiliary storage device and controls each part of the board processing system PS. 【0020】The substrate processing system PS is not necessarily limited to the one shown in Figure 1. For example, the number of process modules and / or transport modules in the substrate processing system may differ from those shown in Figure 1. For example, the number of load ports may be five or more, and the number of load ports may be any number. The substrate processing system may also be a system in which multiple module groups, each including process modules and load lock modules, are connected to a loader module (a so-called loader type system). The substrate processing system may also be a system in which two or more process modules are arranged around a transport module and connected so as to surround the transport module (a so-called cluster type system). 【0021】 Figure 2 is a diagram illustrating an example configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space, and at least one gas outlet for discharging gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20, which will be described later, and the gas outlet is connected to an exhaust system 40, which will be described later. The substrate support unit 11 is located in the plasma processing space and has a substrate support surface for supporting a substrate. 【0022】The plasma generation unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), ECR (Electron Cyclotron Resonance) plasma, helicon wave excited plasma (HWP), or surface wave plasma (SWP), etc. Various types of plasma generation units, including AC (Alternating Current) plasma generation units and DC (Direct Current) plasma generation units, may also be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes an RF (Radio Frequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz. 【0023】The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described herein. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 is implemented, for example, by a computer 2a. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The functions realized by the processing unit 2a1 described herein may be implemented in a circuit or processing circuit, including a general-purpose processor, an application-specific processor, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (Central Processing Unit), a conventional circuit, and / or a combination thereof, programmed to realize the described functions. The processor is considered to be a circuit or processing circuit, including transistors and other circuits. The processor may be a programmed processor that executes a program stored in the storage unit 2a2. This program may be pre-stored in the storage unit 2a2 or retrieved via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or it may be a communication line connected to the communication interface 2a3. The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).In this disclosure, circuits, units, and means are hardware programmed to perform or configured to perform the functions described. Such hardware may be any hardware described in this disclosure, or any hardware known to be programmed to perform or execute the functions described. If such hardware is a processor that is considered to be a type of circuit, such circuit, means, or unit is a combination of hardware and software used to constitute such hardware and / or processor. 【0024】 The following describes an example configuration of a capacitively coupled plasma processing apparatus as an example of a plasma processing apparatus 1. Figure 3 is a diagram illustrating an example configuration of a capacitively coupled plasma processing apparatus. 【0025】 The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply system 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is located inside the plasma processing chamber 10. The shower head 13 is located above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, the side walls 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10. 【0026】The substrate support portion 11 includes a main body portion 111 and a ring member 112. The main body portion 111 has a central region 111a for supporting the substrate W and an annular region 111b for supporting the ring member 112. A wafer is an example of a substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is placed on the central region 111a of the main body portion 111, and the ring member 112 is placed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Therefore, the central region 111a is also called the substrate support surface for supporting the substrate W, and the annular region 111b is also called the ring support surface for supporting the ring member 112. 【0027】In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is placed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic chuck electrode 1111b placed within the ceramic member 1111a. The electrostatic chuck electrode 1111b is also called a clamping electrode. In one embodiment, the electrostatic chuck electrode 1111b is electrically connected or coupled to a chuck power supply. The chuck power supply may be a DC power supply or an AC power supply. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Furthermore, other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have an annular region 111b. In this case, the ring member 112 may be placed on the annular electrostatic chuck or the annular insulating member, or it may be placed on both the electrostatic chuck 1111 and the annular insulating member. In addition, at least one bias electrode, which is electrically connected or coupled to the power supply 31 and / or power supply 32 described later, may be placed inside the ceramic member 1111a. In this case, at least one bias electrode functions as a lower electrode. Also, the conductive member of the base 1110 and the bias electrode inside the ceramic member 1111a may function as multiple lower electrodes. In one embodiment, the first voltage generation unit 32a, which functions as a voltage pulse generation unit described later, is electrically connected or coupled to the bias electrode inside the ceramic member 1111a, and the first RF generation unit 31a, described later, is electrically connected or coupled to the conductive member of the base 1110. Furthermore, the electrostatic chuck electrode 1111b may function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower electrode. 【0028】 The ring member 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one covering ring. The edge rings are formed of a conductive or insulating material, and the covering rings are formed of an insulating material. 【0029】 The substrate support section 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck 1111, the ring member 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed within the base 1110, and one or more heaters are arranged within the ceramic member 1111a of the electrostatic chuck 1111. The substrate support section 11 may also include a heat transfer gas supply section configured to supply heat transfer gas to the gap between the back surface of the substrate W and the central region 111a. 【0030】 The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlet ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s through the plurality of gas inlet ports 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a. 【0031】 The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one processing gas to the shower head 13 from a corresponding gas source 21 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of at least one processing gas. 【0032】The power supply system 30 includes a power supply 31 that is electrically connected to or coupled to the plasma processing chamber 10. In one embodiment, the power supply 31 is electrically connected to or coupled to the plasma processing chamber 10 via at least one impedance matcher. The impedance matcher may be a mechanically controlled matcher or an electronically controlled matcher. The power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the power supply 31 can function as at least part of the plasma generation unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W. 【0033】 The power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode and is configured to generate a source RF signal (source RF power) to generate plasma in the plasma processing space 10s. In one embodiment, the first RF generation unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matcher. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to at least one lower electrode and / or at least one upper electrode. 【0034】The second RF generation unit 31b is electrically connected to or coupled to at least one lower electrode and is configured to generate a bias RF signal (bias RF power). In one embodiment, the second RF generation unit 31b is electrically connected to or coupled to at least one lower electrode via at least one impedance matcher. If the first RF generation unit 31a is electrically connected to or coupled to a lower electrode, the second RF generation unit 31b may be electrically connected to or coupled to the same lower electrode, or to a different lower electrode. The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a lower frequency than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed. 【0035】 The power supply system 30 may also include a power supply 32 that is electrically connected to or coupled to the plasma processing chamber 10. The power supply 32 includes a first voltage generation unit 32a and a second voltage generation unit 32b. In one embodiment, the first voltage generation unit 32a is electrically connected to or coupled to at least one lower electrode and is configured to generate a first voltage signal. The generated first voltage signal is applied to at least one lower electrode. In one embodiment, the second voltage generation unit 32b is electrically connected to or coupled to at least one upper electrode and is configured to generate a second voltage signal. The generated second voltage signal is applied to at least one upper electrode. 【0036】In various embodiments, the first and / or second voltage signals may be pulsed. In this case, the first voltage generation unit 32a and / or the second voltage generation unit 32b function as voltage pulse generation units configured to generate a sequence of voltage pulses. Thus, the sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. In one embodiment, the sequence of voltage pulses has a plurality of cycles, each cycle including a burst of voltage pulses in a first period and a constant reference voltage in a second period. That is, in the sequence of voltage pulses, the burst of voltage pulses is repeated. The absolute value of the voltage level of the voltage pulse is greater than the absolute value of the voltage level of the reference voltage. The voltage pulse may have an arbitrary waveform having a rectangle, trapezoid, triangle, or a combination thereof, and the arbitrary waveform may change over time. The voltage pulse may have positive polarity or negative polarity. The sequence of voltage pulses may also include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. The first and second voltage generation units 32a and 32b may be provided in addition to the power supply 31, and the first voltage generation unit 32a may be provided in place of the second RF generation unit 31b. 【0037】 The exhaust system 40 may be connected to, for example, a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof. 【0038】As described above, at least one process module PM1 to PM6 has a plasma processing chamber 10. The plasma processing chamber 10 provides a processing space 10s inside. The vacuum chamber VCH is connected to the plasma processing chamber 10. The processing space 10s in the plasma processing chamber 10 and the space in the vacuum chamber VCH are connected via a gate valve G1. The transport device TR may have end effectors FK11 and FK12. In one example, the end effector FK11 is located at the tip of the movable part AR11. In one example, the end effector FK12 is located at the tip of the movable part AR12. The transport device TR is configured to move the end effectors FK11 and FK12 between the processing space 10s in the plasma processing chamber 10 and the space in the vacuum chamber VCH. For example, the transport device TR is configured to transport the substrate W on the end effectors FK11 and FK12 to the processing space 10s. The control circuit MC may be integrated with the control unit 2. 【0039】 The configuration of the end effector FK11 will be described below with reference to Figure 4. Figure 4 is a diagram showing an end effector according to one exemplary embodiment. Although Figure 4 shows the configuration of the end effector FK11 as an example, the configuration of the end effector FK12 may also be shown. The end effector FK11 has a horseshoe shape when viewed from the vertical direction. In one embodiment, the end effector FK11 includes a main body FKM and a pair of tip portions FKB. The pair of tip portions FKB protrude from the main body FKM. A gap is defined between the pair of tip portions FKB. The substrate W is supported on the end effector FK11 such that its central axis passes through the gap. 【0040】At least one light source 60 is attached to the end effector FK11. In one embodiment, at least one light source 60 may be attached to the side FKS of the end effector FK11. In the example shown in Figure 4, at least one light source 60 is attached to the side FKS of one of the pair of tip sections FKB. In one example, at least one light source 60 includes at least one light-emitting diode. At least one light source 60 is electrically connected to a power supply unit 6. The power supply unit 6 may be located separately from at least one light source 60. At least one light source 60 is configured to emit reference light. 【0041】 In one embodiment, the substrate processing system PS may include a distance measuring module 5. The distance measuring module 5 has distance sensors. In the example shown in Figure 4, the distance measuring module 5 has distance sensors 52a and 52b. Distance sensors 52a and 52b are attached to a pair of tip portions FKB, respectively. The distance measuring module 5 is configured to measure the distance between the distance sensors 52a and 52b and an object. 【0042】 For example, the distance measurement module 5 may be a confocal displacement sensor. The distance measurement module 5 may include a light source 51, a photoelectric converter 53, and a processing circuit 54. The distance sensors 52a and 52b may be optical input / output units. In one example, the light source 51, the photoelectric converter 53, and the processing circuit 54 may be included in the distance measurement module body 50. The distance measurement module body 50 is located separately from the end effector FK11. For example, the distance sensors 52a and 52b and the distance measurement module body 50 are connected by a plurality of optical fibers FB. The measurement light from the light source 51 is emitted from the distance sensors 52a and 52b. The reflected light reflected by the object is incident on the distance sensors 52a and 52b. The photoelectric converter 53 outputs an electrical signal corresponding to the reflected light. The processing circuit 54 is configured to obtain the distance between the distance sensors 52a and 52b and the object from the electrical signal of the photoelectric converter 53. 【0043】In one embodiment, the substrate processing system PS may include a heater HT. The heater HT is configured to heat at least one light source 60. The heater HT is attached to the end effector FK11. The heater HT may be attached to at least one light source 60. In the example shown in FIG. 4, the heater HT is attached along the longitudinal direction of at least one light source 60. According to the heater HT, at least one light source 60 can be heated uniformly. 【0044】 Hereinafter, the configuration of the light receiving device 80 will be described with reference to FIGS. 5 and 6. FIG. 5 is a partially enlarged cross-sectional view of a plasma processing chamber according to one exemplary embodiment. FIG. 6 is a schematic diagram showing the field of view of a light receiving device according to one exemplary embodiment. The plasma processing chamber 10 has an optical window 70. In one embodiment, the plasma processing chamber 10 has a side wall 10a including the optical window 70. In one example, the side wall 10a may include an optical window 71 different from the optical window 70. In the example shown in FIG. 5, the optical window 70 and the optical window 71 are disposed in an opening formed in the side wall 10a. The optical window 70 is disposed inside the optical window 71. The optical window 70 separates the processing space 10s and the space inside the opening in the plasma processing chamber 10. The optical window 70 is exposed to the processing space 10s. The optical window 71 is disposed outside the optical window 70. The optical window 71 maintains the airtightness inside the plasma processing chamber 10. 【0045】The light-receiving device 80 is located outside the plasma processing chamber 10. The light-receiving device 80 can be optically coupled to the processing space 10s via an optical window 70. In one embodiment, the light-receiving device 80 may have a spectrometer 81 and a focusing optical system 82. The spectrometer 81 and the focusing optical system 82 are connected to each other, for example, by an optical fiber. In the example shown in Figure 5, the focusing optical system 82 is mounted on the side wall 10a so as to cover an opening in which optical windows 70, 71 are located. In one example, the focusing optical system 82 includes a lens 82a. For example, light from the processing space 10s emitted through the optical window 70 reaches the spectrometer 81 via the focusing optical system 82 and the optical fiber. In one example, the light-receiving device 80 is configured to observe the plasma from the plasma light of the plasma in the processing space 10s emitted through the optical window 70. In another example, the focusing optical system 82 may include a parabolic mirror instead of a lens 82a. 【0046】 The field of view of the light-receiving device 80 depends on the numerical aperture NA of the optical fiber connected to the focusing optical system 82 and the focal length L of the lens 82a. The numerical aperture NA of the optical fiber is given by the following formula (1). The radius R of the field of view of the light-receiving device 80 is given by the following formula (2). NA = n × sinθ ... Formula (1) R = L × tan(arcsin(NA)) ... Formula (2) n is the refractive index of the medium around the optical fiber. In one example, if the medium around the optical fiber is air, n can be approximated as n = 1. θ is the maximum angle between the central axis of the optical fiber and the incident ray at an angle that can totally reflect light through the optical fiber. 【0047】 As described above, the transport device TR is configured to transport the substrate W on the end effector FK11 to the processing space 10s. Therefore, at least one light source 60 attached to the end effector FK11 is transported to the processing space 10s by the transport device TR. The light receiving device 80 is configured to receive reference light from at least one light source 60 transported to the processing space 10s through the optical window 70. 【0048】In one embodiment, the light receiving device 80 may be configured to measure the amount of reference light emitted by at least one light source 60 through the optical window 70. The control circuit MC may be configured to calibrate the light receiving device 80 according to the amount of reference light measured by the light receiving device 80. For example, when the measured amount of reference light is smaller than a predetermined value, the control circuit MC may be configured to adjust the sensitivity of the light receiving device 80 so that the measured amount of reference light approaches the predetermined value. 【0049】 The components disposed in the plasma processing chamber 10 are consumed by the plasma in the processing space 10s. The decrease in the transmittance of the optical window 70 due to consumption may affect the observation of the plasma through the optical window 70 by the light receiving device 80. According to the substrate processing system PS, since the reference light from at least one light source 60 is observed by the spectroscope 81 through the optical window 70, the consumption of the optical window 70 can be easily confirmed. Therefore, the substrate processing system PS can easily perform the maintenance of the plasma processing chamber 10. Further, the substrate processing system PS can easily calibrate the light receiving device 80. 【0050】 In one embodiment, the substrate processing system PS may include a diffusion plate 62. As shown in FIGS. 4 and 5, the diffusion plate 62 is attached to at least one light source 60. In FIG. 6, the diffusion plate 62 is not shown. The diffusion plate 62 is configured to diffuse the reference light emitted by at least one light source 60. In one example, the diffusion plate 62 may be formed of frosted glass. In one example, the diffusion plate 62 may be formed of a translucent resin. The reference light can be diffused by being scattered on the surface and / or inside of the diffusion plate 62. The area irradiated by the reference light diffused through the diffusion plate 62 is wider than the area irradiated by the reference light not passing through the diffusion plate 62. Therefore, when the reference light is diffused through the diffusion plate 62, the reference light is likely to irradiate the optical window 70 even if at least one light source 60 is displaced, so the amount of reference light measured by the light receiving device 80 is likely to be stable. 【0051】In one embodiment, the control circuit MC may be configured to control the transport device TR and at least one light source 60 so as to emit a reference light when transporting the substrate W, which is placed on the end effector FK11, to the processing space 10s. According to the substrate processing system PS, maintenance of the plasma processing chamber 10 is performed during idle time, such as the idle time of at least one process module PM1 to PM6. 【0052】 As shown in Figure 6, in one embodiment, at least one light source 60 may include an array 61 of multiple light sources 60. For example, at least one light source 60 includes an array 61 of multiple light sources 60 arranged horizontally. The multiple light sources 60 may be arranged at equal intervals. The array 61 has its longitudinal direction in the horizontal direction. In one example, the number of multiple light sources 60 is five. 【0053】 In one embodiment, the light-receiving device 80 may have a field of view V in the optical window 70. For example, the condensing optical system 82 can define the field of view of the light-receiving device 80. The light-receiving device 80 uses the field of view V as its measurement range. The horizontal width d1 of the array 61 may be greater than the horizontal width d2 of the field of view V in the optical window 70 of the light-receiving device 80. In one embodiment, the horizontal width d1 of the array 61 may be greater than the horizontal width d3 of the condensing optical system 82. In this case, since the horizontal width d1 of the array 61 is greater than the width d2 of the field of view V, even if there is a horizontal displacement in the position of the end effector FK11 to which the array 61 is attached, the area of ​​the array 61 included in the field of view V is unlikely to change. In the example shown in Figure 6, since the horizontal width d1 of the array 61 is greater than the horizontal width d3 of the condensing optical system 82, the horizontal width d1 of the array 61 is definitely greater than the horizontal width d3 of the condensing optical system 82. As a result, the amount of light from the reference light measured by the light receiving device 80 becomes stable. 【0054】As described above, the substrate processing system PS may include a distance measuring module 5. In one embodiment, the substrate processing system PS may further include a reference section. The reference section is located below the end effector FK11 in the movement path of the end effector FK11. In one example, the reference section may include the central region 111a and / or the annular region 111b of the substrate support section 11. The reference section may be located outside the plasma processing chamber 10. The reference section may be part of the gate valve G1. In one embodiment, the control circuit MC may be configured to control the transport device TR to position at least one light source 60 at a predetermined position so that reference light from at least one light source 60 is received by the light receiving device 80 via the optical window 70. With the distance measuring module 5, the distance between the end effector FK11 to which distance sensors 52a and 52b are attached and the object is measured, making it easier to determine the position of at least one light source 60 in the field of view V. With the reference section, it is easier to determine the position of at least one light source 60 in the vertical direction. According to the control circuit MC, at least one light source 60 is positioned at a predetermined location, so the area of ​​the array 61 included in the field of view V is unlikely to change. As a result, the amount of light from the reference light measured by the light receiving device 80 is stable. 【0055】 As described above, the substrate processing system PS may include a heater HT. In one example, at least one light source 60 has at least one light-emitting diode. In one embodiment, the control circuit MC may be configured to control the heater HT and the transport device TR to transport at least one light source 60 into the processing space 10s inside the plasma processing chamber 10 after heating the at least one light source 60 outside the plasma processing chamber 10 in order to reduce the temperature difference between the plasma processing chamber 10 and the temperature of at least one light source 60. 【0056】The temperature of the superstructure of the plasma processing chamber 10, including the showerhead 13 described above, tends to rise. For example, the temperature of the superstructure can rise to about 150°C. The end effector FK 11 and at least one light source 60 transported into the processing space 10s are heated by radiant heat from the superstructure. With the heater HT, at least one light source 60 is preheated before being transported into the processing space 10s, so the rate of temperature change of at least one light source 60 in the processing space 10s is reduced. Therefore, the reference light emitted from at least one light source 60 becomes stable. If at least one light source 60 is at least one light-emitting diode, the wavelength of the reference light changes according to the temperature of at least one light-emitting diode. With the heater HT, at least one light source 60 is preheated before being transported into the processing space 10s, so the wavelength of the reference light becomes stable. As a result, the amount of light for each of the multiple wavelengths becomes stable, improving the accuracy of calibration. 【0057】 In one embodiment, the control circuit MC may be configured to control the heater HT to stop heating at least one light source 60 in order to suppress the temperature rise of at least one light source 60 within the plasma processing chamber 10. In one embodiment, the control circuit MC may be configured to control at least one light source 60 and the heater HT to stop heating at least one light source 60 and to emit reference light from at least one light source 60. According to the control circuit MC, the temperature rise of at least one light source 60 in the processing space 10s is suppressed. 【0058】Refer to Figure 7 below. Figure 7 shows a maintenance device according to one exemplary embodiment. The maintenance device CS comprises at least one light source 60, a transport device TR, and a control circuit MC. In one example, the transport device TR is a transport robot. The transport device TR has a movable part AR 11. In one example, the movable part AR 11 is the arm of the transport robot. At least one light source 60 may be attached to the movable part AR 11. The control circuit MC is configured to transport the movable part AR 11 to the processing space 10s inside the plasma processing chamber 10 so that the reference light from at least one light source 60 is received by a light receiving device 80 located outside the plasma processing chamber 10 through the optical window of the plasma processing chamber 10. With the maintenance device CS, maintenance of the plasma processing chamber 10 can be easily performed as described above. 【0059】 In one embodiment, the maintenance device CS may further include a vacuum chamber VCH1. The vacuum chamber VCH1 houses a transport device TR in its internal space. The vacuum chamber VCH1 is configured to be detachably attached to the plasma processing chamber 10 so as to hermetically connect the internal space and the processing space 10s. In one example, the vacuum chamber VCH1 includes a gate valve G1. The maintenance device CS allows for easy maintenance even on existing substrate processing systems that do not have at least one light source 60. 【0060】 The following describes a maintenance method according to one exemplary embodiment with reference to Figure 8. Figure 8 is a flowchart showing a maintenance method according to one exemplary embodiment. The maintenance method shown in Figure 8 (hereinafter referred to as "method MT") is performed in the substrate processing system PS. 【0061】Method MT includes steps STa, STb, STc, STd, and STe. First, in step STa, at least one light source 60 is heated outside the plasma processing chamber 10 to reduce the temperature difference between the plasma processing chamber 10 and the temperature of at least one light source 60. Subsequently, in step STb, heating to at least one light source 60 is stopped to suppress the temperature rise of at least one light source 60 inside the plasma processing chamber 10. Subsequently, in step STc, the end effector FK11 is transported to the processing space 10s inside the plasma processing chamber 10. As described above, the end effector FK11 is located at the tip of the movable part AR11 of the transport device TR. At least one light source 60 is attached to the end effector FK11. In step STc, at least one light source 60 is transported to the processing space 10s. The order in which steps STb and STc are performed may be reversed. The heating of at least one light source 60 may be stopped outside the plasma processing chamber 10 or inside the plasma processing chamber 10. 【0062】 Next, in step STd, a light receiving device 80 located outside the plasma processing chamber 10 measures the amount of light from at least one reference light source 60 that it receives through the optical window 70 of the plasma processing chamber 10. Finally, in step STe, the light receiving device 80 is calibrated according to the amount of light from the reference light measured by the light receiving device 80. 【0063】 Hereinafter, a light-receiving device 80A according to another exemplary embodiment will be described with reference to Figure 9. Figure 9 is a partially enlarged cross-sectional view of a plasma processing chamber according to another exemplary embodiment. Hereinafter, the light-receiving device 80A will be described in terms of differences from the light-receiving device 80. 【0064】The light receiving device 80A includes a focusing optical system 82 and an adjustment mechanism 90. The focusing optical system 82 is optically coupled to the optical window 70. The adjustment mechanism 90 is configured to adjust the optical axis direction of the focusing optical system 82 so as to maximize the amount of reference light received by the light receiving device 80A via the focusing optical system 82. For example, the adjustment mechanism 90 is configured to adjust the tilt of the focusing optical system 82 in the direction of the optical axis. In one example, the adjustment mechanism 90 is configured to adjust the tilt of the focusing optical system 82 in the direction of the optical axis along a first tilt direction p1 and / or a second tilt direction p2. The second tilt direction p2 intersects the first tilt direction p1. In one example, in the first tilt direction p1, the tilt of the optical axis of the focusing optical system 82 is rotated along the vertical direction. In one example, in the second tilt direction p2, the tilt of the optical axis of the focusing optical system 82 is rotated along the horizontal direction. 【0065】 According to the light receiving device 80A, the optical axis direction of the focusing optical system 82 is adjusted to maximize the amount of reference light received by the light receiving device 80A. Since the reduction in the amount of reference light received by the light receiving device 80A due to the misalignment of the optical axis direction of the focusing optical system 82 is eliminated, the light receiving device 80A can measure the amount of reference light more accurately. The control circuit MC may be configured to control the adjustment mechanism 90. For example, the adjustment mechanism 90 may be configured to be controlled by the control circuit MC to adjust the optical axis direction of the focusing optical system 82 so as to maximize the amount of reference light received by the light receiving device 80A via the focusing optical system 82. 【0066】 In one embodiment, the adjustment mechanism 90 is located between the focusing optical system 82 and the optical window 70. For example, the adjustment mechanism 90 is located between the focusing optical system 82 and the side wall 10a of the plasma processing chamber 10. In one example, the adjustment mechanism 90 may include a piezoelectric element. In another example, the adjustment mechanism 90 may include a stepping motor. The piezoelectric element and the stepping motor are examples of actuators. 【0067】In the example shown in Figure 9, the adjustment mechanism 90 includes a first mechanism 91 and a second mechanism 92. The first mechanism 91 is configured to adjust the tilt of the focusing optical system 82 along a first tilt direction p1. In one example, the first mechanism 91 includes a pair of vertically adjacent actuators. The first mechanism 91 adjusts the tilt of the optical axis of the focusing optical system 82 along the first tilt direction p1 by increasing the thickness of one actuator of the pair and decreasing the thickness of the other actuator of the pair. The second mechanism 92 is configured to adjust the tilt of the optical axis of the focusing optical system 82 along a second tilt direction p2. In one example, the second mechanism 92 includes a pair of horizontally adjacent actuators. The second mechanism 92 adjusts the tilt of the optical axis of the focusing optical system 82 along a second tilt direction p2 by increasing the thickness of one actuator of the pair and decreasing the thickness of the other actuator of the pair. 【0068】 If at least one light source 60 includes an array 61 of multiple light sources 60 arranged horizontally, only one of the multiple light sources 60 may be lit. For example, when the adjustment mechanism 90 adjusts the optical axis direction of the focusing optical system 82, only one of the multiple light sources 60 is lit. In one example, only the middle light source of the multiple light sources 60 arranged horizontally may be lit. Since the light source of the reference light is fixed to one, the light receiving device 80A can adjust the optical axis of the focusing optical system 82 more accurately. 【0069】 The following describes an example of the process STd for measuring the light intensity of a reference light source, with reference to Figure 10. Figure 10 is a flowchart showing the details of an example of the process for measuring the light intensity of a reference light source. In the example shown in Figure 10, the process STd is performed in a substrate processing system PS equipped with a light receiving device 80A. 【0070】In one embodiment, step STd for measuring the amount of light from a reference light includes adjusting the optical axis direction of the focusing optical system 82 so as to maximize the amount of light from the reference light received by the light receiving device 80A via the focusing optical system 82 of the light receiving device 80A, which is optically coupled to the optical window 70. For example, step STd may also include adjusting the tilt of the focusing optical system 82 in the direction of the optical axis. 【0071】 In the example shown in Figure 10, process STd includes processes STd1, STd2, STd3, and STd4. In one example, process STd1 is executed first. In process STd1, the light receiving device 80A measures the light intensity of the reference light. In process STd1, only one of the multiple light sources 60 may be lit. In process STd1, the initial light intensity of the reference light received by the light receiving device 80A is confirmed. The measurement of the light intensity of the reference light may be performed continuously. For example, after the light intensity is measured for the first time in process STd1, the light intensity may be measured continuously up to processes STd2, STd3, and STd4. 【0072】 Next, step STd2 is executed. In step STd2, the optical axis direction of the focusing optical system 82 is adjusted. In step STd2, the optical axis direction of the focusing optical system 82 is adjusted so that the amount of light from the reference light is greater. For example, step STd3 is executed and the amount of light from the reference light is measured by the light receiving device 80A, and the tilt of the focusing optical system 82 is adjusted so that the amount of light in step STd3 is greater than the amount of light in step STd1. In one example, the increase in the amount of light with respect to the displacement in the optical axis direction of the focusing optical system 82 may be obtained from the amount of light in step STd1 and the amount of light in step STd3. Note that if the amount of light from the reference light is measured continuously from step STd1, step STd3 may be executed simultaneously with step STd2. The optical axis direction of the focusing optical system 82 may be adjusted while measuring the amount of light from the reference light. In one example, step STd2 may include the steps of adjusting the tilt of the focusing optical system 82 in the direction of the optical axis along a first tilt direction p1 and adjusting the tilt of the focusing optical system 82 in the direction of the optical axis along a second tilt direction p2. 【0073】Next, step STd4 is executed. In step STd4, it is determined whether the light intensity of the reference light is at its maximum. If the light intensity of the reference light is not at its maximum, step STd2 is repeated. If the light intensity of the reference light is at its maximum, step STd is terminated. For example, if the light intensity does not increase even after step STd2 is executed, it is determined that the light intensity of the reference light is at its maximum. In one example, the light intensity of the reference light may be determined to be at its maximum when the difference between the light intensity in step STd1 and the light intensity in step STd3 is approximately zero. The light intensity of the reference light may also be determined to be at its maximum when the increase in light intensity with respect to the displacement of the focusing optical system 82 in the direction of the optical axis is approximately zero. As described above, the optical axis direction of the focusing optical system 82 can be adjusted to maximize the light intensity of the reference light received by the light receiving device 80A via the focusing optical system 82. 【0074】 Although various exemplary embodiments have been described above, the present invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and modifications may be made. Furthermore, it is possible to combine elements from different embodiments to form other embodiments. Hereinafter, various exemplary embodiments included in this disclosure are described in [E1] to [E20] below. 【0075】[E1] A substrate processing system comprising: a plasma processing chamber having an optical window; a transport chamber connected to the plasma processing chamber; a transport device disposed within the transport chamber and having an end effector, configured to move the end effector between the processing space in the plasma processing chamber and the space in the transport chamber; at least one light source attached to the end effector; and a light receiving device disposed outside the plasma processing chamber and configured to receive reference light from the at least one light source transported to the processing space through the optical window. [E2] The substrate processing system according to E1, wherein the light receiving device further comprises a control circuit configured to measure the amount of reference light emitted from the at least one light source through the optical window and to calibrate the light receiving device according to the amount of light. [E3] The substrate processing system according to E1 or 2, wherein the plasma processing chamber has a side wall including the optical window, and the at least one light source is attached to the side of the end effector. [E4] The substrate processing system according to any one of E1 to 3, wherein the at least one light source comprises an array of a plurality of light sources, the horizontal width of the array being greater than the horizontal width of the field of view of the light receiving device in the optical window. [E5] The substrate processing system according to E4, wherein the light receiving device has a focusing optical system that defines the field of view, the horizontal width of the array being greater than the horizontal width of the focusing optical system. [E6] The substrate processing system according to any one of E1 to 5, further comprising a distance measuring module having a distance sensor attached to the end effector and configured to measure the distance between the distance sensor and an object. [E7] The substrate processing system according to E6, further comprising a reference section located below the end effector in the movement path of the end effector, the reference section being on which the distance between the distance sensor and the reference section is measured.[E8] The substrate processing system according to claim 6 or 7, further comprising a control circuit configured to control the transport device to position the at least one light source at a predetermined position so that the light receiving device receives the reference light from the at least one light source through the optical window. [E9] The substrate processing system according to any one of E1 to 7, further comprising a diffuser plate attached to the at least one light source and configured to diffuse the reference light emitted by the at least one light source. [E10] The substrate processing system according to any one of E1 to 8, further comprising a heater attached to the end effector and configured to heat the at least one light source. [E11] The substrate processing system according to E10, wherein the at least one light source includes at least one light-emitting diode. [E12] The substrate processing system according to E10 or 11, further comprising a control circuit configured to control the heater and the transport device to transport the at least one light source into the processing space within the plasma processing chamber after heating the at least one light source outside the plasma processing chamber in order to reduce the temperature difference between the plasma processing chamber and the temperature of the at least one light source. [E13] The substrate processing system according to E12, wherein the control circuit is configured to control the heater to stop heating the at least one light source in order to suppress the temperature rise of the at least one light source inside the plasma processing chamber. [E14] The substrate processing system according to E13, wherein the control circuit is configured to control the at least one light source and the heater to stop heating the at least one light source and to emit a reference light from the at least one light source. [E15] The substrate processing system according to any one of E1 to 14, further comprising a control circuit configured to control the transport device and the at least one light source to emit a reference light when transporting the substrate placed on the end effector into the processing space.[E16] A maintenance device comprising: a transport device including a movable part; at least one light source attached to the movable part; and a control circuit configured to move the movable part to a processing space within the plasma processing chamber so that a reference light from the at least one light source is received by a light receiving device located outside the plasma processing chamber through the optical window of the plasma processing chamber. [E17] The maintenance device according to E16, further comprising a vacuum chamber in which the transport device is housed in its internal space, the vacuum chamber being configured to be detachably attached to the plasma processing chamber so as to hermetically connect the internal space and the processing space. [E18] A maintenance method comprising: transporting an end effector to which at least one light source is attached, the end effector located at the tip of a movable part of the transport device, into a processing space within the plasma processing chamber; measuring the amount of light from the reference light of the at least one light source received by a light receiving device located outside the plasma processing chamber through the optical window of the plasma processing chamber; and calibrating the light receiving device according to the amount of light. [E19] The substrate processing system according to E1 to 15 or the maintenance apparatus according to E16 and 17, wherein the light receiving device comprises: a focusing optical system optically coupled to the optical window; and an adjustment mechanism configured to adjust the optical axis direction of the focusing optical system so as to maximize the amount of light of the reference light received by the light receiving device via the focusing optical system. [E20] The maintenance method according to E18, wherein the step of measuring the amount of light of the reference light includes adjusting the optical axis direction of the focusing optical system so as to maximize the amount of light of the reference light received by the light receiving device via the focusing optical system of the light receiving device optically coupled to the optical window. 【0076】 From the above description, it will be understood that the various embodiments of this disclosure are described herein for illustrative purposes and can be modified in various ways without departing from the scope and spirit of this disclosure. Accordingly, the various embodiments disclosed herein are not intended to limit the scope and spirit, and the true scope and spirit are shown by the appended claims. 【0077】5... Distance measurement module, 10... Plasma processing chamber, 10a... Side wall, 10s... Processing space, 52a, 52b... Distance sensor, 60... Light source, 61... Array, 62... Diffuser plate, 70, 71... Optical window, 80, 80A... Light receiving device, 82... Focusing optical system, 90... Adjustment mechanism, AR11, AR12, AR31... Movable parts, CS... Maintenance device, d1, d2, d3... Width, FK11, FK12, FK31... End effector, FKS... Side view, HT... Heater, MC... Control circuit, PS... Substrate processing system, TR... Transport device, V... Field of view, VCH1... Vacuum chamber, W... Substrate.

Claims

1. A substrate processing system comprising: a plasma processing chamber having an optical window; a transport chamber connected to the plasma processing chamber; a transport device disposed within the transport chamber and having an end effector, configured to move the end effector between the processing space in the plasma processing chamber and the space in the transport chamber; at least one light source attached to the end effector; and a light receiving device disposed outside the plasma processing chamber and configured to receive reference light from the at least one light source transported into the processing space through the optical window.

2. The substrate processing system according to claim 1, wherein the light receiving device is configured to measure the amount of light of a reference light emitted from at least one light source through the optical window, and further comprises a control circuit configured to calibrate the light receiving device according to the amount of light.

3. The substrate processing system according to claim 1, wherein the plasma processing chamber has a side wall including the optical window, and the at least one light source is mounted on the side of the end effector.

4. The substrate processing system according to any one of claims 1 to 3, wherein the at least one light source includes an array of multiple light sources, and the horizontal width of the array is greater than the horizontal width of the field of view of the light receiving device in the optical window.

5. The substrate processing system according to claim 4, wherein the light receiving device has a focusing optical system that defines the field of view, and the width of the array in the horizontal direction is greater than the width of the focusing optical system in the horizontal direction.

6. The substrate processing system according to claim 1, further comprising a distance measuring module having a distance sensor attached to the end effector and configured to measure the distance between the distance sensor and an object.

7. The substrate processing system according to claim 6, further comprising a reference section located below the end effector in the movement path of the end effector, wherein the distance between the distance sensor and the reference section is measured.

8. The substrate processing system according to claim 6 or 7, further comprising a control circuit configured to control the transport device to position the at least one light source at a predetermined position so that the light receiving device receives the reference light from the at least one light source through the optical window.

9. The substrate processing system according to claim 1, further comprising a diffuser plate attached to the at least one light source and configured to diffuse the reference light emitted by the at least one light source.

10. The substrate processing system according to claim 1, further comprising a heater attached to the end effector and configured to heat the at least one light source.

11. The substrate processing system according to claim 10, wherein the at least one light source includes at least one light-emitting diode.

12. The substrate processing system according to claim 10 or 11, further comprising a control circuit configured to control the heater and the transport device to transport the at least one light source into the processing space within the plasma processing chamber after heating the at least one light source outside the plasma processing chamber, in order to reduce the temperature difference between the plasma processing chamber and the temperature of the at least one light source.

13. The substrate processing system according to claim 12, wherein the control circuit is configured to control the heater to stop heating the at least one light source in order to suppress the temperature rise of the at least one light source within the plasma processing chamber.

14. The substrate processing system according to claim 13, wherein the control circuit is configured to stop heating the at least one light source and to control the at least one light source and the heater so that reference light is emitted from the at least one light source.

15. The substrate processing system according to claim 1, further comprising a control circuit configured to control the transport device and the at least one light source so as to emit a reference light when transporting the substrate placed on the end effector to the processing space.

16. A maintenance device comprising: a transport device including a movable part; at least one light source attached to the movable part; and a control circuit configured to move the movable part into the processing space within the plasma processing chamber so that a reference light from the at least one light source is received by a light receiving device located outside the plasma processing chamber through the optical window of the plasma processing chamber.

17. The maintenance device according to claim 16, further comprising a vacuum chamber in which the transport device is housed within its internal space, the vacuum chamber being detachably configured to connect the internal space and the processing space in an airtight manner to the plasma processing chamber.

18. A maintenance method comprising: transporting an end effector, to which at least one light source is attached, located at the tip of a movable part of a transport device, into a processing space within a plasma processing chamber; measuring the amount of light from a reference light of the at least one light source, received by a light receiving device located outside the plasma processing chamber through an optical window of the plasma processing chamber; and calibrating the light receiving device according to the amount of light.

19. The substrate processing system according to claim 1, wherein the light receiving device comprises: a focusing optical system optically coupled to the optical window; and an adjustment mechanism configured to adjust the optical axis direction of the focusing optical system so as to maximize the amount of light of the reference light received by the light receiving device via the focusing optical system.

20. The maintenance method according to claim 18, wherein the step of measuring the amount of light of the reference light includes adjusting the optical axis direction of the focusing optical system to maximize the amount of light of the reference light received by the light receiving device via the focusing optical system of the light receiving device which is optically coupled to the optical window.

Images