Patent Publication Number: US-2022216035-A1

Title: Vacuum processing apparatus and maintenance apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation application of U.S. application Ser. No. 15/897,228, filed on Feb. 15, 2018, which claims priority to Japanese Patent Application No. 2017-026524 filed on Feb. 16, 2017, the entire contents of which are incorporated herein by reference and priority is claimed to each. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to a vacuum processing apparatus and a maintenance apparatus. 
     BACKGROUND OF THE INVENTION 
     Conventionally, there is known a vacuum processing apparatus for performing various processes on a substrate such as a semiconductor wafer (hereinafter, referred to as “wafer”) or the like in a processing chamber in a vacuum state. For example, a plasma etching apparatus for etching a wafer in a processing chamber in a vacuum state by using plasma is known as the vacuum processing apparatus. 
     In the vacuum processing apparatus, it is required to replace a consumable part in the processing chamber which has been consumed by processing the substrate. For example, in the plasma etching apparatus, a focus ring provided at an outer periphery of the wafer is consumed by etching. In the plasma etching apparatus, an etching rate or the like is affected by the consumption of the focus ring. Therefore, in the plasma etching apparatus, the focus ring that has been consumed by a certain degree needs to be replaced. 
     When the consumed part is replaced, the processing chamber is exposed to the atmosphere. However, in the vacuum processing apparatus, once the processing chamber is exposed to the atmosphere, a considerably long time is required for temperature control and moisture control until the substrate processing is restarted. As a result, the productivity is decreased. 
     Therefore, there has been suggested a technique for replacing a consumed part without exposing the processing chamber to the atmosphere by replacing the consumed part through a transfer system for transferring a substrate to a vacuum processing apparatus while maintaining a vacuum state (see, e.g., Japanese Patent Application Publication No. 2006-196691). 
     However, in the case of replacing the consumed part through the transfer system for transferring a substrate, the transfer system may be contaminated. For example, the focus ring is subjected to a considerable number of etching processes until it is replaced with a new focus ring, compared to a single wafer. Therefore, a large number of deposits are adhered to the focus ring during the etching processes. In the case of replacing the focus ring through the transfer system such as a transfer arm for transferring a wafer or the like, particles may be generated in the transfer system. When the particles are generated in the transfer system, it is required to stop the operation of the transfer system and perform a maintenance operation for cleaning. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect, there is provided a vacuum processing apparatus including: a consumable part which is consumed by processing a substrate; and a processing chamber in which the consumable part is provided, the processing chamber having a first gate through which the substrate is loaded and unloaded and a second gate to and from which a maintenance apparatus for replacing a consumed part is attachable and detachable. 
     In accordance with another aspect, there is provided a maintenance apparatus including: a case with an opening having a size corresponding to a second gate of a vacuum processing apparatus including a processing chamber having a first gate through which a substrate is loaded and unloaded and the second gate different from the first gate, the case being attachable to the second gate while maintaining airtightness; and a maintenance mechanism provided in the case and configured to perform at least one of an operation of detaching a consumed part in the processing chamber through the opening, an operation of attaching a replacement part in the processing chamber and an operation of cleaning the processing chamber. 
     In accordance with the substrate processing apparatus, the consumed part can be replaced while suppressing contamination of the transfer system for transferring a substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the present disclosure will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which: 
         FIG. 1  schematically shows a configuration of a substrate processing system according to an embodiment; 
         FIG. 2  schematically shows a plasma etching apparatus according to an embodiment; 
         FIG. 3A  is a top view schematically showing a maintenance apparatus according to a first embodiment; 
         FIG. 3B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 4A  explains an operation of detaching an adaptor; 
         FIG. 4B  is a perspective view of a detachment mechanism; 
         FIG. 5A  is a top view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 5B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 6A  is a top view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 6B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 7A  is a top view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 7B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 8A  is a top view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 8B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 9  is a top view schematically showing an attaching unit according to the first embodiment; 
         FIG. 10A  is a top view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 10B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment; 
         FIG. 11A  is a top view schematically showing a maintenance apparatus according to a second embodiment; 
         FIG. 11B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 12A  explains a configuration for attaching/detaching an adaptor detaching unit and a linear stage; 
         FIG. 12B  is a perspective view schematically showing a connection unit; 
         FIG. 12C  is a cross sectional view schematically showing the connection unit; 
         FIG. 13A  is a top view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 13B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 14  is a perspective view schematically showing an adaptor support; 
         FIG. 15A  is a top view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 15B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 16A  is a top view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 16B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 17A  is a top view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 17B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 18A  is a top view schematically showing the maintenance apparatus according to the second embodiment; 
         FIG. 18B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment; 
         FIGS. 19 to 22  are cross sectional views schematically showing the maintenance apparatus according to the second embodiment; 
         FIGS. 23 and 24  are cross sectional views schematically showing a maintenance apparatus according to a third embodiment; 
         FIG. 25  is a perspective view schematically showing an example of a frame; and 
         FIG. 26  is a perspective view schematically showing an example of a case formed by stacking a plurality of frames. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments of a vacuum processing apparatus and a maintenance apparatus of the present disclosure will be described in detail with reference to the accompanying drawings. Like reference numerals will be given to like or corresponding parts throughout the drawings. The embodiments are not intended to limit the present disclosure. The embodiments can be appropriately combined without contradicting the processing contents. 
     First Embodiment 
     (Configuration of Substrate Processing System) 
     First, a schematic configuration of a substrate processing system according to an embodiment will be described. The substrate processing system performs a predetermined process on a substrate such as a wafer or the like. In the present embodiment, a case in which a plasma etching process is performed on a substrate will be described as an example.  FIG. 1  shows the schematic configuration of the substrate processing system according to the embodiment. The substrate processing system  1  includes an atmospheric transfer chamber  11  for loading a wafer W that is a substrate for manufacturing a semiconductor device into the substrate processing system  1 , two load-lock chambers  12 A and  12 B, a vacuum transfer chamber  13 , and four vacuum processing apparatuses. Each of the vacuum processing apparatuses performs a predetermined process on the substrate. In the present embodiment, a case in which the vacuum processing apparatus is configured as a plasma etching apparatus  10  for performing a plasma etching process on a wafer W as a substrate will be described as an example. 
     The atmospheric transfer chamber  11  is connected to the vacuum transfer chamber  13  via the load-lock chambers  12 A and  12 B. The plasma etching apparatus  10  is connected to the vacuum transfer chamber  13  while being partitioned from the load-lock chambers  12 A and  12 B. 
     The inside of the atmospheric transfer chamber  11  is in an atmospheric atmosphere and carrier mounting stages  14  for mounting thereon carriers C are attached to the atmospheric transfer chamber  11 . Each of the carriers C accommodates therein a plurality of wafers W. Gate doors GT, which are opened/closed in association with lids of the carriers C connected to the carriers C, are provided at a front wall of the atmospheric transfer chamber  11 . A stocker  2  serving as a storage part is provided at one side surface of the atmospheric transfer chamber  11 . An alignment chamber  3  serving as a position alignment mechanism is provided at the other side surface of the atmospheric transfer chamber  11 . The stocker  2  includes a housing  21  for accommodating and temporarily storing the wafer W or the like. An opening  22  for a first transfer mechanism  15  and a shutter  23  for opening/closing the opening  22  are provided at the housing  21 . In the alignment chamber  3 , a horizontal rotation stage is provided and various alignment controls such as control of a rotation position of the wafer W and the like can be performed. 
     The first transfer mechanism  15  is provided in the atmospheric transfer chamber  11 . The first transfer mechanism  15  transfers the wafer W between the carriers C, the load-lock chambers  12 A and  12 B, the alignment chamber  3  and the stocker  2 . The first transfer mechanism  15  includes a base portion  15   a,  a multi-joint arm  15   b  and a holding portion  15   c.  The arm  15   b  has a base end connected to the base portion  15   a  and a leading end connected to the holding portion  15   c.  The base portion  15   a  is movable horizontally and vertically. The holding portion  15   c  has a U shape when seen from the top. The holding portion  15   c  holds the wafer W. 
     A stage on which the wafer W is mounted and supporting pins capable of moving vertically are provided in each of the load-lock chambers  12 A and  12 B. The wafer W can be transferred between the first transfer mechanism  15  and a second transfer mechanism  16  to be described later by the supporting pins in the load-lock chambers  12 A and  12 B. Further, a vacuum pump and a leakage valve (both not shown) are provided in each of the load-lock chambers  12 A and  12 B. Thus, an atmosphere in each of the load-lock chambers  12 A and  12 B can be switched between an atmospheric atmosphere and a vacuum atmosphere. In other words, it is possible to switch an atmosphere in each of the load-lock chambers  12 A and  12 B for transferring the wafer W between the atmospheric transfer chamber  11  maintained in an atmospheric atmosphere and the vacuum transfer chamber  13  maintained in a vacuum atmosphere. 
     The vacuum transfer chamber  13  is maintained in a vacuum atmosphere. The second transfer mechanism  16  is provided in the vacuum transfer chamber  13 . The second transfer mechanism  16  is substantially the same as the first transfer mechanism  15  except that two arms and two holding portions are provided at one base. The base, the arms and the holding portions of the second transfer mechanism  16  are indicated by reference numerals  16   a,    16   b  and  16   c , respectively. 
     Notation “G” in  FIG. 1  denotes an openable/closable gate valve (partition valve) for partitioning between the chambers and partitioning between the plasma etching apparatuses  10  and the vacuum transfer chamber  13 . The gate valve G is closed normally and opened when the wafer W is transferred between the chambers and between the respective modules and the vacuum transfer chamber  13 . 
     (Configuration of the Plasma Etching Apparatus) 
     Next, a configuration of the plasma etching apparatus  10  according to an embodiment will be described.  FIG. 2  schematically shows the plasma etching apparatus according to the embodiment. The plasma etching apparatus  10  includes an airtight processing chamber  30  that is electrically grounded. The processing chamber  30  is formed in a cylindrical shape and made of, e.g., aluminum having an anodically oxidized surface or the like. The processing chamber  30  defines a processing space where a plasma is generated. A mounting table  31  for horizontally supporting a wafer W is provided in the processing chamber  30 . 
     The mounting table  31  has a substantially cylindrical shape with an upper and a lower surface directed vertically. The upper surface of the mounting table  31  serves as a mounting surface  36   d.  The mounting surface  36   d  of the mounting table  31  is greater than the wafer W. The mounting table  31  includes a base  33  and an electrostatic chuck  36 . 
     The base  33  is made of metal, e.g., aluminum or the like. The base  33  serves as a lower electrode. The base  33  is supported by a supporting member  34  made of an insulator. The supporting member  34  is installed at a bottom portion of the processing chamber  30 . 
     The electrostatic chuck  36  has a flat disc-shaped upper surface. The upper surface serves as the mounting surface  36   d  on which the wafer W is mounted. The electrostatic chuck  36  is provided at a center of the mounting table  31  when seen from the top. The electrostatic chuck  36  includes an electrode  36   a  and an insulator  36   b . The electrode  36   a  is embedded in the insulator  36   b.  A DC power supply  42  is connected to the electrode  36   a.  The wafer W is attracted and held on the electrostatic chuck  36  by a Coulomb force generated by applying a DC voltage from the DC power supply  42  to the electrode  36   a.  A heater  36   c  is provided in the insulator  36   b  of the electrostatic chuck  36 . The heater  36   c  controls a temperature of the wafer W by a power supplied through a power supply unit to be described later. 
     A focus ring  35  made of, e.g., single crystalline silicon, is provided on an upper outer periphery of the mounting table  31 . A cylindrical inner wall member  37  made of, e.g., quartz or the like, is provided to surround an edge of the mounting table  31  and an edge of the supporting member  34 . 
     A power feed rod  50  is connected to the base  33 . The power feed rod  50  is connected to a first RF power supply  40   a  via a first matcher  41   a  and connected to a second RF power supply  40   b  via a second matcher  41   b.  The first RF power supply  40   a  generates power for plasma generation. A high frequency power having a predetermined frequency is supplied from the first RF power supply  40   a  to the base  33  of the mounting table  31 . The second RF power supply  40   b  generates power for ion attraction (bias). A high frequency power having a predetermined frequency lower than that from the first RF power supply  40   a  is supplied from the second RF power supply  40   b  to the base  33  of the mounting table  31 . 
     A coolant path  33   d  is formed in the base  33 . The coolant path  33   d  has one end connected to a coolant inlet line  33   b  and the other end connected to a coolant outlet line  33   c.  In the plasma etching apparatus  10 , a temperature of the mounting table  31  can be controlled by circulating a coolant, e.g., cooling water or the like, through the coolant path  33   d.  In the plasma etching apparatus  10 , it is also possible to form coolant paths at portions of the base  33  which correspond to a region on which the wafer W is mounted and a region on which the focus ring  35  is mounted and separately control temperatures of the wafer W and the focus ring  35 . Further, the plasma etching apparatus  10  may be configured such that a cold heat transfer gas is supplied to a backside of the wafer W and to a bottom surface of the focus ring  35  to separately control the temperatures thereof. For example, a gas supply line for supplying a cold heat transfer gas (backside gas) such as He gas or the like to a backside of the wafer W may be provided to penetrate through the mounting table  31  and the like. The gas supply line is connected to a gas supply source. With this configuration, the wafer W attracted and held on the electrostatic chuck  36  on the top surface of the mounting table  31  can be controlled to a predetermined temperature. 
     A shower head  46  serving as an upper electrode is provided above the mounting table  31  to face the mounting table  31  in parallel therewith. The shower head  46  and the mounting table  31  function as a pair of electrodes (upper electrode and lower electrode). 
     The shower head  46  is provided at a ceiling wall portion of the processing chamber  30 . The shower head  46  includes a main body  46   a  and an upper ceiling plate  46   b  serving as an electrode plate. The shower head  46  is supported at an upper portion of the processing chamber  30  through an insulating member  47 . The main body  46   a  is made of a conductive material, e.g., aluminum having an anodically oxidized surface. The upper ceiling plate  46   b  is detachably held at a bottom portion of the main body  46   a.    
     A gas diffusion space  46   c  is formed in the main body  46   a.  A plurality of gas through holes  46   d  is formed in the bottom portion of the main body  46   a  to be positioned below the gas diffusion space  46   c.  Gas injection holes  46   e  are formed through the upper ceiling plate  46   b  in a thickness direction thereof. The gas injection holes  46   e  communicate with the gas through holes  46   d.  With this configuration, the processing gas supplied to the gas diffusion space  46   c  is distributed in a shower form into the processing chamber  30  through the gas through holes  46   d  and the gas injection holes  46   e.    
     A gas inlet port  46   g  for introducing the processing gas into the gas diffusion space  46   c  is formed in the main body  46   a.  One end of gas supply line  45   a  is connected to the gas inlet port  46   g  and the other end of the gas supply line  45   a  is connected to a processing gas supply source  45  for supplying a processing gas. A mass flow controller (MFC)  45   b  and an opening/closing valve V 2  are disposed in the gas supply line  45   a  in that order from an upstream side. The processing gas for plasma etching is supplied from the processing gas supply source  45  to the gas diffusion space  46   c  through the gas supply line  45   a  and distributed in a shower form into the processing chamber  30  through the gas through holes  46   d  and the gas injection holes  46   e.    
     A variable DC power supply  48   b  is electrically connected to the shower head  46  serving as the upper electrode via a low pass filter (LPF)  48   a.  A power supply of the variable DC power supply  48   b  is on-off controlled by an on/off switch  48   c.  Current/voltage of the variable DC power supply  48   b  and on/off of the on/off switch  48   c  are controlled by a control unit  90  to be described later. As will be described later, when a plasma is generated in the processing space by applying the high frequency power from the first and the second RF power supply  40   a  and  40   b  to the mounting table  31 , the on/off switch  48   c  is turned on by the control unit  90  and a predetermined DC voltage is applied to the shower head  46  serving as the upper electrode, if necessary. 
     A cylindrical ground conductor  30   a  extends upward from a sidewall of the processing chamber  30  to a position higher than a height of the shower head  46 . The cylindrical ground conductor  30   a  has a ceiling wall at the top thereof. 
     A gas exhaust port  81  is formed at a bottom portion of the processing chamber  30 . A gas exhaust unit  83  is connected to the gas exhaust port  81  through a gas exhaust line  82 . The gas exhaust unit  83  has a vacuum pump. By operating the vacuum pump, a pressure in the processing chamber  30  can be decreased to a predetermined vacuum level. 
     A first gate  84  through which the wafer W is loaded/unloaded is provided at an inner sidewall of the processing chamber  30 . A gate valve G for opening/closing the first gate  84  is provided at the first gate  84 . As shown in  FIG. 1 , the first gate  84  is connected to the vacuum transfer chamber  13  through the gate valve G while maintaining airtightness. The wafer W can be loaded into and unloaded from the vacuum transfer chamber  13  in a state where a vacuum atmosphere is maintained. 
     A deposition shield  86  is provided along an inner wall of the processing chamber  30 . The deposition shield  86  has a function of preventing etching by-products (deposits) from being attached to the inner wall of the processing chamber  30 . The deposition shield  86  is detachably provided. 
     The overall operation of the plasma etching apparatus configured as described above is controlled by the control unit  90 . The control unit  90  is, e.g., a computer, and controls the respective components of the plasma etching apparatus  10 . 
     In the plasma etching apparatus  10 , it is required to replace a consumed part in the processing chamber  30  which has been consumed by the etching process using plasma. For example, in the plasma etching apparatus  10 , the focus ring  35  provided at an outer periphery of the wafer W is consumed by the etching process. In the plasma etching apparatus  10 , when the consumed part such as the focus ring  35  or the like is replaced, the processing chamber  30  is exposed to the atmosphere. In that case, a considerably long time is required for temperature control and moisture control until the etching process for the wafer W is restarted. As a result, the productivity is decreased. 
     Therefore, it may be considered to replace the consumed part without exposing the processing chamber  30  to the atmosphere by replacing the consumed part through a transfer system for transferring a wafer W to the plasma etching apparatus  10 . For example, in the substrate processing system  1  shown in  FIG. 1 , the focus ring  35  may be replaced through the transfer system for transferring the wafer W to the plasma etching apparatus  10 , such as the first transfer mechanism  15  in the atmospheric transfer chamber  11 , the load-lock chambers  12 A and  12 B, the second transfer mechanism  16  in the vacuum transfer chamber  13  and the like. 
     However, in the case of replacing the focus ring  35  through the transfer system for transferring the wafer W, the transfer system may be contaminated. For example, the focus ring  35  is subjected to a considerable number of etching processes until it is replaced with a new focus ring, compared to a single wafer W. Therefore, a large number of deposits are adhered to the focus ring  35  during the etching processes. In the case of replacing the focus ring  35 , deposits adhered to the second transfer mechanism  16  of the vacuum transfer chamber  13  become a cause of particles. When the particles are generated in the transfer system, it is required to stop the operation of the transfer system and perform a maintenance operation for cleaning. For example, in the substrate processing system  1  shown in  FIG. 1 , the operation of the entire system is stopped when the operation of the transfer system is stopped to perform the maintenance operation. 
     For example, as shown in  FIG. 1 , in the substrate processing system  1  in which a plurality of plasma etching apparatuses  10  is connected to the vacuum transfer chamber  13 , when all the plasma etching apparatuses  10  are driven, the transfer system consecutively transfers wafers W to the plasma etching apparatuses  10 . However, in the substrate processing system  1 , if one of the plasma etching apparatuses  10  uses the transfer system to replace the focus ring  35 , the other plasma etching apparatuses  10  are stopped. 
     Therefore, in the plasma etching apparatus  10  according to the embodiment, a gate for replacing a consumed part is provided in addition to the first gate  84 . For example, as shown in  FIG. 2 , in the plasma etching apparatus  10 , a second gate  95  is provided at an opposite side of the first gate  84  with respect to the mounting table  31  on which the wafer W is mounted. The second gate  95  is an opening greater than a consumed part to be replaced. The second gate  95  is blocked by an adaptor  96  while maintaining airtightness. For example, the second gate  95  has an outer opening greater than an inner opening and an end surface  95 A is formed between the outer opening and the inner opening. An O-ring and screw holes are provided at the end surface  95 A to be in contact with the adaptor  96  and the adaptor  96  is fixed by screws. The maintenance apparatus  100  to be described later can be attached to and detached from the second gate  95 . For example, as shown in  FIG. 1 , in the plasma etching apparatus  10 , the first gate  84  is connected to the transfer system for the wafer W. Therefore, it is difficult to ensure a space near the first gate  84  of the plasma etching apparatus  10 , whereas it is easy to ensure a space near the opposite side of the first gate  84 . Accordingly, in the plasma etching apparatus  10 , the space for the maintenance apparatus  100  can be easily ensured by providing the second gate  95  at the opposite side of the first gate  84 . When a consumed part needs to be replaced, an operator loosens the screws fixing the adaptor  95  from the plasma etching apparatus  10  having the consumed part to be replaced. Then, the operator attaches the maintenance apparatus  100  to the plasma etching apparatus  10  having the consumed part to be replaced, as indicated by a broken line in  FIG. 1 . 
     (Configuration of the Maintenance Apparatus) 
     Next, a configuration of the maintenance apparatus  100  according to the first embodiment will be described.  FIG. 3A  is a top view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 3B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 3B  is a cross sectional view seen from a bottom side of  FIG. 3A  which is taken along a dashed line  3 B- 3 B in  FIG. 3A .  FIGS. 3A and 3B  show a state in which the maintenance apparatus  100  is attached to the plasma etching apparatus  10 . In the following drawings, the plasma etching apparatus  10  is simply illustrated. Hereinafter, the configuration of the maintenance apparatus  100  will be appropriately described along the sequence of replacing the focus ring  35  as a consumed part. 
     The maintenance apparatus  100  includes a case  101  with an opening  101 A having a size corresponding to that of the second gate  95  of the plasma etching apparatus  10 . An O-ring or the like is provided at a portion around the opening  101 A of the case  101  which is brought into contact with the plasma etching apparatus  10 . The maintenance apparatus  100  is disposed such that the opening  101 A corresponds to the second gate  95  and the opening  101 A is fixed to the second gate  95  by screws or the like while maintaining airtightness. 
     A vacuum gauge  101 B capable of measuring a degree of vacuum is provided in the case  101 . When a consumed part is replaced, an atmosphere in the case  101  of the maintenance apparatus  100  becomes substantially the same as the vacuum atmosphere in the processing chamber  30 . For example, the maintenance apparatus  100  is connected to the gas exhaust unit  83  of the plasma etching apparatus  10  through a gas exhaust line (not shown) and a pressure in the case  101  is decreased to a predetermined vacuum level by the gas exhaust unit  83 . Alternatively, the maintenance apparatus  100  may include a gas exhaust unit for exhausting the case  101 . 
     In the maintenance apparatus  100 , the case  101  has therein a maintenance mechanism for performing at least one of an operation of detaching the consumed part in the processing chamber  30 , an operation of attaching a replacement part in the processing chamber  30  and an operation of cleaning the processing chamber  30 . In the maintenance apparatus  100  of the present embodiment, a robot arm  110 , a detaching unit  120  for detaching the focus ring  35 , a cleaning unit  130  for cleaning the processing chamber  30  and an attaching unit  140  for attaching a new focus ring in the processing chamber  30  are provided as the maintenance mechanism. 
     In the case  101 , supporting tables  102  are arranged at three height levels at a predetermined interval. The detaching unit  120 , the cleaning unit  130  and the attaching unit  140  are placed on the three supporting tables  102 , respectively. The case  101  is partially openable/closeable, and the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  are separately attachable and detachable. In other words, the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  can be separately replaced. 
     The robot arm  110  includes an arm unit  111  having three arms connected by joints, a supporting portion  112  for supporting the arm unit  111  and a hand  113  provided at a leading end of the arm unit  111 . The robot arm  110  can be extended by linearly stretching the three arms of the arm unit  111  or contracted by folding them. The robot arm  110  can hold an object by using the hand  113 . The robot arm  110  is fixed to an elevation table  114  and vertically moved by vertical movement of the elevation table  114 . The overall operations of the robot arm  110  and the elevation table  114  are controlled by a control unit (not shown). The control unit includes a user interface for displaying reception of various manipulation instructions or operational states. An operator inputs an operation instruction through the user interface. The operation instruction may separately specify the vertical movement of the supporting tables  102  or the movement of the robot arm  110 . Or, the manipulation instruction may specify a series of movements. For example, the operation instruction may specify, as an instruction of detaching the focus ring  35 , the vertical movement of the supporting table  102  and a series of movements of the robot arm  110  at the time of detaching the focus ring  35 . 
     The maintenance apparatus  100  includes a detaching unit for detaching the adaptor  96  of the plasma etching apparatus  10 . For example, in the maintenance apparatus  100 , a ball screw  105  and a shaft  106  are provided in parallel at an upper portion of the case  101 . The ball screw  105  can be rotated by a handle H 1  provided at the outside of the case  101  while maintaining airtightness through, e.g., an O-ring or the like. A linear stage  150  is attached to the ball screw  105  and the shaft  106 . An adaptor detaching unit  160  is attached to the linear stage  150 . A groove is formed at a portion of the linear stage  150 , to which the ball screw  105  is attached, to correspond to the ball screw  105 . The linear stage  150  and the adaptor detaching unit  160  are moved along the ball screw  105  and the shaft  106  by the rotation of the ball screw  105 . 
     In the case of detaching the adaptor  96 , an operator rotates the handle H 1  so that the linear stage  150  and the adaptor detaching unit  160  can be moved toward the adaptor  96  as indicated by dashed lines in  FIGS. 3A and 3B . 
     Handles H 2 L and H 2 R for fixing the adaptor detaching unit  160  to the adaptor  96  are provided at side surfaces of the case  101  near the opening  101 A. The handles H 2 L and H 2 R can transfer a rotational driving force of the handles H 2 L and H 2 R to the adaptor detaching unit  160  when the adaptor detaching unit  160  and the adaptor  96  are brought into contact with each other. 
     Since the processing chamber  30  is in a vacuum state during the etching process, the adaptor  96  is fixed to the processing chamber  30  and may not be easily detached even when setting the case  101  of the maintenance apparatus  100  to a vacuum state. Therefore, detachment mechanisms  170  for detaching the adaptor  96  are respectively provided near both end portions of the adaptor detaching unit  160  of the present embodiment. 
       FIG. 4A  explains the detachment of the adaptor. Since the detachment mechanism  170  provided at the handle H 2 L side has the same configuration as that of the detachment mechanism  170  provided at the handle H 2 R side, the detachment mechanism  170  provided at the handle H 2 L side will be described with reference to  FIG. 4A . A positioning hole  96 A for stably fixing the adaptor detaching unit  160  is formed in an end portion of the adaptor  96 . A through-hole  96 B is formed in a portion of the adaptor  96  which faces the end surface  95 A of the second gate  95 . The through-hole  96 B has threads and is internal-threaded (female-threaded). A positioning pin  171  is provided at a portion of the adaptor detaching unit  160  which corresponds to the positioning hole  96 A. A detaching pin  172  constituting the detachment mechanism  170  is provided at a portion of the adaptor detaching unit  160  which corresponds to the through-hole  96 B. 
     The handle H 2 L is coaxially connected to a protruding engagement portion  181  through a rotation shaft  180 . The rotation shaft  180  can be rotated while maintaining airtightness by an O-ring  183  or the like. The protruding engagement portion  181  is rotated by rotating the handle H 2 L. 
     The detachment mechanism  170  has a recessed engagement portion  173  to be engaged with the protruding engagement portion  181  when the adaptor detaching unit  160  is brought into contact with the adaptor  96  at the same height position as the protruding engagement portion  181 . 
       FIG. 4B  is a perspective view of the detachment mechanism. In the detachment mechanism  170 , a groove  174  is formed in a side surface thereof facing the handle H 2 L and vertical width of the groove  174  is increased as it goes away from the recessed engagement portion  173 . The detachment mechanism  170  can guide the protruding engagement portion  181  to the recessed engagement portion  173  through the groove  174 . In the detachment mechanism  170 , when the protruding engagement portion  181  and the recessed engaging portion  173  are coaxially engaged, the protruding engagement portion  181  and the recessed engagement portion  173  can rotate together and the rotational driving force of the handle H 2 L can be transferred to the detachment mechanism  170 . 
     A worm gear  175  is coaxially connected to the recessed engagement portion  173 . The worm gear  175  is rotatably held by a bearing  176  and rotated by rotation of the recessed engagement portion  173 . A wheel  177  is rotated by rotation of the worm gear  175 . The detaching pin  172  has an external-threaded (male-threaded) leading end portion  172 A and an extensible/contractible shaft  172 B. The wheel  177  and the telescopic shaft  172 B have a ball spline structure. The telescopic shaft  172 B is rotatably held by a bearing  178 . 
     In the case of detaching the adaptor  96 , an operator rotates the handle H 1  so that the linear stage  150  and the adaptor detaching unit  160  can be moved toward the adaptor  96  as indicated by the dashed lines in  FIGS. 3A and 3B . When the adaptor detaching unit  160  is brought into contact with the adaptor  96 , the positioning pin  171  is insertion-fitted to the positioning hole  96 A and the detaching pin  172  is insertion-fitted to the through-hole  96 B. Then, the operator rotates the handles H 2 L and H 2 R so that the external threads (male threads) of the leading end portion  172 A of the detaching pin  172  are further insertion-fitted to the internal threads (female threads) of the through-hole  96 B and brought into contact with the end surface  95 A while passing through the through-hole  96 B. Therefore, the end surface  95 A is pressed. Accordingly, even when the adaptor  96  is fixed to the processing chamber  30 , it is possible to detach the adaptor  96 . 
     When the adaptor  96  is detached, the operator rotates the handle H 1  in a reverse direction to that used in the detaching operation so that the linear stage  150  and the adaptor detaching unit  160  can be moved to the original positions.  FIGS. 5A and 5B  show a state in which the adaptor  96  is detached.  FIG. 5A  is a top view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 5B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 5B  is a cross sectional view seen from a bottom side of  FIG. 5A  which is taken along a dashed line  5 B- 5 B in  FIG. 5A . The detached adaptor  96  is moved to a right side while being held by the adaptor detaching unit  160 . 
     Next, an operation of detaching the focus ring  35  will be described.  FIGS. 6A and 6B  show the operation of detaching the focus ring  35 .  FIG. 6A  is a top view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 6B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 6B  is a cross sectional view seen from a bottom side of  FIG. 6A  which is taken along a dashed line  6 B- 6 B in  FIG. 6A . 
     The detaching unit  120  is formed in a disc shape having a size that is substantially the same as that of the focus ring  35 . An adhesive layer  121  is formed at an outer peripheral region of a bottom surface of the detaching unit  120  which corresponds to the focus ring  35 . 
     In the case of detaching the focus ring  35  of the plasma etching apparatus  10 , the elevation table  114  moves to a height position corresponding to the supporting table  102  on which the detaching unit  120  is mounted. The robot arm  110  extends the arm unit  111  toward the detaching unit  120  so that the hand  113  can hold the detaching unit  120 . Then, the robot arm  110  contracts the arm unit  111  while holding the detaching unit  120 . 
     Next, the elevation table  114  moves to a height position corresponding to the opening  101 A as indicated by dashed lines in  FIGS. 6A and 6B . The robot arm  110  extends the arm unit  111  toward the opening  101 A, and moves the detaching unit  120  to a position above the mounting table  31  through the opening  101 A. Then, the robot arm  110  lowers the arm unit  111  so that the detaching unit  120  comes in contact with the mounting table  31 . Accordingly, the focus ring  35  mounted on the mounting table  31  is adhered to the detaching unit  120  by the adhesive layer  121 . 
     The robot arm  110  detaches the focus ring  35  from the mounting table  31  by lifting the arm unit  111 . Then, the robot arm  110  and the elevation table  114  operate in a reverse sequence to that in the case of moving the detaching unit  120  from the supporting table  102  to the position above the mounting table  31 . As a consequence, the detaching unit  120  to which the focus ring  35  is adhered is stored in the original supporting table  102 . 
     Next, an operation of cleaning the mounting surface  36   d  of the mounting table  31  will be described.  FIGS. 7A and 7B  illustrate the operation of cleaning the mounting surface  36   d  of the mounting table  31 .  FIG. 7A  is a top view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 7B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 7B  is a cross sectional view seen from a bottom side of  FIG. 7A  which is taken along a dashed line  7 B- 7 B in  FIG. 7A . 
     The cleaning unit  130  is formed in a disc shape having a size that is substantially the same as that of the mounting surface  36   d  of the mounting table  31 . An adhesive layer  131  is formed on the entire bottom surface of the cleaning unit  130 . 
     In the case of cleaning the mounting surface  36   d  of the mounting table  31 , the elevation table  114  is moved to a height position corresponding to the supporting table  102  on which the cleaning unit  130  is mounted. The robot arm  110  extends the arm unit  111  toward the cleaning unit  130  and holds the cleaning unit  130  through the hand  113 . Then, the robot arm  110  contracts the arm unit  111  while holding the cleaning unit  130 . 
     Next, the elevation table  114  is moved to a height position corresponding to the opening  101 A as indicated by the dashed lines of  FIGS. 7A and 7B . The robot arm  110  extends the arm unit  111  toward the opening  101 A, and moves the cleaning unit  130  to a position above the mounting table  31  through the opening  101 A and then lowers the arm unit  111  so that the cleaning unit  130  comes in contact with the mounting table  31 . Accordingly, undesired substances, such as deposits, dust and the like, on the mounting table  31  are adhered to the adhesive layer  131  of the cleaning unit  130 . As a result, the mounting table  31  is cleaned. 
     The robot arm  110  separates the cleaning unit  130  from the mounting table  31  by lifting the arm unit  111 . Then, the robot arm  110  and the elevation table  114  operate in a reverse sequence to that in the case of moving the cleaning unit  130  from the supporting table  102  to the position above the mounting table  31 . As a consequence, the cleaning unit  130  to which the undesired substances are adhered is stored in the original supporting table  102 . 
     Next, an operation of attaching a new focus ring  35  to the mounting table  31  will be described.  FIGS. 8A and 8B  illustrate the operation of attaching a new focus ring  35  to the mounting table  31 .  FIG. 8A  is a top view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 8B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 8B  is a cross sectional view seen from a bottom side of  FIG. 8A  which is taken along a dashed line  8 B- 8 B in  FIG. 8A . 
     The attaching unit  140  has substantially the same size as that of the mounding surface  36   d  of the mounting table  31  and the focus ring  35  can be attached thereto and detached therefrom. A new focus ring  35  is set to the attaching unit  140 . The attaching unit  140  will be described in detail later. 
     In the case of attaching a new focus ring  35  to the mounting table  31 , the elevation table  114  is moved to a height position corresponding to the supporting table  102  on which the attaching unit  140  is mounted. The robot arm  110  extends the arm unit  111  toward the attaching unit  140  and holds the attaching unit  140  through the hand  113 . Then, the robot arm  110  contracts the arm unit  111  while holding the attaching unit  140 . 
     Next, the elevation table  114  is moved to a height position corresponding to the opening  101 A as indicated by the dashed lines in  FIGS. 8A and 8B . The robot arm  110  extends the arm unit  111  toward the opening  101 A, moves the attaching unit  140  to a position above the mounting table  31  through the opening  101 A, and then lowers the arm unit  111  so that the attaching unit  140  comes in contact with the mounting table  31 . 
     The attaching unit  140  can release the new focus ring  35  when contacting with the mounting table  31 . 
       FIG. 9  is a top view schematically showing the attaching unit according to the first embodiment. Positioning pins  141  are provided at a bottom surface of the attaching unit  140 . When the attaching unit  140  is mounted on the mounting table  31 , the positioning pins  141  are insertion-fitted to positioning holes  36   e  formed in the mounting surface  36   d  of the mounting table  31 . The positioning holes  36   e  may be provided at the mounting table for a single purpose. Or, it is also possible to use existing holes, e.g., holes through which lifter pins for vertically moving the wafer W mounted on the mounting table  31  are inserted. 
     The attaching unit  140  includes a contact pin  142  and a pin  143  for releasing the focus ring  35 . The pin  143  is in contact with a side surface of the contact pin  142  and biased toward the contact pin  142  by a spring  144 . The contact pin  142  has a leading end projecting from the bottom surface of the attaching unit  140 . When the attaching unit  140  is mounted on the mounting table  31 , the leading end of the contact pin  142  is brought into contact with the mounting table  31  and pressed and put in the attaching unit  140  (see ( 1 ) in  FIG. 9 ). A groove  142 A is formed at a position on the side surface of the contact pin  142  which corresponds to with the leading end of the pin  143  when the contact pin  142  is put in the attaching unit  140 . When the contact pin  142  is put in the attaching unit  140 , the leading end of the pin  143  is biased and fitted into the groove  142 A of the pin contact  142  by the spring  144  (see ( 2 ) in  FIG. 9 ). 
     One end portion of an engaging member  145  is fixed to the pin  143 . The other end portion of the engaging member  145  protrudes from the end of the attaching unit  140  by a distance smaller than the depth of the groove  142 A. A new focus ring  35  is engaged with a protruding portion  145 A of the engaging member  145  protruding from the end of the attaching unit  140 . The engaging member  145  is moved as the leading end of the pin  143  is moved into the groove  142 A and, thus, the protruding portion  145 A does not project from the end of the attaching unit  140  (see ( 3 ) in  FIG. 9 ). Accordingly, the engagement between the protruding portion  145 A and the new focus ring  35  is released, and the new focus ring  35  is mounted on the mounting table  31  (see ( 4 ) in  FIG. 9 ). 
     After the focus ring  35  is mounted on the mounting table  31 , the robot arm  110  detaches the attaching unit  140  from the mounting table  31  by lifting the arm unit  111 . Then, the robot arm  110  and the elevation table  114  operate in a reverse sequence to that used in the case of moving the attaching unit  140  from the supporting table  102  to the position above the mounting table  31 . As a consequence, the attaching unit  140  is stored in the original supporting table  102 . 
     After the focus ring  35  is replaced in the above-described manner, the operator attaches the adaptor  96  to the second gate  95  in a reverse sequence to that used in the case of detaching the adaptor  96 . Then, the operator returns the pressure in the case  101  of the maintenance apparatus  100  to an atmospheric pressure.  FIGS. 10A and 10B  show a state in which the replacement of the focus ring  35  is completed.  FIG. 10A  is a top view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 10B  is a cross sectional view schematically showing the maintenance apparatus according to the first embodiment.  FIG. 10B  is a cross sectional view seen from a bottom side of  FIG. 10A  which is taken along a dashed line  10 B- 10 B in  FIG. 10A . 
     In the plasma etching apparatus  10  of the present embodiment, the focus ring  35  which is consumed by the processing of the wafer W is provided in the processing chamber  30 . Further, in the plasma etching apparatus  10 , the first gate  84  used for loading/unloading the wafer W and the second gate  95  to/from which the maintenance apparatus  100  can be attached/detached are provided in the processing chamber  30 . Accordingly, the plasma etching apparatus  10  can replace the focus ring  35  without using the transfer system for transferring a wafer W. As a result, the plasma etching apparatus  10  can replace the focus ring  35  while suppressing contamination of the transfer system for transferring a wafer W. 
     In the plasma etching apparatus  10  of the present embodiment, the second gate  95  is provided at the opposite side of the first gate  84  with respect to the mounting table  31  in the processing chamber  30 . Accordingly, the plasma etching apparatus  10  can ensure a space for the maintenance apparatus  100 . 
     The maintenance apparatus  100  of the present embodiment includes the case  101  with the opening  101 A having a size corresponding to that of the second gate  95  of the plasma etching apparatus  10 . The maintenance apparatus  100  can be attached to the second gate  95  while maintaining airtightness. The maintenance apparatus  100  further includes the maintenance mechanism provided in the case  101 . The maintenance mechanism performs at least one of the operation of detaching the focus ring  35  in the processing chamber  30  through the opening  101 A, the operation of attaching the focus ring  35  in the processing chamber  30  and the operation of cleaning the processing chamber  30 . Accordingly, the maintenance apparatus  100  can replace the focus ring  35  without using the transfer system for transferring a wafer W. As a result, the maintenance apparatus  100  can replace the focus ring  35  while suppressing contamination of the transfer system for transferring a wafer W. 
     The maintenance apparatus  100  of the present embodiment further includes the robot arm  110 , the detaching unit  120  that can be attached to and detached from the robot arm  110 , the attaching unit  140  and the cleaning unit  130 . Accordingly, the maintenance apparatus  100  can perform the operation of detaching the focus ring  35  in the processing chamber  30 , the operation of attaching the focus ring  35  in the processing chamber  30  and the operation of cleaning the processing chamber  30 . 
     The detaching unit  120  of the present embodiment has the adhesive layer  121  on its surface to be in contact with the focus ring  35 . Accordingly, the detaching unit  120  can simply detach the focus ring  35  only through the contact with the focus ring  35 . 
     In the maintenance apparatus  100  of the present embodiment, the detaching unit  120 , the attaching unit  140  and the cleaning unit  130  can be separately provided in and detached from the case  101 . Accordingly, the maintenance apparatus  100  can simply replace the detaching unit  120 , the attaching unit  140  and the cleaning unit  130 . Further, a unit required for a maintenance operation to be performed can be provided to the maintenance apparatus  100 . 
     Second Embodiment 
     Hereinafter, a second embodiment will be described. Since the substrate processing system  1  and the plasma etching apparatus  10  according to the second embodiment have the same configurations as those of the substrate processing system  1  and the plasma etching apparatus  10  according to the first embodiment shown in  FIGS. 1 and 2 , redundant description thereof will be omitted. 
     The configuration of the maintenance apparatus  100  according to the second embodiment will be described. FIG. 
       11 A is a top view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 11B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 11B  is a cross sectional view seen from a bottom side of  FIG. 11A  which is taken along a dashed line  11 B- 11 B in  FIG. 11A .  FIGS. 11A and 11B  show a state in which the maintenance apparatus  100  is attached to the plasma etching apparatus  10 . Like or corresponding parts will be indicated by like reference numerals used in the maintenance apparatus  100  according to the first embodiment. Hereinafter, the configuration of the maintenance apparatus  100  will be appropriately described with reference to the sequence of replacing the focus ring  35  as a consumed part. 
     The maintenance apparatus  100  includes a case  101  with an opening  101 A having a size corresponding to that of the second gate  95  of the plasma etching apparatus  10 . An O-ring or the like is provided at a portion around the opening  101 A of the case  101  which is brought into contact with the plasma etching apparatus  10 . The maintenance apparatus  100  is attached to the second gate  95  by screw fixing or the like while maintaining airtightness. 
     A vacuum gauge  101 B capable of measuring a degree of vacuum is provided to the case  101 . When a consumed part is replaced, an atmosphere in the case  101  of the maintenance apparatus  100  becomes substantially the same as the vacuum atmosphere in the processing chamber  30 . 
     In the maintenance apparatus  100 , the case  101  has therein a maintenance mechanism for performing at least one of an operation of detaching the consumed part in the processing chamber  30 , an operation of attaching a replacement part in the processing chamber  30  and an operation of cleaning the processing chamber  30 . In the maintenance apparatus  100  of the present embodiment, a manually operated arm  200 , a detaching unit  120 , an attaching unit  140  and a cleaning unit  130  constitute the maintenance mechanism. 
     For example, the manually operated arm  200 , the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  are vertically disposed and horizontally arranged side by side near and below the opening  101 A in the case  101 . The case  101  is partially openable/closeable, and the manually operated arm  200 , the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  can be separately provided in the case  101  and removed from the case  101 . In other words, the manually operated arm  200 , the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  can be separately replaced. 
     In the maintenance apparatus  100 , a ball screw  105  and a shaft  106  are disposed in parallel at an upper portion in the case  101 . The ball screw  105  can be rotated by a handle H 1  provided at the outside of the case  101  while maintaining airtightness through, e.g., an O-ring or the like. A linear stage  150  is attached to the ball screw  105  and the shaft  106 . An adaptor detaching unit  160  is detachably attached to the linear stage  150 . In an initial state of the maintenance operation, the adaptor detaching unit  160  is attached to the linear stage  150 . 
       FIG. 12A  explains a configuration for attaching/detaching the adaptor detaching unit to/from the linear stage. The linear stage  150  is provided with two rods  151  which are spaced apart from each other at a predetermined interval. Connection units  161  to be connected to the two rods  152  are provided at portions of the adaptor detaching unit  160  which correspond to the two rods  151 . 
       FIG. 12B  is a perspective view schematically showing the connection unit  161 .  FIG. 12C  is a cross sectional view schematically showing the connection unit  161 . In the connection unit  161 , two connection members  161 A and  161 B, each of which has a recessed portion  162 , are arranged with the recessed portions  162  facing each other. The recessed portions  162  of the connection members  161 A and  161 B are slightly smaller than a radius of the rod  151 . The connection member  161 A has screw holes  163 A and is fixed to the adaptor detaching unit  160  by screws  163 B. The connection member  161 B has screw holes  164 A and is fixed to the adaptor detaching unit  160  by screws  164 B. The screw holes  164 A are elongated along the arrangement direction of the connection members  161 A and  161 B. The connection member  161 B is fixed to be movable back and forth along the arrangement direction of the connection members  161 A and  161 B. The connection unit  161  includes a ball screw  166  rotatably supported by a supporting portion  165 . The ball screw  166  has one end engaged with a recessed engaging portion  167  and the other end in contact with the connection member  161 B. 
     In the connection unit  161 , the gap between the connection member  161 A and the connection member  161 B can be changed by rotating the recessed engaging portion  167  to bias the connection member  161 B through the ball screw  166 . The connection unit  161  is connected to the rod  151  by providing the rod  151  in the recessed portions  162  of the connection members  161 A and  161 B and clamping the rod  151  with the connection members  161 A and  161 B by narrowing the gap between the connection members  161 A and  161 B by rotating the recessed engaging portion  167 . It is preferable to set a diameter of the rod  151  to be slightly greater at a lower portion than at a portion in contact with the connection members  161 A and  161 B in order to prevent the connection unit  161  from being removed from the rod  151 . 
     Referring back to  FIGS. 11A and 11B , a hole is formed in a portion of the linear stage  150  to correspond to the ball screw  105 . The linear stage  150  and the adaptor detaching unit  160  are moved along the ball screw  105  and the shaft  106  by the rotation of the ball screw  105 . The adaptor detaching unit  160  is provided with the detachment mechanism  170 . 
     When detaching the adaptor  96 , the operator rotates the handle H 1  so that the linear stage  150  and the adaptor detaching unit  160  is moved to the adaptor  96  as indicated by broken lines in  FIGS. 11A and 11B . Then, the operator rotates the handles H 2 L and H 2 R so that the adaptor  96  can be detached from the processing chamber  30  by the detachment mechanism  170 . 
     After the adaptor  96  is detached, the operator rotates the handle H 1  in a reverse direction to the rotation direction in the detaching operation so that the linear stage  150  and the adaptor detaching unit  160  is moved to the original positions.  FIGS. 13A and 13B  show a state in which the adaptor  96  is detached.  FIG. 13A  is a top view schematically showing a maintenance apparatus according to the second embodiment.  FIG. 13B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 13B  is a cross sectional view seen from a bottom side of  FIG. 13A  which is taken along the dashed line  13 B- 13 B in  FIG. 13A . The detached adaptor  96  is moved to the right side while being held by the adaptor detaching unit  160 . 
     Handles H 3 L and H 3 R for attaching/detaching the adaptor detaching unit  160  to/from the linear stage  150  are provided at a side surface of the case  101  which is opposite to the side where the opening  101 A is formed. The handle H 3 L is coaxially connected to a projecting engaging portion  191 L through a rotation shaft  190 L. The handle H 3 R is connected to a projected engaging portion  191 R through a rotation shaft  190 R. The rotation shafts  190 L and  190 R can be rotated while maintaining airtightness by an O-ring or the like. The projecting engaging portion  191 L is rotated by rotating the handle H 3 L. The projecting engaging portion  191 R is rotated by rotating the handle H 4 R. When the linear stage  150  is located at the right end, the handle H 3 L, the rotation shaft  190 L and the projecting engaging portion  191 L are engaged with the recessed engaging portion  167  of the connection unit  161  of the adaptor detaching unit  160  at an upper portion in  FIG. 13A . When the linear stage  150  is located at the right end, the handle H 3 R, the rotation shaft  190 R and the projecting engaging portion  191 R are engaged with the recessed engaging portion  167  of the connection unit  161  of the adaptor detaching unit  160  at a lower portion in  FIG. 13A . 
     When the linear stage  150  is located at the right end, the projecting engaging portions  191 L and  191 R are engaged with the recessed engaging portion  167 . Hence, the connection unit  161  can be manipulated by rotating the handles H 3 L and H 3 R, and the adaptor detaching unit  160  can be detached from the linear stage  150 . 
     An adaptor support  210  is provided at a right bottom portion of the maintenance apparatus  100 .  FIG. 14  is a perspective view schematically showing the adaptor support  210 . The adaptor support  210  is formed in a flat plate shape and has a recess  211  formed to correspond to a protrusion on the bottom surface of the adaptor detaching unit  160  and the adaptor  96  so that adaptor  96  and the adaptor detaching unit  160  can be horizontally supported. The recess  211  may be formed through the adaptor support  210 . In the example shown in  FIG. 14 , the recess  211  penetrates through the adaptor support  210 . 
     The adaptor support  210  can be vertically moved along a rail  212  vertically formed on an inner surface of the case  101  by manipulating a handle (not shown). The operator manipulates the handle (not shown) so that the adaptor support  210  can be lifted to support the adaptor  96  and the adaptor detaching unit  160 . Then, the operator rotates the handles H 3 L and H 3 R so that the adaptor detaching unit  160  can be detached from the linear stage  150 . Then, the operator manipulates the handle (not shown) so that the adaptor support  210  can be lowered and the adaptor  96  and the adaptor detaching unit  160  can be moved to the bottom portion of the case  101 . 
     In the maintenance apparatus  100  according to the second embodiment, the manually operated arm  200  is shared by the detaching unit  120 , the attaching unit  140  and the cleaning unit  130 . In the maintenance apparatus  100  according to the second embodiment, the manually operated arm  200  is firstly attached to the linear stage  150  in the case of using the detaching unit  120 , the attaching unit  140  and the cleaning unit  130 . 
     Next, the operation of attaching the manually operated arm  200  to the linear stage  150  will be described.  FIGS. 15A and 15B  illustrate the operation of attaching the manually operated arm  200  to the linear stage  150 .  FIG. 15A  is a top view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 15B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 15B  is a cross sectional view seen from a bottom side of  FIG. 15A  which is taken along a dashed line  15 B- 15 B in  FIG. 15A . 
     The manually operated arm  200  disposed vertically is rotated to be disposed horizontally by a transfer mechanism (not shown) (see ( 1 ) in  FIG. 15B ) and transferred to a position below the linear stage  150  (see ( 2 ) in  FIG. 15B ). The manually operated arm  200  is provided with a connection unit  201  that is the same as the connection unit  161  of the adaptor detaching unit  160 . The projecting engaging portions  191 L and  191 R are engaged with the connection unit  201  provided at the manually operated arm  200 . The operator rotates the handles H 3 L and H 3 R to attach the manually operated arm  200  to the linear stage  150 . 
     Next, the operation of detaching the focus ring  35  will be described. When detaching the focus ring  35 , the detaching unit  120  is attached to the manually operated arm  200 .  FIGS. 16A and 16B  show the operation of attaching the detaching unit  120  to the manually operated arm  200 .  FIG. 16A  is a top view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 16B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 16B  is a cross sectional view seen from a bottom side of  FIG. 16A  which is taken along a dashed line  16 B- 16 B in  FIG. 16A . 
     The detaching unit  120  disposed vertically is rotated to be disposed horizontally by the transfer mechanism (not shown) (see ( 1 ) in  FIG. 16B ) and transferred to a position below the manually operated arm  200  (see ( 2 ) to ( 4 ) in  FIG. 16B ). The passive arm  200  has an attaching unit  220  for detachably attaching a unit. For example, the attaching unit  220  has a vertical rotation shaft, and an engaging portion  221  such as a bevel gear or the like is provided at an upper end of the rotation shaft. 
     A handle H 4  is provided on a top surface of the case  101 . The handle H 4  is coaxially connected to an engaging portion  231 , e.g., a bevel gear or the like, through a rotation shaft  230 . The rotation shaft  230  can be rotated while maintaining airtightness by an O-ring or the like. The engaging portion  231  is rotated by rotating the handle H 4 . The handle H 4 , the rotation shaft  230  and the engaging portion  231  are disposed at a position where the engaging portion  221  and the engaging portion  231  are engaged when the linear stage  150  attached with the manually operated arm  200  is located at the right end. 
     When the linear stage  150  is located at the right end, the engaging portion  221  is engaged with the engaging portion  231 . Accordingly, when the handle H 4  is rotated, the rotation shaft of the attaching unit  220  is rotated through the rotation shaft  230 , the engaging portion  231  and the engaging portion  221  and, thus, the attaching unit  220  can be manipulated. The attaching unit  220  is provided with a holding mechanism for detachably holding a unit by the rotation of the rotation shaft. The holding mechanism may have any structure as long as it can detachably hold a unit. For example, when a holding portion such as a pin or the like is provided at a center of a disc-shaped unit, the attaching unit  220  holds the holding portion. 
     The operator rotates the handle H 4  to attach the detaching unit  120  to the manually operated arm  200 . Then, the operator rotates the handle H 1  so that the linear stage  150  and the manually operated arm  200  can be moved toward the adaptor  96 .  FIGS. 17A and 17B  show a state in which the linear stage  150  and the manually operated arm  200  are moved to the left end toward the adaptor  96 .  FIG. 17A  is a top view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 17B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment. Further,  FIG. 17B  is a cross sectional view seen from a bottom side of  FIG. 17A  which is taken along a dashed line  17 B- 17 B in  FIG. 17A . 
     The manually operated arm  200  has a flat plate-shaped base portion  240 , a head portion  250  provided with the attaching unit  220 , and an extensible/contractible mechanism  260  for extending/contracting the head portion  250  to/from the base portion  240 . For example, the manually operated arm  200  has, as the extensible/contractible mechanism  260 , a ball screw  262  rotatably supported by the base portion  240 . An end portion of the ball screw  262  is coaxially connected to an engaging portion  265 , e.g., a bevel gear or the like. The engaging portion  265  is engaged with the engaging portion  231  when the linear stage  150  and the manually operated arm  200  are located at the left end at the side of the adaptor  96 . 
     The engaging portion  265  is engaged with the engaging portion  231  when the linear stage  150  and the manually operated arm  200  are located at the left end at the side of the adaptor  96 . Accordingly, when the handle H 4  is rotated, the ball screw  262  is rotated. To the ball screw  262 , a supporting member  263  having a groove formed to correspond to the ball screw  262  is attached. The supporting member  263  has a guide hole  264  formed in parallel with the ball screw  262 . The supporting member  263  is fixed to the head portion  250  through the guide hole  264 . Accordingly, when the ball screw  262  is rotated, the supporting member  263  and the head portion  250  are moved along the ball screw  26 . In the manually operated arm  200 , when the ball screw  262  is rotated, the head portion  250  is moved toward and away from the base portion  240  by the extensible/contractible mechanism  260 . 
     In the case of detaching the focus ring  35 , the operator rotates the handle H 4  to extend the head portion  250  from the base portion  240 .  FIGS. 18A and 18B  show a state in which the head portion  250  is extended from the base portion  240 .  FIG. 18A  is a top view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 18B  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment.  FIG. 18B  is a cross sectional view seen from a bottom side of  FIG. 18A  which is taken along a dashed line A-A in  FIG. 18A . 
     The manually operated arm  200  has an elevation mechanism  270  for vertically moving the head portion  250 . 
     The manually operated arm  200  has, e.g., a rotatably supported rotation shaft  272  extending vertically. An engaging portion  273 , e.g., a bevel gear or the like, is provided at an upper end portion of the rotation shaft  272 . A pulley  274  is provided at the rotation shaft  272  and rotated by the rotation of the rotation shaft  272 . The head portion  250  is provided with a cylindrical rotation shaft  275  extending vertically and coaxially around the rotation shaft of the attaching unit  220 . A pulley  276  is provided at the rotation shaft  275 . A belt  277  is wound around the pulleys  274  and  276 . A driving force is transferred by the belt  277 . The pulley  276  is rotated by the rotation of the pulley  274 . The rotation of the pulley  276  leads to the rotation of the rotation shaft  275  and, thus, the base portion  240  is vertically moved. 
     A handle H 5  is provided on a top surface of the case  101 . The handle H 5  is coaxially connected to an engaging portion  281 , e.g., a bevel gear or the like, through a rotation shaft  280 . The rotation shaft  280  can be rotated while maintaining airtightness by an O-ring or the like. The engaging portion  281  is rotated by rotating the handle H 5 . The handle H 5 , the rotation shaft  280  and the engaging portion  281  are disposed at a position where the engaging portion  273  and the engaging portion  281  are engaged when the head portion  250  is extended from the base portion  240  to a position above the mounting table  31 . 
     When the head portion  250  is extended from the base portion  240  to the position above the mounting table  31 , the engaging portion  273  is engaged with the engaging portion  281 . Accordingly, when the handle H 5  is rotated, the driving force is transferred to the head portion  250  through the rotation shaft  280 , the engaging portion  281 , the engaging portion  273 , the pulley  274 , the belt  277 , the pulley  276  and the rotation shaft  275  and, thus, the base portion  240  is vertically moved. 
     In the case of detaching the focus ring  35 , the operator rotates the handle H 5  to lower the base portion  240  so that the detaching unit  120  comes in contact with the mounting table  31 .  FIG. 19  shows a state in which the detaching unit  120  is brought into contact with the mounting table  31 .  FIG. 19  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment. The focus ring  35  mounted on the mounting table  31  is adhered to the detaching unit  120  by the adhesive layer  121 . Then, the operator manipulates the handles H 1 , H 4  and H 5 , in a reverse sequence to that in the case of moving the detaching unit  120  to the position above the mounting table  31 , to move the manually operated arm  200  and the detaching unit  120  to the position shown in ( 4 ) in  FIG. 16B . Then, the operator manipulates the handle H 4  to detach the detaching unit  120  from the manually operated arm  200 . The detaching unit  120  detached from the manually operated arm  200  is transferred to a side surface of the case  101 , which is opposite to the side where the opening  101 A is formed, by the transfer mechanism (not shown). 
       FIG. 20  shows the operation of transferring the detached detaching unit  120 .  FIG. 20  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment. For example, the detaching unit  120  detached from the manually operated arm  200  is lowered by the transfer mechanism (not shown) (see ( 1 ) in  FIG. 20 ), rotated to be disposed vertically (see ( 2 ) in  FIG. 20 ), and transferred as a processed unit to a side surface of the case  101  which is opposite to the side where the opening  101 A is formed (see ( 3 ) in  FIG. 20 ). 
     Next, the operation of cleaning the mounting surface  36   d  of the mounting table  31  will be described. In the case of cleaning the mounting surface  36   d  of the mounting table  31 , the cleaning unit  130  is attached to the manually operated arm  200 .  FIG. 21  shows the operation of attaching the cleaning unit  130  to the manually operated arm  200 .  FIG. 21  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment. 
     The cleaning unit  130  disposed vertically is rotated to be disposed horizontally by a transfer mechanism (not shown) (see ( 1 ) in  FIG. 21 ) and transferred to a position below the manually operated arm  200  (see ( 2 ) to ( 4 ) in  FIG. 21 ). 
     The operator rotates the handle H 4  to attach the cleaning unit  130  to the manually operated arm  200 . Then, as in the case of detaching the focus ring  35 , the operator manipulates the hands H 1 , H 4  and H 5  so that the cleaning unit  130  is transferred to a position above the mounting table  31  and then lowered and brought into contact with mounting table  31 . Then, the operator manipulates the handles H 1  and H 5  in a reverse sequence to that used in the case of moving the cleaning unit  130  to the position above the mounting table  31  to move the manually operated arm  200  and the cleaning unit  130  to the position indicated as ( 4 ) in  FIG. 21 . Then, the operator manipulates the handle H 4  to detach the cleaning unit  130  from the manually operated arm  200 . The cleaning unit  130  detached from the manually operated arm  200  is transferred to a side surface of the case  101 , which is opposite to the side surface where the opening  101 A is formed, by the transfer mechanism (not shown). 
     Next, the operation of attaching a new focus ring  35  to the mounting table  31  will be described. In the case of attaching a new focus ring  35  to the mounting table  31 , the attaching unit  140  is attached to the manually operated arm  200 .  FIG. 22  shows the operation of attaching the attaching unit  140  to the manually operated arm  200 .  FIG. 22  is a cross sectional view schematically showing the maintenance apparatus according to the second embodiment. In  FIG. 22 , the cleaning unit  130  is transferred to a position near the side surface of the case  101  which is opposite to the opening  101 A and and disposed side by side with the detaching unit  120 . Thus, the cleaning unit  130  and the detaching unit  120  are disposed side by side. 
     The attaching unit  140  disposed vertically is rotated to be disposed horizontally by the transfer mechanism (not shown) (see ( 1 ) in  FIG. 22 ) and transferred to a position below the manually operated arm  200  (see ( 2 ) to ( 4 ) in  FIG. 22 ). 
     The operator rotates the handle H 4  to attach the attaching unit  140  to the manually operated arm  200 . Then, as in the case of detaching the focus ring  35 , the operator manipulates the handles H 1 , H 4  and H 5  so that the attaching unit  140  is transferred to the position above the mounting table  31  and then lowered and brought into contact with the mounting table  31 . The attaching unit  140  in contact with the mounting table  31  releases the new focus ring  35 . Accordingly, the new focus ring  35  is mounted on the mounting table  31 . Then, the operator manipulates the handles H 4 , H 5  in a reverse sequence to that used in the case of moving the attaching unit  140  to the position above the mounting table  31  to move the manually operated arm  200  and the attaching unit  140  to the position indicated as ( 4 ) in  FIG. 22 . Then, the operator manipulates the handle H 4  to detach the attaching unit  140  from the manually operated arm  200 . The attaching unit  140  detached from the manually operated arm  200  is transferred to a side position in the case  101  which is opposite to the opening  101 A by the transfer mechanism (not shown). 
     In the case of attaching the adaptor  96  to the opening  101 A, the operator rotates the handles H 3 L and H 3 R to detach the manually operated arm  200  from the linear stage  150 . The manually operated arm  200  detached from the linear stage  150  is transferred to a side position in the case  101  near the opening  101 A by the transfer mechanism (not shown). The detaching unit  120 , the cleaning unit  130  and the attaching unit  140  disposed at the opposite side to of the side surface where the opening  101 A is formed are also transferred to a side position in the case  101  near the opening  101 A by the transfer mechanism (not shown). 
     The operator attaches the adaptor  96  to the second gate  95  in a reverse sequence to that used in the case of detaching the adaptor  96 . Then, the operator returns a pressure in the case  101  of the maintenance apparatus  100  to an atmospheric pressure. 
     In the maintenance apparatus  100  of the present embodiment, the focus ring  35  can be replaced without using the transfer system for transferring a wafer W, as in the case of the maintenance apparatus  100  of the first embodiment. 
     Third Embodiment 
     Hereinafter, a third embodiment will be described. A substrate processing system  1  and a plasma etching apparatus according to the third embodiment have the same configurations as those of the substrate processing system  1  and the plasma etching apparatus  10  according to the first embodiment shown in  FIGS. 1 and 2 . Therefore, redundant description thereof will be omitted. 
     The configuration of the maintenance apparatus  100  according to the third embodiment will be described.  FIG. 23  is a cross sectional view schematically showing the maintenance apparatus according to the third embodiment. Like or corresponding parts will be indicated by like reference numerals used in the maintenance apparatuses  100  according to the first and the second embodiment. 
     The maintenance apparatus  100  includes a case  101  with an opening  101 A having a size corresponding to that of the second gate  95  of the plasma etching apparatus  10 . An O-ring or the like is provided at a portion around the opening  101 A of the case  101  which is brought into contact with the plasma etching apparatus  10 . The maintenance apparatus  100  is attached to the second gate  95  by screw fixing or the like while maintaining airtightness. 
     A vacuum gauge  101 B capable of measuring a degree of vacuum is provided in the case  101 . When a consumed part is replaced, an atmosphere in the case  101  of the maintenance apparatus  100  becomes substantially the same as the vacuum atmosphere in the processing chamber  30 . 
     In the maintenance apparatus  100 , the case  101  has therein a maintenance mechanism for performing at least one of an operation of detaching the consumed part in the processing chamber  30 , an operation of attaching a replacement part in the processing chamber  30  and an operation of cleaning the processing chamber  30 . In the maintenance apparatus  100  of the present embodiment, a manually operated arm  200 , a detaching unit  120 , a cleaning unit  130  and an attaching unit  140  constitute the maintenance mechanism. The manually operated arm  200  is previously attached to the detaching unit  120 . 
     In the case  101 , supporting tables  102  are arranged at three height levels at a predetermined interval near the opening  101 A. The detaching unit  120  attached with the manually operated arm  200 , the cleaning unit  130  and the attaching unit  140  are mounted on the supporting tables  102 , respectively. The case  101  is partially openable/closeable, and the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  can be separately attached and detached. In other words, the detaching unit  120 , the cleaning unit  130  and the attaching unit  140  can be separately replaced. 
     In the maintenance apparatus  100 , a ball screw  105  and a shaft (not shown) are provided in parallel at an upper portion in the case  101 . A linear stage  150  is attached to the ball screw  105  and the shaft (not shown). An adaptor detaching unit  160  is attached to the linear stage  150 . 
     In the maintenance apparatus  100 , an elevation table  114  is provided in a lower portion at a side in the case  101  which is opposite to the opening  101 A. 
     The maintenance apparatus  100  performs the maintenance of the plasma etching apparatus  10  by attaching the respective units to the linear stage  150  by using the elevation table  114 . 
     For example, in the case of detaching the adaptor  96 , the operator rotates the handle H 1  to move that the linear stage  150  and the adaptor detaching unit  160  toward the adaptor  96  as indicated by a dashed line in  FIG. 23 . For example, the adaptor  96  is detached by performing the same operation as that in the second embodiment. 
     For example, in the case of detaching the focus ring  35 , the detaching unit  120  is attached to the linear stage  150  by using the elevation table  114 .  FIG. 24  shows the operation of detaching the focus ring  35 .  FIG. 24  is a cross sectional view schematically showing the maintenance apparatus according to the third embodiment. For example, the adaptor  96  is detached as shown in  FIG. 24  by performing the same operation as that in the second embodiment. 
     In the maintenance apparatus  100  according to the third embodiment, the focus ring  35  can be replaced without using the transfer system for transferring a wafer W, as in the case of the maintenance apparatus  100  according to the first and the second embodiment. 
     While the embodiments of the present disclosure have been described, the technical scope of the present disclosure is not limited to the above-described embodiments. It is obvious to those skilled in the art that various modifications and changes can be made. Any such modifications and changes may be included within the technical scope of the present disclosure as defined by the following claims. 
     For example, in the first to the third embodiment, the case of replacing the focus ring  34  as the consumed part has been described. However, the consumed part is not limited thereto. The maintenance apparatus  100  may also be used for the maintenance such as cleaning of the processing chamber  30  or the like, other than the replacement of the consumed part. 
     In the first to the third embodiment, the case of using the maintenance apparatus  100  for maintenance of the plasma etching apparatus  10  has been described. However, the maintenance apparatus  100  may be used for maintenance of any apparatus having a processing chamber in a vacuum state without being limited thereto. 
     In the first to the third embodiment, the example in which the case  101  is an inseparable container has been described. However, the case  101  of the first to the third embodiment is not limited thereto and may be formed by stacking a plurality of frames including a frame in which a unit can be accommodated.  FIG. 25  is a perspective view schematically showing an example of a frame. A frame  300  shown in  FIG. 25  has a rectangular shape with an open top and an open bottom. A rail  301  to be coupled with a unit is formed on an inner side surface of the frame  300 . The unit can be coupled to and held by the rail  301 . A recess  302  for positioning at the time of stacking the frames  300  is formed on a top surface of each of four corners of the frame  300 . A protrusion corresponding to the recess  302  is formed on a bottom surface of each of the four corners of the frame  300 . The case  101  may be formed by stacking a plurality of frames  300 .  FIG. 26  is a perspective view schematically showing an example of a case formed by stacking a plurality of frames. The case  101  shown in  FIG. 26  is formed by stacking three frames  300  ( 300 A to  300 C). A top surface of the uppermost frame  300 A is sealed by a ceiling plate. A bottom surface of the lowermost frame  300 A is sealed by a bottom plate. As for the uppermost frame  300 A, it is possible to use a box-shaped frame with a closed top and an open bottom. As for the lowermost frame  300 C, it is possible to use a box-shaped frame with an open top and a closed bottom. The frame  300  may be made of any material as long as it ensures a strength against a vacuum atmosphere that is substantially the same as that in the processing chamber  30 . For example, the frame  300  may be made of resin or the like. An opening  101 A may be formed at the uppermost frame  300 . Or, a frame  300  having an opening  101 A may be coupled. By using the case  101  in which a plurality of frames  300  is stacked, it is possible to easily change a unit in response to a maintenance operation to be performed by the maintenance apparatus  100 . In the maintenance apparatus  100 , the case  101  can only have frames for units used for the maintenance operation and, thus, the size of the case  101  can be reduced in accordance with the maintenance operation to be performed. For example, in the case of performing only the cleaning of the processing chamber  30 , a ball screw  105  and a shaft  106  are provided in parallel and the linear stage  140  attached with the adaptor detaching unit  160  is accommodated in the frame  300 A. The manually operated arm  200  and the cleaning unit  130  are accommodated in the frame  300 B. The elevation table  114  is accommodated in the frame  300 C. With the configuration in which the frames  300 A to  300 C are stacked, the maintenance apparatus  100  can perform the cleaning of the processing chamber  30  only. In addition, the maintenance apparatus  100  can be easily transferred on the basis of the case  101 . 
     In the first to the third embodiment, the case in which the operator rotates the handle to move the unit or to detach the adaptor  96  has been described. However, the maintenance apparatus  100  may perform all the maintenance operations by using, e.g., a driving force of an actuator such as a motor or the like. Or, the maintenance apparatus  100  may perform all the maintenance operations by using a driving force of an operator. 
     In the first to the third embodiment, the case in which the second gate  95  of the plasma etching apparatus  10  is blocked by the adaptor  96  while maintaining airtightness has been described. However, a gate valve G may be openably/closeably provided at the second gate  95  of the plasma etching apparatus  10 . In that case, the maintenance apparatus  100  does not require a unit for detaching the adaptor  96 . 
     While the present disclosure has been shown and described with respect to the embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present disclosure as defined in the following claims.