Patent Publication Number: US-2021191270-A1

Title: Substrate treating method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/033,480 filed Jul. 12, 2018, and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0092340 filed on Jul. 21, 2017, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     Embodiments of the inventive concept described herein relate to a substrate treating apparatus and a substrate treating method. 
     Various processes such as cleaning, deposition, photolithography, etching, and ion implantation are performed to manufacture a semiconductor device. A photolithographic process performed to form a pattern plays an important role in achieving high integration of a semiconductor device. 
     The photolithographic process is performed by coating a photosensitive liquid on a substrate. In the process of coating the photosensitive liquid, the photosensitive liquid of a preset amount may be coated while the substrate is rotated. A purge operation may be performed to adjust states of a nozzle for coating the photosensitive liquid and a pipeline connected to the nozzle. The purge operation is performed by discharging the photosensitive liquid of a preset amount. 
     SUMMARY 
     Embodiments of the inventive concept provide a substrate treating apparatus that may efficiently treat a substrate, and a substrate treating method. 
     Embodiments of the inventive concept also provide a substrate treating apparatus that may perform a purge operation while a substrate is treated, and a substrate treating method. 
     In accordance with an aspect of the inventive concept, there is provided a substrate treating apparatus including a first substrate support member and a second substrate support member configured to support a substrate, a plurality of nozzles configured to discharge a treatment liquid to the substrate located in the first substrate support member and the second substrate support member, a nozzle arm configured to support the nozzles, a purge port disposed between the first substrate support member and the second substrate support member, a driving member configured to move the nozzle arm between any two of the first substrate support member, the purge port, and the second substrate support member, and a controller configured to control the nozzle arm and the driving member, wherein the controller controls the nozzle arm and the driving member such that a purge nozzle that is one of the plurality of nozzles performs a purge operation by discharging the treatment liquid to the purge port in a process of moving the nozzle arm to one of the first substrate support member and the second substrate support member after the nozzle arm discharges the treatment liquid from the other of the first substrate support member and the second substrate support member. 
     The controller may allow the purge nozzle to perform a purge operation a preset number of times in the process of moving the nozzle arm between the first substrate support member and the second substrate support member. 
     The purge operations of the preset number of times may be continuously performed in the process of moving the nozzle arm between the first substrate support member and the second substrate support member. 
     The purge operations of the preset number of times may be intermittently performed in the process of moving the nozzle arm between the first substrate support member and the second substrate support member. 
     The purge port may include a cleaner configured to clean the nozzle, and the controller may control the cleaner such that the cleaner cleans the purge nozzle after the purge operations are performed the preset number of times. 
     The controller may generate an alarm if it is determined that the purge nozzle is to be used in the first substrate support member or the second substrate support member after the purge operation of the purge nozzle is started. 
     The substrate treating apparatus may further include a holder in which a cassette in which the substrate is received is located, and the controller may stop carrying-out of the substrate from the cassette if it is determined that the purge nozzle is to be used in the first substrate support member or the second substrate support member after the purge operation of the purge nozzle is started. 
     The controller may stop carrying-in of the substrate to one of the first substrate support member and the second substrate support member, in which the purge nozzle is scheduled to be used, if it is determined that the purge nozzle is to be used in the first substrate support member or the second substrate support member after the purge operation of the purge nozzle is started. 
     The plurality of nozzles may discharge a photosensitive liquid. 
     In accordance with another aspect of the inventive concept, there is provided a substrate treating method wherein a nozzle arm having a plurality of nozzles treats a substrate by discharging a treatment liquid while moving between a first substrate support member and a second substrate support member that support the substrate, and wherein a purge nozzle that is one of the plurality of nozzles performs a purge operation by discharging the treatment liquid to a purge port located between the first substrate support member and the second substrate support member in a process of moving the nozzle arm to one of the first substrate support member and the second substrate support member after the nozzle arm discharges the treatment liquid from the other of the first substrate support member and the second substrate support member. 
     The purge operation of the purge nozzle may be performed a preset number of times in a process of moving the nozzle arm between the first substrate support member and the second substrate support member. 
     The purge port may clean the purge nozzle after the purge nozzle performs the purge operation the preset number of times. 
     An interlock operation may be performed if it is determined that the purge nozzle discharges the treatment liquid to the first substrate support member or the second substrate support member before the purge operation is performed the preset number of times after the purge operation of the purge nozzle is initiated. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The above and other objects and features of the inventive concept will become apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings. 
         FIG. 1  is a view of a substrate treating apparatus, viewed from the top; 
         FIG. 2  is a sectional view of the system of  FIG. 1 , taken along line A-A of  FIG. 1 ; 
         FIG. 3  is a sectional view of the system of  FIG. 1 , taken along line B-B of  FIG. 1 ; 
         FIG. 4  is a sectional view of the facility of  FIG. 1 , taken along a line C-C of  FIG. 1 ; 
         FIG. 5  is a plan view of a resist coating chamber according to an embodiment of the inventive concept; 
         FIG. 6  is a side sectional view of the resist coating chamber of  FIG. 5 ; 
         FIG. 7  is a perspective view of a nozzle arm of  FIG. 5 ; 
         FIG. 8  is a view illustrating a pipeline connected to one of photosensitive liquid nozzles; 
         FIG. 9  is a block diagram illustrating a process for a purge operation; 
         FIG. 10  is a view illustrating a state in which a photosensitive liquid nozzle is purged to a purge port; 
         FIG. 11  is a view illustrating some connection relationships of a controller; and 
         FIG. 12  is a view illustrating a state in which a purge nozzle is being cleaned. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary embodiments of the inventive concept will be described in more detail with reference to the accompanying drawings. The embodiments of the inventive concept may be modified in various forms, and the scope of the inventive concept should not be construed to be limited to the following embodiments. The embodiments of the inventive concept are provided to describe the inventive concept for those skilled in the art more completely. Accordingly, the shapes of the components of the drawings are exaggerated to emphasize clearer description thereof. 
     The system of the present embodiment is used to perform a photolithographic process on a substrate, such as a semiconductor wafer or a flat display panel. In particular, the system of the present embodiment is used to perform a coating process, a development process, and a pre/post-exposure process that is required before and after liquid-immersion and exposure on a substrate. Hereinafter, a case of using a substrate as a substrate may be described as an example. 
       FIGS. 1 to 4  are views schematically illustrating a substrate treating apparatus according to an embodiment of the inventive concept.  FIG. 1  is a view of a substrate treating apparatus, viewed from the top.  FIG. 2  is a sectional view of the facility of  FIG. 1 , taken along line A-A of  FIG. 1 .  FIG. 3  is a sectional view of the system of  FIG. 1 , taken along line B-B of  FIG. 1 .  FIG. 4  is a sectional view of the facility of  FIG. 1 , taken along a line C-C of  FIG. 1 . 
     Referring to  FIGS. 1 to 4 , the substrate treating apparatus  1  includes a load port  100 , an index module  200 , a first buffer module  300 , an application/development module  400 , a second buffer module  500 , a pre/post-exposure treating module  600 , an interface module  700 , a purge module  800 , and a controller  1000 . The load port  100 , the index module  200 , the first buffer module  300 , the application/development module  400 , the second buffer module  500 , the pre/post-exposure treating module  600 , and the interface module  700  are sequentially disposed in a row in one direction. The purge module  800  may be provided in the interface module  700 , and alternatively, the purge module  800  may be provided at various locations, such as a location at which an exposure apparatus  900  at a rear end of the interface module  700  is connected or a lateral side of the interface module  700 . 
     Hereinafter, a direction in which the load port  100 , the index module  200 , the first buffer module  300 , the application/development module  400 , the second buffer module  500 , the pre/post-exposure treating module  600 , and the interface module  700  are disposed will be referred to as a first direction  12 , and a direction that is perpendicular to the first direction  12  when viewed from the top will be referred to as a second direction  14 , and a direction that is perpendicular to the first direction  12  and the second direction  14  will be referred to as a third direction  16 . 
     A wafer W is moved while being received in a cassette  20 . Then, the cassette  20  has a structure that is sealed from the outside. For example, a front open unified pod (FOUP) that has a door on the front side may be used as the cassette  20 . 
     Hereinafter, the load port  100 , the index module  200 , the first buffer module  300 , the application/development module  400 , the second buffer module  500 , the pre/post-exposure treating module  600 , the interface module  700 , and the purge module  800  will be described in detail. 
     (Load Port) 
     The load port  100  has a holder  120  on which the cassette  20 , in which the wafers W are received, is positioned. A plurality of carriers  120  are provided, and are disposed along the second direction  14  in a row. In  FIG. 1 , four carriers  120  are provided. 
     (Index Module) 
     The index module  200  feeds a wafer W between the cassette  20  positioned on the carrier  120  of the load port  100  and the first buffer module  300 . The index module  200  has a frame  210 , an index robot  220 , and a guide rail  230 . The frame  210  has a substantially rectangular parallelepiped shape having an empty interior, and is disposed between the load part  100  and the first buffer module  300 . The frame  210  of the index module  200  may have a height smaller than that of a frame  310  of the first buffer module  300 , which will be described below. The index robot  220  and the guide rail  230  are disposed in the frame  210 . The index robot  220  has a four-axis driven structure such that a hand  221  that directly handles a wafer W is movable and rotatable in the first direction  12 , the second direction  14 , and the third direction  16 . The index robot  220  has a hand  221 , an arm  222 , a support  223 , and a prop  224 . The hand  221  is fixedly installed in the arm  222 . The arm  222  has a flexible and rotatable structure. The support  223  is configured such that the lengthwise direction thereof is disposed along the third direction  16 . The arm  222  is coupled to the support  223  to be movable along the support  223 . The support  223  is fixedly coupled to the prop  224 . The guide rail  230  is provided such that the lengthwise direction thereof is disposed along the second direction  14 . The prop  224  is coupled to the guide rail  230  to be linearly movable along the guide rail  230 . Although not illustrated, the frame  210  is further provided with a door opener that opens and closes a door of the cassette  20 . 
     (First Buffer Module) 
     The first buffer module  300  has a frame  310 , a first buffer  320 , a second buffer  330 , a cooling chamber  350 , and a first buffer robot  360 . The frame  310  has a rectangular parallelepiped shape having an empty interior, and is disposed between the index module  200  and the application/development module  400 . The first buffer  320 , the second buffer  330 , the cooling chamber  350 , and the first buffer robot  360  are situated within the frame  310 . The cooling chamber  350 , the second buffer  330 , and the first buffer  320  are disposed along the third direction  16  sequentially from the bottom. The first buffer  320  is situated at a height corresponding to an application module  401  of the application/development module  400 , which will be described below, and the second buffer  330  and the cooling chamber  350  are situated at a height corresponding to a development module  402  of the application/development module  400 , which will be described below. The first buffer robot  360  is spaced apart by a predetermined distance in the second direction  14  from the second buffer  330 , the cooling chamber  350 , and the first buffer  320 . 
     The first buffer  320  and the second buffer  330  temporarily preserve a plurality of wafers W. The second buffer  330  has a housing  331  and a plurality of supports  332 . The supports  332  are disposed within the housing  331 , and are spaced apart from one another along the third direction  16 . One wafer W is positioned on each of the supports  332 . The housing has openings (not illustrated) on a side on which the index robot  220  is provided, on a side on which the first buffer robot  360  is provided, and on a side on which a development robot  482  is provided so that the index robot  220 , the first buffer robot  360 , and a development robot  482  of the development module  402 , which will be described below, carry a wafer W into or out of the support  332  in the housing  331 . The first buffer  320  has a structure that is substantially similar to that of the second buffer  330 . Meanwhile, the housing  321  of the first buffer  320  has an opening on a side on which the first buffer robot  360  is provided and on a side on which an application robot  432  situated in the application module  401 , which will be described below, is provided. The number of supports  322  provided for the first buffer  320  and the number of supports  332  provided for the second buffer  330  may be the same or different. According to an embodiment, the number of the supports  332  provided for the second buffer  330  may be larger than the number of the supports  322  provided for the first buffer  320 . 
     The first buffer robot  360  feeds a wafer W between the first buffer  320  and the second buffer  330 . The first buffer robot  360  has a hand  361 , an arm  362 , and a support  363 . The hand  361  is fixedly installed in the arm  362 . The arm  362  has a flexible structure, and allows the hand  361  to be moved along the second direction  14 . The arm  362  is coupled to the support  363  to be linearly movable in the third direction  16  along the support  363 . The support  363  has a length extending from a location corresponding to the second buffer  330  to a location corresponding to the first buffer  320 . The support  363  may be provided to extend longer upwards or downwards. The first buffer robot  360  may be provided such that the hand  361  is simply two-axis driven along the second direction  14  and the third direction  16 . 
     The cooling chamber  350  cools a wafer W. The cooling chamber  350  has a housing  351  and a cooling plate  352 . The cooling plate  352  has a cooling unit  353  that cools an upper surface thereof on which a wafer W is positioned and the wafer W. Various types such as a cooling type using cooling water and a cooling type using a thermoelectric element may be used as the cooling unit  353 . A lift pin assembly (not illustrated) that locates a wafer W on the cooling plate  352  may be provided in the cooling chamber  350 . The housing  351  has openings (not illustrated) on a side on which the index robot  220  is provided and on a side on which the development robot  482  is provided so that the index robot  220  and the development robot  482  provided for the development module  402 , which will be described below, carry a wafer W into or out of the cooling plate  352 . Doors (not illustrated) that open and close the aforementioned openings may be provided in the cooling chamber  350 . 
     (Coating/Development Module) 
     The application/development module  400  performs a process of applying a photoresist onto a wafer W before an exposure process and a process of developing the wafer W after the exposure process. The application/development module  400  has a substantially rectangular parallelepiped shape. The application/development module  400  has an application module  401  and a development module  402 . The application module  401  and the development module  402  may be disposed to be partitioned from each other in different layers. According to an example, the application module  401  is situated on the development module  402 . 
     The application module  401  performs a process of applying a photosensitive liquid such as a photoresist onto a wafer W and a heat treating process of, for example, heating and cooling the wafer W before and after the resist applying process. The application module  401  has a resist applying chamber  410 , a bake chamber  420 , and a carrying chamber  430 . The resist applying chamber  410 , the bake chamber  420 , and the carrying chamber  430  are sequentially disposed along the second direction  14 . Accordingly, the resist applying chamber  410  and the bake chamber  420  are spaced apart from each other in the second direction  14  while the carrying chamber  430  is interposed therebetween. A plurality of resist applying chambers  410  may be provided, and a plurality of resist applying chambers  410  may be provided in each of the first direction  12  and the third direction  16 . In the drawings, six resist applying chambers  410  are illustrated as an example. A plurality of bake chamber  420  may be provided in each of the first direction  12  and the third direction  16 . In the drawings, six bake chambers  420  are illustrated as an example. However, unlike this, a larger number of bake chambers  420  may be provided. 
     The carrying chamber  430  is situated in parallel to the first buffer  320  of the first buffer module  300  in the first direction  12 . An application robot  432  and a guide rail  433  may be situated in the carrying chamber  430 . The carrying chamber  430  has a substantially rectangular shape. The application robot  432  feeds a wafer W between the bake chambers  420 , the resist applying chambers  400 , the first buffer  320  of the first buffer module  300 , and the first cooling chamber  520  of the second buffer module  500 . The guide rail  433  is disposed such that the lengthwise direction thereof is parallel to the first direction  12 . The guide rail  433  guides the application robot  432  such that the application robot  432  is linearly moved in the first direction  12 . The application robot  432  has a hand  434 , an arm  435 , a support  436 , and a prop  437 . The hand  434  is fixedly installed in the arm  435 . The arm  435  has a flexible structure such that the hand  434  is movable horizontally. The support  436  is provided such that the lengthwise direction thereof is disposed along the third direction  16 . The arm  435  is coupled to the support  436  to be linearly movable in the third direction  16  along the support  436 . The support  436  is fixedly coupled to the prop  437 , and the prop  437  is coupled to the guide rail  433  to be movable along the guide rail  433 . 
     The resist applying chambers  410  have the same structure. However, the types of photoresists used in the resist applying chambers  410  may be different. As an example, the photoresist may be a chemical amplification resist. The resist applying chamber  410  applies a photoresist onto the wafer W. 
     The bake chamber  420  heat-treats the wafer W. For example, the bake chambers  420  perform a prebake process of eliminating organic substances and moisture on the surface of the wafer W by heating the wafer W at a predetermined temperature before a photoresist is applied or a soft bake process performed after a photoresist is applied onto the wafer W, and performs a cooling process of cooling the wafer W after the heating processes. The bake chamber  420  has a cooling plate  421  and a heating plate  422 . The cooling plate  421  is provided with a cooling unit  423  such as cooling water or a thermoelectric element. The heating plate  422  is provided with a heating unit  424  such as a heating wire or a thermoelectric element. The cooling plate  421  and the heating plate  422  may be provided in one bake chamber  420 . Optionally, some of the bake chambers  420  may include only a cooling plate  421 , and some of the bake chambers  422  may include only a heating plate  422 . 
     The development module  402  performs a development process of eliminating a photoresist by supplying a development liquid to obtain a pattern on the wafer W, and a heat treating process, such as heating and cooling, which are performed on the wafer W before and after the development process. The development module  402  has a development chamber  460 , a bake chamber  470 , and a carrying chamber  480 . The development chamber  460 , the bake chamber  470 , and the carrying chamber  480  are sequentially disposed along the second direction  14 . Accordingly, the development chamber  460  and the bake chamber  470  are spaced apart from each other in the second direction  14  while the carrying chamber  480  is interposed therebetween. A plurality of development chambers  460  may be provided, and a plurality of development chambers  460  may be provided in each of the first direction  12  and the third direction  16 . In the drawings, six development chambers  460  are illustrated as an example. A plurality of bake chamber  470  may be provided in each of the first direction  12  and the third direction  16 . In the drawings, six bake chambers  470  are illustrated as an example. However, unlike this, a larger number of bake chambers  470  may be provided. 
     The carrying chamber  480  is situated in parallel to the second buffer  330  of the first buffer module  300  in the first direction  12 . A development robot  482  and a guide rail  483  may be situated in the carrying chamber  480 . The carrying chamber  480  has a substantially rectangular shape. The development robot  482  feeds the wafer W between the bake chambers  470 , the development chambers  460 , the second buffer  330  and the cooling chamber  350  of the first buffer module  300 , and the second cooling chamber  540  of the second buffer module  500 . The guide rail  483  is disposed such that the lengthwise direction thereof is parallel to the first direction  12 . The guide rail  483  guides the development robot  482  such that the development robot  432  is linearly moved in the first direction  12 . The development robot  482  has a hand  484 , an arm  485 , a support  486 , and a prop  487 . The hand  484  is fixedly installed in the arm  485 . The arm  485  has a flexible structure such that the hand  484  is movable horizontally. The support  486  is provided such that the lengthwise direction thereof is disposed along the third direction  16 . The arm  485  is coupled to the support  486  to be linearly movable in the third direction  16  along the support  486 . The support  486  is fixedly coupled to the prop  487 . The prop  487  is coupled to the guide rail  483  to be linearly movable along the guide rail  483 . 
     The development chambers  460  have the same structure. However, the types of development liquids used in the development chambers  460  may be different. The development chambers  460  eliminate an area of the photoresist on the wafer W, to which light is irradiated. Then, an area of the protective film, to which light is irradiated, is eliminated together. Optionally, only an area of the photoresist and the protective film, to which light is not irradiated, may be eliminated according to the type of the used photoresist. 
     The development chamber  460  has a housing  461 , a support plate  462 , and a nozzle  463 . The housing  461  has an open-topped cup shape. The support plate  462  is situated in the housing  461 , and supports the wafer W. The support plate  462  may be provided to be rotatable. The nozzle  463  supplies a development liquid onto the wafer W positioned on the support plate  462 . The nozzle  463  may have a circular pipe shape, and may supply a development liquid to the center of the wafer W. Optionally, the nozzle  463  may have a length corresponding to the diameter of the wafer W, and the discharge hole of the nozzle  463  may be a slit. The development chamber  460  may be further provided with a nozzle  464  that supplies a cleaning liquid such as deionized water to clean the surface of the wafer W, to which the development liquid is additionally supplied. 
     The bake chamber  470  heat-treats the wafer W. For example, the bake chambers  470  may perform a post bake process of heating the wafer W before the development process, a hard bake process of heating the wafer W after the development process, and a cooling process of cooling the heated wafer after the bake process. The bake chamber  470  has a cooling plate  471  and a heating plate  472 . The cooling plate  471  is provided with a cooling unit  473  such as cooling water or a thermoelectric element. The heating plate  472  is provided with a heating unit  474  such as a heating wire or a thermoelectric element. The cooling plate  471  and the heating plate  472  may be provided in one bake chamber  470 . Optionally, some of the bake chambers  470  may include only a cooling plate  471 , and some of the bake chambers  470  may include only a heating plate  472 . 
     As described above, the application/development module  400  is provided such that the application module  401  and the development module  402  are separated. When viewed from the top, the application module  401  and the development module  402  may have the same chamber disposition. 
     (Second Buffer Module) 
     The second buffer module  500  is provided as a passage through which the wafer W is transported, between the application/development module  400  and the pre/post-exposure module  600 . The second buffer module  500  performs a process such as a cooling process or an edge exposing process on the wafer W. The second buffer module  500  has a frame  510 , a buffer  520 , a first cooling chamber  530 , a second cooling chamber  540 , an edge exposing chamber  550 , and a second buffer robot  560 . The frame  510  has a rectangular parallelepiped shape. The buffer  520 , the first cooling chamber  530 , the second cooling chamber  540 , the edge exposing chamber  550 , and the second buffer robot  560  are situated in the frame  510 . The buffer  520 , the first cooling chamber  530 , and the edge exposing chamber  550  are disposed at a height corresponding to the application module  401 . The second cooling chamber  540  is disposed at a height corresponding to the development module  402 . The buffer  520 , the first cooling chamber  530 , and the second cooling chamber  540  are disposed in a row along the third direction  16 . When viewed from the top, the buffer  520  is disposed along the carrying chamber  430  of the application module  401  in the first direction  12 . The edge exposing chamber  550  is spaced apart from the buffer  520  or the first cooling chamber  530  by a predetermined distance in the second direction  14 . 
     The second buffer robot  560  transports the wafer W between the buffer  520 , the first cooling chamber  530 , and the edge exposing chamber  550 . The second buffer robot  560  is situated between the edge exposing chamber  550  and the buffer  520 . The second buffer robot  560  may have a structure that is similar to that of the first buffer robot  360 . The first cooling chamber  530  and the edge exposing chamber  550  perform a succeeding process on the wafers, on which the application module  401  has performed a process. The first cooling chamber  530  cools the wafer W, on which the application module  401  has performed a process. The first cooling chamber  530  has a structure similar to that of the cooling chamber  350  of the first buffer module  300 . The edge exposing chamber  550  exposes peripheries of the wafers W, on which the first cooling chamber  530  has performed a cooling process. The buffer  520  temporarily preserves the substrates W before the wafers W, on which the edge exposing chamber  550  has performed a process, are transported to a pre-treatment module  601 , which will be described below. The second cooling chamber  540  cools the wafers W before the wafers W, on which a post-treatment module  602 , which will be described below, has performed a process, are transported to the development module  402 . The second buffer module  500  may further have a buffer at a height corresponding to the development module  402 . In this case, the wafers W, on which the post-treatment module  602  has performed a process, may be transported to the development module  402  after being temporarily preserved in the added buffer. 
     (Pre/Post-Exposure Module) 
     When the exposure apparatus  900  performs an immersion/exposure process, the pre/post-exposure module  600  may perform a process of applying a protective film that protects the photoresist film applied to the wafer W during the immersion/exposure process. The pre/post-exposure module  600  may perform a process of cleaning the wafer W after the exposure process. Furthermore, when the application process is performed by using a chemical amplification resist, the pre/post-exposure module  600  may perform a bake process after the exposure process. 
     The pre/post-exposure module  600  has a pre-treatment module  601  and a post-treatment module  602 . The pre-treatment module  601  performs a process of treating the wafer W before the exposure process, and the post-treatment module  602  performs a process of treating the wafer W after the exposure process. The pre-treatment module  601  and the post-treatment module  602  may be disposed to be partitioned from each other in different layers. According to an example, the pre-treatment module  601  is situated on the post-treatment module  602 . The pre-treatment module  601  has the same height as that of the application module  401 . The post-treatment module  602  has the same height as that of the development module  402 . The pre-treatment module  601  has a protective film applying chamber  610 , a bake chamber  620 , and a carrying chamber  630 . The protective film applying chamber  610 , the carrying chamber  630 , and the bake chamber  620  are sequentially disposed along the second direction  14 . Accordingly, the protective film applying chamber  610  and the bake chamber  620  are spaced apart from each other in the second direction  14  while the carrying chamber  630  is interposed therebetween. A plurality of protective film applying chambers  610  are provided, and the plurality of protective film applying chambers  610  are disposed along the third direction  16  to form different layers. Optionally, a plurality of protective film applying chambers  610  may be provided in each of the first direction  12  and the third direction  16 . A plurality of bake chambers  620  are provided, and the plurality of bake chambers  610  are disposed along the third direction  16  to form different layers. Optionally, a plurality of bake chambers  620  may be provided in each of the first direction  12  and the third direction  16 . 
     The carrying chamber  630  is situated in parallel to the first cooling chamber  530  of the second buffer module  500  in the first direction  12 . A pre-treatment robot  632  is situated in the carrying chamber  630 . The carrying chamber  630  has a substantially square or rectangular shape. The pre-treatment robot  632  feeds the wafer W between the protective film applying chambers  610 , the bake chambers  620 , the buffer  520  of the second buffer module  500 , and a first buffer  720  of the interface module  700 , which will be described below. The pre-treatment robot  632  has a hand  633 , an arm  634 , and a support  635 . The hand  633  is fixedly installed in the arm  634 . The arm  634  has a flexible and rotatable structure. The arm  634  is coupled to the support  635  to be linearly movable in the third direction  16  along the support  635 . 
     The protective film applying chamber  610  applies a protective film that protects a resist film during the immersion/exposure process, onto the wafer W. The protective film applying chamber  610  has a housing  611 , a support plate  612 , and a nozzle  613 . The housing  611  has an open-topped cup shape. The support plate  612  is situated in the housing  611 , and supports the wafer W. The support plate  612  may be provided to be rotatable. The nozzle  613  supplies a protection liquid for forming a protective film onto the wafer W positioned on the support plate  612 . The nozzle  613  has a circular pipe shape, and may supply a protection liquid to the center of the wafer W. Optionally, the nozzle  613  may have a length corresponding to the diameter of the wafer W, and the discharge hole of the nozzle  613  may be a slit. In this case, the support plate  612  may be provided in a fixed state. The protection liquid includes an expandable material. The protection liquid may be a material that has a low affinity for a photoresist and water. For example, the protection liquid may include a fluorine-based solvent. The protective film applying chamber  610  supplies a protection liquid to a central area of the wafer W while rotating the wafer W positioned on the support plate  612 . 
     The bake chamber  620  heat-treats the wafer W, to which the protective film is applied. The bake chamber  620  has a cooling plate  621  and a heating plate  622 . The cooling plate  621  is provided with a cooling unit  623  such as cooling water or a thermoelectric element. The heating plate  622  is provided with a heating unit  624  such as a heating wire or a thermoelectric element. The heating plate  622  and the cooling plate  621  may be provided in one bake chamber  620 . Optionally, some of the bake chambers  620  may include only a heating plate  622 , and some of the bake chambers  620  may include only a cooling plate  621 . 
     The post-treatment module  602  has a cleaning chamber  660 , a post-exposure bake chamber  670 , and a carrying chamber  680 . The cleaning chamber  660 , the carrying chamber  680 , and the post-exposure chamber  670  are sequentially disposed along the second direction  14 . Accordingly, the cleaning chamber  660  and the post-exposure bake chamber  670  are spaced apart from each other in the second direction  14  while the carrying chamber  680  is interposed therebetween. A plurality of cleaning chambers  660  are provided, and the plurality of cleaning chambers  610  are disposed along the third direction  16  to form different layers. Optionally, a plurality of cleaning chambers  660  may be provided in each of the first direction  12  and the third direction  16 . A plurality of post-exposure bake chambers  670  are provided, and the plurality of post-exposure bake chambers  610  are disposed along the third direction  16  to form different layers. Optionally, a plurality of post-exposure bake chambers  670  may be provided in plural in each of the first direction  12  and the third direction  16 . 
     When viewed from the top, the carrying chamber  680  is situated in parallel to the second cooling chamber  540  of the second buffer module  500  in the first direction  12 . The carrying chamber  680  has a substantially square or rectangular shape. A post-treatment robot  682  is situated in the carrying chamber  680 . The post-treatment robot  682  transports the wafer W between the cleaning chambers  660 , the post-exposure bake chambers  670 , the second cooling chamber  540  of the second buffer module  500 , and a second buffer  730  of the interface module  700 , which will be described below. The post-treatment robot  682  provided in the post-treatment module  602  may have the same structure as that of the pre-treatment robot  632  provided in the pre-treatment module  601 . 
     The cleaning chamber  660  cleans the wafer W after the exposure process. The cleaning chamber  660  has a housing  661 , a support plate  662 , and a nozzle  663 . The housing  661  has an open-topped cup shape. The support plate  662  is situated in the housing  661 , and supports the wafer W. The support plate  662  may be provided to be rotatable. The nozzle  663  supplies a cleaning liquid onto the wafer W positioned on the support plate  662 . The cleaning liquid may be water such as deionized water. The cleaning chamber  660  supplies a cleaning liquid to a central area of the wafer W while rotating the wafer W positioned on the support plate  662 . Optionally, the nozzle  663  may be linearly moved or rotated from a central area to a peripheral area of the wafer W while the wafer W is rotated. 
     After the exposure process, the bake chamber  670  heats the wafer W, on which the exposure process has been performed, by using a far infrared ray. After the exposure process, in the bake process, the wafer W is heated to finish a property change of the photoresist by amplifying acid produced in the photoresist through the exposure process. After the exposure process, the bake chamber  670  has a heating plate  672 . The heating plate  672  is provided with a heating unit  674  such as a heating wire or a thermoelectric element. After the exposure process, the bake chamber  670  may be further provided with a cooling plate  671  in the interior thereof. The cooling plate  671  is provided with a cooling unit  673  such as cooling water or a thermoelectric element. Optionally, a bake chamber having only a cooling plate  671  may be further provided. 
     As described above, the pre/post-exposure module  600  is provided such that the pre-treatment module  601  and the post-treatment module  602  are completely separated from each other. The carrying chamber  630  of the pre-treatment module  601  and the carrying chamber  680  of the post-treatment module  602  may have the same size, and may completely overlap each other when viewed from the top. The protective film applying chamber  610  and the cleaning chamber  660  may have the same size, and may completely overlap with each other when viewed from the top. The bake chamber  620  and the post-exposure chamber  670  may have the same size, and may completely overlap with each other when viewed from the top. 
     (Interface Module) 
     The interface module  700  feeds the wafer W between two of the pre/post-exposure module  600 , the purge module  800 , and the exposure apparatus  900 . The interface module  700  has a frame  710 , a first buffer  720 , a second buffer  730 , and an interface robot  740 . The first buffer  720 , the second buffer  730 , and the interface robot  740  are situated within the frame  710 . The first buffer  720  and the second buffer  730  are spaced apart from each other by a predetermined distance, and may be stacked. The first buffer  720  is disposed at a location higher than the second buffer  730 . The first buffer  720  is situated at a height corresponding to the pre-treatment module  601 , and the second buffer  730  is disposed at a height corresponding to the post-treatment module  602 . When viewed from the top, the first buffer  720  is disposed along the first direction  12  while forming a row with the carrying chamber  630  of the pre-treatment module  601 , and the second buffer  730  is disposed along the first direction  12  forming a row with the carrying chamber  630  of the post-treatment module  602 . 
     The interface robot  740  is situated to be spaced apart from the first buffer  720  and the second buffer  730  in the second direction  14 . The interface robot  740  transports the wafer W between two of the first buffer  720 , the second buffer  730 , the purge module  800 , and the exposure apparatus  900 . The interface robot  740  has a structure that is substantially similar to that of the second buffer robot  560 . 
     The first buffer  720  temporarily preserves the wafers W, on which the pre-treatment module  601  has performed a process, before they are moved to the exposure apparatus  900 . The second buffer  730  temporarily preserves the wafers W, on which the exposure apparatus  900  has completely performed a process, before they are moved to the post-treatment module  602 . The first buffer  720  has a housing  721  and a plurality of supports  722 . The supports  722  are disposed within the housing  721 , and are spaced apart from one another along the third direction  16 . One wafer W is positioned on each of the supports  722 . The housing  721  has openings (not illustrated) on a side on which the interface robot  740  is provided and on a side on which the pre-treatment robot  632  is provided so that the interface robot  740  and the pre-treatment robot  632  carry a wafer W into or out of the housing  721 . The second buffer  730  has a structure that is substantially similar to that of the first buffer  720 . Meanwhile, the housing  4531  of the second buffer  730  has openings on a side on which the interface robot  740  is provided and on a side on which the post-treatment robot  682  is provided. The interface module may be provided only with buffers and a robot as described above while a chamber that performs a certain process on a wafer is not provided. 
     (Purge Module) 
     The purge module  800  may be disposed in the interface module  700 . In detail, the purge module  800  may be disposed at a location that is opposite to the first buffer  720  around the interface robot  740 . Unlike this, the purge module  800  may be provided at various locations, such as a location at which the exposure apparatus  900  at a rear end of the interface module  700  is connected or a lateral side of the interface module  700 . The purge module  800  performs a gas purging process and a rinsing process on the water on which a protective film for protecting a photoresist is coated in the pre/post-exposure module  600 . 
     The controller ( 1000  of  FIG. 11 ) controls the components of the substrate treating apparatus  1000 . 
       FIG. 5  is a plan view of a resist coating chamber according to an embodiment of the inventive concept.  FIG. 6  is a side sectional view of the resist coating chamber of  FIG. 5 . 
     Referring to  FIGS. 5 and 6 , the resist coating chamber  410  includes a substrate support member  4100 , a treatment liquid supply unit  4300 , and a purge port  4500 . 
     The substrate support member  4100  supports the substrate W during execution of the process. 
     The substrate support member  4100  includes a first substrate support member  4100   a  and a second substrate support member  4100   b.    
     Two substrate support members, that is, the first substrate support members  4100  and the second substrate support member  4100   b  are provided inside the housing  4000  that provides a treatment space, along the movement direction of a nozzle arm  4320 . 
     The substrate support member  4100  is rotated by a substrate support driving member  4120  while the process is executed. The substrate support member  4100  has a support plate  4140  having a circular upper surface, and pin members  4160  that support the substrate W are installed on the upper surface of the support plate  4140 . The substrate W supported by the pin members  4160  is rotated as the substrate support member  4100  is rotated by the substrate support driving member  4120 . 
     A container  4200  is located at a circumference of the substrate support member  4100 . The container  4200  includes a first container  4200   a  located at a circumference of the first substrate support member  4100   a  and a second container  4200   b  located at a circumference of the second substrate support member  4100   b.    
     The container  4200  may have a substantially cylindrical shape. The container  4200  includes an upper cup  4210 . An exhaust hole is formed below the upper cup  4210 . A lower cup  4220  may be provided below the upper cup  4210  to be spaced apart from the upper cup  4210  at a preset interval. The lower cup  4220  forms a lower end of the exhaust hole. A communication hole  4240  connected to the exhaust hole is formed at a lower portion of the container  4200 , and an exhaust pipe  4260  is installed to be communicated with the communication hole  4240 . An exhaust member  4280 , such as a pump  4327 , is connected to the exhaust pipe  4260 , and a negative pressure is provided in the exhaust member  4280  such that the treatment liquid that is scattered due to the rotation of the substrate W and the gases in the container  4200  containing fumes are exhausted. 
       FIG. 7  is a perspective view of a nozzle arm of  FIG. 5 . 
     Referring to  FIGS. 5 to 7 , the treatment liquid supply unit  4300  supplies a treatment liquid to an upper surface of a substrate W positioned on the substrate support member  4100 . The treatment liquid supply unit  4300  has a nozzle arm  4320  provided on one side of the substrate support member  4100 . A plurality of nozzles  4321  and  4322  are located at one end of the nozzle arm  4320 . The nozzle  4321  and  4322  include a plurality of photosensitive liquid nozzles  4321 . The plurality of photosensitive liquid nozzles  4321  may be disposed in a row at one end of the nozzle arm  4320  to be perpendicular to a lengthwise direction of the nozzle arm  4320 . 
     A pre-wet nozzle  4322  may be provided at an end of the nozzle arm  4320 . The pre-wet nozzle  4322  supplies an organic solvent to the substrate W to improve the wetting property of the photosensitive liquid for the substrate W before the photosensitive liquid is supplied to the substrate W. If an organic solvent is supplied before the photosensitive liquid is supplied onto the substrate W, the photosensitive liquid uniformly spreads out onto the substrate W so that a uniform photosensitive film may be formed on the substrate W. 
     The organic solvent supplied from the pre-wet nozzle  4322  to the substrate W may be thinner or the like. 
     Further, the pre-wet nozzle  4322  may be omitted. 
     The nozzle arm  4320  may be disposed on one side of the substrate support member  4100  such that the arrangement direction of the nozzles  4321  and  4322  may pass through the center of the substrate W positioned on the substrate support member  4100 . 
     The nozzle arm  4320  on which the plurality of nozzles  4321  and  4322  are mounted, may be linearly moved along the arrangement direction of the nozzles  4321  and  4322  by the driving member  4400 . The driving member  4400  includes a nozzle arm support member  4410  and a guide member  4420 . The nozzle arm support member  4410  is coupled to an opposite end of the nozzle arm  4320 . The nozzle arm support member  4410  may have a rod shape that extends from one side to a lower side of the nozzle arm  4320 . The guide member  4420  is connected to a lower end of the nozzle arm support member  4410 . The guide member  4420  is disposed on one side of the substrate support member  4100  to be perpendicular to a lengthwise direction of the nozzle arm  4320  on the plan disposition structure of  FIG. 5 . The guide member  4420  is located along a spacing direction of the first substrate support member  4100   a  and the second substrate support member  4100   b . The guide member  4420  may have a rail shape, and guides a linear movement of the nozzle arm support member  4410 . The nozzle arm support member  4410  may be provided such that the length of the nozzle arm support member  4410  may vary vertically. 
     By the driving member  4400  having the above-described configuration, the treatment liquid supply unit  4300  may be moved between the first substrate support member  4100   a  and the second substrate support member  4100   b  while being linearly moved. Accordingly, after being moved to the second substrate support member  4100   b  after the photosensitive liquid is supplied to the substrate located in the first substrate support member  4100   a  with one of the plurality of photosensitive liquid nozzles  4321 , the treatment liquid supply unit  4300  may supply the photosensitive liquid to the substrate located in the second substrate support member  4100   b  with one of the plurality of photosensitive liquid nozzles  4321 . 
     The photosensitive liquid nozzle  4321  that supplies the photosensitive liquid to the substrate located in the first substrate support member  4100   a  and the photosensitive liquid nozzle  4321  that supplies the photosensitive liquid to the substrate located in the second substrate support member  4100   b  may be the same or different. Further, the carrying-in of the substrate to the first substrate support member  4100   a  and the carrying-in of the substrate to the second substrate support member  4100   b  may be alternately performed. The process of supplying the photosensitive liquid to the substrate may be repeatedly performed while the nozzle arm  4320  is moved between the first substrate support member  4100   a  and the second substrate support member  4100   b.    
     The purge port  4500  is located between the first substrate support member  4100   a  and the second substrate support member  4100   b . The purge port  4500  is provided such that the nozzle arm  4320  is located below the movement paths of the nozzles  4321  and  4322  when the nozzle arm  4320  is moved between the first substrate support member  4100   a  and the second substrate support member  4100   b.    
       FIG. 8  is a view illustrating a pipeline connected to one of photosensitive liquid nozzles. 
     Referring to  FIG. 8 , the photosensitive liquid nozzle  4321  is connected to a tank  4326  through a supply pipe  4325 . The tank  4326  stores a photosensitive liquid. A pump  4327  that provides a pressure, by which the photosensitive liquid flows, may be located in the supply pipe  4325 . A valve  4328  that opens and closes the supply pipe  4325  may be located in the supply pipe  4325 . The plurality of photosensitive liquid nozzles  4321  may be individually connected to the pipes. Accordingly, all or some of the plurality of photosensitive liquid nozzles  4321  may supply photosensitive liquids having different compositions to the substrate. 
     According to the substrate treating apparatus  1 , the photosensitive liquid nozzle  4321  has to be purged sometimes during use thereof. This case may include a case in which it is necessary to discharge a photosensitive liquid in the pipeline to remove generated particles, a case in which the pipeline has to become stable after the pump  4327 , the valve  4328 , and the filter of the pipeline are exchanged, and a case in which the pipeline has to become stable after the photosensitive liquid stored in the tank  4326  is exchanged and a newly exchanged photosensitive liquid is filled in the entire pipeline. The purge operation is performed by discharging a photosensitive liquid of a preset amount through the nozzle  4321 , and according to occasions, the amount of the discharged photosensitive liquid may correspond to several amounts of tank  4326  and the photosensitive liquid may be discharged for several hours or several days. 
     The substrate treating apparatus according to an embodiment of the inventive concept performs a purge operation while performing a process of supplying the photosensitive liquid to the substrate with the nozzle arm  4320 . 
       FIG. 9  is a block diagram illustrating a process for a purge operation.  FIG. 10  is a view illustrating a state in which a photosensitive liquid nozzle is purged to a purge port.  FIG. 11  is a view illustrating some connection relationships of a controller. 
     Hereinafter, a case of initiating a purge operation when the nozzle arm  4320  is moved from the first substrate support member  4100   a  to the second substrate support member  4100   b  will be described as an example. However, the inventive concept is not limited thereto, but the purge operation may be initiated when the nozzle arm  4320  is moved from the second substrate support member  4100   b  to the first substrate support member  4100   a.    
     Referring to  FIGS. 9 to 11 , the controller  1000  controls the components of the substrate treating apparatus  10  for a purge operation, as follows. 
     The nozzle arm  4320  is located above the first substrate support member  4100   a , and one of a plurality of photosensitive liquid nozzles  4321  supplies a photosensitive liquid to a substrate. If the photosensitive liquid of a preset amount is completely supplied, the nozzle arm  4320  is moved towards the second substrate support member  4100   b.    
     If the nozzle arm  4320  is moved towards the second substrate support member  4100   b  and is vertically arranged with the purge port  4500 , the photosensitive liquid nozzle  4321   a  (hereinafter, the purge nozzle), which will perform a purge operation, of the plurality of photosensitive liquid nozzles  4321  performs the purge operation by discharging the photosensitive liquid of a preset amount to the purge port  4500  (S 10 ). When the purge nozzle  4321   a  performs a purge operation, the nozzle arm  4320  may be temporarily stopped above the purge port  4500 . Further, when the purge nozzle  4321   a  performs a purge operation, the nozzle arm  4320  may be moved towards the second substrate support member  4100   b  at a preset speed. The purge operation of the purge nozzle  4321   a  is performed while the nozzle arm  4320  is moved from the first substrate support member  4100   a  to the second substrate support member  4100   b , it hardly influences the operation of treating the substrate while the nozzle arm  4320  is moved from the first substrate support member  4100   a  to the second substrate support member  4100   b.    
     If the nozzle arm  4320  is located above the second substrate support member  4100   b , and one of a plurality of photosensitive liquid nozzles  4321  supplies the photosensitive liquid to the substrate. Then, the photosensitive liquid nozzle  4321  that supplies the photosensitive liquid may be the same as or different from the photosensitive liquid nozzle  4321  that supplied the photosensitive liquid from the first substrate support member  4100   a  shortly before. However, the purge nozzle  4321   a  is excluded from the photosensitive nozzle  4321  that supplies the photosensitive liquid. Accordingly, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the second substrate support member  4100   b  is the same as the purge nozzle  4321   a , the controller  1000  performs an interlock operation. For example, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the second substrate support member  4100   b  is the same as the purge nozzle  4321   a , the controller  1000  may generate an alarm through an alarm generating unit  1200 . Further, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the second substrate support member  4100   b  is the same as the purge nozzle  4321   a , the controller  1000  may stop carrying-in of the substrate to the second substrate support member  4100   b . Further, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the second substrate support member  4100   b  is the same as the purge nozzle  4321   a , the controller  1000  may stop carrying-out of a substrate that is scheduled to be carried into the second substrate support member  4100   b  from a cassette. If the photosensitive liquid of a preset amount is completely supplied, the nozzle arm  4320  is moved towards the first substrate support member  4100   a.    
     If the nozzle arm  4320  is moved towards the first substrate support member  4100   a  and is vertically arranged with the purge port  4500 , the purge module  4321   a  performs a purge operation by discharging the photosensitive liquid of a preset amount to the purge port  4500 . When the purge nozzle  4321   a  performs a purge operation, the nozzle arm  4320  may be temporarily stopped above the purge port  4500 . Further, when the purge nozzle  4321   a  performs a purge operation, the nozzle arm  4320  may be moved towards the first substrate support member  4100   a  at a preset speed. 
     If the nozzle arm  4320  is located above the first substrate support member  4100   a , one of a plurality of photosensitive liquid nozzles  4321  supplies a photosensitive liquid to a substrate. Then, the photosensitive liquid nozzle  4321  that supplies the photosensitive liquid may be the same as or different from the photosensitive liquid nozzle  4321  that supplied the photosensitive liquid from the second substrate support member  4100   b  shortly before. The purge nozzle  4321   a  is excluded from the photosensitive nozzle  4321  that supplies the photosensitive liquid. Accordingly, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the first substrate support member  4100   a  is the same as the purge nozzle  4321   a , the controller  1000  may generate an alarm through an alarm generating unit  1200 . Further, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the first substrate support member  4100   a  is the same as the purge nozzle  4321   a , the controller  1000  may stop carrying-in of the substrate to the first substrate support member  4100   a . Further, if it is determined that the photosensitive liquid nozzle  4321  that will supply the photosensitive liquid to the first substrate support member  4100   a  is the same as the purge nozzle  4321   a , the controller  1000  may stop carrying-out of a substrate that is scheduled to be carried into the first substrate support member  4100   a  from a cassette. 
     Thereafter, when the nozzle arm  4320  supplies the photosensitive liquid to the substrate while being moved between the first substrate support member  4100   a  and the second substrate support member  4100   b , the purge nozzle  4321   a  repeatedly performs a purge operation (S 20 ). The purge operation of the purge nozzle  4321   a  is repeated a preset number of times until the amount of the photosensitive liquid discharged from the purge nozzle  4321   a  reaches a preset amount. The number of times may be set or adjusted in a manner in which the operator inputs the number of times through an input unit  1200 . Further, the preset number of times may be set differently according to a type in which a purge operation is initiated, such as a purge operation after exchange of the pipelines, a purge operation after exchange of the photosensitive liquids, and a purge operation for removing particles. 
       FIG. 12  is a view illustrating a state in which a purge nozzle is being cleaned. 
     Referring to  FIG. 12 , the purge port may provide a cleaner  4510 . The cleaner  4510  may supply a cleaning liquid to the nozzles  4321  and  4322  to clean the nozzles  4321  and  4322 . 
     If the purge nozzle  4321   a  purges the photosensitive liquid a preset number of times, the purge port  4500  cleans the purge nozzle  4321   a  in a process of moving the nozzle arm  4320  from one of the first substrate support member  4100   a  and the second substrate support member  4100   b  to the other of the first substrate support member  4100   a  and the second substrate support member  4100   b  (S 30 ). 
     In the above-mentioned example, the case in which the purge operation of the purge nozzle  4321   a  is continuously performed when the nozzle arm  4320  is moved between the first substrate support member  4100   a  and the second substrate support member  4100   b  has been described. However, the purge operation of the purge nozzle  4321   a  may be intermittently performed. If it is necessary to move the nozzle arm  4320  without any time delay by the purge operation of the purge nozzle  4321   a , for example, the substrate is completely promptly carried into the substrate support member  4100  located in the movement direction of the substrate, the nozzle arm  4320  may be moved to the following substrate support member  4100  without any purge operation of the purge nozzle  4321   a  even after the purge operation is initiated. Further, in a process of moving the nozzle arm  4320  to the following substrate support member  4100 , the purge nozzle  4321   a  may perform a purge operation. 
     According to an embodiment of the inventive concept, the substrate treating apparatus  10   b  may perform an operation of purging the photosensitive liquid nozzle  4321  while the treatment liquid supply unit  4300  performs a process of supplying the photosensitive liquid to the substrate. Accordingly, because the operation of purging the photosensitive liquid nozzle  4321  is performed at the same time when the substrate treating apparatus performs a process, productivity may be improved. 
     Further, the operation of purging two or more photosensitive liquid nozzles  4321  may be performed at the same time. In detail, the substrate treating apparatus performs purge operations on a first purge nozzle and a second purge nozzle at the same time. In a process of moving the nozzle arm  4320  from one of the first substrate support member  4100   a  and the second substrate support member  4100   b  to the other of the first substrate support member  4100   a  and the second substrate support member  4100   b , the controller  1000  may perform a control such that the first purge nozzle purges the photosensitive liquid in the purge port  4500 . Thereafter, even before an operation of purging the first nozzle is completed, the controller  1000  initiates the operation of purging the second purge nozzle, and in a process of moving the nozzle arm  4320  from one of the first substrate support member  4100   a  and the second substrate support member  4100   b  to the other of the first substrate support member  4100   a  and the second substrate support member  4100   b , the controller  1000  may perform a control such that the second purge nozzle purges the photosensitive liquid in the purge port  4500 . Further, even after the operation of purging the second purge nozzle is initiated, the operation of purging the first purge nozzle may be performed again. When the purge operations are performed on the two purge nozzles, the controller  100  may allow an operation of purging the first purge nozzle or the second purge nozzle to be completed first regardless of the initiation sequence of the purge operation. 
     According to an embodiment of the inventive concept, a substrate treating apparatus that efficiently treats a substrate and a substrate treating method may be provided. 
     Further, according to an embodiment of the inventive concept, a substrate treating apparatus that may perform a purge operation while a substrate is treated and a substrate treating method may be provided. 
     The above description exemplifies the inventive concept. Furthermore, the above-mentioned contents describe the exemplary embodiment of the inventive concept, and the inventive concept may be used in various other combinations, changes, and environments. That is, the inventive concept can be modified and corrected without departing from the scope of the inventive concept that is disclosed in the specification, the equivalent scope to the written disclosures, and/or the technical or knowledge range of those skilled in the art. The written embodiment describes the best state for implementing the technical spirit of the inventive concept, and various changes required in the detailed application fields and purposes of the inventive concept can be made. Accordingly, the detailed description of the inventive concept is not intended to restrict the inventive concept in the disclosed embodiment state. Furthermore, it should be construed that the attached claims include other embodiments.