Abstract:
A semiconductor treating device ( 1 ) includes treating chamber ( 2 ) connected to a common transportation chamber ( 8 ) and treating a substrate (W) to be treated. A gas supply system ( 40 ) for supplying system ( 40 ) for supplying a predetermined gas to each of the treating chambers ( 2 ) is attached to each chamber. The gas supply system ( 40 ) has a primary side connection unit ( 23 ) connected to the source of the predetermined gas and has a flow rate control unit ( 13 ). The primary side connection unit ( 23 ) connected to the source of the predetermined gas and has a flow rate control unit ( 13 ). The primary side connection unit ( 23 ) is placed on the lower side of the corresponding treating chamber ( 2 ). The flow rate control unit ( 13 ) is placed on a gas line for supplying the gas from the primary side connection unit ( 23 ) to the corresponding treating chamber ( 2 ). The flow rate control unit ( 13 ) is provided such that at least a part of it is superposed on the upper side of the primary side connection unit ( 23 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a semiconductor processing apparatus; and, more particularly, to a cluster tool type (also referred to as a multi-chamber type) processing apparatus in which a plurality of processing chambers are connected to a common transfer chamber. As used herein, the term “semiconductor processing” means a variety of processes for forming semiconductor layers, insulating layers, conductive layers and the like in a predetermined pattern on a target substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display (“LCD”) or a flat panel display (“FPD”), to thereby fabricate on the target substrate semiconductor devices and other structures including wiring lines, electrodes and so forth connected to the semiconductor devices.  
       BACKGROUND OF THE INVENTION  
       [0002]      FIG. 14  is a top view schematically showing a conventional cluster tool type semiconductor processing apparatus. This processing apparatus  1  includes a normal pressure transfer system  5  that takes out a wafer W from cassettes  3  mounted on load ports  4  and transfers the wafer W under an atmospheric pressure. The processing apparatus  1  further includes a vacuum transfer system  7  connected to a transfer chamber  6  of the normal pressure transfer system  5  through load lock chambers  11  and adapted to transfer the wafer W under a predetermined vacuum pressure. Connected to around a common transfer chamber  8  of the vacuum transfer system  7  are a plurality of vacuum processing chambers  2  each of which accommodates the wafer W on a one-by-one basis and performs a process such as a chemical vapor deposition (“CVD”) or the like in a predetermined gas atmosphere.  
         [0003]     In order to supply gases to the processing chambers  2 , a gas box  50  connected to a gas source is disposed at one lateral side or a rear surface portion of the processing apparatus  2 . Collectively received within the gas box  50  are flow rate control units connected to gas supply conduits  51  through which gases are supplied to the respective processing chambers  2 .  
         [0004]     In such a processing apparatus, the distance between each of the processing chambers  2  and the gas box  50 , i.e., the extension length of each gas supply conduit  51 , becomes long. Further, there occur mechanical differences between the processing chambers due to the fact that the extension lengths of the gas supply conduits  51  differ from each other. This may adversely affect the controllability of a pressure range, the control responsiveness and eventually the process performance. In addition, the gas box is installed on a floor independently of the processing apparatus, which increases a footprint.  
         [0005]     Meanwhile, Japanese Patent Laid-open Publication No. 2001-156009 discloses a batch type vertical heat treatment apparatus in which a gas box is disposed at a side surface of an apparatus main body. This vertical heat treatment apparatus is distinguished from the cluster tool type processing apparatus that includes a plurality of single-wafer processing chambers.  
       SUMMARY OF THE INVENTION  
       [0006]     It is, therefore, an object of the present invention to provide a semiconductor processing apparatus capable of improving a process performance and reducing a footprint.  
         [0007]     In accordance with a first aspect of the present invention, there is provided a semiconductor processing apparatus including:  
         [0008]     a common transfer chamber;  
         [0009]     a plurality of processing chambers, connected to the common transfer chamber, for processing a substrate;  
         [0010]     a transfer mechanism, disposed within the common transfer chamber, for transferring the substrate with respect to the processing chambers; and  
         [0011]     a plurality of gas supply systems for supplying predetermined gases, the gas supply systems being provided in the processing chambers, respectively,  
         [0012]     wherein each of the gas supply systems includes:  
         [0013]     a primary-side connection unit connected to gas sources of the predetermined gases, the primary-side connection unit being disposed underneath the corresponding one of the processing chambers;  
         [0014]     a flow rate control unit for controlling flow rates of the predetermined gases, the flow rate control unit being disposed on gas lines through which the gases are supplied from the primary-side connection unit to the corresponding processing chamber, the flow rate control unit being disposed above the primary-side connection unit so as to at least partially overlap therewith; and  
         [0015]     a gas box for enclosing the flow rate control unit, the gas box having a cover removably attached thereto for providing access to the flow rate control unit.  
         [0016]     In accordance with a second aspect of the present invention, there is provided a semiconductor processing apparatus including:  
         [0017]     a common transfer chamber;  
         [0018]     a plurality of processing chambers, connected to the common transfer chamber, for processing a substrate;  
         [0019]     a transfer mechanism, disposed within the common transfer chamber, for transferring the substrate with respect to the processing chambers; and  
         [0020]     a plurality of gas supply systems for supplying predetermined gases, the gas supply systems being provided in the processing chambers, respectively,  
         [0021]     wherein each of the gas supply systems includes:  
         [0022]     a primary-side connection unit connected to gas sources of the predetermined gases, the primary-side connection unit being disposed underneath a removable floor panel of a room in which the apparatus is installed, the floor panel having a cover which is detachable for providing access to the primary-side connection unit;  
         [0023]     a flow rate control unit for controlling flow rates of the predetermined gases, the flow rate control unit being disposed on gas lines through which the gases are supplied from the primary-side connection unit to the corresponding one of the processing chambers, the flow rate control unit being disposed under the corresponding processing chamber such that at least a part thereof lies under the corresponding processing chamber; and  
         [0024]     a gas box for enclosing the flow rate control unit, the gas box having a cover removably attached thereto for providing access to the flow rate control unit. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments, given in conjunction with the accompanying drawings, in which:  
         [0026]      FIG. 1  is a perspective view schematically showing a semiconductor processing apparatus in accordance with a first embodiment of the present invention;  
         [0027]      FIG. 2  is a schematic top view of the apparatus shown in  FIG. 1 ;  
         [0028]      FIG. 3  is a piping diagram illustrating a gas supply system employed in the apparatus shown in  FIG. 1 ;  
         [0029]      FIG. 4  is a side elevational view depicting a gas supply system employed in the apparatus shown in  FIG. 1 ;  
         [0030]      FIG. 5  is a perspective view schematically showing a gas box of the gas supply system depicted in  FIG. 4 ;  
         [0031]      FIG. 6  is a perspective view schematically showing a primary-side connection unit of the gas supply system depicted in  FIG. 4 ;  
         [0032]      FIG. 7  is a perspective view schematically showing an trunk unit of the gas supply system depicted in  FIG. 4 ;  
         [0033]      FIG. 8  is a perspective view schematically showing a connection structure of trunk pipelines of the gas supply system depicted in  FIG. 4 ;  
         [0034]      FIG. 9  is a perspective view schematically showing a semiconductor processing apparatus in accordance with a second embodiment of the present invention;  
         [0035]      FIG. 10  is a side elevational view illustrating a flow rate control unit employed in the apparatus shown in  FIG. 9 ;  
         [0036]      FIG. 11  is a top view showing a primary-side connection unit employed in the apparatus shown in  FIG. 9 ;  
         [0037]      FIG. 12  is a side elevational view illustrating the primary-side connection unit shown in  FIG. 11 ;  
         [0038]      FIG. 13  is a piping diagram depicting a mechanism for concurrently closing switching valves of gas lines by a remote control operation, in a modification of the first and the second embodiment; and  
         [0039]      FIG. 14  is a top view schematically illustrating a conventional cluster tool type semiconductor processing apparatus. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0040]     Hereinafter, preferred embodiments of the present invention will be described with reference to accompanying drawings. In the following description, like parts or components having substantially the same function and configuration will be designated by like reference numerals, and no duplicate description will be given unless otherwise needed.  
       First Embodiment  
       [0041]      FIG. 1  is a perspective view schematically showing a semiconductor processing apparatus in accordance with a first embodiment of the present invention.  FIG. 2  is a schematic top view of the apparatus shown in  FIG. 1 . The processing apparatus  1  is of a cluster tool type (also referred to as a multi-chamber type) wherein six processing chambers  2  are connected to around a common transfer chamber  8 . The processing chambers  2  make it possible to conduct a series of processes with respect to a target substrate, e.g., a semiconductor wafer W.  
         [0042]     More specifically, the processing apparatus  1  includes a normal pressure transfer system  5  that takes out a wafer W from cassettes  3  mounted on load ports  4  and transfers the wafer W under an atmospheric pressure. The processing apparatus  1  further includes a vacuum transfer system  7  connected to a transfer chamber  6  of the normal pressure transfer system  5  through load lock chambers  11  and adapted to transfer the wafer W under a predetermined vacuum pressure. Connected to around the common transfer chamber (vacuum transfer chamber)  8  of the vacuum transfer system  7  are a plurality of vacuum processing chambers  2  that accommodate the wafer W on a one-by-one basis and perform processes such as a chemical vapor deposition (“CVD”) and the like in a predetermined gas atmosphere.  
         [0043]     Inside the transfer chamber  6  of the normal pressure transfer system  5 , there is provided a transfer arm mechanism  9  for transferring the wafer W between the load ports  4  and the load lock chambers  11 . The transfer chamber  6  is configured in an elongated shape and the transfer arm mechanism  9  is mounted for movement along a longitudinal direction of the transfer chamber  6 . The plural load ports  4  are disposed at one side of the transfer chamber  6 , while one ends of the load lock chambers  11  are connected to the other side of the transfer chamber  6  through respective gate valves G. At one longitudinal end of the transfer chamber  6 , there is provided an orienter  10  serving to align the position of the wafer W.  
         [0044]     Inside the transfer chamber  8  of the vacuum transfer system  7 , there is disposed a transfer arm mechanism  12  for transferring the wafer W between the load lock chambers  11  and the processing chambers  2 . The transfer chamber  8  is configured in an elongated shape and the transfer arm mechanism  12  is mounted for movement along a longitudinal direction of the transfer chamber  8 . The other ends of the load lock chambers  11  are connected to one end of the transfer chamber  8  through respective gate valves G. Connected to the load lock chambers  11 , the transfer chamber  8  and the processing chambers  2  is a vacuum generation system capable of controlling the insides thereof to a predetermined pressure. Although two load lock chambers  11  are disposed side by side in the illustrated embodiment, a single load lock chamber may be employed.  
         [0045]      FIG. 3  is a piping diagram illustrating a gas supply system employed in the apparatus shown in  FIG. 1 .  FIG. 4  is a side elevational view depicting the gas supply system employed in the apparatus shown in  FIG. 1 .  FIG. 5  is a perspective view schematically showing a gas box of the gas supply system depicted in  FIG. 4 .  
         [0046]     In order to supply gases to the respective processing chambers  2 , the gas supply systems  40  are disposed underneath the respective processing chambers  2 . Each of the gas supply system  40  is provided with gas box  14  enclosing a flow rate control unit  13  and a primary-side connection unit  23 . The primary-side connection unit  23  is connected to a plurality of gas sources. Within the gas box  14 , the flow rate control unit  13  is disposed on gas lines through which gases are supplied from the primary-side connection unit  23  to the corresponding processing chamber  2 .  
         [0047]     Each of the flow rate control units  13  has a plurality of pipelines  16  which are respectively connected to plural kinds of gas sources GS 1 , GS 2  and so forth through the primary-side connection unit  23 . Disposed on each of the respective pipelines  16  is a flow rate controller  17  such as a flow control system (“FCS”) (made by Fujikin Corporation, Japan) and a mass flow controller (“MFC”). The FCS is a pressure-type flow rate controller that monitors the pressure in the gas line to control the flow rate of gas. The FCS is highly sensitive to pressure variation and enjoys a broadened control range at the time when a secondary-side pressure becomes low. For these reasons, the FCS is suitable for a pipeline of short length and is cost-effective.  
         [0048]     Valves V 1  and V 2  are disposed on each of the pipelines  16  at upstream and downstream sides of the flow rate controller  17 . A pipeline  18  for supplying a nonreactive purge gas, e.g., N 2  gas, is connected to between the upstream side valve V 1  and the flow rate controller  17  through a valve V 3 . Although not shown in  FIG. 3 , a pressure indicator  19  and a regulator  20  (not required in the FCS) are disposed at the upstream side of the valve V 1 . Each of the valves V 1 , V 2  and V 3  is, for example, a pneumatically operated valve (air operation valve). The flow rate controller  17 , the valves V 1  to V 3 , the pressure indicator  19  and the regulator  20  on each pipeline  16  are all installed on the top surface of the flow rate control unit  13  in view of the maintenance thereof.  
         [0049]     The downstream sides of the respective pipelines  16  are connected to a common outlet conduit  21 , which in turn is detachably connected to a gas supply conduit  15  leading to the corresponding one of the processing chambers  2 . Namely, the flow rate controllers  17  provided in one-to-one relationship with plural kinds of gases are connected to the corresponding processing chamber  2  by way of the common conduits  21  and  15 . A filter  22  and a valve V 4  are disposed on the gas supply conduit  15 .  
         [0050]      FIG. 6  is a perspective view schematically showing the primary-side connection unit  23  of the gas supply system  40  depicted in  FIG. 4 .  FIG. 7  is a perspective view schematically showing a trunk unit  28  of the gas supply system  40  depicted in  FIG. 4 .  FIG. 8  is a perspective view schematically showing a connection structure of trunk pipelines of the gas supply system  40  depicted in  FIG. 4 .  
         [0051]     The primary-side connection unit (also referred to as a template)  23  is provided on the floor of a clean room, in which the processing apparatus  1  is installed, in such a manner that it is located just below the corresponding processing chamber  2 . Before the processing apparatus  1  is installed in the clean room, the primary-side connection unit  23  is mounted on the floor of the clean room in advance through plumbing works. The floor of the clean room is constructed by fitting together a plural number of floor panels (also referred to as grating panels)  24 .  
         [0052]     As illustrated in  FIG. 6 , the primary-side connection unit  23  includes a plurality of pipelines  25  and a case  26  enclosing the pipelines  25 . A filter  27  and a valve V 5  are disposed on each of the pipelines  25 . The valve V 5  is, for example, a pneumatically operated valve (air operation valve). The primary-side connection unit  23  is connected to the flow rate control unit  13  through a trunk unit (also referred to as a connection unit)  28  in which trunk pipelines are gathered together.  
         [0053]     Referring to  FIG. 7 , the trunk unit  28  includes a plurality of pipelines  32  each having connection portions  30  and  31  at opposite ends, and a case  33  enclosing the pipelines  32 . The trunk unit  28  is disposed in front of the primary-side connection unit  23  and underneath the flow rate control unit  13 . As depicted in  FIG. 8 , one connection portion  30  of each of the pipelines  32  is connected to a pipeline connection portion  34  of the primary-side connection unit  23 . The other connection portion  31  of each of the pipelines  32  is connected to a pipeline connection portion  35  of the flow rate control unit  13  through an auxiliary pipeline  36 , which has connection portions  37  and  38  at the opposite ends thereof, respectively.  
         [0054]     Referring back to  FIG. 4 , the gas box  14  is removably attached to the cases  26  and  33  and cooperates therewith to hermetically enclose internal components such as the primary-side connection unit  23 , the flow rate control unit  13  and the trunk unit  28 . This prevents any gas from being leaked out of the gas box  14 . The gas box  14  is installed such that the rear part thereof lies under the plan view contour of the corresponding processing chamber  2 . Disposed underneath the processing chamber  2  is a housing  41  that accommodates a power supply unit (not shown) and the like. The rear half part of the gas box  14  is inserted in the housing  41  by, e.g., about 140 mm. This helps to reduce the footprint of the processing apparatus  1 .  
         [0055]     The flow rate control unit  13  is disposed above the primary-side connection unit  23  so as to at least partially overlap with the latter. In other words, the flow rate control unit  13  is positioned inclined downwardly from the inner portion located above the primary-side connection unit  23  (the position of the valve V 2  in  FIG. 4 ) toward the outer portion located in front of the primary-side connection unit  23  (the position of the regulator  20  in  FIG. 4 ). The outer portion of the flow rate control unit  13  protrudes outwardly beyond the plan view contour of the corresponding processing chamber  2 .  
         [0056]     In the meantime, a removably attached cover  42  defines the front and the top surface of the gas box  14 . Normally, the interior of the gas box  14  remains hidden by the housing  41  and therefore is not visible. Removal of the cover  41  enables an operator to readily gain access to the valves V 1  to V 3  and other components disposed on the top surface of the flow rate control unit  13 . This helps to improve the maintainability of the flow rate control unit  13 .  
         [0057]     Among the six processing chambers  2 , the processing chambers for performing a same process are configured to have a substantially same specification. Further, the gas supply systems  40  installed for the processing chambers  2  of the same specification are designed to have a substantially same specification. Moreover, the distance between the flow rate control unit  13  and the corresponding processing chamber  2  is set to be equal in the respective gas supply systems  40  of the same specification.  
         [0058]     The cluster tool type semiconductor processing apparatus  1  in accordance with the present embodiment provides the following advantageous effects. Namely, since the gas boxes  14  of the gas supply systems  40  are disposed underneath the respective processing chambers  2  in a one-to-one relationship, it becomes possible to shorten the distance (pipeline length) L between the processing chamber  2  and the corresponding gas box  14 . This reduces a pressure loss, thus making possible to draw down the pressure at which the gas is supplied. Furthermore, by making the lengths L of the pipelines equal, it is possible to eliminate the mechanical difference between the processing chambers  2  that perform the same process.  
         [0059]     According to an experiment, it took about 1.0 second to reach an average pressure in the pipelines when the pipeline length L is about 7,000 mm under the condition that the pipelines have a diameter of ½ inches and the total gas flow rate is equal to 1,200 sccm. In contrast, at the time when the pipeline length L is reduced to about 4,000 mm, it took about 0.6 second to reach the average pressure, which proved the improvement of responsiveness.  
         [0060]     The following advantages are attainable in case the FCS (pressure type flow rate controller) is used as the flow rate controllers  17 . Specifically, the pressure type flow rate controller uses the principle that, when the upstream side pressure P 1  and the downstream side pressure P 2  of a built-in orifice satisfy the relationship of P 1 ≧2×P 2 , the flow rate is proportional to the upstream side pressure P 1 . Accordingly, as the downstream side pressure P 2  is set to a smaller value, the upstream side pressure P 1  can be set within a wider range and, therefore, the flow rate control range becomes larger. By shortening the pipeline length L as in this embodiment, the downstream side pressure P 2  can be reduced, so that it is possible to broaden the permissible range (control range) of the upstream side pressure P 1  if the FCS (pressure type flow rate controller) is selected as the flow rate controller  17 . On the contrary, the flow rate control range cannot be broadened in case of a MFC (mass flow controller). Further, measurement error may probably occur if a typical MFC is inclined as illustrated in  FIG. 4 , whereas no such problem takes place in the pressure type flow rate controller. In addition, although the MFC requires use of the regulator  20  to maintain the upstream side pressure constant, no regulator is needed in the pressure type flow rate controller.  
         [0061]     The primary-side connection unit  23  connected to the gas sources is installed on the floor and underneath the respective processing chambers  2 . The flow rate control unit  13  is disposed above the primary-side connection unit  23  so as to at least partially overlap with the latter. The flow rate control unit  13  and the primary-side connection unit  23  are connected to each other through the trunk unit  28  having the trunk pipelines gathered together. The gas box  14  enclosing these units  13 ,  23  and  28  is installed such that the rear part thereof lies under the plan view contour of the processing chamber  2 . This helps to make the gas supply system  40  compact in structure, thus reducing the footprint of the processing apparatus.  
         [0062]     Within the gas box  14 , the flow rate control unit  13  is disposed to be inclined between the corresponding processing chamber  2  and the primary-side connection unit  23 . Further, the cover  42  is removably attached to the gas box  14  to define the front and the top surface of the latter. This helps to improve the maintainability for the flow rate control unit  13  within the gas box  14 .  
       Second Embodiment  
       [0063]      FIG. 9  is a perspective view schematically showing a semiconductor processing apparatus in accordance with a second embodiment of the present invention.  FIG. 10  is a side elevational view illustrating a flow rate control unit employed in the apparatus shown in  FIG. 9 .  
         [0064]     In the first embodiment set forth above, the primary-side connection unit  23  is installed on the floor and underneath the corresponding processing chamber  2  and the flow rate control unit  13  is disposed above the primary-side connection unit  23  so as to overlap with the latter. In contrast, in the second embodiment, the primary-side connection unit  23  is installed beneath a removable floor panel  24   a  of a clean room in which the processing apparatus  1  is placed. The floor panel  24   a  is provided with a detachable cover  46  that, when detached, allows an operator to gain access to the primary-side connection unit  23 .  
         [0065]     In order to supply gases to the respective processing chambers  2 , the flow rate control unit  13  of the gas supply system  40  is disposed underneath each of the processing chambers  2 . The flow rate control unit  13  is structurally the same as that of the first embodiment and hermetically enclosed within the gas box  14  in the same manner as described above with regard to the first embodiment. Unlike the first embodiment, however, the flow rate control unit  13  is connected to the primary-side connection unit  23  of the gas supply system  40  through trunk pipelines  32  which extend to below the floor of the clean room. The floor panel  24   a  to which the primary-side connection unit  23  is attached is not disposed immediately below the corresponding processing chamber  2  but placed at a position somewhat distant from the processing chamber  2  in view of the accessibility thereto.  
         [0066]      FIG. 11  is a top view showing the primary-side connection unit  23  employed in the apparatus shown in  FIG. 9 .  FIG. 12  is a side elevational view illustrating the primary-side connection unit  23  shown in  FIG. 11 .  
         [0067]     The floor panels  24  and  24   a  of the clean room are arranged lengthwise and crosswise with no gap left therebetween, each of which has a side of, e.g., about 600 mm in size. Support members  43  disposed at four corners of each of the floor panels  24  are adapted to support the respective floor panels  24  at a predetermined height from above a floor base  44 . The primary-side connection unit  23  is attached underneath the floor panel  24   a . The floor panel  24   a  having the primary-side connection unit  23  thereunder is placed at a preset position in place of the normal floor panel  24 .  
         [0068]     The primary-side connection unit  23  has a case  26  opened at its top. The case  26  is secured to the undersurface of the floor panel  24   a . The floor panel  24   a  has an opening  45  that provides access to the primary-side connection unit  23 . The opening  45  is closed by the openable cover  46 , which seals the internal space of the case  26 .  
         [0069]     Accommodated within the case  26  are pipelines  25  which are respectively connected to a plurality of gas sources. Each of the pipelines  25  is arranged in such a manner that the inlet and the outlet end thereof are oriented in the same direction. The operator can manipulate valves V 5  disposed on the pipelines  25  after opening the cover  46 , so that the valves V 5  may be a manually-operated valve. The pipelines  25  are connected to the flow rate control unit  13  in the gas box  14  through the trunk unit  28  having the gathered trunk pipelines  32  extending to below the floor panels  24  (see  FIG. 9 ).  
         [0070]     In accordance with the processing apparatus  1  of the second embodiment, the gas box  14  containing the flow rate control unit  13  is disposed underneath each of the processing chambers  2  and on the floor of the clean room. The flow rate control unit  13  is detachably coupled through the trunk unit  28  to the primary-side connection unit  23 , which lies under the floor panel  24   a  at a position distant from the gas box  14 . The floor panel  24   a  has the opening  45  that provides access to the primary-side connection unit  23  and the openable cover  46  closing the opening  45 . The trunk unit  28  is disposed in place by attaching the case containing the trunk pipelines  32  to the underside of the floor panel  24 .  
         [0071]     With such arrangements, the operator can gain access to the primary-side connection unit  23  with ease, so that the maintainability thereof is improved. Furthermore, works can be done safely, thank to the fact that no pipeline or valve is disposed on the floor panels  24 .  
         [0072]     (Common Modification of First and Second Embodiments)  
         [0073]      FIG. 13  is a piping diagram depicting a mechanism for concurrently closing switching valves of gas lines by a remote control operation, in a modification of the first and the second embodiment. For the sake of simplicity in illustration, the flow rate control unit  13  and the like are not shown in  FIG. 13 .  
         [0074]     In case of conducting a maintenance for the processing apparatus  1 , it is desirable that the valves (switching valves) V 5  of the primary-side connection units  23  connected to all of the processing chambers  2  are in a closed condition from the viewpoint of safety. In the first embodiment, however, the valves V 5  are hidden under the flow rate control unit  13  as illustrated in  FIG. 4  and therefore cannot be manually operated with ease. Likewise, in the second embodiment, the valves V 5  lie underneath the floor as can be seen in  FIG. 12 , which makes it necessary to open the cover  46  of the floor panel  24   a  prior to manipulating the valves V 5 .  
         [0075]     In accordance with this modification, each of the valves V 5  is a type operated by an air pressure and kept closed when no air pressure is applied thereto (a so-called normally-closed air operation valve). Further, a lock-out valve  49  that is a three-way valve of the type electrically operable and kept closed in a load-free condition (normally closed) is disposed on a common upstream line  48  through which the air is supplied to the valves V 5 .  
         [0076]     As a result, when a maintenance work is carried out, all of the valves (switching valves) V 5  can be concurrently closed through a remote control operation merely by closing off the lock-out valve  49  to cut off the air supply. Accordingly, by applying this modification to the first embodiment, it becomes possible to avoid the difficulty which would otherwise be encountered in manipulating the valves V 5  hidden under the flow rate control unit  13 . Further, by applying this modification to the second embodiment, there is no need to open the cover  46  of the floor panel  24   a  in an attempt to manipulate the valves V 5 .  
         [0077]     Although the vacuum processing apparatus has been exemplified in the first and the second embodiment, the present invention may be equally applied to a normal pressure processing apparatus that performs a process under an atmospheric pressure. Moreover, the present invention may also be applied to other substrates than the semiconductor wafer, e.g., a glass substrate for a flat panel.  
       INDUSTRIAL APPLICABILITY  
       [0078]     In accordance with the semiconductor processing apparatus of the present invention, a process performance can be improved while a footprint can be reduced.