Abstract:
A substrate transfer apparatus, for transferring a substrate from a first module to a second module, includes a moving base having a Y-motion axis for moving the moving base in Y-direction, and a substrate holding member mounted to the moving base via X-motion axis so as to move relative to the moving base to be in an advanced position and a retracted position relative to the moving base. The X-motion axis operates when the Y-motion axis is operating, if the X-motion axis must be parallel to the Y-motion axis when transferring the substrate from the substrate holding member to the second module.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a substrate transfer technique for transferring a substrate between modules. 
       BACKGROUND ART 
       [0002]    In a photolithography process as one of the semiconductor manufacturing processes, a resist pattern is formed by applying a resist to the surface of a semiconductor wafer (hereinafter referred to as “wafer”), by exposing the resist with a predetermined pattern, and by developing the exposed resist. Such a process is generally performed by using a system comprising a coating and developing apparatus configured to perform resist application and development and an exposure apparatus connected to the coating and developing apparatus. 
         [0003]    The coating and developing apparatus includes resist coating modules each configured to apply a resist onto a wafer, and developing modules each configured to supply a developing solution to the wafer, and further includes heating modules each configured to heat a wafer before or after processed in the resist coating modules and the developing modules. Between the respective modules, and between the coating and developing apparatus and the exposure apparatus, wafers are transferred by substrate transfer units each provided with an arm. 
         [0004]    An example of the conventional substrate transfer unit is briefly described with reference to  FIG. 14 . In  FIG. 14 , the reference number  101  depicts a guide; the reference number  102  depicts a frame capable of horizontal movement; the reference number  103  depicts an elevating table; and the reference number  104  depicts a rotating table. The reference number  105  depicts arms each for holding a wafer W capable of moving forward (advancing) and rearward (retracting) with respect to the rotating table  104 . Thus, the substrate transfer unit  100  shown in  FIG. 14  has a four-axis structure including moving mechanisms for linear motion along a horizontal motion axis (Y-axis), for linear motion along a vertical motion axis (Z-axis), for rotating motion about a rotational axis (θ-axis), and for linear motion along a substrate transfer axis (X-axis). The assembly comprising the frame  102 , the elevating table  103 , and the rotating table  104 , which moves the arms  105  between the modules, is referred to as “moving part  110 ”. 
         [0005]    In one example, modules  108  and  109  are located at different heights as shown in  FIG. 14 . When a wafer W is transferred between these modules  108  and  109 , the frame  102 , the elevating table  103 , and the rotating table  104  are operated such that the arm  105  is positioned to face one of the modules in front of that module. Thereafter, the advancing motion of the arm  105  toward the module is started, and the wafer W is transferred between the module and the arm  105 . 
         [0006]    The frame  102 , the elevating table  103 , and the rotating table  104  may be operated in different time frames. They, however, are simultaneously operated in order to improve throughput. In the graph shown in  FIG. 15 , the abscissa axis indicates time passage; and arrows respectively indicate the motion periods of motion axes of the substrate transfer unit  100 .  FIGS. 16(   a ),  16 ( b ),  16 ( c ) and  16 ( d ) respectively show transfer states of the wafer W at time points E 1 , E 2 , E 3  and E 4  in the graph.  FIGS. 17(   a ),  17 ( b ),  17 ( c ) and  17 ( d ) respectively show the position of the arm  105  with the rotating table  104  in the corresponding  FIGS. 16(   a ),  16 ( b ),  16 ( c ) and  16 ( d ). Herein, the movement of the moving part  110  from a position in front of the transfer-departure module  108  to a position in front of the transfer-destination module  109  is referred to as “intermodular travel”, and the advancing motion of the arm  105  is referred to as “substrate transfer motion”. 
         [0007]    During the intermodular travel, if all axis motions are performed at their maximum speeds, the time required for Y-axis motion (i.e., horizontal motion of the frame  102 ) is longest. As shown by the dotted arrows in  FIG. 15 , the time required for the Z-axis motion (i.e., vertical motion of the elevating table  103 ) and the time required for the θ-axis motion (i.e., rotating motion of the rotating table  104 ) are shorter than the time required for the Y-axis motion. However, as described above, since the substrate transfer motion (X-axis motion) is performed after the completion of the intermodular travel, the motion speed of the Z-axis motion and the motion speed of the θ-axis motion need not set so high. Thus, the motion speeds of the Z-axis motion and the θ-axis motion are set lower than their highest possible speeds such that the Z-axis motion and the θ-axis motion are both finished at the time when the Y-axis motion is finished, i.e., concurrently with the elapse of time t 1  from the start of the Y-axis motion. Thus, if the advancing motion (i.e., X-axis motion; substrate transfer motion of the arm  105 ) requires time t 2 , the time equivalent to the sum of time t 1  and time t 2  is required to complete the intermodular travel and the substrate transfer motion. However, further improvement in throughput is desired for the aforementioned coating and developing apparatus. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a technique for increasing the speed at which a substrate is transferred between modules, thereby improving a throughput. 
         [0009]    The present invention provides a method of transferring a substrate between a first module and a second module using a substrate transfer apparatus, wherein, in plan view, the first and second modules both face a transfer path, the transfer path extends substantially linearly, and the second module is located on an imaginary extension of the transfer path, and wherein the substrate transfer apparatus includes: a moving base configured to move along the transfer path; and a substrate holding member mounted to the moving base so as to move relative to the moving base to be in an advanced position and a retracted position relative to the moving base, said method comprising: transferring a substrate from the first module to the substrate holding member; moving the moving base along the transfer path toward the second module; advancing the substrate holding member relative to the moving base to place the substrate holding member in the advanced position; and transferring the substrate from the substrate holding member placed in the advanced position to the second module, wherein the advancing of the substrate holding member relative to the moving base is performed when the moving of the moving base along the transfer path toward the second module is being performed. 
         [0010]    In one preferred embodiment, the method may further include: moving the moving base away from the second module along the transfer path, after completion of the transferring the substrate from the substrate holding member to the second module; and retracting the substrate holding member relative to the moving base when the moving of the moving member along the transfer path away from the second module is being performed. 
         [0011]    In one preferred embodiment, the method may further include: rotating the substrate holding member or vertically moving the substrate holding member. 
         [0012]    In one preferred embodiment, the method may further include: rotating the substrate holding member and vertically moving the substrate holding member, wherein the advancing of the substrate holding member relative to the moving base is performed after transferring the substrate from the first module to the substrate holding member, and after the later one of completion of the rotating of the substrate holding member and completion of the vertical moving of the substrate holding member. 
         [0013]    The present invention further provides a method of transferring a substrate between a first module and a second module using a substrate transfer apparatus, wherein, in plan view, the first and second modules both face a transfer path, the transfer path extends substantially linearly in Y-direction, and the second module is located on an imaginary extension in the Y-direction of the transfer path, and wherein the substrate transfer apparatus includes: a moving base having a horizontal, Y-motion axis for moving the moving base in the Y-direction; and a substrate holding member mounted to the moving base via a horizontal, X-motion axis so as to move relative to the moving base to be in an advanced position and a retracted position relative to the moving base, said method comprising: transferring a substrate from the first module to the substrate holding member; moving the moving base toward the second module by operating the Y-motion axis; advancing the substrate holding member relative to the moving base by operating the X-motion axis, in order to place the substrate holding member in the advanced position; and transferring the substrate from the substrate holding member placed in the advanced position to the second module, wherein the operating of the X-motion axis is performed when the operating of the Y-motion axis is being performed, if the X-motion axis must be parallel to the Y-motion axis when transferring the substrate from the substrate holding member to the second module. 
         [0014]    In one preferred embodiment, the substrate transfer apparatus may further include a θ-motion axis for moving the substrate holding member about a vertical axis, and said method may further include turning the substrate holding member by operating the θ-motion axis after the transferring of the substrate from the first module to the substrate holding member, so that the X-motion axis is oriented parallel to the Y-motion axis. 
         [0015]    In one preferred embodiment, the advancing of the substrate holding member relative to the moving base by operating the X-motion axis is performed after completion of the turning of the substrate holding member by operating the θ-motion axis. 
         [0016]    In one preferred embodiment, the substrate transfer apparatus may further include a θ-motion axis for moving the substrate holding member about a vertical axis, and a Z-motion axis for moving a substrate holding member vertically, and said method may further includes turning the substrate holding member by operating the θ-motion axis after the transferring of the substrate from the first module to the substrate holding member, so that the X-motion axis is oriented parallel to the Y-motion axis, and vertically moving the substrate holding member by operating the Z-motion axis after the transferring of the substrate from the first module to the substrate holding member, so that the substrate holding member located at the same level as the second module, wherein the operating of the X-motion axis is performed after the later one of completion of turning the substrate holding member by the θ-motion axis and completion of the vertical moving of the substrate holding member by the Z-motion axis. 
         [0017]    The present invention also provides a storage medium for performing the aforementioned method, and a coating and developing apparatus employing the aforementioned substrate transfer apparatus configured to perform the aforementioned method. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a plan view of a coating and developing apparatus including a substrate transfer apparatus in one embodiment of the present invention. 
           [0019]      FIG. 2  is a perspective view of the coating and developing apparatus. 
           [0020]      FIG. 3  is a longitudinal side view of the coating and developing apparatus. 
           [0021]      FIG. 4  is an expanded view showing an arrangement of modules of the coating and developing apparatus. 
           [0022]      FIG. 5  is a perspective view of a wafer transfer unit provided in a processing block of the coating and developing apparatus. 
           [0023]      FIG. 6  is a flowchart showing judgments performed by a controller of the coating and developing apparatus. 
           [0024]      FIG. 7  is a graph showing operations of respective motion axes of the substrate transfer apparatus. 
           [0025]      FIG. 8  is a view showing transfer steps performed by the substrate transfer apparatus. 
           [0026]      FIG. 9  is a view showing transfer steps performed by the substrate transfer apparatus. 
           [0027]      FIG. 10  is a graph showing another example of operations of the respective motion axes of the substrate transfer apparatus. 
           [0028]      FIG. 11  is a plan view showing an example of another coating and developing apparatus. 
           [0029]      FIG. 12  is a schematic view indicating modules which the transfer principle may be applied. 
           [0030]      FIG. 13  is a side view showing a layout of modules. 
           [0031]      FIG. 14  is a perspective view of a substrate transfer apparatus. 
           [0032]      FIG. 15  is a graph explaining conventional operations of respective motion axes performed by the substrate transfer apparatus. 
           [0033]      FIG. 16  is a plan views showing conventional transfer steps performed by the substrate transfer apparatus. 
           [0034]      FIG. 17  is a side views showing conventional transfer steps performed by the substrate transfer apparatus. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     First Embodiment 
       [0035]    There will be described a coating and developing apparatus  1 , which is equipped with a substrate transfer apparatus (substrate transfer unit) in one embodiment of the present invention.  FIG. 1  is a plan view of a resist pattern forming system, which is constituted by connecting an exposure apparatus C 4  to the coating and developing apparatus  1 .  FIG. 2  is a perspective view of the system.  FIG. 3  is a vertical sectional view of the coating and developing apparatus  1 .  FIG. 4  is an expanded view showing a module arrangement in the coating and developing apparatus  1 . Herein, any place in the coating and developing apparatus  1  on which a substrate (e.g., a wafer W) is placed may be referred to as “module”. 
         [0036]    The coating and developing apparatus  1  is provided with a carrier block C 1  having stages  11 . A wafer transfer unit  12  is configured to take a wafer W out of a hermetic carrier  10  placed on the stage  11 , and to convey the wafer W to a processing block B 2 . The wafer transfer unit  12  is also configured to receive a processed wafer W from the processing block C 2 , and to return the wafer W into the carrier  10 . 
         [0037]    As shown in  FIG. 3 , the processing block C 2  is constituted by stacking a first block (DEV layer) B 1  provided for a developing process, a second block (BCT layer) B 2  provided for forming an antireflection film below a resist film, a third block (COT layer) B 3  provided for forming a resist film, and a fourth block (ITC layer) B 4  provided for forming a protective film above the resist film, in that order from below. 
         [0038]    The respective layers of the processing block C 2  have essentially the same structure, regarding the module/unit layout, in plan view. Herein, the fourth block (ITC layer) B 4  is described by way of example. The ITC layer B 4  includes a liquid processing section  40 . The liquid processing section  40  is provided with chemical-liquid coating modules (ITCs)  41   a  to  41   d  each configured to apply a chemical liquid onto a resist film. The chemical liquid forms a water-repellent protective film for protecting the resist film. The ITC layer B 4  further includes unit shelves U 1  to U 5 , which are opposed to the liquid processing section  40  and arrayed from the side of the carrier block C 1  to the side of an interface block C 3 . The unit shelves U 1  to U 5  include heating modules (HPs)  42   a  to  42   j  each having a heating plate for heating a wafer W placed thereon. Each of the unit shelves U 1  to U 5  is structured by stacking two of the heating molds (HP). 
         [0039]    The ITC layer B 4  is provided with a wafer transfer unit A 4 . With reference to  FIG. 5 , the structure of the wafer transfer unit A 4  is described. The wafer transfer unit A 4  has a guide  51  extending horizontally from the side of the carrier block C 1  to the side of the interface block C 3 . A frame  52  is provided to move along the guide  51 . An elevating table  53  is provided on the frame  52  to move vertically along a vertical axis. A rotating table  54  is provided on the elevating table  53  to rotate about a vertical axis. The rotating table  54  has a drive unit, not shown, which is configured to horizontally move the arms  55 , independently, forward and rearward. 
         [0040]      FIG. 5  shows that the arm  55  is located on a retracted position for intermodular travel (travel between the modules). When a wafer W is transferred between the arm  55  and one of the modules, the arm  55  is moved to its forward position with respect to the rotating table  54 . The arm  55  has a base portion  56  that surrounds the periphery of a wafer W, and supporting portions  57  that support the rear surface of the wafer W. As described above, the wafer transfer unit A 4  is structured as a four-axis mechanism having four drive units for movements along a horizontal axis (Y-axis), movement along a vertical axis (Z-axis), movement about a rotational axis (θ-axis), and movement along a substrate transfer axis (X-axis), respectively. The assembly comprising the frame  52 , the elevating table  53  and the rotating table  54  is referred to as “moving part  50 ” that moves the arms  55  for intermodular travel. 
         [0041]    In plan view, a transfer area R 1  having an elongated rectangle shape is defined between the array of the unit shelves U 1  to U 5  and the liquid processing section  40 . The opposing longitudinal ends of the transfer area R 1  are defined by unit shelves U 6  and U 7  described below, in other words, unit shelves U 6  and U 7  are located on a longitudinal, imaginary extension of the transfer area R 1 . The arms  55  move within the transfer area R 1  so as to transfer wafers W among modules including: modules in the unit shelves U 1  to U 5 , the chemical-liquid coating modules (ITCs)  41   a  to  41   d , and modules in the unit shelves U 6  and U 7 . Each module has transfer means comprising elevating pins (not shown). When the arm  55  of the wafer transfer unit A 4  (or an arm of each transfer unit described below) enters a certain module, the elevating pins are raised and lowered, so that a wafer W is transferred between the arm and the module (in detail, a table, a stage, a chuck or the like where the wafer is placed within the module). Alternatively, the arm having entered the module may be raised and lowered, such that the wafer W is transferred between the arm and the module. 
         [0042]    The third block (COT layer B 3 ) is briefly described. Instead of the chemical-liquid coating modules (ITCs)  41   a  to  41   d , a liquid processing section of the third block B 3  is provided with resist coating modules (COTs)  31   a  to  31   d  each configured to apply a resist onto a wafer W. Unit shelves U 1  to U 5  include heating modules (HPs)  32   a  to  32   j.    
         [0043]    Next, the second block (BCT layer B 2 ) is described. Instead of the chemical-liquid coating modules (ITCs)  41   a  to  41   d , a liquid processing section of the second block B 2  is provided with antireflection-film forming modules (BCTs)  21   a  to  21   d  each configured to apply a chemical liquid for forming an antireflection film. Unit shelves U 1  to U 5  include heating modules (HPs)  22   a  to  221  and hydrophobing modules (ADHs)  23   a  to  23   c . The heating modules (HPs)  22   a  to  221  are each configured to heat a wafer W on which the chemical liquid has been applied. Each hydrophobing module (ADH) includes a heating plate for heating a wafer W placed thereon, and a gas supply mechanism for supplying a hydrophobing gas to the wafer W heated by the heating plate. The hydrophobing module (ADH) improves adhesion of a film to the wafer surface. The unit shelves U 1  to U 5  are each structured by stacking aforementioned modules at three levels. In one example of the operation of the apparatus mentioned later, the modules of the unit shelves U 1  to U 5  and the antireflection-film forming modules BCTs  21   a  to  21   d  are not used, and the second block  132  is used as a transfer passage along which a wafer W is transferred from the below-described unit shelf U 6  to the unit shelf U 7 . 
         [0044]    The first block (DEV layer)  131  is described. A liquid processing section of the first block B 1  is composed of two stacked layers. Instead of the chemical-liquid coating modules (ITCs)  41   a  to  41   d , the liquid processing part of the first block B 1  is provided with developing modules (DEVs)  61   a  to  61   h  each configured to supply a developer to a wafer W so as to develop a resist film. Unit shelves U 1  to U 5  include heating modules (PEBs)  62   a  to  62   i  each configured to heat a wafer W that has been already exposed but is not yet developed, and heating modules (POSTs)  63   a  to  63   f  each configured to heat a developed wafer W. The respective unit shelves U 1  to U 5  are structured by stacking the aforementioned modules at three levels. 
         [0045]    The unit shelf U 6  is disposed in the processing block C 2  on the side of the carrier block C 1 . In the unit shelf U 6 , there are stacked transfer modules TRS and CPL, a buffer module BU, and a wafer transfer part  14  provided to transfer a wafer W to and from a shuttle  13  (described below). The transfer module TRS includes a stage for placing a wafer W thereon; and the transfer module CPL includes a stage for placing a wafer W thereon and a temperature adjusting means for adjusting the temperature of the wafer W placed on the stage. The buffer module BU can accommodate therein a plurality of wafer W at vertical intervals. Disposed near the unit shelf U 6  is a wafer transfer unit D 1  having an arm that moves vertically to transfer a wafer W between modules included in the unit shelf U 6 . 
         [0046]    The unit shelf U 7  is disposed in the processing block C 2  on the side of the interface block C 3 . In the unit shelf U 7 , there are stacked a transfer module CPL, a hydrophobing module ADH, and a wafer transfer part  15  provided to transfer a wafer W from the shuttle  13  to the interface block C 3 . Disposed near the unit shelf U 7  is a wafer transfer unit D 2  having an arm that moves vertically to transfer a wafer W between the modules included in the unit shelf U 7 . The shuttle  13  is disposed on an upper part in the DEV layer B 1 . The shuttle  13  transfers a wafer W directly from the transfer part  14  of the unit shelf U 6  to the transfer part  15  of the unit shelf U 7 . Although many transfer modules TRS and CPL and the buffer modules BU are disposed in the unit shelves U 6  and U 7 ,  FIG. 4  shows only the modules used in one example of the transfer operation described later. 
         [0047]    The interface block C 3  is provided with a wafer transfer unit  16  to transfer a wafer W between the modules of the unit shelf U 7  and the exposure apparatus C 4 . The wafer transfer unit  16  and the wafer transfer unit  12  (in the carrier block C 1 ) have approximately the same structure as those of the wafer transfer units A 1  to A 4  disposed in the respective processing blocks B 1  to B 4 , but the former differs from the latter in the shape of the arm and the number of the arm. As shown in  FIG. 1 , guides  51  of the wafer transfer units  12  and  16  horizontally extend in a direction perpendicular to the guide  51  of the wafer transfer units A 1  to A 4 . The exposure apparatus C 4  performs, for example, an immersion exposure by which a wafer W is exposed while a liquid film is being formed on the surface of the wafer W. 
         [0048]    The coating and developing apparatus  1  is equipped with a controller  1 A comprising a computer. The controller  1 A includes a program, a memory, a data processing part comprising a CPU, and so on. The program incorporates commands (respective steps) in order that control signals are sent from the controller  1 A to the respective component members of the coating and developing apparatus  1  so that series of process steps are performed. Based on the control signals, operations of the not-shown driving mechanisms for driving the arms  55 , the frame  52 , the elevating table  53 , and the rotating table  54  are controlled, whereby a wafer W is transferred as described below. In addition, the memory includes an area in which values of process parameters such as a process temperature, a process period, supply rates of chemical liquids, and a power, are stored. When the CPU executes the respective commands of the program, these process parameters are read out, and control signals corresponding to the parameter values are sent to the respective component members of the coating and developing apparatus  1 . The program (including a program for input operations and display of the process parameters) is stored in a storage medium such as a flexible disc, a compact disc, a hard disc, an MO (magnetoptical disc), or a memory card, and is installed in the controller  1 A. 
         [0049]    When a wafer W is transferred between the modules, the controller  1 A carries out judgments shown in  FIG. 6 , thereby to control the motions (operations) of the wafer transfer unit. 
         [0050]    At first, the controller  1 A judges whether or not the direction of the motion of the arm  55  (X-axis motion) along which the arm  55  enters the transfer-destination module is the same as the direction of the horizontal motion (Y-axis motion) of the arm  55  from the transfer-departure module to the transfer-destination module (step S 1 ). In detail, taking the operation of the wafer transfer unit A 4  shown in  FIG. 5  as an example, it is judged whether (a) the direction of the horizontal motion (Y-axis motion) of the moving part  50  for the intermodular travel by which the moving part  50  is moved from a position in front of the transfer-departure module to a position in front of the transfer-destination module is the same as (b) the direction of the wafer (substrate) transfer motion (X-axis motion) by which the arm  55  is entered the transfer-destination module. It should be noted that, in the example, the direction of the X-axis motion is depends on the status of θ-axis (i.e., orientation of the rotating table  54 ) while the direction of the Y-axis motion (along the guide  51 ) is fixed, and thus the judgment result depends on the position of the transfer-destination module. 
         [0051]    If the judgment result in step S 1  is YES, then the controller  1 A judges whether or not the time required for the Y-axis motion is longer than any of the times required for the motions of the other axes (i.e., Z-axis and θ-axis), during the intermodular travel (step S 2 ). It should be noted that: the wafer transfer unit A 4  shown in  FIG. 5  performs the intermodular travel by the combination of the Y-axis motion (horizontal motion of frame  52 ), the Z-axis motion (vertical motion of elevating table  53 ) and the θ-axis motion (rotating motion of the rotating table  54 ); and the times required for the respective motions are determined on condition that the respective axes are operated at their maximum speeds. 
         [0052]    If the judgment result in step S 2  is YES, the controller  1 A determined that the Y-axis motion (for intermodular travel of the moving part  50 ) and the X-axis motion (i.e., wafer transfer motion of the arm  55  for entering the transfer-destination module) should be performed simultaneously (step S 3 ). In this case, the controller  1 A determines the axis which requires the second longest time to complete the motion thereof; and after completion of the motion of that axis thus determined, the controller  1 A starts the X-axis motion. If the judgment result in step S 1  is NO or if judgment result in step S 2  is NO, the X-axis motion is started after completion of intermodular travel of the moving part  50 . 
         [0053]    The wafer transfer route in this embodiment is described. The carrier  10  containing wafers W is placed on the stage  11 , and a wafer W in the carrier  10  is taken out of the carrier  10  by the wafer transfer unit  12  and is conveyed to one of the transfer modules CPL 1  to CPL 3  in the unit shelf U 6  located at the same level as the second block (BCT layer) B 2 . Thereafter, the wafer W received in one of the transfer modules CPL 1  to CPL 3  is transferred by the wafer transfer unit A 2  to one of the hydrophobing modules ADH 1  to ADH 3  of the unit shelf U 7 , in which the surface of the wafer W is made hydrophobic. 
         [0054]    After the hydrophobing process, the wafer W is transferred, in the following order, to: the wafer transfer unit D 2 ; one of the transfer modules CPL 4  and CPL 5  of the unit shelf U 7  located at the same height position as the COT layer B 3 ; the wafer transfer unit A 3 ; and one of the resist coating modules (COTs)  31   a  to  31   d , whereby a resist is applied onto the surface of the wafer W to form a resist film. 
         [0055]    Thereafter, the wafer W is transferred, in the following order, to: the wafer transfer unit A 3 ; one of the heating modules (HPs)  32   a  to  32   j ; the wafer transfer unit A 3 ; one of the transfer modules CPL 6  to CPL 8  of the unit shelf U 6 ; the wafer transfer unit D 1 ; the buffer module BU 1  located at the same level as the ITC layer  134 ; the wafer transfer unit A 4 ; one of the transfer modules CPL 9  to CPL 11  of the unit shelf U 7 ; the wafer transfer unit A 4 ; and one of the chemical-liquid coating modules (ITCs)  41   a  to  41   d , whereby a chemical liquid is applied onto the surface of the wafer W to form a protective film. Thereafter, the wafer W is transferred, in the following order, to: the wafer transfer unit A 4 : one of the heating modules (HPs)  42   a  to  42   j ; the wafer transfer unit A 4 , and one of the transfer modules TRS 1  and TRS 2  of the unit shelf U 6 . 
         [0056]    Thereafter, the wafer W is transferred to the wafer transfer unit D 1  and then to the shuttle  13  located on the transfer part  14 . The wafer W is then conveyed to the transfer part  15  by the shuttle and then is transferred to the wafer transfer unit  16  of the interface block C 3 . Thereafter, the wafer W is transferred to the exposure apparatus C 4 , and is subjected to an immersion exposure process. After that, the wafer W is transferred by the wafer transfer unit  16  from the exposure apparatus C 4  to one of the transfer modules CPL 12  to CPL 14  of the unit shelf U 7  located at the same level as the DEV layer  131 . Then, the wafer W is transferred by the wafer transfer unit A 1  to one of the heating modules (PEBs)  62   a  to  62   i , and then to one of the developing modules (DEVs)  61   a  to  61   h , whereby a developer is supplied to the surface of the wafer W to develop the wafer W. After that, the wafer W is transferred by the wafer transfer unit A 1  to one of the heating modules (POSTs)  63   a  to  63   f  in which the wafer W is baked. Following thereto, the wafer W is transferred by the wafer transfer unit A 1  to one of the transfer modules CPL 15  and CPL 16  of the unit shelf U 6 , and is returned to the carrier  10  by the wafer transfer unit  12 . 
         [0057]    In the aforementioned transfer route, in a case where the wafer W is transferred by one of the wafer transfer units A 1  to A 4 , if the transfer-destination module is one of the modules in the unit shelves U 6  and U 7 , the judgment result of the step S 1  is YES. In such a wafer transfer operation between modules, if the judgment result of the step S 2  is YES, the Y-axis motion of the moving part  50  and the X-axis motion of the arm  55  are simultaneously performed. Hereinafter, the manner in which the wafer is transferred from the transfer module CPL 1  to the hydrophobing module ADH 1  is described, as a typical example of the wafer transfer operation including the aforementioned simultaneous motions, is described with reference to  FIGS. 7 to 9 . 
         [0058]    The abscissa axis of the graph in  FIG. 7  shows time passage. The graph of  FIG. 7  shows the status of the respective axes, from the time point when the moving part  50  is located in front of the transfer  1  module CPL 1  and the arm  55  having received the wafer W from the transfer module CPL 1  is in its retracted position, to the time point when the moving part  50  is located in front of the hydrophobing module ADH 1  and the arm  55  is moved to its advanced position to enter the hydrophobing module ADH 1 . White arrows indicate the motions of the respective axes. The left-handed end of each white arrow corresponds to the time point when the motion of the corresponding axis starts, and the right-handed end of each white arrow corresponds to the time point when the motion of the corresponding axis is finished. Each axis is continuously operated throughout the length of the white arrow. The upper portion of the graph of  FIG. 7  shows the operation in which the Y-axis motion of the moving part  50  and the X-axis motion of the arm  55  are simultaneously performed (in other words, the motion periods of the Y-axis motion and the X-axis motion overlap), while the lower portion of the graph shows the operation in which motion periods of the Y-axis motion and the X-axis motion do not overlap (which is described in the BACKGROUND ART part of this specification). (a) to (e) of FIG.  8  show the positions of the moving part  50  and the arm  55 , in plan view, at time points K 1  to K 5 , respectively, shown in  FIG. 7 ; (a) to (e) of  FIG. 9  show the positions (vertical positions) of the moving part and the arm  55 , in side view at the time points K 1  to K 5 , respectively. In this example, as shown in  FIG. 7 , the motion period of the Z-axis motion (vertical motion of the elevating table  53 ) is the second longest next to the motion period of the Y-axis motion (horizontal motion of the frame  52 ). The motion period of the Z-axis motion is represented by “t 3 ”. 
         [0059]    The arm  55  moves to its advanced position with respect to the rotating table  54  to enter the transfer module CPL 1 , receives the wafer W from the transfer module CPL 1 , and moves to its retracted position to be withdrawn from the transfer module CPL 1 . The status at the time point (K 1 ) just when the withdrawal of the arm  55  (back to its retracted position) is completed is shown in  FIGS. 8(   a ) and  9 ( a ). Thereafter, the horizontal motion (Y-axis motion) of the frame  52  toward the hydrophobing module ADH 1  along the transfer area R 1 , the upward (vertical) motion (Z-axis motion) of the elevating table  53  toward the hydrophobing module ADH 1 , and the rotating motion (θ-axis motion) of the rotating table  54  for changing the direction of the arm  55  from a direction facing the transfer module CPL  1  to a direction facing the hydrophobing module ADH 1  are started at the same time, and those motions are performed at their maximum possible speeds (from time point K 1  to K 2 ). As shown in  FIGS. 8(   b ) and  9 ( b ), the rotating motion of the rotating table  54  is finished, while the frame  52  and the elevating table  53  are moved continuously. Then, as shown in  FIGS. 8(   c ) and  9 ( c ), the motion of the elevating table  53  is finished (time point K 2 ). 
         [0060]    While the frame  52  is being moved, the advancing motion of the arm  55  (X-axis motion) toward the hydrophobing module ADH 1  is started. As shown in  FIGS. 8(   d ) and  9 ( d ), the motion of the frame  52  and the advancing motion of the arm  55  toward the hydrophobing module ADH 1  are continued (time points K 2  to K 3 ). Then, as shown in  FIGS. 8(   e ) and  9 ( e ), the motion of the frame  52  is finished so that the moving part  50  is located in front of the hydrophobing module ADH 1 , and the arm  55  enters the hydrophobing module ADH 1  (time points K 4  to K 5 ). After that, the elevating pins (not shown) provided in the hydrophobing module ADH 1  are moved upward to support the rear surface of the wafer W, whereby the wafer W is transferred to the hydrophobing module ADH 1 . 
         [0061]    The transfer principle may be summarized as follows:
       all the motions other than the substrate transfer motion (i.e., X-axis motion of the arm) are performed at the maximum speeds;   the advancing motion of the arm  55  is started after the situation, where the advancing motion of the arm  55  will not result in collision of the wafer W or the arm  55  with the modules surrounding the transfer area R 1 , has been established; and   the motion period during which the moving part  50  is performing horizontal motion (Y-axis motion) and the motion period during which the arm  55  moves from its retracted position to its advanced position overlap.       
 
         [0065]    Due to the transfer operation in the above manner, the time required for the intermodular travel and the substrate transfer motion may be the sum (t 2 +t 3 ) of the time (t 2 ) required for the Z-axis motion (elevating table  53 ) and the time (t 3 ) required for the X-axis motion (arm  55 ). 
         [0066]    Since the time t 1  required for the Y-axis motion (horizontal motion of the frame  52 ) is longer than the time t 3  required for the Z-axis motion (vertical motion of the elevating table), the total time required for the transferring of the wafer W can be reduced by a time t 4 , which is equivalent to the difference between the time t 3 , and the time t 3 , as compared with the case where the advancing motion of the arm starts after completion of the intermodular travel. This may result in improvement of the system throughput. 
         [0067]    After the wafer W is transferred from the arm  55  to the hydrophobing module ADH 1 , the moving part  50  moves away from the hydrophobing module ADH 1  along the transfer area R 1  to receive another wafer W from the transfer module CPL 1 . At this time, the movement of the moving part  50  along the transfer area R 1  (Y-axis motion) and the retracting motion of the arm  55  (X-axis motion) are simultaneously performed. Namely, the arm  55  and the moving part  50  are operated in the order opposite to that for loading of the wafer W into the hydrophobing module ADH 1 , and are returned to the position in front of the transfer module CPL 1 . When the moving part  50  and the arm  55  are moved toward the transfer module CPL 1 , the advancing motion (X-axis motion) of the arm  55  toward the transfer module CPL 1  may be performed during the movement of the moving part  50  along the transfer area R 1 . 
         [0068]    In the above example, the transfer module CPL 1  and the hydrophobing module ADH 1  are disposed on the opposite ends of the BCT layer  132  of the processing block C 2 . Thus, it takes relatively long time for the Y-axis motion of the wafer transfer unit A 2 . Accordingly, the transfer time may be remarkably reduced if the X-axis motion of the arm  55  is performed simultaneously with the Y-axis motion of the moving part  50 . 
         [0069]    Similarly, in a case where a wafer W is transferred from the buffer module BU 1  to one of the transfer modules CPL 9  to CPL 11  in the ITC layer  64 , and in a case where a wafer W is transferred from the transfer module CPL 2  or CPL 3  to one of the hydrophobing modules ADH 1  to ADH 3  in the BCT layer  132 , the transfer-departure module and the transfer-destination module are located on the opposite ends of the processing block C 2 , and thus it takes relatively long time for the Y-axis motions of the wafer transfer units A 2  and A 4 . Accordingly, the foregoing transfer method is effective in remarkably reducing the transfer time. 
         [0070]    The foregoing transfer principle is applicable if the direction of the X-axis motion (advancing motion) of the arm  55  for entering the transfer-destination module is parallel to the Y-axis motion. Accordingly, the foregoing transfer principle is applicable to a case where a wafer W is transferred by the wafer transfer unit (A 1 -A 4 ) from a module in any one of the unit shelves U 1  to U 5  to a module in the unit shelf U 6  or U 7 , and also applicable to a case where a wafer W is transferred by the wafer transfer unit (A 1 -A 4 ) from a module in the liquid processing part to a module in the unit shelf U 6  or U 7 . Of course, the foregoing transfer principle is applicable to a case where a wafer W is transferred between a module in the unit shelf U 6  and a module in the unit shelf U 7 . 
         [0071]    In the above example shown in  FIG. 7 , the motion period of the elevating table  53  (Z-axis motion) is longer than the motion period of the rotating table  54  (θ-axis motion). Meanwhile,  FIG. 10(   a ) shows an example in which the motion period of θ-axis motion is longer than the motion period of the Z-axis motion. In this case, the X-axis motion is started at the time point when the θ-axis motion is finished after the Z-axis motion has been finished. If the wafer transfer unit A 4  is controlled in this manner, the time required for the intermodular travel and the wafer transfer motion is the sum of time t 5  and time t 2 , where time t 5  is motion period of the θ-axis motion (the time required for complete the θ-axis motion when the θ-axis is operated at its maximum possible speed). Thus, as compared with the case in which the advancing motion (X-axis motion) of the arm  55  starts after completion of the intermodular travel, the time required for the wafer transfer may be reduced by a difference between the time t 5  and the time t 1  (t 1  is the motion period of the Y-axis motion). 
         [0072]    In the above case where the motion period of the θ-axis motion is longer than the motion period of the Z-axis motion, the following control is also possible. Namely, as shown in  FIG. 10(   b ), the X-axis motion may be started in the course of the θ-axis motion after the Z-axis motion has been finished, as long as the arm  55  and the wafer W do not collide with the modules surrounding the transfer area R 1 . 
         [0073]    Alternatively, when the motion period of the Z-axis motion is longer than the motion period of the θ-axis motion, which is shown in  FIG. 7 , the X-axis motion may be started in the course of the Z-axis motion after the θ-axis motion has been finished, as long as the arm  55  and the wafer W do no collide with the modules surrounding the transfer area R 1 . 
         [0074]    Alternatively, the X-axis motion may be started in the course of the Z-axis motion and the θ-axis motion, as long as the arm  55  and the wafer W do not collide with the modules surrounding the transfer area R 1 . 
         [0075]    By simultaneously performing the intermodular travel and the substrate transfer motion (X-axis motion) as shown in  FIGS. 7 and 10 , the time required for wafer transfer can be reduced at most by time t 2  required for the X-axis motion, as compared with the case in which the substrate transfer motion is started after completion of the intermodular travel. 
         [0076]    The advantageous effect is obtained by the fact that the motion periods of the Y-axis motion and the X-axis motion overlap. Thus, in the example shown in  FIG. 7 , the X-axis motion may be started after a certain time has elapsed after completion of the Z-axis motion. Also, in the example shown in  FIG. 10 , the X-axis motion may be started after a certain time has elapsed after completion of the θ-axis motion. 
       Second Embodiment 
       [0077]    Referring to  FIG. 11 , as viewed from a carrier block C 1  toward an exposure apparatus C 4 , modules  61  and  62  are disposed on the left end and the right end of the interface block C 3 , respectively, and modules  63  and  64  are disposed on the left end and the right end of the carrier block C 1 , respectively. The modules  61  and  62  on the interface block C 3  are each constituted as an inspection module, one being configured to inspect the thickness of a film formed on the surface of a wafer before exposure, and the other being configured to inspect the number of particles on the wafer W before exposed. The modules  63  and  64  disposed on the carrier block C 1  are each constituted as an inspection module, one being configured to inspect the line width of a resist pattern of a developed wafer W, and the other being configured to inspect the number of particles on the wafer W. 
         [0078]    The differences between the transfer route in the coating and developing apparatus  1  in the second embodiment shown in  FIG. 11  and the transfer route previously described in connection with the first embodiment are as follows: A wafer W, which has been conveyed from a processing block C 2  to a wafer transfer unit  16  of the interface block C 3 , is transferred to the modules  61  and  62  in that order for sequential inspection. Then, the wafer W is transferred to the exposure apparatus C 4 . The wafer W, which has been developed and conveyed to transfer module CPL 15  or CPL 16 , is transferred by a wafer transfer unit  12  to the modules  63  and  64  in that order for sequential inspection. Then, the wafer W is returned to a carrier C. In this embodiment, when the wafer W is transferred from the module  63  to the module  64 , and from the module  61  to the module  62 , the direction of the Y-axis motion (which is parallel to the guide  51 ) and the direction the X-axis motion (advancing motion) of the arm  55  are the same. Thus, the foregoing transfer principle is applicable. 
         [0079]      FIG. 12  corresponds to  FIG. 11 , and shows that modules with dot-hatch may be transfer-destination modules to which the foregoing transfer principle is applicable, while modules with shade-hatch may be transfer-destination modules to which the foregoing transfer principle is not applicable. If a wafer W is transferred to a transfer-destination module with shade-hatch, the direction of the wafer transfer motion (X-axis motion) of the arm  55  is perpendicular to the direction of the horizontal motion (Y-axis motion) of the wafer transfer unit indicated by arrows. In such a case, the wafer transfer motion is starts after completion of the intermodular travel. 
         [0080]    The modules  61  to  64  may be replaced with a certain kind of module other than inspection modules. For example, one of the modules  61  and  62  may be constituted as an edge exposure module configured to expose the peripheral portion of a resist film formed on a wafer. In this case, the inspection may be performed after the peripheral exposure. Similarly, one of the modules  63  and  64  may be constituted as an edge exposure module, and the inspection may be performed after the peripheral exposure, for example. 
         [0081]    It should be noted that the aforementioned transfer routes and processes are raised by way of example, and the transfer manner is not limited thereto. Moreover, the shuttle  13  may be provided with a moving part ( 50 ) and an arm ( 55 ) capable of being horizontally moved, similarly to the wafer transfer unit A 4  or  16 , and the conveying parts  14  and  15  of the unit shelves U 6  and U 7  may be constituted as transfer modules configured for transferring of a wafer W between the conveying parts ( 14 ,  15 ) and the wafer transfer units (D 1 ,  16 ). In this case, the shuttle  13  may transfer a wafer from the transfer part  14  to the transfer part  15  using the foregoing transfer principle. 
         [0082]    In the above example, the moving part  50  is configured to move the arm  55  both for rotation (θ-axis motion) and vertical motion (Z-axis motion). However, it is not necessary for the moving part  50  to have both the rotating means for rotating the arm  55  and the elevating means for vertically moving the arm  55 . For example, as shown in  FIG. 13(   a ), if the modules  71  and  72  (which may be a transfer-departure module and a transfer-destination module and vice versa) are located at different levels but are oriented the same direction, the rotating means may be omitted. Alternatively, as shown in  FIG. 13(   b ), if the modules  71  and  72  are oriented different directions but are located at the same level, the elevating means may be omitted. In these cases, the foregoing transfer principle is also applicable.