Patent Publication Number: US-2005118000-A1

Title: Treatment subject receiving vessel body, and treating system

Description:
FIELD OF THE INVENTION  
      The present invention relates to a treatment subject receiving vessel body for accommodating and transferring a treatment subject such as a semiconductor wafer or the like in a sealed state and to a treating system having multiple processing apparatuses.  
     BACKGROUND OF THE INVENTION  
      In order to manufacture a semiconductor integrated circuit, various processes such as film forming, etching, oxidation and diffusion are performed on a wafer. Further, to be in line with the trend of miniaturization and high integration of semiconductor integrated circuit, and to improve the throughput and the yield, a processing apparatus designed as a so-called cluster tool has been disclosed, wherein multiple processing apparatuses performing a same process or otherwise performing different processes are connected with one another via a common transfer chamber such that various processes can be sequentially executed without exposing wafers to the atmosphere, in, e.g., Japanese Patent Laid-open Publication Nos. 2000-208589 and 2000-299367. Further, the assignee of the present invention also filed a patent application on an improved cluster tool type processing system apparatus (Patent Application No. 2001-060968).  
       FIG. 7  is a schematic diagram that illustrates an example of a treating system, which is in conventional cluster tool form. As shown in  FIG. 7 , a treating system  2  includes three processing apparatuses  4 A,  4 B and  4 C; a first transfer chamber  6 ; two loadlock chambers  8 A and  8 B having a preheating or cooling device; a second transfer chamber  10 ; and two cassette chambers  12 A and  12 B.  
      The three processing apparatuses  4 A to  4 C are all connected to the first chamber  6 . The two loadlock chambers  8 A and  8 B are interposed in parallel between the first and the second transfer chambers  6 ,  10 . Further, the two cassette chambers  12 A and  12 B are connected to the second transfer chamber  10 . Further, gate valves G, which can be opened and closed airtightly, are interposed between the chambers.  
      In the first and second transfer chambers  6  and  10 , a first and second multi-joint transfer arms  14 ,  16  that are capable of bending, stretching and revolving are installed respectively. By using the first and second transfer arms  14 ,  16  for holding and transferring a semiconductor wafer W, the wafer W is transported. Further, installed in the second transfer chamber  10  is a position alignment mechanism  22  having a rotatable table  18  and an optical sensor  20 . The position alignment mechanism  22  performs a position alignment by detecting orientation flats or notches of the wafer W by rotating the wafer W taken from the cassette chamber  12 A or  12 B.  
      In processing a semiconductor wafer W, first by the second transfer arm  16  of the second transfer chamber  10  maintained under atmospheric pressure in an N 2  atmosphere, a semiconductor wafer W not yet processed is unloaded from either one of the cassette chambers, e.g., the cassette C  12 A, and then mounted on the rotatable table  18  of the position alignment mechanism  22  in the second transfer chamber  10 . Further, while the rotatable table  18  performs position alignment by rotating, the transfer arm  16  stands by without moving. With respect to the period it takes for the position alignment, it is, for example, about 10 to 20 seconds. Once the position alignment is completed, the transfer arm  16 , which has been standing by, holds the wafer W obtained after the position alignment and transports it into either one of the loadlock chambers, e.g., the loadlock chamber  8 A. In the loadlock chamber  8 A, the wafer is preheated as necessary. At the same time, the inside of the loadlock chamber  8 A is vacuum pumped to a certain pressure level.  
      When such preheating operation is completed, a gate valve G is opened and, thus, the inside of the loadlock chamber  8 A communicates with the inside of the first transfer chamber  6  which has been maintained at a vacuum state in advance. The preheated wafer W is transported into a certain processing apparatus, e.g., the processing apparatus  4 A, by the first transfer arm  14  and then is subject to a certain process such as a film forming process for metal or insulating film or the like.  
      A processed semiconductor wafer W is returned to the earlier cassette C of, e.g., the cassette chamber  12 A. With respect to the transporting route of the processed wafer W to be returned, for example, it includes another loadlock chamber  8 B, where the wafer W is cooled to a certain temperature and thereafter is returned. Further, the processed wafer W can be subjected to the position alignment performed by the position alignment mechanism  22  as necessary, before it is housed by the cassette C.  
     SUMMARY OF THE INVENTION  
      In line with the trend of high miniaturization, high integration, thinner film and increasing number of layers, the demand for various functions of an integrated circuit has been increasing. As a result, with respect to manufacturing semiconductor integrated circuits, there is a tendency to shift from a mass production of a small variety to a small-lot production of a large variety.  
      In this case, with respect to the cluster tool type treating system as illustrated in  FIG. 7 , the first transfer chamber  6  needs be expanded to a larger size in order to install more processing apparatuses, so that the system itself becomes considerably large. Further, with respect to the wafer size, since there has been a tendency to shift from 8 inches (200 mm) to a larger size of 300 mm, the size of the first transfer chamber  6  to which the processing apparatuses  4 A to  4 C are connected becomes one step larger.  
      The present invention has been developed to solve the aforementioned problematic issues effectively. It is, therefore, an object of the present invention to provide a treatment subject receiving vessel body capable of being carried and accommodating a plurality of treatment subjects in a hermetically sealed state.  
      It is another object of the present invention to provide a treating system using the treatment subject receiving vessel body.  
      The present invention provides a treatment subject receiving vessel body, including: a vessel main body capable of being carried; a treatment subject support member, disposed in the vessel main body, for supporting a plurality of treatment subjects; a joint port formed at one side surface of the vessel main body and communicating with an interior of the vessel main body; an openable and closable gate valve installed at the joint port; and an openable and closable exhaust port disposed in the vessel main body to exhaust the vessel main body, wherein the vessel main body becomes sealed airtight when the gate valve and the exhaust port are closed.  
      In accordance with the present invention, multiple treatment subjects can be accommodated in the vessel main body capable of being carried in a hermetically sealed state. The inside of the vessel main body can be maintained at a vacuum state or filled with an inactive gas atmosphere.  
      Preferably, the vessel main body includes an exhaust opening; a vacuum pump connected to an exhaust opening; and a backing space connected to an exhaust side of the vacuum pump, the exhaust port being installed at the backing space.  
      In this case, it is possible to maintain the inside of the vessel main body at a high vacuum level. Further, a pump power supply for operating the vacuum pump is preferably installed at the vessel main body.  
      Further, the present invention provides a treating system including: the treatment subject receiving vessel body described above; a first transport auxiliary chamber having at one side thereof a vessel body port to which the treatment subject receiving vessel body is connected and having therein a transport arm mechanism for transporting a treatment subject; a second transport auxiliary chamber having at one side thereof a vessel body port to which the treatment subject receiving vessel body is connected and having therein a transport arm mechanism for transporting the treatment subject; and a vessel body transfer unit for transporting the treatment subject receiving vessel body between the first transport auxiliary chamber and the second transport auxiliary chamber.  
      In accordance with the present invention, it is possible to transfer the treatment subject between the first transport auxiliary chamber and the second transport auxiliary chamber while the treatment subject is accommodated in the treatment subject receiving vessel body.  
      Preferably, a processing chamber for performing a process on the treatment subject is further provided, and wherein the second transport auxiliary chamber is located such that another side thereof is adjacent to the processing chamber and the transport arm mechanism therein is capable of transporting the treatment subject between the processing chamber and the treatment subject receiving vessel body.  
      Further, preferably, it is possible that a loading/unloading port, onto which a cassette vessel containing plural treatment subjects is placed, is further provided, and wherein the first transport auxiliary chamber is located such that another side thereof is adjacent to the loading/unloading port, and the transport arm mechanism therein transports the treatment subject between the cassette vessel and the treatment subject receiving vessel body.  
      Furthermore, it is preferable that a loading/unloading port onto which a cassette vessel containing plural treatment subjects is placed and a common transfer chamber installed adjacent to the loading/unloading port are further provided, wherein the first transport auxiliary chamber is located such that another side thereof is adjacent to the common transfer chamber and the transport arm mechanism therein transports the treatment subject between the cassette vessel and the treatment subject receiving vessel body. In this case, more preferably, the common transfer chamber includes a positioning mechanism for performing positioning of the treatment subject.  
      Further, desirably, the vessel body port of the first transport auxiliary chamber is provided with an openable and closable gate valve, and the vessel body port of the second transport auxiliary chamber is also provided with an openable and closable gate valve.  
      In this case, more preferably, the first transport auxiliary chamber is provided with a gas exhaust line; the second transport auxiliary chamber is also provided with a gas exhaust line; a port gas supply line and a port gas exhaust line are installed outside the gate valve of the vessel body port of the first transport auxiliary chamber; and a port gas supply line and a port gas exhaust line are also installed outside the gate valve of the vessel body port of the second transport auxiliary chamber.  
      More preferably, the first transport auxiliary chamber is provided with a gas supply line and the second transport auxiliary chamber is also provided with a gas supply line. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic diagram illustrating a treating system for a treatment subject in accordance with a preferred embodiment of the present invention;  
       FIG. 2  shows a cross sectional view illustrating an exemplary treatment subject receiving vessel body connected to a first transport auxiliary chamber;  
       FIG. 3  provides a perspective view illustrating an example of a treatment subject receiving main body;  
       FIG. 4  shows a cross sectional view illustrating an example of a treatment subject receiving vessel body connected to a second transport auxiliary chamber;  
       FIG. 5  presents an example of a vessel body transfer unit;  
       FIG. 6  represents a modified example of a treatment subject receiving vessel body; and  
       FIG. 7  offers a schematic diagram illustrating a conventional treating system of a treatment subject. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Hereinafter, a preferred embodiment of a treatment subject receiving vessel body and a treating system of the present invention will be described in detail with reference to the accompanying drawings.  
       FIG. 1  is a schematic diagram illustrating a treating system of a treatment subject in accordance with a preferred embodiment of the present invention.  FIG. 2  shows a cross sectional view illustrating an example of a treatment subject receiving vessel body linked with a first transport auxiliary chamber.  FIG. 3  provides a perspective view illustrating an example of a treatment subject receiving main body.  FIG. 4  shows a cross sectional view illustrating an example of a treatment subject receiving vessel body linked with a second transport auxiliary chamber.  FIG. 5  shows an example of a vessel body transfer unit. Here, a semiconductor wafer is used as a treatment subject.  
      First, a treating system for processing a treatment subject will be described with reference to  FIG. 1 . A treating system  30  is composed of a processing unit  32  for performing various processes such as a film forming process, an etching process on a semiconductor wafer W as a treatment subject and a transfer unit  34  for loading and unloading the wafer W into and from the processing unit  32 .  
      The transfer unit  34  has a common transfer chamber  36  formed of an elongated box body circulating clean air therein. Installed at one elongated side of the common transfer chamber  36  are cassette stages  38 A,  38 B and  38 C serving as loading/unloading ports in which multiple (three in this example) cassette vessels C are disposed. Each of the cassette stages  38 A,  38 B and  38 C is provided with a single cassette vessel C. Each of the cassette vessels C can accommodate therein, e.g., 25 wafers W at the maximum, while the wafers W being mounted in multiple stages having a same pitch therebetween. As for the cassette vessels C, it is acceptable to use a sealed structure vessel having its inside filled with an inactive gas, e.g., a N 2  gas atmosphere or the like, or an open structure vessel having its inside exposed to the atmosphere. In such manner, it is possible to load and unload the wafer into and from the common transfer chamber  36 .  
      Installed in the common transfer chamber  36  is a common transfer mechanism  40  for transferring the wafer W along the length direction thereof (X direction). The common transfer mechanism  40  is fixed on a base  42 . The base  42  is slidably supported on a guide rail  44  and is movable by a linear motor (not shown) or the like, while the guide rail  44  lies on the center line (X direction) of the common transfer chamber  36 .  
      Further, the common transfer mechanism  40  has two multi-joint transfer arms  46 ,  48  disposed at upper and lower two stage positions. Each of the transfer arms  46 ,  48  is capable of contracting and extending in the R direction, i.e., from its center toward the radial direction. Further, the bending and stretching of each of the transfer arms  46 ,  48  can be separately controlled. Two-pronged forks are fastened to the front ends of the transfer arms  46 ,  48 , respectively. Accordingly, the wafers W can be directly held on each of the forks.  
      Each rotation axis of the transfer arms  46 ,  48  is rotatably connected in a coaxial orientation to the base  42 . Each rotation axis can rotate, e.g., in the θ direction, which is the revolving direction with respect to the base  42  as a unit.  
      Further, each rotation axis is movable as a unit in the vertical direction, i.e., Z direction, with the base  42  as the hub.  
      Therefore, the transfer arms  46 ,  48  can each move in the X, Z, R and θ direction. Further, the configuration of the common transfer mechanism  40  is not limited to the aforementioned structure having the transfer arms  46 ,  48  overlapping in the upper and lower two stage positions.  
      Moreover, installed at the other end of the X direction of the common transfer chamber  36  is an orienter  50  serving as a positioning mechanism for performing positioning of the wafer. The orienter  50  has a reference platform  52  rotated by a driving motor (not shown). The reference platform  52  rotates while the wafer W is mounted thereon. Installed at the outer periphery of the reference platform  52  is an optical sensor  54  for detecting the peripheral portion of the wafer W. The optical sensor  54  is composed of a linear lighting emitting device (not shown) having a certain length while the device is installed along the radial direction of the reference platform  52 , and a photo detection device (not shown) disposed to face the corresponding lighting emitting device with the peripheral portion of the wafer interposed therebetween. The lighting emitting device irradiates a laser beam toward an end portion of the wafer and then the photo detection device detects a variance of detection condition. Based on the detection result, it is possible to determine the degree of eccentricity, the eccentric direction of the wafer W and the position of rotating direction, i.e., orientation, of, e.g., notches or orientation flats formed as a cutoff mark on the wafer W.  
      Further, installed at the other side of the lengthwise direction of the common transfer chamber  36  are multiple (three in this example) first transport auxiliary chambers  56 A,  56 B and  56 C via openable/closable gate valves  58 A,  58 B and  58 C, respectively. Installed in each of the first transport auxiliary chambers  56 A,  56 B and  56 C are a pair of buffer mounting tables  60 ,  62  for temporarily mounting and standing by thereon the wafer W. Here, the buffer mounting table  60  near the common transfer chamber  36  is referred to as the first buffer mounting table while the buffer mounting table  62  on the opposite side is referred to as the second buffer mounting table. Installed between the buffer mounting tables  60  and  62  are transport arm mechanisms  64 A,  64 B and  64 C having multi-joint arms capable of contracting, extending, revolving and elevating. Forks are installed at the front ends of the transport arm mechanisms  64 A,  64 B and  64 C, so that the wafer W can be transported between the first and the second buffer mounting tables  60  and  62  by using a corresponding fork. Further, here, in order to carry out an efficient transfer of the wafer W, each of the buffer mounting tables  60  and  62  can hold two wafers W at the upper and the lower portion. In addition, installed at each of the other end of the first transport auxiliary chambers  56 A to  56 C are vessel body ports  68 A,  68 B and  68 C having openable and closeable gate valves  66 A,  66 B and  66 C, respectively. As illustrated in  FIG. 2 , at the leading end of the vessel body ports  68 A,  68 B and  68 C, joint flanges  70  are formed. To a corresponding joint flange  70 , a treatment subject receiving vessel body  72 , which is a characteristic feature of the present invention, can be detachably joined. Here, since each of the vessel body ports  68 A to  68 C has the completely same structure, the vessel body port  68 A is representatively is shown in  FIG. 2 .  FIG. 2  provides a cross sectional view taken along line A-A in  FIG. 1 .  
      Further, installed in each of the first transport auxiliary chambers  56 A to  56 C are gas supply lines  74 A,  74 B and  74 C respectively for introducing therein a certain gas such as an inactive gas including a N 2  gas or the like, if necessary. Further, installed in each of the first transport auxiliary chambers  56 A to  56 C are gas exhaust lines  76 A,  76 B and  76 C respectively for vacuum pumping the inner atmosphere, if necessary. Accordingly, each of the first transport auxiliary chambers  56 A to  56 C has a loadlock device capable of repeating an atmospheric pressure and a vacuum atmosphere.  
      Further, installed respectively at each of the outside of the gate valves  66 A to  66 C of the vessel body ports  68 A to  68 C are port gas supply lines  78 A,  78 B and  78 C for supplying therein a certain gas if necessary and port gas exhaust lines  80 A,  80 B and  80 C for vacuum pumping as necessary. As a result of this, it is possible to control the pressure level in the joint space between each of the vessel body ports  68 A to  68 C and the treatment subject receiving vessel body  72 .  
      A seal member  82  such as O-ring or the like is installed on each cross section of the joint flanges  70  (see  FIG. 2 ) along the circumference direction thereof. As a result, the flange  70  is guaranteed to be sealed airtight to the treatment subject receiving vessel body  72  when they are put together.  
      Further, a vessel platform  84  (not shown in  FIG. 1 , see  FIG. 2 ) is installed under the respective vessel body ports  68 A to  68 C such that the platform extends to the front ends of the ports. The vessel platform  84  is installed so that it can slide forward and backward when necessary. On the top surface of the vessel platform  84 , the treatment subject receiving vessel body  72  can be mounted. In addition, installed on the top surface of the vessel platform  84  are a positioning groove  86  in slot form and an exhaust joint nozzle  88  facing upward, which also serves as a joint. The exhaust joint nozzle  88  is connected to a vacuum exhaust system  90 .  
      Meanwhile, as shown in  FIGS. 2 and 3 , the treatment subject receiving vessel body  72  includes a thin vessel-shaped vessel main body  92  having one side thereof exposed. The vessel main body  92  is made of, e.g., aluminum or stainless steel. At the open side of the vessel main body  92 , a joint port  96  having a gate valve  94  is formed. A joint flange  98  is formed at the cross section of the joint port  96 . The joint flange  98  can be airtightly connected to the joint flange  70  (see  FIG. 2 ) of the respective first transport auxiliary chambers  56 A to  56 C.  
      Installed in the vessel main body  92  is a treatment subject support member  100  for supporting the wafer W. Specifically, the treatment subject support member  100  includes, e.g., three support columns  102  made of quartz (only two are shown in  FIG. 2 ) wherein the columns are disposed upright at different points along the wafer&#39;s circumference. Further, supporting ledge  104  installed at each of the support columns  102  toward the center of the circumference can support multiple wafers W, e.g., two in this example in the upper and lower stages. The number of wafers W to be held is not limited to two but can be one or more than two.  
      Further, multiple positioning projections  106  are projected downward on the lower surface of the bottom portion of the vessel main body  92 . The positioning projections  106  are fitted in the positioning grooves  86  formed at the vessel platform  84 , thereby positioning the vessel main body  92 .  
      Further, installed at the bottom portion of the vessel main body  92  is an exhaust port nozzle  108 , which is directed downward to exhaust the inner atmosphere of the vessel main body  92  and which also serves as a joint. The exhaust port nozzle  108  is detachably connected to the exhaust joint nozzle  88  of the vessel platform  84 . As a result, the treatment subject receiving vessel body  72  can be transported as a single unit.  
      Meanwhile, referring back to  FIG. 1 , six processing chambers  110 A to  110 F are arranged in two rows and three columns in the processing unit  32 . In each of the processing chambers  110 A to  110 F, same or different kinds of processes are performed on the wafer W. Further, with each of the processing chambers  110 A to  110 F., second transport auxiliary chambers  114 A to  114 F are linked up via each openable/closable gate valves  112 A to  112 F, respectively. Further, installed in each of the second transport auxiliary chambers  114 A to  114 F are transport arm mechanisms  116 A to  116 F having multi-joint arms capable of elevating, revolving, contracting and extending.  
      Further, similar to the structure of the first transport auxiliary chambers  56 A to  56 C, vessel body ports  120 A to  120 F having openable/closeable gate valves  118 A to  118 F are installed at the other ends of the second transport auxiliary chambers  114 A to  114 F. As illustrated in  FIG. 4 , a joint flange  122  is formed at each of the leading ends of the vessel body ports  120 A to  120 F. The treatment subject receiving vessel body  72  can be detachably connected to the corresponding joint flange  122 . Here, since each of the vessel body ports  120 A to  120 F consists of the completely same configuration, the vessel body port  120 F is representatively shown in  FIG. 4 .  FIG. 4  is a cross sectional view taken along line F-F in  FIG. 1 .  
      Further, installed in each of the second transport auxiliary chambers  114 A to  114 F are gas supply lines  124 A to  124 F respectively for introducing therein a certain gas such as an inactive gas of a N 2  gas or the like as necessary. Further, installed in each of the second transport auxiliary chambers  114 A to  114 F are gas exhaust lines  126 A to  126 F respectively for vacuum pumping the inner atmosphere when necessary. As a result of this, each of the second transport auxiliary chambers  114 A to  114 F has a loadlock function capable of repeating an atmospheric pressure and a vacuum atmosphere.  
      Further, installed at the outside of the gate valves  118 A to  118 F of the vessel body ports  120 A to  120 F respectively are port gas supply lines  128 A to  128 F for supplying therein a certain gas when necessary and port gas exhaust lines  130 A to  130 F for vacuum pumping when necessary. As a result of this, it is possible to control the pressure level in the joint space between each of the vessel body ports  120 A to  120 F and the treatment subject receiving vessel body  72 .  
      In addition, a seal member  132  such as O-ring or the like is installed on each cross section of the joint flanges  122  (see  FIG. 4 ) along the circumference direction thereof. As a result, the flange  122  is guaranteed to be sealed airtight to the treatment subject receiving vessel body  72  when they are put together.  
      Further, a vessel platform  134  (not shown in  FIG. 1 , see  FIG. 4 ) is installed under the respective vessel body ports  120 A to  120 F so that the platform extends to the front ends of the ports. The vessel platform  134  is installed so that it can slide forward and backward when necessary. On the top surface of the vessel platform  134 , the treatment subject receiving vessel body  72  can be mounted. In addition, installed on the top surface of the vessel platform  134  are a positioning groove  136  in slot form and an exhaust joint nozzle  138  facing upward, which also serves as a joint. The exhaust joint nozzle  138  is connected to a vacuum exhaust system  140 .  
      In addition, a vessel transfer unit  142  shown in  FIG. 5  is installed in order to transport the treatment subject receiving vessel body  72  between each of the first transport auxiliary chambers  56 A to  56 C and each of the second transport auxiliary chambers  114 A to  114 F respectively.  
      Specifically, the vessel transfer unit  142  is composed of a guide rail  144  typically installed at the ceiling portion and a pair of support arms  146  moving along the guide rail  144 . The pair of support arms  146  are designed so that they can expand and contract so that the treatment subject receiving vessel body  72  can be held therebetween. Further, the support arms  146  are connected to a moving body  150  via an extendable/contractible rod  148 , wherein the moving body  150  is slidably supported on the guide rail  144 . Further, the guide rail  144  is installed along the transfer path  152  illustrated in  FIG. 1 . Accordingly, as described above, the treatment subject receiving vessel body  72  can be transported to a certain location. Further, the vessel transfer unit is not limited to the aforementioned configuration but can be a robot type vessel transfer unit used, for example, in a machine shop. Further, the vessel transfer unit can be a vessel transfer unit, which uses a linear motor and a rail. In the end, the configuration does not matter as long as the vessel transfer unit is able to transfer the vessel body  72 .  
      Hereinafter, a transfer method performed by using the above-described treating system  30  will be discussed.  
       FIG. 1  shows the configuration wherein the treatment subject receiving vessel body  72  is connected to the two first transport auxiliary chambers  56 A and  56 B and the four second transport auxiliary chambers  114 A to  114 C and  114 F.  
      First, a general route of the wafer W will be discussed. The wafer is taken out from each of the cassette vessels C by the common transfer mechanism  40  and then transferred to the orienter  50 . Next, the wafer is mounted on the reference platform  52  of the orienter  50 , where its positioning is determined. The wafer of which positioning has been determined is received and held by the common transfer mechanism  40  and then transferred to the front of any one of the first transport auxiliary chambers, e.g., a first transport auxiliary chamber  56 A. Then, after a pressure adjustment is performed, the gate valve  58 A of the first transport auxiliary chamber  56 A is opened so that the wafer can be held on the first buffer mounting table  60  in the first transport auxiliary chamber  56 A. In the same manner, a second wafer to be processed is held on the mounting table  60 .  
      At this time, if a processed wafer is on the first buffer mounting table  60 , it is replaced with an unprocessed wafer so the processed wafer would be returned to the cassette C. In this way, when two unprocessed wafers are accommodated in the first transport auxiliary chamber  56 A, the interior of the first transport auxiliary chamber  56 A is vacuum pumped to carry out a pressure control.  
      Here, as illustrated in  FIG. 2 , in the treatment subject receiving vessel body  72  mounted on the vessel platform  84 , when the vessel body is mounted thereon, the exhaust port nozzle  108  installed at the lower portion of the treatment subject receiving vessel body  72  gets connected with the exhaust joint nozzle  88  of the vessel platform  84 . Further, the interior of the vessel main body  92  is vacuum pumped in advance to a certain pressure.  
      Further, when the vessel body  72  is connected to the vessel body port  68 A of the first transport auxiliary chamber  56 A, the sealed space  154  (see  FIG. 2 ) formed between the vessel body port  68 A and the joint port  96  of the vessel body  72  is occupied by clean air at atmospheric pressure. Therefore, the inner atmosphere of the sealed space  154  is vacuum pumped from the port gas exhaust line  80 A, thereby controlling the inner pressure of the sealed space  154 .  
      As a result of this, when the inner pressure levels of the first transport auxiliary chamber  58 A, the sealed space  154  and the vessel body  72  are adjusted to an approximately equal pressure level, each of the gate valves  66 A and  94  (see  FIG. 2 ) is kept open. Further, by using the transport arm mechanism  64 A in the first transport auxiliary chamber  58 A, two unprocessed wafers W are transported and held on a treatment subject support member  100  in the vessel body  72 . Further, only one wafer may be transported and mounted while leaving the other supporting ledge  104  unoccupied. At this time, if a processed wafer W is held on the treatment subject support member  100 , the processed wafer W is firstly loaded into the first transport auxiliary chamber  58 A and then the unprocessed wafer W is transported.  
      As above, when the unprocessed wafer W is completely loaded into the vessel body  72 , each of the gate valves  66 A and  94  is closed. Thereafter, air is introduced into the sealed space  154  via the port gas supply line  78 A installed in the vessel body port  68 A, thereby restoring the interior of the sealed space  154  to atmospheric pressure. Accordingly, the vessel body  72  can be physically separated from the vessel body port  68 A. Further, by moving slightly the vessel platform  84  on which the vessel body  72  is mounted towards the direction of vessel body separation, the vessel body  72  is separated from the vessel body port  68 A. At this time, the interior of the vessel body  72  is still maintained in a vacuum condition.  
      Next, by using a vessel transfer unit  142 , which is installed on the ceiling portion as illustrated in  FIG. 5 , the vessel body  72  is transferred to, e.g., the second transport auxiliary chamber  114 F of the processing chamber  110 F.  
      Here, the unprocessed wafer W is unloaded towards the second transport auxiliary chamber  114 F in reverse order of the prior description with respect to the first transport auxiliary chamber  56 A. Namely, as shown in  FIG. 4 , by sliding the vessel platform  134  towards the joining side (left side in the drawing), the vessel body port  120 F of the second transport auxiliary chamber  114 F gets connected to the joint port  96  of the vessel body  72 , thereby forming the sealed space  156 . Thereafter, by vacuum pumping the sealed space  156  from the port gas exhaust line  130 F, the atmospheric pressure of the sealed space becomes approximately equal to the inner pressure of the second transport auxiliary chamber  114 F which has been kept in a vacuum condition in advance. Next, both gate valves  118 F and  94  are opened and, thus, the interior of the vessel body  72  communicates with the interior of the second transport auxiliary chamber  114 F so that the unprocessed wafer W is transported from the vessel body  72  into the second transport auxiliary chamber  114 F.  
      Here, if the processed wafer W is in the second transport auxiliary chamber  114 F, only one, not two, unprocessed wafer W may be accommodated in the vessel body  72  and then transported while having a free space for mounting a processed wafer. Otherwise, a buffer mounting table may be separately installed in the second transport auxiliary chamber  114 F. Otherwise, the transport arm mechanism  116 F in the second transport auxiliary chamber  114 F may be a two peak type arm mechanism having the same structure as the common transfer mechanism  40 . Regardless, a transfer set up which will not cause a deadlock while exchanging a processed wafer with an unprocessed wafer is used.  
      As described above, the unprocessed wafer W is loaded into the second transport auxiliary chamber  114 F. Meanwhile, the processed wafer W is accommodated in the vessel body  72 . Thereafter, the sealed space  156  is restored to atmospheric pressure, and the vessel body  72  is separated from the vessel body port  120 . In addition, the vessel body  72  housing the processed wafer W is returned to, e.g., the initial first transport auxiliary chamber  56 A. Further, the vessel body  72  may be vacuum pumped by the vacuum exhaust unit  140  even when the vessel body  72  is mounted on the mounting table  134 .  
      As described above, the vessel body  72  can always be maintained in a vacuum atmosphere. Accordingly, it is possible to prevent the formation of a native oxide or the like on the wafer surface.  
      Further, since the vessel body  72 , which can be sealed airtight and is portable, is used, it is possible to eliminate the conventionally required large-sized common transfer chamber (corresponding to the first transfer chamber  6  of  FIG. 7 ), i.e., so-called transfer chamber.  
      Further, in this embodiment, although a case where the interior of the vessel body  72  is always maintained in a vacuum condition has been discussed, it is not limited thereto. The vessel body  72  may be changed with an inactive gas such as a N 2  gas or Ar gas or the like. For example, as will be described later with reference to  FIG. 6 , a gas supply port may be installed at the bottom portion of the vessel body  72  and also a gas supply joint nozzle at both vessel platforms  84  and  134  so that N 2  gas or Ar gas is fed into the vessel body  72  as necessary.  
      In order to maintain a high vacuum level in the treatment subject receiving vessel body  72 , the configuration illustrated in  FIG. 6  can be used.  FIG. 6  shows a modified example of the treatment subject receiving vessel body. With respect to the configuration illustrated in  FIG. 6 , its discussion is omitted while parts identical to those in  FIG. 2  will be assigned the same reference numerals.  
      In the bottom portion of the treatment subject receiving vessel body  160  shown in  FIG. 6 , a gas exhaust port  162  having a relatively large aperture is formed. The gas exhaust port  162  is directly connected to a vacuum pump  164  such as turbomolecular pump or the like. Further, a backing space  166  having a relatively large capacity is adjacently installed at the exhaust side of the vacuum pump  164 . Accordingly, the pressure of the exhaust side of the vacuum pump  164  can be lowered as low as possible.  
      Further, the backing space  166  is connected to the exhaust port nozzle  108  having the same structure as illustrated in  FIG. 2 . Moreover, installed at the rear portion of the vessel main body  92  of the vessel body  160  is a rechargeable pump power source  168  for rotating the vacuum pump  164 . The pump power source  168  includes a pump controller, which is not shown, and is capable of rotating the vacuum pump  164  when necessary.  
      Further, installed in the bottom portion of the vessel main body  92  is a gas supply port  170  for supplying required gases into the vessel main body  92 . A gas supply joint nozzle  172  facing the gas supply port  170 , which functions as a joint and is detachably connected to the gas supply port  170 , is installed in the vessel platform  84 . As a result, it is possible to supply an inactive gas such as a N 2  gas or an Ar gas or the like into the vessel main body  92  as necessary. Further, the gas supply port  170  and the gas supply joint nozzle  172  can be installed at the aforementioned apparatus example as illustrated in  FIG. 2 .  
      Further, it is possible to install a power joint for supplying power to the pump power source  168  in the vessel platform  84 .  
      Further, the structure of each of the vessel platform  134  installed at each of the second transport auxiliary chambers  114 A to  114 F can be identical to that of the vessel platform  84  illustrated in  FIG. 6 .  
      In the aforementioned treatment subject receiving vessel body  160 , it is possible to supply an inactive gas as necessary. Further, since vacuum pumping can be performed in two stages by employing the vacuum pump  164  composed of a turbomolecular pump and a vacuum pump (not shown) of the vacuum exhaust system  90 , a higher vacuum level in the vessel body  160  can be maintained.  
      Especially, in case the vessel body  160  is separated from the vessel platform  84  and then individually transported, the vacuum pump  164  is always rotated by power from the pump power source  168  installed therein as a unit so that the inner atmosphere of the vessel main body  92  is exhausted to the backing space  166 . Accordingly, it is possible to maintain a higher vacuum level in the vessel body  160 .  
      Further, as described above, when the vessel body  160  is mounted on the vessel platform  84 , the inner atmosphere of the backing space  166  is vacuum pumped from the vacuum exhaust system  90  to the exterior of the system.  
      Further, in the aforementioned apparatus, the common transfer chamber  36  having therein the common transfer mechanism  40  is installed. However, by omitting the common transfer chamber  36 , a wafer may be directly loaded from each of the loading/unloading ports  38 A to  38 C into each of the first transport auxiliary chambers  56 A to  56 C respectively.  
      Further, even though the semiconductor wafer W has been described as the example of a treatment subject, without being limited thereto, the present invention can be applied to a glass substrate, an LCD substrate or the like.  
      While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.