Patent Publication Number: US-9833817-B2

Title: Gas purge unit, load port apparatus, and installation stand for purging container

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority of Japanese Patent Application No. 2015-108741, filed on May 28, 2015. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a gas purge unit, a load port apparatus, and an installation stand for purging container. 
     2. Description of the Related Art 
     For example, manufacturing process of semiconductors includes the following technique (bottom purge) a gas supply nozzle is arranged on an installation stand of a load port apparatus and is made contact with a gas supply port provided at a bottom part of a wafer transport container to introduce a purge gas therethrough and clean the inner atmosphere of the wafer transport container by the purge gas. 
     In such a technique, the gas supply nozzle and the gas supply port may be dislocated due to positional variation or inclination of the gas supply port. This space causes a problem of leakage of inert gas supplied from the gas supply nozzle or a problem of intrusion of the outside air into the wafer transport container via the space. 
     To solve such a problem, mechanisms for pivotting a nozzle body or a tip of the nozzle are disclosed (see Patent Document 1 and Patent Document 2). In these mechanisms, however, a nozzle member having a nozzle opening or part thereof is pivoted, and thus there is a limit to make nozzle structure smaller. 
     Also, these techniques need a portion where an elastic member is rubbed to pivot a nozzle member having a nozzle opening or part thereof and ensure sealing property. Thus, rubbing chips (particles) generated by friction of the portion may flow into a water transport container via a passage. 
     In the conventional techniques, a space may be generated between a nozzle tip and a supply part when only a small amount of extraneous matter is generated at the rubbed portion to worsen the motion of the pivoted portion and hinder followingness. 
     Patent Document 1: Japanese Patent Laid-Open No. 2012-164948 
     Patent Document 2: Japanese Patent Laid-Open No. 2014-36185 
     SUMMARY OF THE INVENTION 
     The present invention has been achieved in consideration of the circumstances. It is an object of the invention to provide a gas purge unit, a load port apparatus, and an installation stand for purging container, all of which are excellent in seal performance between a flowing opening and a nozzle opening, and are capable of filling inside the purging container with cleaning gas without mixing particles or so. 
     To achieve the above object, the gas purge unit according to a first aspect of the present invention is for flowing a cleaning gas into a purging container having, a flowing port with a flowing opening via the flowing port, and comprises: 
     a nozzle member provided with a nozzle opening for flowing the cleaning gas and a cylindrical projection projecting from an upper surface of a base portion to upward; 
     a pivotable body arranged in ring shape on the base portion to surround the cylindrical projection with a first space and provided with a contact part capable of detachably contacting with the flowing port on a tip portion of the pivotable body; and a first pivot support portion with ring shape held between a rear end of the pivotable body and the base portion in a compressively elastically deformable manner along a longitudinal direction of the cylindrical projection, 
     wherein: 
     the contact part is composed of an elastic member; 
     a second space is formed between the rear end of the pivotable body and the upper surface of the base portion; 
     the first space and the second space allow the pivotable body to pivot with respect to the nozzle member and absorb an angle of inclination of the pivotable body; and 
     the pivotable support portion is compressively elastically deformed in a range of the first space and the second space. 
     In the gas purge unit according to the first aspect of the present invention, the flowing port (intake port or exhaust port, in the same hereinafter) of the purging container detachably contacts with the contact part, which is formed at the tip portion of the pivotable body provided around the cylindrical projection of the nozzle member. The pivotable body with the contact part is supported by the ring-shaped first pivot support portion, and it compressively elastically deforms along the longitudinal direction of the cylindrical projection. Then, the pivotable body can pivot. 
     Thus, even when the flowing port is displaced positionally or inclined due to positional displacement or inclination of the purging container, the first pivot support portion compressively elastically deforms, which makes the pivotable body pivot in accordance with positional displacement or inclination of the purging container. As a result, the contact part formed at the tip portion of the pivotable body closely contacts with the flowing port around the flowing opening; (intake opening or exhaust opening, in the same hereinafter). 
     The ring-shaped first pivot support portion is arranged between the rear end of the pivotable body and the base portion of the nozzle member in an elastically deformable manner, and functions as a seal member. Thus, the seal performance therebetween is maintained. Thus, the pivotable body can satisfactorily seal the nozzle opening and the flowing opening isolated from outside air, and they can be airtightly connected. 
     Since the contact part is composed of elastic member, the flowing port and the pivotable body closely contact with each other even if the flowing port, where the contact part contacts, is composed of hard material. In this respect too, the pivotable body can satisfactorily seal the nozzle opening and the flowing opening isolated from outside air, and they can be airtightly connected. Note that, this is the case even if the flowing port, where the contact part contacts, is composed of soft material. 
     Thus, the cleaning gas supplied (or exhausted, in the same hereinafter) from the nozzle opening can flow from the flowing opening into (or exhausted, in the same hereinafter) the purging container without leaking to outside or mixing outside air thereinto. Then, the inside thereof can be satisfactorily filled with the gas and maintained in a clean condition. 
     Note that, the first pivot support portion just compressively elastically deforms between the rear end of the pivotable body and the base portion of the nozzle member, and is then hardly rubbed. Thus, particles or so due to rubbing hardly occur. Further, since the compressive and elastic deformation of the first pivot support portion enables the pivotable body to pivot, the pivotable portion moves smoothly, following capability is excellent, and a clearance between a tip of a nozzle member and an intake port hardly occurs. 
     Further, since the nozzle opening of the nozzle member, a movable portion (pivotable body), and a position adjusting portion (first pivot support portion) are independently constituted, the nozzle itself is not inclined and lowering of movability caused by a deposition on the nozzle hardly occurs, so that the seal performance does not deteriorate. In addition, the nozzle itself is not inclined, which makes it easier to supply the cleaning gas thereto. Further, since an elastically deformable portion should just be formed in a local position, the nozzle can be made smaller as a whole. 
     Since the pivotable body is arranged in a ring shape to surround the cylindrical projection, the nozzle opening and the pivotable body are positioned in the self-alignment manner. The nozzle opening is formed at the tip of the cylindrical projection, which makes a distance between the first pivot support portion and the nozzle opening larger. As a result, there is little risk that particles possibly caused by the first pivot support portion are mixed from the nozzle opening into the purging container. 
     The contact part may be arranged to protrude toward the purging container more than a tip of the cylindrical projection. By arranging the contact part in this way, it is possible to effectively prevent the tip oldie nozzle member (tip of the cylindrical projection) from impacting on the flowing port. Note that, when the tip of the nozzle member goes into the flowing opening without impacting on the flowing port, the contact part may not be arranged to protrude toward the purging container more than the tip of the cylindrical projection. 
     The gas purge unit according to the first aspect of the present invention may further comprise a second pivot support portion with ring shape held between an inner circumferential portion of the pivotable body and an outer circumferential portion of the cylindrical projection in a compressively elastically deformable manner along a direction vertical to the longitudinal direction of the cylindrical projection. In this case, the first and second pivot support portions function as two seal members, and seal performance between the nozzle member and the pivotable body can be further improved. In addition, the second pivot support portion is provided, so that it is possible to effectively prevent the inner circumferential surface of the pivotable body from impacting on the outer circumferential surface of the cylindrical projection even if the pivotable body pivots. 
     The gas purge unit according to the first aspect of the present invention may further comprise a stopper member configured to restrict the pivotable body to moving from the base portion of the nozzle member toward the flowing port and configured to fail to restrict the pivotable body to moving toward the base portion. In that case, when the nozzle member is detached from the flowing port, the pivotable body is forced to be detached from the flowing port along with the node member, so that it is possible to effectively prevent the contact part of the pivotable body from adhering to the intake port. 
     The gas purge unit according to a second aspect of the present invention is for flowing a cleaning gas into a purging container having a flowing port with a flowing opening via the flowing port, and comprises: 
     a nozzle member provided with a nozzle opening for flowing the cleaning gas on a top surface of a base portion; 
     a pivotable body arranged in ring shape on the base portion to surround the nozzle opening and provided with a contact part capable of detachably contacting with the flowing port; 
     a pivot support portion with ring shape held between a rear end of the pivotable body and the base portion of the nozzle member in a compressively elastically deformable manner; and 
     a stopper member configured to restrict the pivotable body to moving from the base portion of the nozzle member toward the flowing port and configured to fail to restrict the pivotable body to moving toward the base portion, 
     wherein: 
     the contact part is composed of an elastic member; 
     a space is formed between the rear end of the pivotable body and the upper surface of the base portion so as to allow the pivotable body to pivot with respect to the nozzle member and absorb an angle of inclination of the pivotable body; and 
     the pivotable support portion is compressively elastically deformed in a range of the space. 
     In the gas purge unit according to the second aspect of the present invention, the flowing port of the purging container detachably contacts with the contact part formed at the tip portion of the pivotable body. The pivotable body with the contact part is supported by the ring-shaped pivot support portion, and it deforms compressively elastically. Then, the pivotable body pivots. 
     Thus, even when the flowing port is displaced positionally or inclined due to positional displacement or inclination of the purging container, the pivot support portion compressively elastically deforms, which makes the pivotable body pivot in accordance with positional displacement or inclination of the purging container. As a result, the contact part formed at the tip portion of the pivotable body closely contacts with the flowing port around the flowing opening. 
     The ring-shaped pivot support portion is arranged between the rear end of the pivotable body and the base portion of the nozzle member in an elastically deformable manner, and functions as a seal member. Thus, the seal performance therebetween is maintained. Thus, the pivotable body can satisfactorily seal the nozzle opening and the flowing opening isolated from outside air, and they can be airtightly connected. 
     Since the contact part is composed of elastic member the flowing port and the pivotable body closely contact with each other even if the flowing port, where the contact part contacts, is composed of hard material. In this respect too, the pivotable body can satisfactorily seal the nozzle opening and the flowing opening isolated from outside air, and they can be airtightly connected. Note that, this is the case even if the flowing port, where the contact part contacts, is composed of soft material. 
     Thus, the cleaning gas supplied from the nozzle opening can flow from the flowing opening into the purging container without leaking to outside or mixing outside air thereinto. Then, the inside thereof can be satisfactorily filled with the gas and maintained in a clean condition. 
     Note that, the pivot support portion just compressively elastically deforms between the rear end of the pivotable body and the base portion of the nozzle member, and is then hardly rubbed. Thus, particles or so due to rubbing hardly occur. Further, since the compressive and elastic deformation of the pivot support portion enables the pivotable body to pivot, the pivotable portion moves smoothly, following capability is excellent, and a clearance between a tip of a nozzle member and an intake port is hardly formed. 
     Further, since the nozzle opening of the nozzle member, a movable portion (pivotable body), and a position adjusting portion (pivot support portion) are independently constituted, the nozzle itself is not inclined and lowering of movability caused by a deposition on the nozzle hardly occurs, so that the seal performance does not deteriorate. In addition, the nozzle itself is not inclined, which makes it easier to supply the cleaning gas thereto. Further, since an elastically deformable portion should just be loaned in a local position, the nozzle can be made smaller as a whole. 
     The gas purge unit according to the second aspect of the present invention comprises a stopper member configured to restrict the pivotable body to moving from the base portion of the nozzle member toward the flowing port and configured to fail to restrict the pivotable body to moving toward the base portion. Thus, when the nozzle member is detached from the flowing port, the pivotable body is forced to be detached from the flowing port along with the nozzle member, so that it is possible to effectively prevent the contact part of the pivotable body from adhering to the intake port. Further, the stopper member also has a function of aligning the pivotable body and the nozzle opening of the nozzle member. 
     The pivotable body may have the contact part composed of an elastic member and a pivotable base portion joined with the contact part and the pivotable base portion may be composed of metal. Since the pivotable base portion is composed of metal, a portion where the pivotable base portion is needed can be reduced to the minimum, and a risk of generation of particles etc. can be further reduced. Note that, the contact part and the pivotable base portion may be formed integrally by elastic member. After the contact part and the pivotable base portion are formed integrally by elastic member, only the pivotable base portion may have an enhanced rigidity compared with other portions. On the contrary, the contact part and the pivotable base portion may be famed integrally by a high rigidity member, and only the contact part may have an enhanced elasticity. 
     A housing recess to which the contact part is attached and a positioning projection located inside a radial direction of the housing recess may be formed on the pivotable base portion. The positioning projection allows the contact part composed of elastic member to be favorably positioned with respect to the pivotable base and attached thereto. 
     The elastic member may be composed of rubber material discharging little outgas. This configuration can reduce a risk of containing organic component gas in the cleaning gas and improve cleanliness in the purging container. Note that, the pivot support portion (including both the first pivot support portion and the second pivot support portion) may be also composed of rubber material discharging little outgas. 
     The contact part may be a flat surface. A convex portion may be formed on the contact part. The contact part may be a tapered slope formed at the tip of the pivotable body. 
     A load port apparatus of the present invention includes the above-mentioned gas purge unit. An installation stand for a purging container of the present invention includes the above-mentioned gas purge unit. The gas purge unit of the present invention may be placed on other devices or other locations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a load port apparatus to which a gas purge unit according to one embodiment of the present invention is applied. 
         FIG. 2  is a cross-sectional view showing a relation between the gas purge unit assembled in the load port apparatus shown in  FIG. 1  and a FOUP as a purging container. 
         FIG. 3A  is a detailed cross-sectional view of a main part of the gas purge unit shown in  FIG. 2 , and shows a state where an intake port is away from an intake nozzle. 
         FIG. 3B  is a detailed cross-sectional view of a main part of the gas purge unit shown in  FIG. 2 , and shows a state where an intake port is inclined and attached to an intake nozzle. 
         FIG. 4A  is a cross-sectional view of a main part of a pivotable seal apparatus used for a gas purge unit according to another embodiment of the present invention. 
         FIG. 4B  is a cross-sectional view of a main part of a pivotable seal apparatus used for a gas purge unit according to further another embodiment of the present invention. 
         FIG. 4C  is a cross-sectional view of a main part of a pivotable seal apparatus used for a gas purge unit according to further another embodiment of the present invention. 
         FIG. 4D  is a cross-sectional view of a main part of a pivotable seal apparatus used for a gas purge unit according to further another embodiment of the present invention. 
         FIG. 5A  is a schematic view showing a step where a door of a FOUP is opened by a load port apparatus. 
         FIG. 5B  is a schematic view showing the following step of  FIG. 5A . 
         FIG. 5C  is a schematic view showing the following step of  FIG. 5B . 
         FIG. 5D  is a schematic view showing the following step of  FIG. 5C . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the present invention will be explained based on embodiments shown in the figures. 
     First Embodiment 
     As shown in  FIG. 1 , a load port apparatus  10  according to one embodiment of the present invention is connected to a semiconductor processing apparatus  60 . The load port apparatus  10  has an installation stand  12  and a movable table  14 . The table  14  is movable in the X-axis direction on the installation stand  12 . Note that, in the figures, the X-axis represents a moving direction of the table  14 , the Z-axis represents a vertical direction, and the Y-axis represents a direction vertical to the X-axis and the Z-axis. 
     A sealed transport container  2  can be detachably placed on a top in the Z-axis direction of the table  14 . The container  2  is made of a pot, a FOUP, or the like for transporting a plurality of wafers  1  while they are sealed and stored. The container  2  has a casing  2   a . A space for housing the wafers  1  to be processed is formed in the casing  2   a . The casing  2   a  has an approximately box shape where an opening is formed on one of its surfaces in the horizontal direction. 
     Also, the container  2  has a lid  4  for sealing an opening  2   b  of the casing  2   a . Shelves (not shown) for vertically overlapping the wafers  1  held horizontally are arranged in the easing  2   a . Each of the wafers  1  placed on the shelves is housed in the container  2  at regular intervals. 
     The load port apparatus  10  is an interface device for transporting the wafers  1  housed in a sealed state in the container  2  into the semiconductor processing apparatus  60  while maintaining a clean condition. The load port apparatus  10  has a door  18  opening and closing a delivery port  13  of a wall member  11 . The wall member  11  is configured to function as part of a casing for sealing inside of the semiconductor processing apparatus  60  in a clean condition, or as part of a casing for sealing inside of an apparatus such as an EFEM connecting the semiconductor processing apparatus  60  and the load port apparatus  10  in a clean condition. The movement of the door  18  will be briefly explained with reference to  FIG. 5A  to  FIG. 5D . 
     As shown in  FIG. 5A , when the container  2  is installed on the table  14 , a bottom gas purge mentioned below is performed. Then, as shown in  FIG. 5B , under a condition that the bottom gas purge is being performed, the table  14  is moved in the X-axis direction, and an opening edge  2   c  with the lid  4  airtightly sealing the opening  2   b  of the container  2  enters the delivery port  13  of the wall member  11 . 
     At the same time, the door  18  located inside of the wall  11  (opposite side to the table  14 ) is engaged with the lid  4  of the container  2 . At that time, a space between the opening edge  2   c  and an opening edge of the delivery port  13  is sealed by gasket or so, and the space is sealed in a good condition. Thereafter, as shown in  FIG. 5C , the container  2  and the wall  11  are internally connected by moving the door  18  together with the lid  4  in parallel along the X-axis direction or moving them rotationally, detaching the lid  4  from the opening edge  2   c , and opening the opening  2   b . At that time, the bottom gas purge may be continuously operated, or in addition to the bottom purge, a purge gas (cleaning gas), including nitrogen gas or other inert gas, may blow out from the inside of the wall  11  into the container  2  (front purge). 
     Next, as shown in  FIG. 5D , when the door  18  is moved downward in the Z-axis in the wall  11 , the opening  2   b  of the container  2  is completely opened to the inside of the wall  11 , and the wafers  1  are delivered into the wall  11  through the opening  2   b  by such as a robot hand arranged inside of the wall  11 . At that time, the container  2  and the wall  11  are internally cut off from the outside air, and the bottom purge and or the front purge may be continuously operated to maintain a clean environment within the container  2 . An operation opposite to the above may be carried out to return the wafers  1  to the inside of the container  2  and detach it from the table  14 . 
     As shown in  FIG. 2 , one or more positioning pins  16  are embedded on a top surface  14   a  of the table  14  and engaged with concave parts of the positioning portion  3  arranged on the bottom of the casing  2   a . This uniquely determines a positional relation between the container  2  and the table  14 . 
     During storage or transportation of the wafers  1 , the sealed transport container  2  is internally sealed, and the surroundings of the wafers  1  are maintained in a clean environment. When the sealed transport container  2  is positioned to be placed on the top surface  14   a  of the movable table  14 , an intake port  5  and an exhaust port  6 , which are formed on the bottom surface of the sealed transport container  2 , are respectively airtightly connected to an intake pivotable seal apparatus  30  of an intake gas purge unit  20  and an exhaust pivotable seal apparatus  50  of an exhaust gas purge unit  40 . In the present embodiment, the bottom gas purge is performed in the container  2  by the intake gas purge unit  20  and the exhaust gas purge unit  40 . Note that, in the figures, the purge port  5 , the exhaust port  6 , the intake gas purge unit  20 , the exhaust gas purge unit  40  and the like are illustrated in an enlarged manner compared with the container  2  for easy understanding, but are different from actual dimension ratio. 
     The intake port  5  and the exhaust port  6  are respectively provided with an intake opening  5   a  and an exhaust opening,  6   a , and they can be connected to inside of the casing  2   a  via check valves  5   b  and  6   b . The check valve  5   b , which is provided in the middle of the intake opening  5   a , permits an inflow of a cleaning gas attempting to go into the casing  2   a  via the intake opening  5   a  with a predetermined pressure or higher. However, the check valve  5   b  does not permit an outflow opposite thereto. 
     The check valve  6   b , which is provided in the way of the exhaust opening  6   a , permits an outflow of a cleaning gas attempting to go outside from the casing  2   a  via the exhaust opening  6   a  with a predetermined pressure or higher. However, the check valve  6   b  does not permit an inflow opposite thereto. By providing the valves  5   b  and  6   b , the inside of the container  2  is not connected to outside air via the intake opening  5   a  or the exhaust opening  6   a  during transportation or storage of the container  2  as long as the gas purge unit  20  or  40  is connected to the intake port  5  or the exhaust port  6 . 
     As shown in  FIG. 2 , in the present embodiment, the intake gas purge unit  20  and the exhaust gas purge unit  40  have similar structures. The units  20  and  40  are housed inside of the movable table  14 . Only heads of the pivotable seal apparatuses  30  and  50  of the units  20  and  40  protrude upward in the Z-axis direction from the top surface  14   a  of the table  14 . 
     The intake gas purge unit  20  has an intake member  24  provided with an intake passage  22  for providing a cleaning gas such as nitrogen gas or other inert gas. The intake member  24  is arranged inside of the table  14 . An intake nozzle  28  provided with a nozzle opening  26  is airtightly connected onto the top of the intake member  24  in the Z-axis direction. Then, the nozzle opening  26  and the intake passage  22  are connected. The nozzle opening  26  is airtightly connected into the intake pivotable seal apparatus  30 . 
     The exhaust gas purge unit  40  has an exhaust member  44  provided with an exhaust passage  42  for exhausting a cleaning gas such as nitrogen gas or other inert gas. The exhaust member  44  is arranged inside of the table  14 . An exhaust nozzle  48  provided with a nozzle opening  46  is airtightly connected onto the top of the exhaust member  44  in the Z-axis direction. Then, the nozzle opening  46  and the exhaust passage  42  are connected. The nozzle opening  46  is airtightly connected into the exhaust pivotable seal apparatus  50 . 
     In the present embodiment, the intake pivotal seal apparatus  30  and the exhaust pivotable seal apparatus  50  have the same structure. Thus, only the intake pivotable seal apparatus  30  will be explained in detail, and the exhaust pivotable seal apparatus  50  will not be explained. 
     As shown in  FIG. 3A , the intake nozzle  28  as a nozzle member has a plate base portion  28   a  and a cylindrical projection  28   b . The cylindrical projection  28   b  protrudes from the central part of the base portion  28   a  to upward in the Z-axis direction. The nozzle opening  26  is formed at an internal upper area of the cylindrical projection  28   b . The intake pivotable seal apparatus  30  has a pivotable body  31 . The pivotable body  31  is arranged in a ring shape to surround the cylindrical projection  28   b  with a predetermined clearance d 1  (one-side clearance). 
     In the present embodiment, the pivotable body  31  has a contact part  34  with ring plate shape composed of elastic member and a pivotable base portion  311  joined with the contact part  34 . In the contact part  34 , a housing recess  33   a  to which the contact part  34  is attached and a positioning projection  33   b  located inside a radial direction of the housing recess  33   a  are formed on the pivotable base portion  311  so as to be along an outer circumference of a tip portion  33  of the pivotable body  31 . An upper surface of the contact part  34  can detachably contact with the intake port  5 . The contact part  34  is joined with the pivotable base portion  311  by means of adhesion of glue or fusion. 
     The elastic member composing the contact part  34  is composed of synthetic resin, rubber material, or the like, and is preferably composed of rubber material discharging little outgas. The rubber material discharging little outgas includes, for example, fluorine-based rubber, ethylene-propylene rubber (EPM), ethylene propylene dime rubber (EPDM), and the like. 
     An O-ring groove is formed on a rear end  32  of the pivotable body  31 , and an O-ring  35  is housed thereon as a first pivot support portion. The O-ring  35  is held between the rear end  32  of the pivotable body  31  and the base portion  28   a  of the nozzle  28  in a compressively elastically deformable manner. The size of the O-ring groove is determined so that the O-ring  35  protrudes from the rear end  32  toward the base portion  28   a.    
     A clearance h 0  between the rear end  32  of the pivotable body  31  and the top surface of the base portion  28   a  is determined so that the pivotable body  31  is allowed to pivot for the nozzle  28 , and preferably absorbs an angle at which the intake port is inclined. The O-ring  35  compressively elastically deforms within the range of the clearance h 0 . A clearance d 1  between an inner circumferential surface of the pivotable body  31  and an outer circumferential surface of the cylindrical projection  28   b  is as large as the clearance h 0 . However, they are not necessarily the same, and the clearance h 1  may be larger than the clearance h 0 . Preferably, the clearance d 1  is one where the intake nozzle  28  and the pivotable body  31  are not contacted. 
     A ring-shaped stopper member  36  is arranged on the outer circumference of the pivotable body  31  and is fixed to the base portion  28   a  of the nozzle  28  by a bolt  37  or so. An inner engagement piece  36   a  is continuously or intermittently formed along the circumferential direction on an inner circumferential upper edge of the stopper member  36 . The inner engagement piece  36   a  is engaged with an outer engagement piece  32   a  formed continuously or intermittently along the circumferential direction on an outer circumferential lower portion of the pivotable base portion  311  of the pivotable body  31 . 
     As a result, the pivotable body  31  is not limited to move toward the base portion  28   a , but is limited to move from the base portion  28   a  of the nozzle member  28  toward the intake port  5 . That is, within the range of the predetermined clearance h 0 , the pivotable body  31  can pivot due to the elastic deformation of part of the O-ring  35 . Note that, the stopper member  36  may be arranged intermittently along the circumferential direction. 
     In the present embodiment, the upper surface of the contact part  34  is arranged to protrude toward the container  2  more than a tip  28   c  of the cylindrical projection  28   b  with the predetermined height h 1 . In this arrangement, the tip  28   c  of the nozzle  28  can be effectively prevented from impacting on the intake port  5 . Note that, when the tip of the nozzle  28  goes into the intake opening  5   a  without impacting on the intake port  5 , the contact part  34  may not be arranged to protrude toward the container  2  more than the tip  28   c  of the cylindrical projection  28   b.    
     In the present embodiment, the upper surface of the contact part  34  is arranged to protrude toward the container  2  more than a tip of the positioning projection  33   b  of the pivotable base portion  311  with a predetermined height h 2 . In this arrangement, the tip of the positioning projection  33   b  of the pivotable base portion  311  can be effectively prevented from impacting on the intake port  5 . Note that, when the tip of the positioning projection  33   b  goes into the intake opening  5   a  without impacting on the intake port  5 , the contact part  34  may not be arranged to protrude toward the container  2  more than the tip of the positioning projection  33   b.    
     A Z-axis direction height h 3  of the housing recess  33   a  is determined in view of positioning, and is not limited. A radial width t 1  of the positioning projection  33   b  is also determined in view of positioning, and is not limited. The positioning projection  33   b  should be provided for positioning of the contact part  34 , but may not be formed if positioning is performed by another means. In this case, t 1  and h 3  are zero. The outer circumferential surface of the contact part  34  is preferably flush with the outer circumferential surface of the pivotable base portion  311 , but may protrude from the outer circumferential surface of the pivotable base portion  311  with a predetermined t 2  or may be dented on the contrary. 
     The pivotable base portion  311  of the pivotable body  31  is preferably harder than the elastically deformable O-ring  35  and is also preferably hard not to be deformed even if the O-ring  35  is deformed when the contact part  34  contacts with the intake opening  5   a . For example, the O-ring  35  is comprised of material which does not pass through gas and has enough thickness. The O-ring  35  is specifically comprised of such as rubber, soft plastic, or sponge. As is the case with the rubber material composing, the contact part  34 , the O-ring  35  is preferably composed of rubber material discharging little outgas, but is not necessarily be composed of the same material. 
     The pivotable base portion  311  is made from a material having poor elasticity, large hardness, and a feature of preventing gas from passing through at an operating pressure. The pivotable base portion  311  is specifically comprised of metal such as aluminum, steel, copper, or titanium, but is not limited to be comprised thereof as long as it is comprised of a material having a large hardness. The pivotable body  31  may be comprised of such as plastic, glass, or rubber. 
     Since the pivotable base portion  311  is composed of hard material, such as metal, a portion where elasticity is needed can be reduced to the minimum, and a risk of generation of particles etc. can be further reduced. In particular, a portion of the pivotable base portion  311  where the outer engagement piece  32   a  is formed is engaged with the inner engagement piece  36   a  of the stopper member  36 , and is preferably composed of metal etc. The stopper member  36  is also preferably composed of metal etc. 
     Note that, in the present embodiment, the contact part  34  is separately formed from the pivotable base portion  311 , but may be formed integrally with the pivotable base portion  311  by elastic member. In this case, only the pivotable base portion  311  may be reformed to a portion that is harder than the contact part  34 . On the contrary, only the contact part  34  may have an enhanced elasticity by integrally forming the contact part  34  and the pivotable base portion  311  with a high rigidity member. 
     In the present embodiment, the O-ring  35  and the pivotable base portion  311  are separately formed, but may be formed integrally by elastic member. In this case, only a portion corresponding to the pivotable base portion  311  may be reformed to a portion that is harder than a portion corresponding to the O-ring  35 . On the contrary, only the portion corresponding to the O-ring  35  may have an enhanced elasticity by integrally forming the portion corresponding to the O-ring  35  and the pivotable base portion  311  with a high rigidity member. 
     As shown in  FIG. 3A  and  FIG. 3B , the upper surface of the contact part  34  contacts with a contact bottom surface  5   c  surrounding the intake opening  5   a  of the intake port  5 . A gasket sheet for sealing not shown may be mounted on the contact bottom surface  5   c , but the contact bottom surface  5   c  may be a metal surface. In this case, if the contact part  34  is elastic member, adhesive force between the contact part  34  and the contact bottom surface  5   c  is particularly improved. 
     As shown in  FIG. 3B , the O-ring  35  is composed of a compressively elastically deformable material such as rubber. Thus, even if the container  2  is placed to be inclined toward the table  14  to some degree, airtightness of the container  2  is maintained because the O-ring  35  elastically deforms, the pivotable body  31  pivots, and the upper surface of the ring-shaped contact part  34  is in close contact with the contact bottom surface  5   c  over the whole circumference. 
     When a purge gas is supplied to the intake passage  22  in a condition shown in  FIG. 3B , an internal pressure of the nozzle opening  26  is heightened, the check valve  5   b  opens, and the purge gas is supplied from the nozzle opening  26  into the container  2  via the intake opening  5   a . In the container  2 , pressure is heightened by the purge gas, and the check valve  6   b  of the exhaust opening  6   a  shown in  FIG. 2  opens. Then, the purge gas is exhausted via the exhaust opening  6   a , the nozzle opening  46 , and the exhaust passage  42 . Thus, the container  2  is filled with a clean purge gas, which improves cleanliness of inside of the container  2 . 
     In the gas purge units  20  and  40  of the present invention, the contact part  34 , which is provided with the tip portion of the pivotable body  31  provided with the intake nozzle  28  (or the exhaust nozzle  48 , in the same hereinafter), is detachably contacted with the intake port  5  (or the exhaust port  6 , in the same hereinafter) of the container  2 . The pivotable body  31  with the contact part  34  is supported by the ring-shaped O-ring  35 , and the O-ring  35  deforms compressively elastically along the longitudinal direction of the cylindrical projection  28   b . As a result, the pivotable body  31  pivots. 
     Thus, as shown in  FIG. 3B , even when the intake port  5  is displaced positionally or inclined due to positional displacement or inclination of the container  2 , the O-ring  35  compressively elastically deforms, which makes the pivotable body  31  pivot in accordance with positional displacement or inclination of the container  2 . As a result, the contact part  34  formed at the tip portion  33  of the pivotable body  31  is closely contacted with the intake port  5  around the intake opening  5   a  (or the exhaust opening  6   a , in the same hereinafter). The O-ring  35  is arranged between the rear end  32  of the pivotable body  31  and the base portion  28   a  of the nozzle  28  in an elastically deformable manner, and functions as a seal member. Thus, the seal performance therebetween is maintained. Thus, the pivotable body  31  can satisfactorily isolate and seat the nozzle opening  26  and the intake opening  5   a  from outside air, and they can be airtightly connected. 
     Further, since the contact part  34  is composed of elastic member, the flowing port  5  and the pivotable body  31  closely contact with each other even if the contact bottom surface  5   c  of the flowing port  5 , where the contact part  34  contacts, is composed of hard material. In this respect too, the pivotable body  31  can isolate and seal the nozzle opening  26  and the intake opening  5   a  from outside air, and they can be airtightly connected. Note that, this is the case even if the bottom surface  5   c  of the flowing port  5 , where the contact part  34  contacts, is composed of soft material. 
     Thus, the purge gas supplied (or exhausted, in the same hereinafter) from the nozzle opening  26  can flow (or exhaust, in the same hereinafter) into the container  2  from the intake opening  5   a , without leaking to outside or mixing outside air thereinto, satisfactorily fill inside thereof with the purge gas, and maintain the inside in a clean condition. 
     Note that, the O-ring  35  just compressively elastically deforms between the rear end  32  of the pivotable body  31  and the base portion  28   a  of the nozzle  28 , and is then hardly rubbed. Thus, particles or so due to rubbing hardly occur. Further, since the O-ring  35  enables the pivotable body  31  to pivot by just deforming compressively elastically, the pivotable portion moves smoothly, following capability is excellent, and a clearance between the nozzle  28  and the intake port  5  is hardly formed. 
     Further, in the present embodiment, since the nozzle  28  with the nozzle opening  26 , the movable portion (pivotable body  31 ), and a position adjusting portion (O-ring  35 ) are independently constituted, the nozzle  28  itself is not inclined and the seal performance does not deteriorate without lowering of movability caused by a deposition on the nozzle  28 . In addition, the nozzle  28  itself is not inclined, which makes it easier to supply the cleaning gas thereto. Further, since an elastically deformable portion should just be formed in a local position, the nozzle  28  can be made smaller as a whole. 
     In the present embodiment, the pivotable body  31  is arranged in a ring shape to surround the cylindrical projection  28   b , and the nozzle opening  26  is formed at the tip of the cylindrical projection  28   b . Thus, a distance between the O-ring  35  and the nozzle opening  26  is made larger, and there is little risk that particles possibly caused by the O-ring  35  are mixed from the nozzle opening  26  into the container  2 . 
     Further, in the present embodiment, the gas purge unit has the stopper member  36 . Thus, when the nozzle  28  is detached from the intake port  5 , the pivotable body  31  is forced to be detached from the intake port  5  along with the nozzle  28 , so that it is possible to effectively prevent the contact part  34  of the pivotable body  31  from adhering to the intake port  5 . Further, the stopper member  36  also has a function of aligning the pivotable body  31  and the nozzle opening  26  of the nozzle  28 . 
     Second Embodiment 
       FIG. 4A  is a cross sectional view of a main part of a pivotable seal apparatus  30   a  used for a gas purge unit  20   a  according to other embodiment of the present invention. The pivotable seal apparatus  30   a  is used for either or both of intake and exhaust. Except for the following, the second embodiment has structures similar to the first embodiment mentioned above and demonstrates similar effects. 
     As shown in  FIG. 4A , in this embodiment, a nozzle opening  26  is directly formed in a base portion  28   a   1  of an intake nozzle  28 A, and the cylindrical projection  28   b  mentioned in the first embodiment is not present. Other structures are similar to the first embodiment mentioned above. 
     In this embodiment, an inner circumferential surface of a pivotable body  31  serves as a part of the nozzle opening  26 . In the present embodiment, since the cylindrical protection  28   b  is not present, structures become simpler than the first embodiment. Other effects of the present embodiment are similar to the first embodiment except that effects demonstrated by having the cylindrical projection  28   b  of the first embodiment are not obtained. 
     Third Embodiment 
       FIG. 4B  is a cross sectional view of a main part of a pivotable seal apparatus  30   b  used for a gas purge unit  20   b  according to further other embodiment of the present invention. The pivotable seal apparatus  30   b  is used for either or both of intake and exhaust. Except for the following, the third embodiment has structures similar to the first embodiment mentioned above and demonstrates similar effects. 
     As shown in  FIG. 4B , this embodiment has structures similar to the first embodiment mentioned above except that the stopper member  36  of the first embodiment is not present. That is, in this embodiment the stopper member  36  of the first embodiment is not formed on an outer circumference of a pivotable body  31 B. Thus, an outer engagement piece  32   a  shown in  FIG. 4A  does not need to be formed on an outer circumferential lower portion of a pivotable base portion  311 B of the pivotable body  31 . 
     In this embodiment, the pivotable body  31 B is arranged in a ring shape to surround a cylindrical projection  28   b . Thus, a nozzle opening  26  and the pivotable body  31 B are positioned in the self-alignment manner even if the stopper member  36  is not present. In the present embodiment, since the stopper member  36  is not present, structures become simpler than the first embodiment. Other effects of the present embodiment are similar to the first embodiment except that effects demonstrated by having the stopper member  36  of the first embodiment are not obtained. 
     Fourth Embodiment 
       FIG. 4C  is a cross sectional view of a main part of a pivotable seal apparatus  30   c  used for a gas purge unit  20   c  according to further other embodiment of the present invention. The pivotable seal apparatus  30   c  is used for either or both of intake and exhaust. Except for the following, the fourth embodiment has structures similar to the third embodiment mentioned above and demonstrates similar effects. 
     As shown in  FIG. 4C , the pivotable seal apparatus  30   c  of this embodiment has a first O-ring  35   a  and a second O-ring  35   b  as the pivot support bodies bolding a pivotable body  31 C pivotably to an intake nozzle  28 C. The first O-ring  35   a  is housed in an O-ring groove formed on a base portion  28   a   2 , which is located around a cylindrical projection  28   b   2  of a nozzle  28 C. The first O-ring  35   a  corresponds to the O-ring  35  of the embodiments mentioned above, and has function similar thereto. 
     The second O-ring  35   b  is a ring-shaped seal member held between an inner circumferential portion of the pivotable body  31 C and an outer circumferential portion of the cylindrical projection  28   b   2  in a compressively elastically deformable manner along directions (the X-axis and Y-axis plane directions) vertical to a longitudinal direction of the cylindrical projection  28   b   2 . The first O-ring  35   a  and the second O-ring  35   b  are composed of the same material as the O-ring  35  in the previous embodiments, but are not be necessarily composed of the same material. 
     In the present embodiment, the first O-ring  35   a  and the second O-ring  35   b  function as two seal members, which further improves seal performance between the nozzle  28 C and the pivotable body  31 C. By providing the second O-ring  35   b , it is possible to effectively prevent the inner circumferential surface of the pivotable body  31 C from impacting on the outer circumferential surface of the cylindrical projection  28   b   2  even if the pivotable body  31 C pivots. 
     In the present embodiment, an O-ring groove is formed on the inner circumferential surface of a pivotable base portion  311 C of the pivotable body  31 C to provide the second O-ring  35   b  between the cylindrical projection  28   b   2  and the pivotable body  31 C. A shallow groove for positioning the O-ring is also formed on the outer circumferential surface of the cylindrical projection  28   b   2  at a position corresponding to the O-ring groove in the Z-axis direction. 
     In the present embodiment, a contact part  34  having a tapered slope where an outer diameter becomes narrower on the side of the tip is joined with a housing recess  33   a  of the pivotable base portion  311 C on a tip portion  33  of the pivotable body  31 C. A tip surface of a positioning projection  33   b  is a slope that is flush with the contact part  34 . The tip surface of the positioning projection  33   b  and the tip of the contact part  34  go into an intake opening  5   a  of an intake port  5 , and an intermediate positional part of the tapered slope consisting the contact part  34  is then sealed by contacting with an inner edge of the intake opening  5   a  of the port  5 . Other elects of the present embodiment are similar to the third embodiment shown in  FIG. 4B  except that effects based on having the second O-ring  35   b  are added. 
     Fifth Embodiment 
       FIG. 4D  is a cross sectional view of a main part of a pivotable seal apparatus  30   d  used for a gas purge unit  20   d  according to further other embodiment of the present invention. The pivotable seal apparatus  30   d  is used for either or both of intake and exhaust. Except for the following, the fifth embodiment has structures similar to the fourth embodiment mentioned above and demonstrates similar effects. 
     As shown in  FIG. 4D , the pivotable seal apparatus  30   d  of this embodiment is a variation of the pivotable seal apparatus  30   c  of the embodiment shown in  FIG. 4C  and is different from the example shown in  FIG. 4  in cross sectional shape of a first O-ring  35   c  and a second O-ring  35   d . That is, although the cross sectional shape of the O-rings of the embodiments mentioned above is a circle, cross sectional shape of the O-rings  35   c  and  35   d  of this embodiment is a rectangle as a whole. Each side of the rectangle is dented, and corners thereof protrude. 
     The O-rings  35   c  and  35   d  with such a cross sectional shape are favorably housed in O-ring grooves and are hard to be displaced. Since the O-rings  35   c  and  35   d  can be compressively elastically deformed in a relatively wide range, a pivotable body  31 D is expected to pivot in a wider range. Other effects of the present embodiment are similar to the fourth embodiment shown in  FIG. 4C . Note that unlike the fourth embodiment, the contact part  34  joined with the tip portion  33  of a pivotable base portion  311 D does not have a tapered slope in the present embodiment. This contact part  34  has an upper surface that is parallel to a plane including the X-axis and the Y-axis, and is a ring-shaped contact part as with the first embodiment. 
     Note that, the present invention is not limited to the embodiments mentioned above, but can be variously changed within a scope thereof. 
     For example, the gas purge units  20  and  40  may not be necessarily comprised of the same structures, but may be comprised of different structures. For example, one of the gas purge units  20  and  40  may have one of the pivotable seal apparatuses of  FIG. 3A  and  FIG. 4A  to  FIG. 4D , and the other gas purge unit may have a pivotable seal apparatus other than the pivotable seal apparatus. Instead, either the gas purge unit  20  or  40  may be only comprised of structures of the gas purge unit according to the present invention. 
     In the above embodiments, the O-rings are used as pivot support bodies. However, in addition to the O-rings, other seal members compressively elastically deformable such as packing or gasket may be also used. 
     In the embodiments mentioned above, the gas purge unit of the present invention is applied to the load port apparatus  10 , but may be applied to other devices. For example, the gas purge unit of the present invention may be attached to such as shelves or installation stands for spreading and storing a plurality of the containers  2 . Instead, the gas purge unit of the present invention may be provided with other devices or places. 
     NUMERICAL REFERENCES 
     
         
           1  . . . wafer 
           2  . . . sealed transport container 
           2   a  . . . casing 
           2   h  . . . opening 
           2   c  . . . opening edge 
           3  . . . positioning portion 
           4  . . . lid 
           5  . . . intake port (flowing port) 
           5   a  . . . intake opening (flowing opening) 
           6  . . . exhaust port (flowing port) 
           6   a  . . . exhaust opening (flowing opening) 
           10  . . . load port apparatus 
           11  . . . wall member 
           12  . . . installation stand 
           13  . . . delivery port 
           14  . . . movable table 
           16  . . . positioning pin 
           18  . . . door 
           20 ,  20   a  to  20   d  . . . intake gas purge unit 
           22  . . . intake passage 
           24  . . . intake member 
           26  . . . nozzle opening 
           28 ,  28 A . . . intake nozzle (nozzle member) 
           28   a ,  28   a   1 ,  28   a   2  . . . base portion 
           28   b ,  28   b   2  . . . cylindrical projection 
           30 ,  30   a  to  30   d  . . . intake pivotable seal apparatus 
           31 ,  31 B,  31 C,  31 D . . . pivotable body 
           311 ,  311 B,  311 C,  311 D . . . pivotable base portion 
           32  . . . rear end 
           32   a  . . . outer engagement piece 
           33  . . . tip portion 
           33   a  . . . housing recess 
           33   b  . . . positioning projection 
           34  . . . contact part 
           35  . . . O-ring (first pivot support portion) 
           35   a ,  35   c  . . . first O-ring (first pivot support portion) 
           35   b ,  35   d  . . . second O-ring (second pivot support portion) 
           36  . . . stopper member 
           36   a  . . . inner engagement piece 
           37  . . . bolt 
           40  . . . exhaust gas purge unit 
           43  . . . exhaust passage 
           44  . . . exhaust member 
           46  . . . nozzle opening 
           48  . . . exhaust nozzle (nozzle member) 
           50  . . . exhaust pivotable seal apparatus 
           60  . . . semiconductor processing apparatus