Patent Publication Number: US-2023141911-A1

Title: Substrate processing system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2021-182487 filed on Nov. 9, 2021, the entire contents of which is incorporated herein by reference. 
     BACKGROUND 
     Technical Field 
     Various aspects and embodiments of the present disclosure relate to a substrate processing system. 
     Description of the Background 
     Patent Literature 1 explains that “each processing tool  200  includes an improved equipment front end module (EFEM)  204  to accommodate at least a part of a loadlock  208 ”. Patent Literature 1 further explains that the loadlock  208  extends in the EFEM  204 , instead of being positioned outside the EFEM  204  in the space between the EFEM  204  and a vacuum transfer module (VTM)  212 . 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2020-510310 
       
    
     BRIEF SUMMARY 
     One or more aspects of the present disclosure are directed to a substrate processing system installable in a small installation area. 
     A substrate processing system according to one aspect of the present disclosure includes one or more process modules and a vacuum transfer module. At least one of the one or more process modules and the vacuum transfer module at least partially overlap with each other as viewed from above. 
     The substrate processing system according to various aspects and embodiments of the present disclosure is installable in a small installation area, as compared with conventional systems. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a plan view of an exemplary substrate processing system according to one embodiment. 
         FIG.  2    is a side view of the exemplary substrate processing system as viewed in the direction indicated by arrow C in  FIG.  1   . 
         FIG.  3    is a side view of the exemplary substrate processing system as viewed in the direction indicated by arrow D in  FIG.  1   . 
         FIG.  4    is a side view of the exemplary substrate processing system as viewed in the direction indicated by arrow E in  FIG.  1   . 
         FIG.  5    is a diagram of the substrate processing system in  FIG.  1    showing its exemplary back surface. 
         FIG.  6    is a schematic cross-sectional view of the substrate processing system illustrated in  FIGS.  1  and  5   , showing its exemplary cross section taken along line A-A. 
         FIG.  7    is a schematic cross-sectional view of the substrate processing system illustrated in  FIGS.  1  and  5   , showing its exemplary cross section taken along line B-B. 
         FIG.  8    is a schematic cross-sectional view of an exemplary process module (PM). 
         FIG.  9    is a diagram describing an example system (or structure) in a particular state during a process for transferring a substrate. 
         FIG.  10    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  11    is a diagram describing an example support used in transferring and receiving the substrate. 
         FIG.  12    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  13    is a diagram describing an example support used for transferring and receiving the substrate. 
         FIG.  14    is a diagram describing an exemplary positional relationship between a substrate support and an arm. 
         FIG.  15    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  16    is a diagram describing an example support used for transferring and receiving the substrate. 
         FIG.  17    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  18    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  19    is a diagram describing an example support used for transferring and receiving the substrate. 
         FIG.  20    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  21    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  22    is a diagram describing the example system in a particular state during a process for transferring the substrate. 
         FIG.  23    is a schematic cross-sectional view of a substrate processing system in another example. 
         FIG.  24    is a schematic cross-sectional view of a substrate processing system in another example. 
         FIG.  25    is a schematic cross-sectional view of a substrate processing system in another example. 
         FIG.  26    is a schematic cross-sectional view of a substrate processing system in another example. 
         FIG.  27    is a schematic cross-sectional view of a substrate processing system in another example. 
         FIG.  28    is a schematic cross-sectional view of a substrate processing system in another example. 
     
    
    
     DETAILED DESCRIPTION 
     A substrate processing system according to one or more embodiments will be described with reference to the drawings. The substrate processing system according to one or more embodiments of the disclosure is not limited to the embodiments described below. 
     To process more substrates per unit time, a substrate processing system may include an increased number of processing modules for processing substrates. An increased number of processing modules can increase the size of a substrate processing system that includes, for example, multiple processing modules, a vacuum transfer module, a loadlock module, and an atmospheric transfer module. A substrate processing system with an increased size uses a larger installation area (footprint) in, for example, a clean room at a facility, thus causing difficulty in arranging multiple substrate processing systems. Substrate processing systems that use smaller installation areas are thus awaited. 
     A substrate processing system according to one or more embodiments of the present disclosure is installable in a smaller installation area. 
     Structure of Substrate Processing System  10   
       FIG.  1    is a plan view of an exemplary substrate processing system  10  according to one embodiment.  FIG.  2    is a side view of the exemplary substrate processing system  10  as viewed in the direction indicated by arrow C in  FIG.  1   .  FIG.  3    is a side view of the exemplary substrate processing system  10  as viewed in the direction indicated by arrow D in  FIG.  1   .  FIG.  4    is a side view of the exemplary substrate processing system  10  as viewed in the direction indicated by arrow E in  FIG.  1   .  FIG.  5    is a diagram of the substrate processing system  10  in  FIG.  1    showing its exemplary back surface.  FIG.  1    illustrates, together with the substrate processing system  10 , a control device  12  (also referred to as a “controller”) that controls the entire substrate processing system  10 . 
     The substrate processing system  10  includes a vacuum transfer module (VTM)  20 , multiple process modules (PMs)  30 , a loadlock module (LLM)  40 , an equipment front end module (EFEM)  50 , and multiple load ports (LPs)  60 . 
     The VTM  20  transfers a substrate W in a vacuum atmosphere. The term vacuum herein refers to a pressure lower than atmospheric pressure. The VTM  20  transfers the substrate W between the PM  30  and the LLM  40  or between multiple PMs  30  in a vacuum atmosphere. In the present embodiment, at least one PM  30  and the VTM  20  overlap with each other at least partially as viewed from above. In the present embodiment, being viewed from “above” refers to viewing an upper surface in the vertical direction. Similarly, one object being “over” another object refers to a first object that is positioned to at least partially overlap a second object that underlies the first object such that a complete view of an upper surface of the second object is blocked by the presence of the first object as viewed from above. Likewise, “under” in this context refers to the position of the second object with respect to the first object. As with “above”, neither “over” nor “under” required a complete overlapping of the first object&#39;s footprint with respect to the second object&#39;s footprint. In the example of  FIGS.  1  to  5   , the VTM  20  is located on at least one PM  30  as viewed from above. Although the substrate processing system  10  includes one VTM  20  in the example of  FIGS.  1  to  5   , the techniques described according to the present disclosure are not limited to this particular configuration. The substrate processing system  10  may include more than one VTM  20 . 
     Each PM  30  performs processing (e.g., plasma processing) on a substrate W, including etching and film deposition. Each PM  30  may perform the same step or a different step of the manufacturing steps. Although the substrate processing system  10  includes eight PMs  30  in the example of  FIGS.  1  to  5   , the techniques described according to the present disclosure are not limited to this particular configuration. The substrate processing system  10  may include fewer or more than eight PMs  30 . 
     Although each PM  30  appears square as viewed from above in the example of  FIGS.  1  to  5   , the techniques described according to the present disclosure are not limited to this particular configuration. Each PM  30  may be, for example, polygonal, circular, or elliptic as viewed from above. A polygonal PM  30  may be triangular, quadrilateral (e.g., rectangular, rhombic, or trapezoidal), pentagonal, hexagonal, or octagonal as viewed from above. 
     The LLM  40  controllably switches an internal pressure between a vacuum atmosphere and an ambient atmosphere. The LLM  40  and at least one PM  30  overlap with each other at least partially as viewed from above. In the present embodiment, at least a part of the VTM  20  is located between at least one PM  30  and the LLM  40 . In the present embodiment, the VTM  20 , at least one PM  30 , and the LLM  40  overlap with one another at least partially as viewed from above. In the example of  FIGS.  1  to  5   , the LLM  40  is located on the VTM  20 . Although the substrate processing system  10  includes one LLM  40  in the example of  FIGS.  1  to  5   , the techniques described according to the present disclosure are not limited to this particular configuration. The substrate processing system  10  may include more than one LLM  40 . 
     The EFEM  50  transfers the substrate W in an ambient atmosphere. The EFEM  50  is an example of an atmospheric transfer module. The EFEM  50  has a side wall with multiple LPs  60 . The EFEM  50  includes, on its side wall, gate valves  51  corresponding to the respective LPs  60  as shown in, for example,  FIG.  4   . The EFEM  50  transfers the substrate W between a front opening unified pod (FOUP) installed in the corresponding LP  60  and the LLM  40  in an ambient atmosphere. Although the substrate processing system  10  includes one EFEM  50  in the example of  FIGS.  1  to  5   , the techniques described according to the present disclosure are not limited to this particular configuration. The substrate processing system  10  may include more than one EFEM  50 . Although the substrate processing system  10  includes three LPs  60  in the example of  FIGS.  1  to  5   , the techniques described according to the present disclosure are not limited to this particular configuration. The substrate processing system  10  may include fewer or more than three LPs  60 . 
     The substrate processing system  10  may include an alignment module that adjusts the position and orientation of the substrate W. The alignment module may be included in any of the components, but may be included in, for example, the VTM  20 , the EFEM  50 , or the LLM  40 . 
     The control device  12  processes computer-executable instructions that cause the substrate processing system  10  to perform various steps described in the present disclosure. The control device  12  may control the components of the substrate processing system  10  to perform various steps described herein. In one embodiment, some or all of the components of the control device  12  may be included in the substrate processing system  10 . The control device  12  is implemented by, for example, a computer  12   a  including a processor  12   a   1 , a storage device (e.g., a computer readable memory)  12   a   2 , and a communication interface  12   a   3 . The processor  12   a   1  performs various control operations by reading a program from the storage device  12   a   2  and executing instructions contained in the program. This program may be prestored in the storage device  12   a   2  or may be obtained through a medium as appropriate. The obtained program is stored into the storage device  12   a   2 , read from the storage device  12   a   2 , and executed by the processor  12   a   1 . The medium may be one of various storage media readable by the computer  12   a , or a communication line connected to the communication interface  12   a   3  that provides program instructions from a remote source. The processor  12   a   1  may be one or more central processing unit(s) (CPUs), graphical processing unit(s) (GPUs), and/or hybrid processors with programmable devices and programmed/programmable devices (e.g., application specific integrated circuits (ASICs), programmable logic devices (PLDs) and the like). The processor  12   a   1 , as well as other processors described herein, need not be a signal processor, but can be more or more processors located adjacent to one another, or separated by some distance and connected by way of the communication line, or a different communication line. For example, the processor  12   a   1  may include a local processor and/or cloud processing resources implemented in one or more remote locations. The storage device  12   a   2  may be a random-access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid-state drive (SSD), or a combination of these memories. The communication interface  12   a   3  may communicate with the substrate processing system  10  through a communication line such as the physical layer (e.g., Ethernet) of a local area network (LAN). Also, “communication line” in this context may be a wireless communication link that conveys digital information via wireless transmissions such as 5G, WiFi, or the like. The communication interface  12   a   3  may also include a dedicated interface, such as a display panel and/or touch-panel for displaying status information and allowing for control input. 
       FIG.  6    is a schematic cross-sectional view of the substrate processing system  10  illustrated in  FIGS.  1  and  5   , showing its exemplary cross section taken along line A-A.  FIG.  7    is a schematic cross-sectional view of the substrate processing system  10  illustrated in  FIGS.  1    and  5 , showing its exemplary cross section taken along line B-B. 
     A transfer robot  52  is located in the EFEM  50 . The transfer robot  52  transfers the substrate W between the FOUP installed in the corresponding LP  60  and the LLM  40 . The transfer robot  52  can move within the EFEM  50 , for example, in the direction along arrow C in  FIG.  1   . The transfer robot  52  includes a substrate support  520  on which the substrate W is placeable, and an arm  521  that moves the substrate support  520 . The arm  521  includes a cylinder  521   a  and a cylinder  521   b . The cylinder  521   a  is located in the EFEM  50  to have the axis in the vertical direction. The cylinder  521   b  is placeable in the cylinder  521   a . The cylinder  521   b  in the EFEM  50  is coaxial with the cylinder  521   a . The arm  521  is extendable in the vertical direction along the axis of the cylinder  521   a  to move the substrate support  520  in the vertical direction by sliding the cylinder  521   b  relative to the cylinder  521   a . This structure reduces the installation area of the transfer robot  52 . 
     A gate valve  42  is located between the EFEM  50  and the LLM  40 . A gate valve  43  is located between the LLM  40  and the VTM  20 . A transfer robot  41  is located in the LLM  40 . The transfer robot  41  includes a substrate support  410  on which the substrate W is placeable. 
     A transfer robot  21  is located above the PM  30  in the VTM  20 . The transfer robot  21  includes a substrate support  210  on which the substrate W is placeable. A transfer robot  22  and a transfer robot  23  are located between adjacent PMs  30  in the VTM  20 . The transfer robot  22  includes a substrate support  220  on which the substrate W is placeable. The transfer robot  23  includes a substrate support  230  on which the substrate W is placeable. A gate valve  31  is located between the VTM  20  and the PM  30  as shown in, for example,  FIG.  7   . 
     Structure of PM  30   
       FIG.  8    is a schematic cross-sectional view of an exemplary PM  30 . In the present embodiment, the PM  30  is, for example, a capacitively coupled plasma (CCP) processing apparatus. The PM  30  includes a plasma processing chamber  310 , a gas supply unit  320 , a power supply  330 , and an exhaust system  340 . The PM  30  also includes a substrate support  311  and a gas inlet unit. The gas inlet unit allows at least one process gas to be introduced into the plasma processing chamber  310 . The gas inlet unit includes a shower head electrode  313 . The substrate support  311  is located in the plasma processing chamber  310 . The shower head electrode  313  is located above the substrate support  311 . In one embodiment, the shower head electrode  313  defines at least a part of the ceiling of the plasma processing chamber  310 . The plasma processing chamber  310  has a plasma processing space  310   s  defined by the shower head electrode  313 , a side wall  310   a  of the plasma processing chamber  310 , and the substrate support  311 . The plasma processing chamber  310  has at least one gas inlet for supplying at least one process gas into the plasma processing space  310   s  and at least one gas outlet for discharging the gas from the plasma processing space  310   s . The plasma processing chamber  310  is grounded. The shower head electrode  313  and the substrate support  311  are electrically insulated from the housing of the plasma processing chamber  310 . The side wall  310   a  of the plasma processing chamber  310  has an opening  32  for loading and unloading the substrate W. The opening  32  is opened and closed by the gate valve  31 . 
     The substrate support  311  includes a body  3111  and a ring assembly  3112 . The body  3111  includes a central area  3111   a  for supporting the substrate W and an annular area  3111   b  for supporting the ring assembly  3112 . A wafer is an example of the substrate W. The annular area  3111   b  of the body  3111  surrounds the central area  3111   a  of the body  3111  as viewed in plan. The substrate W is located on the central area  3111   a  of the body  3111 . The ring assembly  3112  is located on the annular area  3111   b  of the body  3111  to surround the substrate W on the central area  3111   a  of the body  3111 . The central area  3111   a  is also referred to as a substrate support surface for supporting the substrate W. The annular area  3111   b  is also referred to as a ring support surface for supporting the ring assembly  3112 . 
     In one embodiment, the body  3111  includes a base  31110  and an electrostatic chuck (ESC)  31111 . The base  31110  includes a conductive member. The conductive member in the base  31110  may function as a lower electrode. The ESC  31111  is located on the base  31110 . The ESC  31111  includes a ceramic member  31111   a  and an electrostatic electrode  31111   b  located inside the ceramic member  31111   a . The ceramic member  31111   a  includes a central area  3111   a . In one embodiment, the ceramic member  31111   a  also includes an annular area  3111   b . Other members surrounding the ESC  31111 , such as an annular ESC or an annular insulating member, may include the annular area  3111   b . In this case, the ring assembly  3112  may be located on the annular ESC or the annular insulating member, or may be located on both the ESC  31111  and the annular insulating member. At least one radio frequency (RF) electrode coupled to an RF power supply  331  or at least one direct current (DC) electrode coupled to a DC power supply  332 , or both the RF electrode and the DC electrode (described later) may also be located inside the ceramic member  31111   a . In this case, at least one RF electrode or at least one DC electrode, or both the electrodes serve as a lower electrode. When a bias RF signal or a DC signal or both (described later) are provided to at least one RF electrode or at least one DC electrode or to both the electrodes, the RF electrode or the DC electrode, or both the electrodes are also referred to as a bias electrode(s). The conductive member in the base  31110  and at least one RF electrode or at least one DC electrode, or both the electrodes may function as multiple lower electrodes. The electrostatic electrode  31111   b  may also function as a lower electrode. The substrate support  311  includes at least one lower electrode. 
     The ring assembly  3112  includes one or more annular members. In one embodiment, one or more annular members include one or more edge rings and at least one cover ring. The edge ring is formed from a conductive material or an insulating material. The cover ring is formed from an insulating material. 
     The substrate support  311  may also include a temperature control module that adjusts at least one of the ESC  31111 , the ring assembly  3112 , or the substrate W to a target temperature. The temperature control module may include a heater, a heat-transfer medium, a channel  31110   a , or a combination of these. The channel  31110   a  allows a heat-transfer fluid such as brine or gas to flow. In one embodiment, the channel  31110   a  is defined in the base  31110 , and one or more heaters are located in the ceramic member  31111   a  in the ESC  31111 . The substrate support  311  may include a heat-transfer gas supply to supply a heat-transfer gas to the space between the back surface of the substrate W and the central area  3111   a.    
     The shower head electrode  313  introduces at least one process gas from the gas supply unit  320  into the plasma processing space  310   s . The shower head electrode  313  has at least one gas inlet  313   a , at least one gas diffusing compartment  313   b , and multiple gas inlet ports  313   c . The process gas supplied to the gas inlet  313   a  passes through the gas diffusing compartment  313   b  and is introduced into the plasma processing space  310   s  through the multiple gas inlet ports  313   c . The shower head electrode  313  also includes at least one upper electrode. In addition to the shower head electrode  313 , the gas inlet unit may include one or more side gas injectors (SGIs) that are installed in one or more openings in the side wall  310   a.    
     The gas supply unit  320  may include at least one gas source  321  and at least one flow controller  322 . In one embodiment, the gas supply unit  320  allows supply of at least one process gas from each gas source  321  to the shower head electrode  313  through the corresponding flow controller  322 . Each flow controller  322  may include, for example, a mass flow controller or a pressure-based flow controller. The gas supply unit  320  may further include one or more flow rate modulators that supply one or more process gases at a modulated flow rate or in a pulsed manner. 
     The power supply  330  includes an RF power supply  331  that is coupled to the plasma processing chamber  310  through at least one impedance matching circuit. The RF power supply  331  allows supply of at least one RF signal (RF power) to at least one lower electrode or at least one upper electrode, or to both the electrodes. This causes plasma to be generated from one or more process gases supplied into the plasma processing space  310   s . The RF power supply  331  may thus at least partially serve as a plasma generator that generates plasma from one or more process gases in the plasma processing chamber  310 . A bias RF signal is provided to at least one of the lower electrodes to generate a bias potential in the substrate W, thus drawing ion components in the plasma to the substrate W. 
     In one embodiment, the RF power supply  331  includes a first RF generator  331   a  and a second RF generator  331   b . The first RF generator  331   a  is coupled to at least one lower electrode or at least one upper electrode, or to both the electrodes through at least one impedance matching circuit and generates a source RF signal (source RF power) for plasma generation. In one embodiment, the RF signal has a frequency within the range of 10 to 150 MHz. In one embodiment, the first RF generator  331   a  may generate multiple source RF signals with different frequencies. The generated one or more source RF signals are provided to at least one lower electrode or at least one upper electrode, or to both the electrodes. 
     The second RF generator  331   b  is coupled to at least one lower electrode through at least one impedance matching circuit and generates a bias RF signal (bias RF power). 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 source RF signal. In one embodiment, the bias RF signal has a frequency within the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator  331   b  may generate multiple bias RF signals with different frequencies. The generated one or more bias RF signals are provided to at least one lower electrode. In various embodiments, at least one of the source RF signal or the bias RF signal may be pulsed. 
     The power supply  330  may also include a DC power supply  332  coupled to the plasma processing chamber  310 . The DC power supply  332  includes a first DC generator  332   a  and a second DC generator  332   b . In one embodiment, the first DC generator  332   a  is connected to at least one lower electrode and generates a first DC signal. The generated first bias DC signal is applied to at least one lower electrode. In one embodiment, the second DC generator  332   b  is connected to at least one upper electrode and generates a second DC signal. The generated second DC signal is applied to at least one upper electrode. 
     In various embodiments, at least one of the first DC signal or the second DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode or at least one upper electrode, or to both the electrodes. The voltage pulse may have a rectangular, trapezoidal, or triangular pulse waveform, or a combination of these pulse waveforms. In one embodiment, a waveform generator that generates a sequence of voltage pulses based on DC signals is connected between the first DC generator  332   a  and at least one lower electrode. Thus, the first DC generator  332   a  and the waveform generator are included in a voltage pulse generator. When the second DC generator  332   b  and the waveform generator are included in a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have positive 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 DC generator  332   a  and the second DC generator  332   b  may be provided in addition to the RF power supply  331 , or the first DC generator  332   a  may replace the second RF generator  331   b.    
     The exhaust system  340  may be, for example, connected to a gas outlet  310   e  in the bottom of the plasma processing chamber  310 . The exhaust system  340  may include a pressure control valve and a vacuum pump. The pressure in the plasma processing space  310   s  is regulated by the pressure control valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination of these. 
     Procedure for Transferring Substrate W 
     An example procedure for transferring a substrate W in the substrate processing system  10  will now be described with reference to  FIGS.  9  to  22   . 
     A FOUP  61  containing substrates W is first installed in the LP  60 , and the gate valve  51  is opened. The substrate support  520  in the transfer robot  52  is placed into the FOUP  61 , and a substrate W is placed on the substrate support  520 . The substrate W is unloaded from the FOUP  61  as shown in, for example,  FIG.  9   . 
     The arm  521  ( FIG.  6   ) then extends to cause the substrate W on the substrate support  520  to be elevated to the position of the gate valve  42  as shown in, for example,  FIG.  10   . The gate valve  42  is then opened, with the LLM  40  being in an ambient atmosphere. As shown in  FIG.  10   , for example, the substrate support  520  receiving the substrate W is then placed into the LLM  40 , and the substrate W is transferred from the substrate support  520  in the transfer robot  52  to the substrate support  410  in the transfer robot  41 . 
     When the substrate W is transferred and received, the positional relationship between the substrate support  410  in the transfer robot  41  and the substrate support  520  in the transfer robot  52  is as shown in, for example,  FIG.  11   .  FIG.  11    is a diagram describing an example process for transferring and receiving the substrate W. The substrate support  410  in the transfer robot  41  and the substrate support  520  in the transfer robot  52  can transfer and receive the substrate W between the two without interfering with each other. 
     As shown in, for example,  FIG.  12   , the substrate support  520  in the transfer robot  52  is then retrieved from within the LLM  40 , and the gate valve  42  is closed. The pressure in the LLM  40  is then decreased from an ambient atmosphere to a vacuum atmosphere. The substrate support  410  receiving the substrate W moves to above the gate valve  43 , and the gate valve  43  is opened. As the transfer robot  22  below the gate valve  43  extends, the substrate support  220  in the transfer robot  22  is placed into the LLM  40  as shown in, for example,  FIG.  12   . The substrate support  220  in the transfer robot  22  then lifts the substrate W on the substrate support  410  in the transfer robot  41 . The substrate support  410  in the transfer robot  41  is retrieved from above the gate valve  43 . The substrate W is thus transferred from the substrate support  410  in the transfer robot  41  to the substrate support  220  in the transfer robot  22 . 
     In the present embodiment, the transfer robot  22  includes the substrate support  220  on which the substrate W is placeable, and an arm  221  that moves the substrate support  220  in the vertical direction. The arm  221  includes a cylinder  221   a  and a cylinder  221   b . The cylinder  221   a  is located in the VTM  20  to have the axis in the vertical direction. The cylinder  221   b  is placeable in the cylinder  221   a . The cylinder  221   b  in the VTM  20  is coaxial with the cylinder  221   a . The arm  221  is extendable in the vertical direction along the axis of the cylinder  221   a  to move the substrate support  220  in the vertical direction by sliding the cylinder  221   b  relative to the cylinder  221   a . This structure reduces the installation area of the transfer robot  22 . The cylinder  221   a  is an example of the first cylinder, and the cylinder  221   b  is an example of the second cylinder. 
     When the substrate W is transferred and received, the positional relationship between the substrate support  410  in the transfer robot  41  and the substrate support  220  in the transfer robot  22  is as shown in, for example,  FIG.  13   .  FIG.  13    is a diagram describing an example process for transferring and receiving the substrate W. The substrate support  410  in the transfer robot  41  and the substrate support  220  in the transfer robot  22  can transfer and receive the substrate W between them without interfering with each other. When the substrate W is transferred from the substrate support  410  in the transfer robot  41  to the substrate support  220  in the transfer robot  22 , the cylinder  221   a  in the arm  221  moves through a space between parts of the substrate support  230  in the transfer robot  23  as shown in, for example,  FIG.  14   . The cylinder  221   a  in the arm  221  thus does not interfere with the substrate support  230  in the transfer robot  23 . 
     As the arm  221  in the transfer robot  22  retracts, the substrate W is transferred from the substrate support  220  in the transfer robot  22  to the substrate support  230  in the transfer robot  23  as shown in, for example,  FIG.  15   . The positional relationship between the substrate support  220  in the transfer robot  22  and the substrate support  230  in the transfer robot  23  is as shown in, for example,  FIG.  16   . The substrate support  220  in the transfer robot  22  and the substrate support  230  in the transfer robot  23  can transfer and receive the substrate W between them without interfering with each other. The gate valve  31  in the PM  30  is then opened, the substrate support  230  receiving the substrate W is placed into the PM  30 , and the substrate W is loaded into the PM  30  as shown in, for example,  FIG.  17   . 
     When the substrate W is unloaded from the PM  30 , the substrate W in the PM  30  is placed on the substrate support  230  in the transfer robot  23  and unloaded from the PM  30 . The substrate W is transferred from the substrate support  230  in the transfer robot  23  to the substrate support  220  in the transfer robot  22 , and the gate valve  43  is opened. As the arm  221  in the transfer robot  22  extends, the substrate support  220  receiving the substrate W is placed into the LLM  40 . The substrate support  410  in the transfer robot  41  is then placed below the substrate support  220  in the transfer robot  22 . As the arm  221  in the transfer robot  22  retracts, the substrate W is transferred from the substrate support  220  in the transfer robot  22  to the substrate support  410  in the transfer robot  41 . The gate valve  43  is closed, and the pressure in the LLM  40  is then increased from a vacuum atmosphere to an ambient atmosphere. The gate valve  42  is then opened, the substrate support  520  in the transfer robot  52  is placed into the LLM  40 , and the substrate W is transferred from the substrate support  410  in the transfer robot  41  to the substrate support  520  in the transfer robot  52 . As the arm  521  in the transfer robot  52  retracts, the substrate support  520  receiving the substrate W is placed into the FOUP  61 . The substrate W is thus stored into the FOUP  61 . 
     When a substrate W is loaded into another PM  30 , the substrate W unloaded from the LLM  40  by the transfer robot  22  is transferred to the substrate support  210  in the transfer robot  21  as shown in, for example,  FIG.  18   . The positional relationship between the substrate support  220  in the transfer robot  22  and the substrate support  210  in the transfer robot  21  is as shown in, for example,  FIG.  19   . The substrate support  220  in the transfer robot  22  and the substrate support  210  in the transfer robot  21  can transfer and receive the substrate W between them without interfering with each other. 
     The transfer robot  21  then moves the substrate W to above the transfer robot  22  located near the other PM  30 . As the arm  221  in the transfer robot  22  located near the other PM  30  extends, the substrate support  220  in the transfer robot  22  lifts the substrate W from the substrate support  210  in the transfer robot  21  as shown in, for example,  FIG.  20   . The substrate W is then transferred from the substrate support  210  in the transfer robot  21  to the substrate support  220  in the transfer robot  22 . The substrate support  210  in the transfer robot  21  then retracts from below the substrate support  220  in the transfer robot  22 . 
     As the arm  221  in the transfer robot  22  retracts, the substrate W is then transferred from the substrate support  220  in the transfer robot  22  to the substrate support  230  in the transfer robot  23  as shown in, for example,  FIG.  21   . The gate valve  31  in the PM  30  is then opened, the substrate support  230  receiving the substrate W is placed into the PM  30 , and the substrate W is loaded into the PM  30  as shown in, for example,  FIG.  22   . 
     A description of one embodiment is described as set forth above. As described above, the substrate processing system  10  according to the present embodiment includes one or more PMs  30  and the VTM  20 . At least one PM  30  and the VTM  20  overlap with each other at least partially as viewed from above. This structure reduces the installation area of the substrate processing system  10 . 
     An economic value from the substrate processing system  10  can be evaluated by an index (or metric) defined by, for example, a wafer price per space (WPPS). The WPPS is calculated using, for example, Formula 1 below. 
       WPPS=(WPD×operation rate×yield)/installation area×equipment price  (1)
 
     In Formula 1 above, the wafers per day (WPD) is the number of substrates W that can be processed per day. 
     The structure according to the present embodiment can reduce (as compared with conventional systems) the installation area in Formula 1 above, and can increase the value of the WPPS (as compared with conventional systems), and thus the overall economic value of the substrate processing system  10 . 
     In the above embodiment, the VTM  20  is located on at least one PM  30 , which is one characteristic that simplifies the structure of the substrate processing system  10 . 
     In the above embodiment, the substrate processing system  10  further includes the LLM  40  connected to the VTM  20 . At least one PM  30  and the LLM  40  overlap with each other at least partially as viewed from above. Consequently, this structure reduces the installation area of the substrate processing system  10 . 
     In the above embodiment, at least a part of the VTM  20  is located between at least one PM  30  and the LLM  40 . At least one PM  30 , the VTM  20 , and the LLM  40  overlap with one another at least partially as viewed from above. This structure reduces the installation area of the substrate processing system  10 . 
     In the above embodiment, the LLM  40  is located on the VTM  20 . This simplifies the structure of the substrate processing system  10 . 
     In the above embodiment, the substrate processing system  10  includes the transfer robot  22  located in the VTM  20  to transfer and receive the substrate W between the VTM  20  and the PM  30 . The transfer robot  22  includes the substrate support  220  on which the substrate W is placeable, and the arm  221  that moves the substrate support  220  in the vertical direction. The arm  221  includes the cylinder  221   a  with the axis in the vertical direction, and the cylinder  221   b  placeable in the cylinder  221   a  and coaxial with the cylinder  221   a . The arm  221  is extendable along the axis of the cylinder  221   a  to move the substrate support  220  in the vertical direction by sliding the cylinder  221   b  relative to the cylinder  221   a . This structure reduces the installation area of the transfer robot  22 . 
     Others Features and Characteristics 
     The techniques, structures, and arrangements according to the present disclosure are not limited to the embodiments described above, and may be changed variously within the scope of the present disclosure. 
     In the above embodiment, for example, the LLM  40  is located on the VTM  20 , but the present disclosure is not limited to this approach. In other embodiments, the LLM  40  may be located adjacent to the VTM  20 . In this case as well, at least one PM  30  and the VTM  20  overlap with each other at least partially as viewed from above. The substrate processing system  10  is installable in a smaller installation area than when the VTM  20 , the PMs  30 , the LLM  40 , and the EFEM  50  are all arranged horizontally. 
     When the LLM  40  is located adjacent to the VTM  20  as well, the PMs  30  and the LLM  40  may overlap with each other at least partially as shown in, for example,  FIG.  23   . FIG.  23  is a schematic cross-sectional view of a substrate processing system  10  in another example. The substrate processing system  10  including the VTM  20 , the PMs  30 , and the LLM  40  in the illustrated arrangement is also installable in a smaller installation area. 
     In the above embodiment, the VTM  20  is partially located on at least one PM  30 , and the LLM  40  is located on the VTM  20 , but the present disclosure is not limited to this approach. In other embodiments, as shown in, for example,  FIG.  24   , the VTM  20  may be located on the LLM  40 , and at least one PM  30  may be located on a part of the VTM  20 .  FIG.  24    is a schematic cross-sectional view of a substrate processing system  10  in another example. In the example of  FIG.  24   , the arm  221  in the transfer robot  22  in the VTM  20  is extendable in the vertical direction from an upper portion of the VTM  20  to move the substrate support  220 . The substrate processing system  10  according to the present embodiment is also installable in a smaller installation area. 
     In the above embodiment, multiple PMs  30  are arranged horizontally, but the technique according to the present disclosure is not limited to this. In another embodiment shown in, for example,  FIG.  25   , multiple PMs  30  may be stacked in the vertical direction.  FIG.  25    is a schematic cross-sectional view of a substrate processing system  10  in another example. In the example of  FIG.  25   , the multiple PMs  30  are stacked in the vertical direction in pairs. In the example of  FIG.  25   , the arm  231  in each transfer robot  23  is extendable in the vertical direction to load and unload a substrate W to and from the upper PM  30  and to load and unload a substrate W to and from the lower PM  30 . The substrate processing system  10  including the multiple PMs  30  is thus installable in a smaller installation area as well. Although two PMs  30  are stacked in the vertical direction in the example of  FIG.  25   , more than two PMs  30  may be stacked in the vertical direction. 
     Although the EFEM  50  is located lateral to the VTM  20  in the above embodiment, the technique according to the present disclosure is not limited to this. In other embodiments, the EFEM  50  and the VTM  20  may overlap with each other at least partially as viewed from above. At least one LP  60  and the LLM  40  may overlap with each other at least partially as viewed from above.  FIG.  26    is a schematic cross-sectional view of a substrate processing system  10  in another example. The substrate processing system  10  in the example of  FIG.  26    includes the EFEM  50  located on the VTM  20  and multiple LPs  60  located on the LLM  40 . In the example of  FIG.  26   , the arm  521  in the transfer robot  52  in the EFEM  50  is extendable in the vertical direction from an upper portion of the EFEM  50  to move the substrate support  520  in the vertical direction. The substrate processing system  10  according to the present embodiment is also installable in a smaller installation area. 
     Although the substrate processing system  10  illustrated in  FIG.  26    includes multiple LLMs  40  located lateral to the EFEM  50 , the technique according to the present disclosure is not limited to this. In other embodiments, the LLM  40  may be located under the EFEM  50  as shown in, for example,  FIG.  27   .  FIG.  27    is a schematic cross-sectional view of a substrate processing system  10  in another example. In the example of  FIG.  27   , the transfer robot  41  in the LLM  40  receives the substrate W and transfers the substrate W through the gate valve  43  to the substrate support  220  in the transfer robot  22 . In the example of  FIG.  27   , the VTM  20  includes no transfer robot  21 . Although the LLM  40  includes two transfer robots  41  in the example of  FIG.  27   , the LLM  40  may include a single transfer robot  41 . 
     Although the substrate processing system  10  illustrated in  FIG.  26    includes multiple PMs  30  arranged horizontally, the technique according to the present disclosure is not limited to this. In other embodiments, multiple PMs  30  may be stacked in the vertical direction as shown in, for example,  FIG.  28   .  FIG.  28    is a schematic cross-sectional view of a substrate processing system  10  in another example. Although two PMs  30  stacked in the vertical direction in the example of  FIG.  28   , more than two PMs  30  may be stacked in the vertical direction. The substrate processing system  10  including the multiple PMs  30  is thus installable in a smaller installation area as well. 
     Although each PM  30  uses CCP for processing in the above embodiment as an example of a plasma source, the plasma source is not limited to this. Plasma sources other than CCP include, for example, inductively coupled plasma (ICP), microwave-excited surface wave plasma (SWP), electron cyclotron resonance plasma (ECP), and helicon wave excited plasma (HWP). 
     Each PM  30  in the above embodiment uses plasma to process the substrate W, but the technique according to the present disclosure is not limited to this. Each PM  30  that performs processing on the substrate W may be a device that performs non-plasma processing, such as heat treatment or chemical vapor deposition (CVD). 
     The embodiments disclosed herein are illustrative in all aspects and should not be construed to be restrictive. The above embodiments may be implemented in various forms. The components in the above embodiments may be eliminated, substituted, or modified in various forms without departing from the spirit and scope of the claims. 
     REFERENCE SIGNS LIST 
     
         
         W Substrate 
           10  Substrate processing system 
           12  Control device 
           12   a  Computer 
           12   a   1  Processor 
           12   a   2  Storage 
           12   a   3  Communication interface 
           20  Vacuum transfer module (VTM) 
           21  Transfer robot 
           210  Substrate support 
           22  Transfer robot 
           220  Substrate support 
           221  Arm 
           221   a  Cylinder 
           221   b  Cylinder 
           23  Transfer robot 
           230  Substrate support 
           231  Arm 
           30  Process module (PM) 
           31  Gate valve 
           32  Opening 
           310  Plasma processing chamber 
           310   a  Side wall 
           310   e  Gas outlet 
           310   s  Plasma processing space 
           311  Substrate support 
           3111  Body 
           31110  Base 
           31111  Electrostatic chuck (ESC) 
           3112  Ring assembly 
           313  Shower head electrode 
           320  Gas supply unit 
           321  Gas source 
           322  Flow controller 
           330  Power supply 
           331  Radio frequency (RF) power supply 
           332  Direct current (DC) power supply 
           340  Exhaust system 
           40  Loadlock module (LLM) 
           41  Transfer robot 
           410  Substrate support 
           42  Gate valve 
           43  Gate valve 
           50  Equipment front end module (EFEM) 
           51  Gate valve 
           52  Transfer robot 
           520  Substrate support 
           521  Arm 
           521   a  Cylinder 
           521   b  Cylinder 
           60  Load port (LP) 
           61  Front opening unified pod (FOUP)