Patent Publication Number: US-2007110548-A1

Title: Processing apparatus

Description:
TECHNICAL FIELD  
      The present invention relates to a processing apparatus that takes out an object to be processed from a hermetic container and conducts a predetermined process to the object to be processed.  
     BACKGROUND ART  
      As one of semiconductor manufacturing apparatuses, for example, there is a thermal processing apparatus that conducts a heat treatment to a plurality of semiconductor wafers (hereafter, to be simply referred to as “wafer”) in a batch. This thermal processing apparatus is provided with a conveying in-and-out area where a carrier that is a container containing a plurality of wafers is conveyed in and out by an automatic conveying robot or by an operator, and a loading area where the wafers in the container are transferred and placed onto a wafer boat that is a substrate holder and are conveyed in and out from a heat treating furnace.  
      In this thermal processing apparatus, an atmosphere in the loading area is kept cleaner than an atmosphere in the conveying in-and-out area. In addition, in order to prevent that a natural oxide film is generated (adhered) on the wafers, the conveying in-and-out area on an atmospheric air side and the loading area are separated by a partition, and for example, an inside of the loading area is an atmosphere filled with an inert gas, such as a nitrogen (N 2 ) gas, or an atmosphere filled with a clean dry air.  
      Additionally, in order to restrain that the wafers are polluted by particles, a hermetic container (also referred to as a closed-type carrier), wherein a wafer taking-out port on a front side thereof is hermetically closed by a lid, is suitably used (refer to  FIG. 1 ).  
       FIG. 10  is a cross-sectional view that shows a structure of a door mechanism in an example of conventional thermal processing apparatuses.  FIG. 10  shows a condition wherein a hermetic carrier abuts on a partition  100  that defines a conveying in-and-out area S 1  and a loading area S 2 .  
      In the partition  100 , an opening part  101  for making the conveying in-and-out area S 1  and the loading area S 2  communicate with each other is formed. A door  102  for opening and closing the opening part  101  is provided with a lid opening-and-closing mechanism  103  for opening and closing a lid of a carrier.  
      The carrier  120  is capable of containing internally a plurality of wafers W that are objects to be processed. On one surface of a main carrier body  121  of the carrier  120 , a taking-out port  122  is provided. The taking-out port  122  is closed by a lid  123  that is made detachable. Namely, the carrier  120  is a hermetic carrier. The carrier  120  is placed on a stage  110  provided in the conveying in-and-out area S 1 . Thereafter, when the stage  110  proceeds, an opening edge portion of the taking-out port  122  of the carrier  120  abuts on an opening edge portion of the opening part  101 . Then, the lid  123  is removed from the main carrier body  121  by the lid opening-and-closing mechanism  103 .  
      More concretely, in a condition wherein the door  102  abuts on the partition  100  and the opening part  101  is closed, the lid opening-and-closing mechanism  103  provided at the door  102  opens the lid  123  of the carrier  120 . Then, the inside of the carrier  120  is replaced by a nitrogen gas by means of, for example, a not-shown nitrogen gas replacing unit. In the meantime, the lid opening-and-closing mechanism  103  holding the lid  123  is moved backward with respect to the partition  100  by means of a driving unit  104  in the door  102 . As described above, the door  102  is withdrawn in a condition wherein the door  102  contains the lid  123  and the like. Here, the door  102  is withdrawn, for example, by being moved away from the opening part  101  along an anterior-posterior axis  105  and then by being moved, for example, downward along a vertical axis  106 . Accordingly, the inside of the carrier  120  and a space in the loading area S 2  are communicated with each other, and the wafers W in the carrier  120  are conveyed into the loading area S 2  by means of a not-shown wafer transferring mechanism.  
      As described above, the wafers W that are objects to be processed are moved between the carrier  120  and the loading area S 2 . Here, it is necessary for the space for conveying the wafer W to be maintained in an atmosphere of greatly clean.  
      So far, techniques to restrain an influence of particles accompanied by opening of a lid of a carrier or opening of a door have been variously suggested.  
      For example, in Japanese Patent Laid-Open Publication No. 2000-150613, a hermetic container (carrier) having a detachable lid at an opening part of a front surface thereof and containing an object to be processed (wafer) therein, and a wafer transferring-and-placing mechanism that conveys the wafer inside the hermetic container into a separated transferring-and-placing room (a loading area) and thereafter conveys the wafer into a processing room, are disclosed. In addition, the transferring-and-placing room on an opposite side to the opening part of the hermetic container is provided with a separated room to reduce pressure difference between the transferring-and-placing room and the hermetic container, and a lid opening-and-closing mechanism to open and close the lid of the hermetic container is provided in the separated room.  
      Additionally, in Japanese Patent Laid-Open Publication No. 2002-093880, an apparatus is disclosed, comprising a stage (a conveying in-and-out area) on which a cassette (a hermetic carrier) containing a plurality of semiconductor wafers (objects to be processed) is placed, a processing portion (a loading area) for conducting a predetermined process to the wafer, a partition which separates the stage from the processing portion and which is provided with an opening for transfer at a position corresponding to the opening of the cassette placed on the stage, a shutter member (a door) which is arranged on a side of the processing portion so as to open and close a lid, provided at the opening of the cassette placed on the stage and capable of being opened and closed, through the opening for transfer, and a shutter driving mechanism (a door opening-and-closing mechanism) which drives the shutter member, the shutter member including a holding portion (a lid opening-and-closing mechanism) to hold the lid, an opening for suction being formed at a circumference of the holding portion located at a position corresponding to a circumference of the opening of the cassette.  
      In either apparatus described above, when a space in an outside space area in which the carrier containing the wafers is placed and a space in an inside space area in which a predetermined process is conducted to the wafers are communicated with each other, particles in the outside space area are restrained from entering into the inside of the carrier and adhering to the wafers and from flowing into the atmosphere in the inside space area, and accordingly pollution of the wafers is prevented.  
      However, even though the techniques as described above are used, it is actually still difficult to sufficiently reduce an influence degree of particles upon wafers, when a space in an outside space area, in which a carrier containing the wafers is placed, and a space in an inside space area, in which a predetermined process is conducted to the wafers, are communicated with each other.  
     SUMMARY OF THE INVENTION  
      This invention has been made based on the above consideration, and an object of the invention is to provide a processing apparatus for processing an object to be processed contained in a hermitic container, wherein it is possible to reduce as far as possible an adverse effect of a particle in an outside space area against the object to be processed and against an inside space area and to surely prevent pollution of the object to be processed, when the outside space area in which the carrier is transferred and placed and the inside space area which is kept in clean atmosphere, for example, are communicated with each other.  
      The present invention is a processing apparatus for an object to be processed, comprising a partition that defines an outside space area in which a container hermetically containing an object to be processed and having a lid is conveyed and an inside space area in which the object to be processed taken out from the container is conveyed, an opening part provided in the partition through which the two space areas are communicated with each other, a door mechanism that can close the opening part, a lid opening-and-closing mechanism provided at the door mechanism capable of opening and closing the lid of the container located at a predetermined position in the outside space area under a situation wherein the door mechanism closes the opening part, a driving unit that moves the lid opening-and-closing mechanism away from the container relatively to the door mechanism, a cover member that defines a driving-unit arrangement room in which the driving unit is contained in the door mechanism, and a gas-discharging mechanism that discharges a gas in the driving-unit arrangement room.  
      According to the present invention, the driving unit that moves the lid opening-and-closing mechanism away from the container is located inside a driving-unit arrangement room formed separately from a door-mechanism space which is formed between the door mechanism itself and the container by the door mechanism, and the gas-discharging mechanism is provided to discharge the gas in the drive-unit arrangement room, so that a dust is removed by the gas-discharging mechanism even when the dust is generated by movement of the driving unit for opening and closing the lid of the container. Therefore, it is surely prevented that the dust enters into the door-mechanism space and adheres on the object to be processed in the container, and also prevented that the clean atmosphere and so on in the inside space area is polluted when the door mechanism is opened. As a result, a degree of the adverse effect by the dust (particle) against the object to be processed is restrained to be small and the object to be processed to which a predetermined process has been conducted can keep a high clean level.  
      Preferably, an end edge of the opening part on a side of the inside space area forms a plane inclined against the partition, and the door mechanism is hermetically connectable with the end edge and movable in a plane direction of the partition.  
      In this case, possibility that a dust is generated by a withdrawing movement of the door mechanism is reduced. Therefore, it is more surely prevented that the object to be processed or the clean atmosphere in the inside space area are polluted by the dust.  
      In addition, preferably, a sealing member is provided at the whole circumference of an end edge of the opening part on a side of the outside space area, and the lid opening-and-closing mechanism is hermetically connectable with the sealing member by an action of the driving unit under a situation wherein the door mechanism closes the opening part.  
      In this case, it is possible to prevent that the door-mechanism space is exposed to the atmosphere in the outside space area even when the container is not located at a predetermined position (on the stage, for example). Therefore, it is surely prevented that a dust floating in the outside space area, for example, enters into the door-mechanism space.  
      For example, the sealing member is a member having a Y-shaped section.  
      Incidentally, if the space inside the carrier and the space of the inside space area are communicated with each other at once, a dust existing in the door-mechanism space rises up due to a pressure difference between a pressure inside the carrier and a pressure in the inside space area, and then adheres on the object to be processed in the container and mixes into the inside of inside space area. Therefore, it is preferable that the door mechanism has a pressure-adjusting mechanism that can gradually open through one space and the other space with respect to the door mechanism in order to leisurely reduce a difference pressure between the both spaces to substantially zero. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view showing a hermetic container in such a condition that a lid is removed;  
       FIG. 2  is a perspective view showing a vertical thermal processing apparatus according to one embodiment of the present invention;  
       FIG. 3  is a longitudinal sectional view showing an inside structure of the vertical thermal processing apparatus shown in  FIG. 2 ;  
       FIG. 4  is a plan view showing the inside structure of the vertical thermal processing apparatus shown in  FIG. 2 ;  
       FIG. 5  is a longitudinal sectional view showing one example of a door mechanism which opens and closes an opening part formed in a partition, in such a condition that a carrier containing a wafer abuts on the partition;  
       FIG. 6  is a back view of the door mechanism shown in  FIG. 5 ;  
       FIG. 7  is a partial cross-sectional view showing a condition wherein a bottom of the carrier and an engaging member of a second stage are engaged;  
       FIG. 8  is a cross-sectional view, similar to  FIG. 5 , showing a condition wherein the door mechanism is withdrawn upward and a space inside a conveying in-and-out area and a space inside a loading area are communicated with each other;  
       FIG. 9  is a cross-sectional view, similar to  FIG. 5 , showing a condition wherein the opening part in the partition is closed by the door mechanism when the carrier is not on the second stage; and  
       FIG. 10  is a cross-sectional view showing a structure of a door mechanism in one example of a conventional thermal processing apparatus in such a condition that a hermetic carrier abuts on a partition which defines a conveying in-and-out area and a loading area. 
    
    
     BEST MODE FOR CARRYING OUT THE PRESENT INVENTION  
      In a processing apparatus of the present invention, a hermetic container containing an object to be processed is placed at a predetermined position, and then the object to be processed is taken out from the container, and conveyed into an inside space area, which is maintained under a clean atmosphere, to be subjected to a predetermined process.  
      A carrier  10  including a main carrier body  11  is used, for example, as a container containing the object to be processed, as shown in  FIG. 1 . A taking-out port  11 A is opened at one surface of the main carrier body  11 . The taking-out port  11 A is closed by a lid  12  that is provided to be removable. The carrier  10  is, for example, made of resin. The object to be processed is, for example, a wafer W whose diameter is 300 mm. The carrier  10  is composed so as to be capable of holding a plurality of, for example, 25 wafers W in a tier-like manner.  
      The lid  12  of the carrier  10  includes a not-shown latch mechanism (a lock mechanism) for the lid  12  to be held at the taking-out port  11 A. When the latch mechanism is unlatched (released) by a lid opening-and-closing mechanism which is described later, the lid  12  can be removed from the main carrier body  11 .  
      In  FIG. 1, 13  represent a keyhole used for unlatching the latch mechanism. An unlock member of the lid opening-and-closing mechanism is inserted into the keyhole  13  and engaged with it.  14  represents a square-shaped flange portion provided above a top surface of the carrier  10  via a space.  15  represents a recess portion, whose cross section is round-shaped, formed at a center part of the flange portion  14 .  
      Next, a vertical thermal processing apparatus in one embodiment of the present invention is explained in details.  
       FIG. 2  is a perspective view showing an appearance of the vertical thermal processing apparatus according to this embodiment.  FIGS. 3 and 4  are respectively a longitudinal sectional view and a plan view showing an inside structure of the vertical thermal processing apparatus shown in  FIG. 2 .  FIG. 5  is a longitudinal sectional view showing an outline of a structure of one example of a door mechanism which opens and closes an opening part formed in a partition, under a condition wherein the carrier containing the wafers abuts to the partition.  FIG. 6  is a back view of the door mechanism shown in  FIG. 5 .  
      In FIGS.  2  to  4 ,  20  represents a housing which composes an outer cover of the processing apparatus. In this housing  20 , a conveying in-and-out area S 1  that is an outside space area, in which the above-described hermetic carrier  10  containing the wafers W that are objects to be processed is conveyed, and a loading area S 2  that is an inside space area, in which the wafers W being taken out from the carrier  10  are conveyed, are defined (divided) by a partition  21 .  
      The atmosphere of the conveying in-and-out area S 1  is, for example, an air atmosphere, to be concrete, an environmental atmosphere of a clean room in which the thermal processing apparatus is installed. On the other hand, the atmosphere of the loading area S 2  is maintained to be an inert gas atmosphere cleaner than the atmosphere of the conveying in-and-out area S 1 , such as a nitrogen (N 2 ) gas atmosphere or a clean dry gas (an air which includes less particles and less organic constituents and whose dew point is maintained not higher than −60° C.) atmosphere.  
      The conveying in-and-out area S 1  includes a first conveying area S 1 A located on a front side of the thermal processing apparatus and a second conveying area S 1 B located on a back side thereof.  
      In the first conveying area S 1 A, two first stages  22 ,  23  are arranged side by side in the right-and-left direction (in the vertical direction in  FIG. 4 ). Accordingly, when the carrier  10  is placed on any one of the first stages  22 ,  23 , it can be conveyed by a carrier conveying mechanism  31  which is described later.  
      On a placing surface of each of the first stages  22 ,  23 , positioning pins  24  for fitting with a recess portion formed at a bottom portion of the carrier  10  to locate the carrier  10  on the first stages  22 ,  23  are provided, for example, at three spots (refer to  FIG. 2 ).  
      Additionally, on a front side of the housing  20 , a panel part  25 , whose cross section shape seen from above is C-shaped, is provided in such a manner that it surrounds an upper space of the first stages  22 ,  23 . An area surrounded by the panel part  25  is an area wherein the carrier  10  is transferred between a not-shown automatic conveying robot movable along a ceiling portion in a clean room and the first stages  22 ,  23 .  
      In the second conveying area S 1 B in the conveying in-and-out area S 1 , two second stages  26 ,  27  respectively corresponding to the first stages  22 ,  23  are arranged side by side in an anterior-posterior direction with respect to the first stages  22 ,  23 .  
      The second stages  26 ,  27  are composed so that they are capable of proceeding and withdrawing in the anterior-posterior direction (in the right-and-left direction in  FIG. 4 ) between a position wherein the carrier  10  is placed thereon by means of a carrier conveying mechanism  31  to be described later and a position wherein the carrier  10  abuts to the partition  21 , by means of, for example, a driver composed of an air cylinder (not shown).  
      Similar to the first stages  22 ,  23 , positioning pins  28  for positioning the carrier  10  are provided at three spots on each placing surface of the second stages  26 ,  27 . Additionally, on each placing surface of the second stages  26 ,  27 , as shown in  FIG. 7 , a hook-shaped engaging member  29  to be engaged with an engaging recess portion  16  at a bottom portion of the carrier  10  is provided. The engaging member  29  is composed pivotable around a horizontal axis by a driver  29 A between a position to engage with the engaging recess portion  16  of the carrier  10  and a position wherein the engagement is disengaged.  
      In an upper part of the second conveying area S 1 B, a carrier storing part  30  for storing the carrier  10  temporarily is provided. The carrier storing part  30  in this example is composed of a shelf having two steps and two rows.  
      Furthermore, in the second conveying area S 1 B, a carrier conveying mechanism  31  which conveys the carrier  10  between the first stages  22 ,  23  and the second stages  26 ,  27  as well as between the second stages  26 ,  27  and the carrier storing part  30 , and between the first stages  22 ,  23  and the carrier storing part  30 , is provided.  
      The carrier conveying mechanism  31  comprises: a guide part  32  extending right and left and freely movable upward and downward; a moving part  33  that moves right and left while guided by the guide part  32 ; and a joint arm  34  provided at the moving part  33  to hold the flange portion  14  on the top surface of the carrier  10  and to convey the carrier  10  in the horizontal direction.  
      The loading area S 2  is provided with a vertical heat treating furnace  40  whose lower end is opened as a furnace opening. On a lower side of the heat treating furnace  40 , a wafer boat  41 , which is a holder for holding a plurality of wafers W in a tier-like manner, is placed on a cap  43  via an insulation member  42 . The cap  43  is supported on an elevating mechanism  44 . By means of the elevating mechanism  44 , the wafer boat  41  is conveyed in or out of the heat treating furnace  40 .  
      The loading area  52  is provided with a wafer transferring mechanism  45 , which transfers the wafers W between the wafer boat  41  and the carrier  10  on the second stages  26 ,  27 . The wafer transferring mechanism  45  is composed as a plurality of, for example  5 , arms  48  capable of proceeding and of withdrawing and provided at a moving part  47  that moves along a guide mechanism  46  extending right and left and that can pivot around a vertical axis.  
      In the partition  21  defining the conveying in-and-out area S 1  and the loading area S 2 , an opening part  21 A is formed at a position corresponding to each of the second stages  26 ,  27 . The opening part  21 A can cause the inside of the carrier  10  and the space of the loading area S 2  to communicate with each other when the carrier  10  placed on the second stages  26 ,  27  abuts to the partition  21 . An end edge of the opening part  21 A on a side of the conveying in-and-out area S 1  is provided with a sealing member  50  for hermetically connecting with the carrier  10 , in details, with an opening end edge of the taking-out port  11 A of the carrier  10 , at the whole circumference of the end edge of the opening part  21 A.  
      This sealing member  50  is, for example, composed of a packing whose cross section is Y-shaped.  
      Additionally, on a side of the conveying in-and-out area S 1  of the partition  21 , pressing means  55 ,  56  for pressing an upper surface of the carrier  10  placed on the second stages  26 ,  27  from above to stabilize the pose of the carrier  10  when the lid  12  is opened and closed, are provided at respective positions corresponding to the second stages  26 ,  27 .  
      In this embodiment, an opening plane of the opening part  21 A is formed in an inclined condition with respect to a conveying direction of the wafer. Concretely, as shown in  FIG. 5 , an inclined opening plane is formed by allowing a frame member  60 , whose cross section is a substantial wedge-shaped, to be fitted tightly in the opening part formed in the partition  21 .  
      Furthermore, a side edge portion of the opening part  21 A of the partition  21  is provided with a nitrogen gas supplier (not shown). Accordingly, an inert gas, for example, a nitrogen gas is supplied under a condition wherein the lid  12  of the carrier  10  has been removed, and the atmosphere of the carrier  10  is replaced by a nitrogen gas atmosphere.  
      On a side of the loading area S 2  of the partition  21 , provided is a door mechanism  70  which opens and closes the opening part  21 A. The door mechanism  70  is held by holding members  66 ,  66  which are provided to be capable of moving respectively on two guide shafts  65 ,  65  extending upward and downward along the partition  21  in such a manner that they are arranged side by side from each other (in the right and left direction in  FIG. 6 ).  
      The door mechanism  70  includes a door  71 , which forms an atmosphere adjusting space separated from the loading area S 2  by abutting to the opening plane of the opening part  21 A. The door  71  hermetically closes the opening part  21 A via a sealing member  79  provided at the frame member  60 .  
      A lid opening-and-closing mechanism  75  which opens and closes the lid  12  of the carrier  10  is provided inside the door  71 . In addition, a driving unit  76  which moves the lid opening-and-closing mechanism  75  in a direction for connecting or disconnecting to the carrier  10  (in the right and left direction in  FIG. 5 ) is arranged in a driving-unit arrangement room  81  formed and defined by the cover member  80  at a lower end portion of the door  71 . On an upper defining wall of the driving-unit arrangement room  81 , a guiding groove  81 A to guide a supporting member for supporting the lid opening-and-closing mechanism  75  is formed.  
      The lid opening-and-closing mechanism  75  includes an unlock member  77  which can tightly fit in the keyhole  13  of the lid  12  of the carrier  10  and is exposed to an outside surface of the outer box, and a driving unit  78  composed of, for example, an air cylinder provided inside the outer box. Under a condition wherein the unlock member  77  is inserted into the keyhole  13  of the lid  12  and is tightly fitted therein, when the unlock member  77  is rotated by an bending and/or stretching movement of the driving unit  78 , lock of the lid  12  of the carrier  11  is adapted to be unlocked.  
      The lid opening-and-closing mechanism  75  is moved forward to the conveying in-and-out area S 1  by the driving unit  76  and abuts to the lid  12  of the carrier  10  under a condition wherein the door  71  is closed and the conveying in-and-out area S 1  and the loading area S 2  are closed. At this time, the lid opening-and-closing mechanism  75  is also hermetically connected to the sealing member  50  which is provided on the partition  21 . Accordingly, a high-level air-tightness is secured between the conveying in-and-out area S 1  and the loading area S 2 . And then, the lid opening-and-closing mechanism  75  is moved apart from the opening part  21 A after holding the lid  12  of the carrier  10  in order to convey the wafers W in the carrier  10  to the loading area S 2 . Accordingly, the lid  12  is contained inside the door  71 .  
      The door mechanism  70  is provided with a gas-discharging mechanism for discharging a gas from an inside of the driving-unit arrangement room  81  and from an inside of the outer box of the lid opening-and-closing mechanism  75 .  
      In the concrete, the gas-discharging mechanism comprises: a suction port  86  A opening to the inside space of the driving-unit arrangement room  81 ; a suction port  86 B opening to the inside space of the lid opening-and-closing mechanism  75 ; a common gas-discharging port  87  provided at an outside of the door mechanism  70  and connected to each of the suction ports  86 A,  86 B; and a suction means (not shown), such as a pump and so on, provided at an outside of the processing apparatus.  
      Furthermore, when the door mechanism  70  opens the opening part  21 A of the partition  21 , the door mechanism  70  has a function for adjusting pressure so as to leisurely reduce a pressure difference between a pressure inside the carrier  10  and a pressure of the loading area S 2  to substantially zero.  
      In the concrete, an opening  90  formed at a back wall of the door  71  is provided with a damper mechanism  92  through a filter  91 . The pressure inside the door  71  is adjusted by controlling a movement of the damper mechanism  92  to gradually open the opening  90 . For example, when the pressure in the carrier  10  is 19.6×10 4 -29.4×10 4  Pa (20-30 mAq) and the pressure in the loading area S 2  is 49×10 4 -98×10 4  Pa (50-100 mAq) under a condition wherein the lid  12  has been removed and a nitrogen gas has been purged, the pressure in the carrier  10  is adjusted so as to become the same as the pressure in the loading area S 2  by taking a time for 1-10 seconds.  
      Hereinafter, an operation of the vertical thermal processing apparatus as described above is explained.  
      Firstly, the carrier  10  is moved down through the inside space of the panel part  25  by the not-shown automatic conveying robot which moves along the ceiling portion of the clean room, and is placed on the first stage  22  ( 23 ). And then, the carrier  10  is conveyed onto the second stage  26  ( 27 ) by means of the carrier conveying mechanism  31 .  
      Next, the second stage  26  ( 27 ) is moved to a side of the partition  21 . Accordingly, the end edge of the opening of the taking-out port  11 A of the carrier  10  hermetically abuts to the end edge of the opening of the partition  21  via the sealing member  50 . Under this situation, the pressing means  55  ( 56 ) is driven by an appropriate driving unit and is made to lie on its side. At this time, a protruding portion (not shown) of the pressing means  55  ( 56 ) is tightly fitted in the recess portion  15  of the flange portion  14  of the carrier  10 , and the carrier  2  is fixed in such a condition that the carrier  2  is pressed from above by the pressing means  55  ( 56 ).  
      Thereafter, the gas-discharging mechanism in the door mechanism  70  is activated, and the atmosphere in the lid opening-and-closing mechanism  75  and in the driving-unit arrangement room  81  is discharged at a flow rate of, for example, 0.01-0.1 m 3 /min. Under this situation, the lock of the lid  12  of the carrier  10  is unlocked by the lid opening-and-closing mechanism  75 , and the lid opening-and-closing mechanism  75  is withdrawn with holding the lid  12 . Accordingly, the inside space of the carrier  10  is opened. Under this situation, an inert gas such as a nitrogen gas is supplied horizontally into the carrier from a gas-supplying pipe at a flow rate of, for example, 0.05-0.5 m 3 /min. Accordingly, the atmosphere in the carrier  10  and the door  71  is replaced by the inert gas. At this time, since the inert gas is introduced in a relatively large amount, there is a possibility that the pressure in the carrier  10  rises up and also the air-tightness between the end edge of the opening part of the carrier  10  and the sealing member  50  is damaged due to a shock when the gas is introduced. However, since the carrier  10  is pressed from above by the pressing means  55  ( 56 ), the carrier  10  is not dislocated actually and the air-tightness is not damaged.  
      After that, the damper mechanism  92  is activated and the pressure in the carrier  10  is adjusted so as to leisurely become the same pressure as in the loading area S 2  after some time. Then, as shown in  FIG. 8 , the door mechanism  70  is moved upward along the partition  21  and withdrawn from the opening part  21 A in such a condition that it contains the lid opening-and-closing mechanism  75  holding the lid  12  in the door  71 , in order not to interrupt the transferring movement of the wafers W by the wafer transferring mechanism  45 . Accordingly, the inside of the carrier  10  and the space of the loading area S 2  are communicated with each other.  
      After that, the wafers W in the carrier  10  are taken out one after another and placed on the wafer boat  41  by the wafer transferring mechanism  45 . When the transferring of the wafers is finished, a reverse movement to one described above is conducted. Namely, the opening part  21 A is hermetically closed by the door mechanism  70 , the lid  12  of the carrier  10  is closed by the lid opening-and-closing mechanism  75 , the fixation by the pressing means  55  ( 56 ) is removed, the second stage  26  ( 27 ) is withdrawn and the carrier  10  is moved away from the partition  21 , and the carrier  10  is transferred into the carrier storing part  30  by the carrier conveying mechanism  31  to be kept therein temporally.  
      On the other hand, when a predetermined number of wafers W are mounted on the wafer boat  41 , the wafer boat  41  is conveyed into the heat treating furnace  40 . The heat treating furnace  40  conducts a predetermined heat treatment, for example, a CVD treatment, an annealing treatment, an oxidation treatment and so on, to the wafers W. Thereafter, the conveying movement of the carrier  10  from the carrier storing part  30  to the second stage  26  ( 27 ) by the carrier conveying mechanism  31 , the opening movement of the lid by the lid opening-and-closing mechanism  75 , the withdrawing movement of the door mechanism  70 , and the transferring movement of the wafers by the wafer transferring mechanism  45 , are conducted in order, so that the wafers W are returned to the carrier  10 . After that, the lid  12  is closed by the lid opening-and-closing mechanism  75  and the carrier  10  is conveyed to an outside of the apparatus.  
      In this way, according to the processing apparatus having the structure described above, since the driving unit  76  of the lid opening-and-closing mechanism  75  is arranged in the driving-unit arrangement room  81  separated from the door mechanism space (the space inside the door  71 ) which is formed between the door mechanism  70  and the carrier  10  as well as it is provided with the gas-discharging mechanism for discharging the gas inside the driving-unit arrangement room  81 , even when a dust is raised accompanied by a sliding movement in the anterior-posterior direction of the driving unit  76  when the lid  12  of the carrier  10  is opened or closed, the dust is discharged to outside through the suction port  86 A and removed. In addition, a dust which is raised accompanied by the opening-and-closing movement of the lid by the lid opening-and-closing mechanism  75  is also discharged to outside through the suction port  86 B and removed. Therefore, it is possible to surely prevent a dust from entering into the space inside the door mechanism and adhering to the wafers W in the carrier  10 , and also it is possible to surely prevent the clean atmosphere in the loading area S 2  from being polluted when the door mechanism  70  is opened. As a result, an adverse effect on the wafers W by a dust (particles) can be lessened to a small degree.  
      Additionally, in this processing apparatus, the air of the space inside the door mechanism is also discharged via the suction port  86 A through the guiding groove  81 A provided at the upper defining wall forming the driving-unit arrangement room  81 . Therefore, an adverse effect on the wafers W by a dust (particles) can be lessened to as small a degree as possible.  
      In addition, since the door mechanism  70  is composed so as to be moved in parallel to any direction in the plane of the partition  21 , an upward direction in the example shown in the figure, along the partition  21  and to be withdrawn from the opening part  21 A, the number of moving portions(sliding spots) relating to the lid opening-and-closing movement is lessened so as to reduce the possibility that a dust is raised accompanied by the withdrawing movement of the door mechanism  70 , compared with the conventional door mechanism explained with reference to  FIG. 10 , for example. Accordingly, it is possible to further surely prevent the wafers W or the atmosphere in the loading area S 2  from being polluted by a dust.  
      Furthermore, since it is such a composition that the sealing member  50  is provided at the end edge on the side of the conveying in-and-out area Si of the opening part  21 A, and the lid opening-and-closing mechanism  75  provided at the door mechanism  70  is connected closely to the sealing member  50  and sealed hermetically in a condition wherein the opening portion  21 A is closed, as is shown in  FIG. 9 , the space inside the door mechanism is not exposed to the atmosphere of the conveying in-and-out area S 1  even when the carrier  10  is not placed on the second stage  26  ( 27 ). Accordingly, it is possible to surely prevent a dust, which is for example floating in the conveying in-and-out area S 1 , from entering into the space inside the door mechanism.  
      Additionally, when the carrier  10  and the space in the loading area S 2  are communicated with each other all at once, the dust existing in the space inside the door mechanism is stirred up because of the pressure difference between the pressure in the carrier  10  and the pressure in the loading area S 2 , and is allowed to adhere to the wafers W in the carrier  10  and to get mixed into the loading area S 2 . However, since the door mechanism  70  is provided with the damper mechanism  92  that leisurely adjusts the pressure in order to reduce the pressure difference between the pressure in the loading area S 2  and the pressure in the carrier  10  to substantially zero, it is possible to surely prevent the troubles described above, and to surely prevent the wafers from being polluted.  
      When a heat treatment was conducted to wafers having a diameter of 300 mm in the thermal processing apparatus provided with the door mechanism shown in  FIG. 10 , the increase of number of particles not less than 0.16 μm per one RUN was 10. In comparison with this, when a heat treatment was conducted to wafers having a diameter of 300 mm in the thermal processing apparatus of the present invention, the increase of number of particles not less than 0.1 μm per one RUN was 2. That is, it was confirmed that it is possible to surely restrain pollution of the wafers by the particles according to the present invention.  
      Although the embodiment of this present invention has been explained as above, the present invention is not limited to the embodiment described above and it is possible to add various changes.  
      For example, the present invention can be applied not only to the vertical thermal processing apparatus but also to any apparatus to conduct a predetermined process to an object to be processed, such as a thermal processing apparatus of sheet-fed type, an apparatus for applying a resist or developing, an ion implantation apparatus and so on.  
      In addition, the atmosphere in the loading area is not limited to an inert gas but it may be a clean dry air. In this case, after the carrier abuts to the partition, the clean dry air may be supplied into the carrier so that the atmosphere in the carrier may be replaced by the clean dry air.  
      Additionally, the present invention is applicable for an apparatus in which an area for conveying a carrier and an area for conveying the carrier to an outside are provided at separated places.  
      Furthermore, in the above embodiment, a suction duct can be provided in the loading area so as to surround the circumference of the door mechanism in such a manner that the withdrawing direction of the door mechanism is opened. In this case, even when a dust is raised accompanied by the withdrawing movement of the door mechanism, the dust is removed by the suction duct. Therefore, an adverse effect on the wafers and the clean atmosphere in the loading area by particles can be lessened to as small a degree as possible, and it is possible to surely restrain the pollution of the wafers. Moreover, it is possible to contain a cable air tube and so on, which is connected to the gas-discharging port, in the suction duct. In this case, even when a dust and so on are raised due to the movement of the cable air tube accompanied by the withdrawing movement of the door mechanism, an adverse effect on the wafers is surely prevented.