Patent Publication Number: US-2017372926-A1

Title: Substrate treating unit, baking apparatus including the same, and substrate treating method using baking apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     A claim for priority under 35 U.S.C. §119 is made to Korean Patent Application No. 10-2016-0079241 filed Jun. 24, 2016, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     Embodiments of the inventive concept described herein relate to an apparatus for treating a substrate, and more particularly to an apparatus for heating a substrate. 
     Various processes such as photographing, etching, deposition, and cleaning are performed to manufacture a semiconductor device. The photographing process is a process for forming patterns, and plays an important role in high integration of semiconductor devices. 
     The photographing process mainly includes an application process, an exposure process, and a development process, and baking process are performed before and after the exposure process. The baking process is a process for heat-treating a substrate, and if a substrate is positioned on a heating plate, the substrate is heat-treated through a heater provided in the interior of the heating plate. 
       FIG. 1  is a sectional view illustrating a general baking unit. 
     Referring to  FIG. 1 , the baking unit includes a housing  2  providing a space for performing a baking process in the interior thereof, a heater  3  installed in the interior of the housing  2  to heat a substrate s, and an exhaust line  4 . 
     The fumes generated in a process of performing a baking process is exhausted to the outside through exhaust lines  4 , and exterior air is introduced through an inlet  5 . 
     The conventional baking apparatus  1  is implemented in a centrally concentrated exhaustion manner in which exhaust lines  4  are provided at the center of an upper side of the housing  1 , and an internal temperature of the housing is lowered in a process in which external gas of low temperature is introduced into the housing through the inlets. Further, according to the conventional baking apparatus, the fumes are attached to inner surfaces of the exhaust lines in a process of discharging the fumes through the exhaust lines, causing the exhaust passages of the exhaust lines to be smaller. 
     Further, the conventional baking process depends on performance of the heater and control of the heater to improve the uniformity of the thickness of the substrate thin film, and the exterior air introduced into the housing without control is spotlighted as a main cause of determining the thickness of the substrate thin film. 
     SUMMARY 
     Embodiments of the inventive concept provide a heating unit in which the film thicknesses of areas of a substrate may be adjusted by adjusting the flow rates of exterior air introduced into a housing for different zones, a baking apparatus including the same, and a substrate treating method using the baking apparatus. 
     Embodiments of the inventive concept also provide a heating unit that may restrain air introduced from the outside when a substrate is heated from influencing a temperature of the substrate, a baking apparatus including the same, and a substrate treating method using the baking apparatus. 
     Embodiments of the inventive concept provide a heating unit that may prevent fumes from being adsorbed again in a substrate treating process, a baking apparatus including the same, and a substrate treating method using the baking apparatus. 
     The technical objects of the inventive concept are not limited to the above-mentioned ones, and the other unmentioned technical objects will become apparent to those skilled in the art from the following description. 
     In accordance with an aspect of the inventive concept, there is provided a heating unit including a housing providing a treatment space in the interior thereof, a heating plate supporting a substrate in the treatment space, a heating member provided in the heating plate and configured to heat-treat the substrate supported by the heating plate, an exhaust member configured to exhaust gas in an interior space of the housing, and an exterior gas supply part installed in the housing and configured to supply exterior gas into the treatment space, wherein the exterior gas supply part includes a plurality of inlets provided in the housing, and a plurality of flow rate adjusting members installed in the inlets, respectively, and configured to adjust flow rates of the exterior gas introduced into the inlets. 
     Each of the flow rate adjusting members may include an opening cover configured to adjust an opening degree of the corresponding inlet. 
     The exterior gas supply part may further include a plurality of cover driving parts configured to drive the opening covers, and a flow rate control part configured to control the cover driving parts. 
     The exhaust member may include a guide member installed at an upper portion of the housing to face the heating plate and having an exhaust hole at the center thereof, and an exhaust pipe passing through an upper surface of the housing to be connected to the exhaust hole. 
     The guide member may be divided into an introduction area spaced apart from an inner wall of an upper surface and an inner wall of a side surface of the chamber such that the exterior gas above the guide member is introduced through the introduction area and an exhaust area through which the exterior gas below the guide member is exhausted. 
     An area of the guide member may be larger than an area of the substrate when viewed from the top. 
     Each of the flow rate adjusting members may include a flow rate control valve installed in the corresponding inlet. 
     The heating unit may further include a plurality of heater installed in the housing and configured to heat the exterior gas introduced into the housing through the inlets, respectively. 
     The housing may be divided into a plurality of circumferential zones, and the heating unit may further include a heater control part for individually controlling the heaters installed in the zones. 
     The heaters may be installed on a side wall of the housing. 
     The housing may include a lower body having an open-topped cylindrical shape and in which the heating plate is locate, an upper body located on the opened upper side of the lower body and coupled to the lower body in an open-bottomed vessel shape to provide a treatment space in the interior thereof, and a body elevating part configured to elevate the upper body. 
     In accordance with another aspect of the inventive concept, there is provided a baking apparatus including a process chamber providing a heat treating space in the interior thereof and having a slot for carrying a substrate in and out on one side thereof, a cooling plate located in the heat treating space of the process chamber and configured to cool the substrate, and a heating unit configured to heat the substrate, wherein the heating unit includes a housing providing a treatment space in the interior thereof, an exterior gas supply part having an inlet provided in the housing such that exterior gas is introduced into the treatment space and a flow rate adjusting part configured to adjust a flow rate of the exterior gas introduced through the inlet, a heating plate supporting a substrate in the treatment space, a heating member provided in the heating plate and configured to heat-treat the substrate supported by the heating plate, and an exhaust member configured to exhaust gas in an interior space of the housing, 
     Each of the flow rate adjusting members may include an opening cover configured to adjust an opening degree of the inlet, and the exterior gas supply part may include a cover driving part configured to drive the opening cover, and a flow rate control part configured to control the cover driving part. 
     The exhaust member may include a guide member installed at an upper portion of the housing to face the heating plate and having an exhaust hole at the center thereof, and an exhaust pipe passing through an upper surface of the housing to be connected to the exhaust hole, and the guide member may be divided into an introduction area spaced apart from an inner wall of an upper surface and an inner wall of a side surface of the chamber such that the exterior gas above the guide member is introduced through the introduction area and an exhaust area through which the exterior gas below the guide member is exhausted. 
     The housing may be divided into a plurality of circumferential zones, and the heating unit may include a plurality of heaters installed in the zones and configured to heat the exterior gas introduced into the housing through the inlets, and a heater control part configured to individually control the heaters. 
     The heaters may be installed on a side wall of the housing. 
     Exterior gas introduced into the interior of a hosing through inlets formed in the housing may be provided onto a substrate and exhausted through an exhaust member provided at an upper portion of the housing together with fumes generated from the substrate, and the exterior gas may be introduced into the housing through adjustment of a flow rate of the exterior gas. 
     The flow rate of the exterior gas may be adjusted by flow rate adjusting part in the inlets. 
     The exterior gas introduced into the housing through the inlets may be heated before being provided to the substrate. 
     The exterior gas may be heated by heaters installed in the housing. 
     The heaters may be circumferentially provided on an inside of a side wall of the housing to be individually controlled. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The above and other objects and features will become apparent from the following description with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified, and wherein: 
         FIG. 1  is a sectional view illustrating a general baking unit; 
         FIG. 2  is a view of the substrate treating facility, viewed from the top; 
         FIG. 3  is a sectional view of the facility of  FIG. 2 , taken along line A-A of  FIG. 2 ; 
         FIG. 4  is a sectional view of the facility of  FIG. 2 , taken along line B-B of  FIG. 1 ; 
         FIG. 5  is a sectional view of the facility of  FIG. 2 , taken along a line C-C of  FIG. 2 ; 
         FIG. 6  is a plan view illustrating a baking unit according to an embodiment of the inventive concept; 
         FIG. 7  is a sectional view illustrating a heating unit for performing a heating process of  FIG. 6 ; 
         FIG. 8  is a plan view illustrating a heating member provided in the interior of the heating plate of  FIG. 7 ; 
         FIG. 9  is a plan view illustrating an upper body of a housing; 
         FIG. 10  is an enlarged view illustrating a main part of an exterior gas supply part installed in the upper body; 
         FIG. 11  is a plan view illustrating heaters installed in the housing; and 
         FIG. 12  is a view illustrating air currents in the heating unit. 
     
    
    
     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 facility of the present embodiment of the inventive concept may be used to perform a photography process on a substrate such as a semiconductor substrate or a flat display panel. In particular, the facility of the present embodiment may be connected to an exposure apparatus to perform an application process and a development process on a substrate. Hereinafter, a case of using a wafer as a substrate may be described as an example. 
       FIGS. 2 to 5  are views schematically illustrating a substrate treating facility according to an embodiment of the inventive concept.  FIG. 2  is a view of the substrate treating facility, viewed from the top.  FIG. 3  is a sectional view of the facility of  FIG. 2 , taken along line A-A of  FIG. 2 .  FIG. 4  is a sectional view of the facility of  FIG. 2 , taken along line B-B of  FIG. 1 .  FIG. 5  is a sectional view of the facility of  FIG. 2 , taken along a line C-C of  FIG. 2 . 
     Referring to  FIGS. 2 to 5 , the substrate treating facility  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 , and an interface module  700 . 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. 
     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 substrate 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 , and the interface module  700  will be described in detail. 
     The load port  100  has a carrier  120  on which the cassette  20 , in which the substrates 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. 
     The index module  200  feeds a substrate 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 port  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 substrate 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 . 
     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 substrates 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 substrate W is positioned on each of the supports  332 . The housing  331  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, carries a substrate 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  332  provided for the first buffer  320 . 
     The first buffer robot  360  feeds a substrate 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 substrate 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 substrate W is positioned and the substrate 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 substrate 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 robot  402 , which will be described below, carry a substrate 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 . 
     The application/development module  400  performs a process of applying a photoresist onto a substrate W before an exposure process and a process of developing the substrate 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 substrate W and a heat treating process of, for example, heating and cooling the substrate W before and after the resist applying process. The application module  401  has a resist applying chamber  410 , a baking unit  420 , and a carrying chamber  430 . The resist applying chamber  410 , the baking unit  420 , and the carrying chamber  430  are sequentially disposed along the second direction  14 . Accordingly, the resist applying chamber  410  and the baking unit  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 baking units  420  may be provided in each of the first direction  12  and the third direction  16 . In the drawings, six baking units  420  are illustrated as an example. However, unlike this, a larger number of baking units  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 substrate W between the baking units  420 , the resist applying chambers  410 , 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 substrate W. The resist applying chamber  410  has a housing  411 , a support plate  412 , and a nozzle  413 . The housing  411  has an open-topped cup shape. The support plate  412  is situated in the housing  411 , and supports the substrate W. The support plate  412  may be provided to be rotatable. The nozzle  413  supplies a photoresist onto the substrate W positioned on the support plate  412 . The nozzle  413  has a circular pipe shape, and may supply a photoresist to the center of the substrate W. Optionally, the nozzle  413  may have a length corresponding to the diameter of the substrate W, and the discharge hole of the nozzle  413  may be a slit. Further, additionally, a nozzle  414  for supplying a cleaning liquid such as deionized water to clean a surface of the substrate W, to which the photoresist is applied, may be further provided in the resist applying chamber  410 . 
     The baking unit  420  heat-treats the substrate W. For example, the baking units  420  perform a prebake process of eliminating organic substances and moisture on the surface of the substrate W by heating the substrate W at a predetermined temperature before a photoresist is applied or a soft bake process performed after a photoresist is applied onto the substrate W, and performs a cooling process of cooling the substrate W after the heating processes. 
       FIG. 6  is a plan view illustrating a baking unit according to an embodiment of the inventive concept.  FIG. 7  is a sectional view illustrating a heating unit for performing a heating process of  FIG. 6 . 
     Referring to  FIGS. 6 and 7 , the baking unit  420  may include a process chamber  423 , a cooling plate  422 , and a heating unit  800 . 
     The process chamber  423  provides a heat treating space  802  in the interior thereof. The process chamber  423  may have a rectangular hexahedral shape. The cooling plate  422  may cool the substrate heated by the heating unit  421 . The cooling plate  422  may be located in the heat treating space  802 . The cooling plate  422  may have a circular plate shape. Cooling water or a cooling unit, such as a thermoelectric element, is provided in the interior of the cooling plate  422 . For example, the cooling plate  422  may cool the heated substrate to a room temperature. 
     The heating unit  800  heats the substrate. The heating unit  800  may include a housing  860 , a heating plate  810 , a heating member  830 , an exterior gas supply part  840 , a heater  880 , and an exhaust member  870 . 
     The housing  860  provides a treatment space  802 , in which a process of heating the substrate W is performed. The housing  860  includes a lower body  862 , an upper body  864 , and a driver (not illustrated). 
     The lower body  862  may have an open-topped vessel shape. The heating plate  810  and the heating member  830  are located in the lower body  862 . The lower body  862  includes dual insulation covers to prevent devices located around the heating plate  810  from being thermally deformed. The dual insulation covers  862   a  and  862   b  minimize the peripheral devices of the heating plate  810  from being exposed to heat of high temperature generated by the heating member  830 . The dual insulation covers  862   a  and  862   b  include a primary insulation cover  862   a  and a secondary insulation cover  862   b , and the primary insulation cover  862   a  and the secondary insulation cover  862   b  may be spaced apart from each other. 
     The upper body  864  has a bottom-topped vessel shape. The upper body  864  is combined with the lower body  862  to define a treatment space  802  therebetween. The upper body  864  has a diameter that is larger than that of the lower body  862 . The upper body  864  is located above the lower body  862 . The upper body  864  may be moved upwards and downwards by the driver. The upper body  864  may be moved upwards and downwards to be moved to a lifted location and a lowered location. Here, the lifted location is a location at which the upper body  864  and the lower body  862  are spaced apart from each other, and the lowered location is a location at which the upper body  864  and the lower body  862  contact each other. At the lowered location, an aperture between the upper body  864  and the lower body  862  are blocked. Accordingly, if the upper body  864  is moved to the lowered location, a treatment space  802  is formed by the upper body  864 , the lower body  862 , and the heating plate  810 . 
     Although not illustrated, the housing  860  may include a sealing member for preventing exterior air from being introduced into the treatment space. As an example, the sealing member may seal an aperture between the lower body  862  and the upper body  864 . 
     The heating plate  810  may be located in the heat treating space  802 . The heating plate  810  is located on one side of the cooling plate  422 . The heating plate  810  is provided to have a circular plate shape. An upper surface of the heating plate  810  is provided as a support area, on which the substrate W is positioned. Referring to  FIG. 8 , a plurality of pin holes  812  are formed on an upper surface of the heating plate  810 . For example, three pin holes  812  may be provided. The pin holes  812  are located to be spaced apart from each other along a circumferential direction of the heating plate  810 . The pin holes  812  are spaced apart from each other at the same interval. A lift pin (not illustrated) is provided in each of the pin holes  812 . The lift pin may be moved upwards and downwards by a driving member (not illustrated). 
     The heating member  830  heats the substrate W positioned on the heating plate  810  to a preset temperature.  FIG. 8  is a transverse sectional view illustrating a heating member provided in the interior of the heating plate of  FIG. 7 . Referring to  FIG. 8 , the heating member  830  includes a plurality of heat emitting bodies  830 . The heat emitting bodies  830  are located in the interior of the heating plate  810 . The heat emitting bodies  830  are located on the same plane. The heat emitting bodies  830  heat different areas of the heating plate  810 . The different areas of the heating plate  810  are provided as heating zones heated by the heat emitting bodies  830 . The heating zones one-to-one correspond to the heat emitting bodies  830 . For example, fifteen heating zones may be provided. For example, the heating member  830  may be a thermoelectric element, a heating wire, or a surface heating emitting body. 
       FIG. 9  is a plan view illustrating an upper body of a housing.  FIG. 10  is an enlarged view illustrating a main part of an exterior gas supply part installed in the upper body. 
     Referring to  FIGS. 9 and 10 , the exterior gas supply part  840  is provided on an upper surface of the upper body  864 . Exterior gas is introduced into the treatment space  802  of the housing through the exterior gas supply part  840 , and the introduced exterior gas is exhausted to the exhaust member  870  together with fumes generated on the substrate. 
     The exterior gas supply part  840  may include a plurality of inlets  842 , a plurality of opening covers  844  that are flow rate adjusting members, a plurality of cover driving parts  846 , and a flow rate control part  848 . 
     A plurality of inlets  842  may be provided on an upper surface of the upper body  864 . According to an example, when viewed from the top, the inlets  842  may be sequentially arranged along a circumferential direction of the upper body  864  with respect to the center of the upper surface of the upper body  864 . The flow rate adjusting members may be installed in the inlets  842 , respectively. The flow rate adjusting members are adapted to adjust the flow rates of the exterior gas introduced into the inlets  842 , and as an example, may be the opening covers  844  configured to adjust opening degrees of the inlets  842 , respectively. The opening covers  844  may be rotated by the cover driving parts  846  to open and close the inlets  842 . The cover driving parts  846  are controlled by the flow rate control part  848 . In the embodiment, the flow rate adjusting members may be flow control valves, in addition to the opening covers, and the flow rate adjusting members configured to adjust the opening degrees of the inlets may be various devices, in addition to the above-mentioned units. 
     In the embodiment, eight inlets  842  may be provided in the upper body  864 , and the inlets  842  may individually control the flow rates of the exterior gas introduced into the housing  860  through rotation of the opening covers  844 . Accordingly, the treatment space of the housing  860  is divided into eight areas, and air currents on the substrate may be controlled by adjusting the flow rates of the exterior gas introduced into the areas. The thickness of the substrate thin film may be adjusted by controlling air currents on the substrate for a plurality of areas. 
     Although it has been described in the embodiment that the inlets  842  are formed on the upper surface of the upper body  864 , the inventive concept is not limited thereto and the inlets  842  may be formed on a side surface of the upper body  864 . 
     The exhaust member  870  may include a guide member  872  and an exhaust pipe  874 . 
     The guide member  872  faces the heating plate  810 , and is spaced apart from an inner wall of an upper surface and an inner wall of a side surface of the upper body  864 . Accordingly, an upper space  804  above the guide member  872  and a lower space  806  below the guide member  872  may be formed in the treatment space  802  of the housing  860 . The upper space  804  may be an introduction area in which exterior gas introduced through the exterior gas supply part  840  flows, and the lower space  806  may be an exhaust area in which the gas introduced to an upper part of the substrate and fumes generated by the substrate are exhausted. 
     The guide member  872  may be a circular plate having an exhaust hole  873  at the center thereof, and the exhaust pipe  874  passes through the upper body  864  to be connected to the exhaust hole  873 . Further, the size of the guide member  872  may be larger than the size of the substrate. 
       FIG. 11  is a plan view illustrating heaters installed in the housing. 
     Referring to  FIGS. 7 and 11 , the heaters  880  may be installed in the housing  860 . The housing  860  may be divided into a plurality of circumferential zones, and the heaters  880  may be installed in the zones, respectively. As an example, the heaters  880  may be installed in a side wall of the housing  860  corresponding to a path along which exterior gas is introduced to flow. The heaters  880  may be individually controlled by the heater control part  882 . The heater control part  882  may control the heaters  880  such that the temperatures of the corresponding areas satisfy the purpose of the heaters  880 . 
     In this way, the temperatures of the exterior gas introduced into the interior of the housing  860  through the exterior gas supply part  840  may increase while the exterior gas passes through the corresponding areas in which the heaters  880  are installed. As the heaters  880  increase the temperature of the exterior gas, the temperature of the gas exhausted through the exhaust member also increases so that the fumes may be prevented from being adsorbed to the housing  860  or the exhaust pipe  874 . 
       FIG. 12  is a view illustrating air currents in the heating unit. 
     Referring to  FIG. 12 , the exterior gas introduced through the exterior gas supply part  840  is not directly introduced to the upper surface of the substrate W but flows to a periphery of the treatment space  802  along the upper space  872   a  provided by the guide member  872 . The exterior gas is introduced into the lower space  872   b  of the guide member  872  while the temperature of the exterior gas is increased by the heaters  880 . Further, while the baking process is performed, the gas of the lower space  872   b  and the fumes evaporated from the substrate are discharged through the exhaust pipe  874 . 
     Referring to  FIGS. 2 to 5  again, the development module  402  includes a process of eliminating a photoresist by supplying a development liquid to obtain a pattern on the substrate W, and a heat treating process, such as heating and cooling, which are performed on the substrate W before and after the development process. The development module  402  has a development chamber  460 , a baking unit  470 , and a carrying chamber  480 . The development chamber  460 , the baking unit  470 , and the carrying chamber  480  are sequentially disposed along the second direction  14 . Accordingly, the development chamber  460  and the baking unit  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 baking units  470  may be provided in each of the first direction  12  and the third direction  16 . In the drawings, six baking units  470  are illustrated as an example. However, unlike this, a larger number of baking units  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 substrate W between the baking units  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 substrate W, to which light is irradiated. Then, an area of the protection film, to which light is irradiated, is eliminated together. Optionally, only an area of the photoresist and the protection 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 substrate W. The support plate  462  may be provided to be rotatable. The nozzle  463  supplies a development liquid onto the substrate 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 substrate W. Optionally, the nozzle  463  may have a length corresponding to the diameter of the substrate 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 substrate W, to which the development liquid is additionally supplied. 
     The baking unit  470  of the development module  402  heat-treats the substrate W. For example, the baking units  470  may perform a post bake process of heating the substrate W before the development process, a hard bake process of heating the substrate W after the development process, and a cooling process of cooling the heated substrate W after the bake process. The baking unit  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 baking unit  470 . Optionally, some of the baking units  470  may include only a cooling plate  471 , and some of the bake chambers  470  may include only a heating plate  472 . Because the baking units  470  of the development module  402  have the same configuration as that of the baking chambers of the application module  401 , a detailed description thereof will be omitted. 
     The second buffer module  500  is provided as a passage through which the substrate 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 substrate 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 substrate 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 substrates W, on which the application module  401  has performed a process. The first cooling chamber  530  cools the substrate 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 substrates W, on which the first cooling chamber  530  has performed a cooling process. The buffer  520  temporarily preserves the substrates W before the substrates 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 substrates W before the substrates 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 substrates 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. 
     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 substrate W during the immersion/exposure process. The pre/post-exposure module  600  may perform a process of cleaning the substrate 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 substrate W before the exposure process, and the post-treatment module  602  performs a process of treating the substrate 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 baking unit  620 , and a carrying chamber  630 . The protective film applying chamber  610 , the carrying chamber  630 , and the baking unit  620  are sequentially disposed along the second direction  14 . Accordingly, the protective film applying chamber  610  and the baking unit  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 baking units  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 baking units  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 substrate W between the protective film applying chambers  610 , the baking units  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 substrate 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 substrate 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 substrate 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 substrate W. Optionally, the nozzle  613  may have a length corresponding to the diameter of the substrate 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 substrate W while rotating the substrate W positioned on the support plate  612 . 
     The baking unit  620  heat-treats the substrate W, to which the protective film is applied. The baking unit  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 baking unit  620 . Optionally, some of the baking units  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 baking unit  670 , and a carrying chamber  680 . The cleaning chamber  660 , the carrying chamber  680 , and the post-exposure baking unit  670  are sequentially disposed along the second direction  14 . Accordingly, the cleaning chamber  660  and the post-exposure baking unit  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 baking units  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 baking units  670  may be provided 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 substrate W between the cleaning chambers  660 , the post-exposure baking units  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 substrate 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 substrate W. The support plate  662  may be provided to be rotatable. The nozzle  663  supplies a cleaning liquid onto the substrate 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 substrate W while rotating the substrate 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 substrate W while the substrate W is rotated. 
     After the exposure process, the bake unit  670  heats the substrate W, on which the exposure process has been performed, by using a far infrared ray. After the exposure process, in the bake process, the substrate 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 baking unit  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 baking unit  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 baking unit 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 baking unit  620  and the post-exposure baking unit  670  may have the same size, and may completely overlap with each other when viewed from the top. 
     The interface module  700  feeds the substrate W between the pre/post-exposure module  600  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 substrate W between the first buffer  720 , the second buffer  730 , 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 substrates 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 substrates 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 substrate 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  721  is provided so that the interface robot  740  and the pre-treatment robot  632  carry a substrate W into or out of the cooling plate  722 . 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 substrate is not provided. 
     According to the embodiments of the inventive concept, the thicknesses of the substrate for areas may be adjusted by adjusting the flow rates of exterior gas introduced into the housing by the flow rate adjusting member for zones. 
     According to the embodiments of the inventive concept, the temperature distribution of the substrate may be prevented from being uneven and fumes may be prevented from being adsorbed again, by providing exterior gas introduced into the housing by the flow rate adjusting members to the upper side of the substrate after the exterior gas is heated by the heaters.